buttons in add_logic and add_table works properly well now

.envrc

@@ -0,0 +1 @@
+use flake

.gitignore

@@ -1,2 +1,8 @@
 /target
 .env
+/tantivy_indexes
+server/tantivy_indexes
+steel_decimal/tests/property_tests.proptest-regressions
+.direnv/
+canvas/*.toml
+.aider*

Cargo.toml

@@ -1,19 +1,55 @@
 [workspace]
-members = ["client", "server", "common"]
+members = ["client", "server", "common", "search", "canvas"]
 resolver = "2"
 
 [workspace.package]
 # TODO: idk how to do the name, fix later
-# name = "Multieko2"
-version = "0.3.5"
+# name = "komp_ac"
+version = "0.5.0"
 edition = "2021"
 license = "GPL-3.0-or-later"
 authors = ["Filip Priečinský <filippriec@gmail.com>"]
 description = "Poriadny uctovnicky software."
 readme = "README.md"
-repository = "https://gitlab.com/filipriec/multieko2"
+repository = "https://gitlab.com/filipriec/komp_ac"
 categories = ["command-line-interface"]
 
 # [workspace.metadata]
 # TODO:
-# documentation = "https://docs.rs/accounting-client"`
+# documentation = "https://docs.rs/accounting-client"
+
+[workspace.dependencies]
+# Async and gRPC
+tokio = { version = "1.44.2", features = ["full"] }
+tonic = "0.13.0"
+prost = "0.13.5"
+async-trait = "0.1.88"
+prost-types = "0.13.0"
+
+# Data Handling & Serialization
+serde = { version = "1.0.219", features = ["derive"] }
+serde_json = "1.0.140"
+time = "0.3.41"
+
+# Utilities & Error Handling
+anyhow = "1.0.98"
+dotenvy = "0.15.7"
+lazy_static = "1.5.0"
+tracing = "0.1.41"
+
+# Search crate
+tantivy = "0.24.1"
+
+# Steel_decimal crate
+rust_decimal = { version = "1.37.2", features = ["maths", "serde"] }
+rust_decimal_macros = "1.37.1"
+thiserror = "2.0.12"
+regex = "1.11.1"
+
+# Canvas crate
+ratatui = { version = "0.29.0", features = ["crossterm"] }
+crossterm = "0.28.1"
+toml = "0.8.20"
+unicode-width = "0.2.0"
+
+common = { path = "./common" }

README.md

@@ -1,5 +1,7 @@
 # Hey
 
+This is only work in progress, until release 1.0.0 this is for development use cases only.
+
 I run development like this:
 
 Server:
@@ -12,3 +14,12 @@ Client:
 cargo watch -x 'run --package client -- client'
 ```
 
+Client with tracing:
+```
+ENABLE_TRACING=1 RUST_LOG=client=debug cargo watch -x 'run --package client -- client'
+```
+
+Client with debug that cant be traced
+```
+cargo run --package client --features ui-debug -- client
+```

canvas/.gitignore

@@ -0,0 +1 @@
+docs_prompts/

canvas/CANVAS_MIGRATION.md

@@ -0,0 +1,324 @@
+# Canvas Library Migration Guide
+
+## Overview
+
+This guide covers the migration from the legacy canvas library structure to the new clean, modular architecture. The new design separates core canvas functionality from suggestions features, providing better type safety and maintainability.
+
+## Key Changes
+
+### 1. **Modular Architecture**
+```
+# Old Structure (LEGACY)
+src/
+├── state.rs              # Mixed canvas + suggestions
+├── actions/edit.rs       # Mixed concerns
+├── gui/render.rs         # Everything together
+└── suggestions.rs        # Legacy file
+
+# New Structure (CLEAN)
+src/
+├── canvas/               # Core canvas functionality
+│   ├── state.rs         # CanvasState trait only
+│   ├── actions/edit.rs  # Canvas actions only
+│   └── gui.rs           # Canvas rendering
+├── suggestions/         # Suggestions dropdown features (not inline autocomplete)
+│   ├── state.rs         # Suggestion provider types
+│   ├── gui.rs           # Suggestions dropdown rendering
+│   ├── actions.rs       # Autocomplete actions
+│   └── gui.rs           # Autocomplete dropdown rendering
+└── dispatcher.rs         # Action routing
+```
+
+### 2. **Trait Separation**
+- **CanvasState**: Core form functionality (navigation, input, validation)
+- Suggestions module: Optional dropdown suggestions support
+
+### 3. **Rich Suggestions**
+Replaced simple string suggestions with typed, rich suggestion objects.
+
+## Migration Steps
+
+### Step 1: Update Import Paths
+
+**Find and Replace these imports:**
+
+```rust
+# OLD IMPORTS
+use canvas::CanvasState;
+use canvas::CanvasAction;
+use canvas::ActionContext;
+use canvas::HighlightState;
+use canvas::CanvasTheme;
+use canvas::ActionDispatcher;
+use canvas::ActionResult;
+
+# NEW IMPORTS
+use canvas::canvas::CanvasState;
+use canvas::canvas::CanvasAction;
+use canvas::canvas::ActionContext;
+use canvas::canvas::HighlightState;
+use canvas::CanvasTheme;
+use canvas::dispatcher::ActionDispatcher;
+use canvas::canvas::ActionResult;
+```
+
+**Complex imports:**
+```rust
+# OLD
+use canvas::{CanvasAction, ActionDispatcher, ActionResult};
+
+# NEW
+use canvas::{canvas::CanvasAction, dispatcher::ActionDispatcher, canvas::ActionResult};
+```
+
+### Step 2: Clean Up State Implementation
+
+**Remove legacy methods from your CanvasState implementation:**
+
+```rust
+impl CanvasState for YourFormState {
+    // Keep all the core methods:
+    fn current_field(&self) -> usize { /* ... */ }
+    fn get_current_input(&self) -> &str { /* ... */ }
+    // ... etc
+
+    // ❌ REMOVE these legacy methods:
+    // fn get_suggestions(&self) -> Option<&[String]>
+    // fn get_selected_suggestion_index(&self) -> Option<usize>
+    // fn set_selected_suggestion_index(&mut self, index: Option<usize>)
+    // fn activate_suggestions(&mut self, suggestions: Vec<String>)
+    // fn deactivate_suggestions(&mut self)
+}
+```
+
+### Step 3: Implement Rich Autocomplete (Optional)
+
+**If you want suggestions dropdown features:**
+
+```rust
+use canvas::{SuggestionItem};
+
+impl YourFormState {
+    fn supports_suggestions(&self, field_index: usize) -> bool {
+        // Define which fields support suggestions
+        matches!(field_index, 2 | 3 | 5) // Example: only certain fields
+    }
+
+    // Manage your own suggestion state or rely on FormEditor APIs
+
+    // Manage your own suggestion state or rely on FormEditor APIs
+}
+```
+
+**Add suggestions storage to your state (optional, if you need to persist outside the editor):**
+```rust
+pub struct YourFormState {
+    // ... existing fields
+    // Optional: your own suggestions cache if needed
+    // pub suggestion_cache: Vec<SuggestionItem>,
+}
+```
+
+### Step 4: Migrate Suggestions
+
+**Old way (simple strings):**
+```rust
+let suggestions = vec!["John".to_string(), "Jane".to_string()];
+form_state.activate_suggestions(suggestions);
+```
+
+**New way (rich objects):**
+```rust
+let suggestions = vec![
+    SuggestionItem::new(
+        hit1,                                    // Your data object
+        "John Doe (Manager) | ID: 123".to_string(), // What user sees
+        "123".to_string(),                       // What gets stored
+    ),
+    SuggestionItem::simple(hit2, "Jane".to_string()), // Simple version
+];
+form_state.set_autocomplete_suggestions(suggestions);
+```
+
+### Step 5: Update Rendering
+
+**Old rendering:**
+```rust
+// Manual suggestions rendering
+if editor.is_suggestions_active() {
+    suggestions::gui::render_suggestions_dropdown(/* ... */);
+}
+```
+
+**New rendering:**
+```rust
+// Canvas handles everything
+use canvas::render_canvas_default;
+
+let active_field_rect = render_canvas(f, area, form_state, theme, edit_mode, highlight_state);
+
+// Suggestions dropdown (if active)
+if editor.is_suggestions_active() {
+    canvas::suggestions::render_suggestions_dropdown(
+        f, f.area(), active_field_rect.unwrap(), theme, &editor
+    );
+}
+}
+```
+
+### Step 6: Update Method Calls
+
+**Replace legacy method calls:**
+```rust
+# OLD
+form_state.deactivate_suggestions();
+
+# NEW - Option A: Add your own method
+impl YourFormState {
+    pub fn deactivate_suggestions(&mut self) {
+        self.autocomplete_active = false;
+        self.autocomplete_suggestions.clear();
+        self.selected_suggestion_index = None;
+    }
+}
+editor.ui_state_mut().deactivate_suggestions();
+
+# NEW - Option B: Suggestions via editor APIs
+editor.ui_state_mut().deactivate_suggestions();
+```
+
+## Benefits of New Architecture
+
+### 1. **Clean Separation of Concerns**
+- Canvas: Form rendering, navigation, input handling
+- Autocomplete: Rich suggestions, dropdown management, async loading
+
+### 2. **Type Safety**
+```rust
+// Old: Stringly typed
+let suggestions: Vec<String> = vec!["user1".to_string()];
+
+// New: Fully typed with your domain objects
+let suggestions: Vec<SuggestionItem<UserRecord>> = vec![
+    SuggestionItem::new(user_record, display_text, stored_value)
+];
+```
+
+### 3. **Rich UX Capabilities**
+- **Display vs Storage**: Show "John Doe (Manager)" but store user ID
+- **Loading States**: Built-in spinner/loading indicators
+- **Async Support**: Designed for async suggestion fetching
+- **Display Overrides**: Show friendly text while storing normalized data
+
+### 4. **Future-Proof**
+- Easy to add new suggestion features
+- Canvas features don't interfere with suggestions
+- Modular: Use only what you need
+
+## Advanced Features
+
+### Display Overrides
+Perfect for foreign key relationships:
+
+```rust
+// User selects "John Doe (Manager) | ID: 123"
+// Field stores: "123" (for database)
+// User sees: "John Doe" (friendly display)
+
+impl CanvasState for FormState {
+    fn get_display_value_for_field(&self, index: usize) -> &str {
+        if let Some(display_text) = self.link_display_map.get(&index) {
+            return display_text.as_str(); // Shows "John Doe"
+        }
+        self.inputs().get(index).map(|s| s.as_str()).unwrap_or("") // Shows "123"
+    }
+    
+    fn has_display_override(&self, index: usize) -> bool {
+        self.link_display_map.contains_key(&index)
+    }
+}
+```
+
+### Progressive Enhancement
+Start simple, add features when needed:
+
+```rust
+// Week 1: Basic usage
+SuggestionItem::simple(data, "John".to_string());
+
+// Week 5: Rich display
+SuggestionItem::new(data, "John Doe (Manager)".to_string(), "John".to_string());
+
+// Week 10: Store IDs, show names
+SuggestionItem::new(user, "John Doe (Manager)".to_string(), "123".to_string());
+```
+
+## Breaking Changes Summary
+
+1. **Import paths changed**: Add `canvas::` or `dispatcher::` prefixes
+2. **Legacy suggestion methods removed**: Replace with SuggestionItem-based dropdown or custom methods
+3. **No more simple suggestions**: Use `SuggestionItem` for typed suggestions
+4. **Trait split**: `AutocompleteCanvasState` is now separate and optional
+
+## Troubleshooting
+
+### Common Compilation Errors
+
+**Error**: `no method named 'get_suggestions' found`
+**Fix**: Remove legacy method from `CanvasState` implementation
+
+**Error**: `no 'CanvasState' in the root`
+**Fix**: Change `use canvas::CanvasState` to `use canvas::canvas::CanvasState`
+
+**Error**: `trait bound 'FormState: CanvasState' is not satisfied`
+**Fix**: Make sure your state properly implements the new `CanvasState` trait
+
+### Migration Checklist
+
+- [ ] Updated all import paths
+- [ ] Removed legacy methods from CanvasState implementation
+- [ ] Added custom suggestion methods if needed
+- [ ] Updated usage to SuggestionItem
+- [ ] Updated rendering calls
+- [ ] Tested form functionality
+- [ ] Tested suggestions functionality (if using)
+
+## Example: Complete Migration
+
+**Before:**
+```rust
+use canvas::{CanvasState, CanvasAction};
+
+impl CanvasState for FormState {
+    fn get_suggestions(&self) -> Option<&[String]> { /* ... */ }
+    fn deactivate_suggestions(&mut self) { /* ... */ }
+    // ... other methods
+}
+```
+
+**After:**
+```rust
+use canvas::canvas::{CanvasState, CanvasAction};
+use canvas::SuggestionItem;
+
+impl CanvasState for FormState {
+    // Only core canvas methods
+    fn current_field(&self) -> usize { /* ... */ }
+    fn get_current_input(&self) -> &str { /* ... */ }
+    // ... other core methods only
+}
+
+// Use FormEditor + SuggestionsProvider for suggestions dropdown
+    type SuggestionData = Hit;
+    
+    fn supports_suggestions(&self, field_index: usize) -> bool {
+        self.fields[field_index].is_link
+    }
+    
+    // Maintain suggestion state through FormEditor and DataProvider
+    
+    // Maintain suggestion state through FormEditor and DataProvider
+}
+```
+
+This migration results in cleaner, more maintainable, and more powerful code!

canvas/Cargo.toml

@@ -0,0 +1,115 @@
+[package]
+name = "canvas"
+version.workspace = true
+edition.workspace = true
+license = "MIT OR Apache-2.0"
+authors.workspace = true
+description = "Form/textarea for TUI"
+readme.workspace = true
+repository.workspace = true
+categories.workspace = true
+
+[dependencies]
+ratatui = { workspace = true, optional = true }
+crossterm = { workspace = true, optional = true }
+anyhow.workspace = true
+tokio = { workspace = true, optional = true }
+toml = { workspace = true }
+serde.workspace = true
+unicode-width.workspace = true
+thiserror = { workspace = true }
+
+tracing = "0.1.41"
+tracing-subscriber = "0.3.19"
+async-trait.workspace = true
+regex = { workspace = true, optional = true }
+ropey = { version = "1.6.1", optional = true }
+once_cell = "1.21.3"
+syntect = { version = "5.2.0", optional = true, default-features = false, features = ["default-fancy"] }
+
+[dev-dependencies]
+tokio-test = "0.4.4"
+
+[features]
+default = ["textmode-vim"]
+gui = ["ratatui", "crossterm"]
+suggestions = ["tokio"]
+cursor-style = ["crossterm"]
+validation = ["regex"]
+computed = []
+textarea = ["dep:ropey","gui"]
+syntect = ["dep:syntect", "gui", "textarea"]
+keymap = ["gui"]
+
+# text modes (mutually exclusive; default to vim)
+textmode-vim = []
+textmode-normal = []
+
+all-nontextmodes = [
+    "gui",
+    "suggestions",
+    "cursor-style",
+    "validation",
+    "computed",
+    "textarea",
+    "keymap"
+]
+
+[[example]]
+name = "suggestions"
+required-features = ["suggestions", "gui", "cursor-style"]
+path = "examples/suggestions.rs"
+
+[[example]]
+name = "suggestions2"
+required-features = ["suggestions", "gui", "cursor-style"]
+path = "examples/suggestions2.rs"
+
+[[example]]
+name = "canvas_cursor_auto"
+required-features = ["gui", "cursor-style"]
+path = "examples/canvas_cursor_auto.rs"
+
+[[example]]
+name = "validation_1"
+required-features = ["gui", "validation", "cursor-style"]
+
+[[example]]
+name = "validation_2"
+required-features = ["gui", "validation", "cursor-style"]
+
+[[example]]
+name = "validation_3"
+required-features = ["gui", "validation", "cursor-style"]
+
+[[example]]
+name = "validation_4"
+required-features = ["gui", "validation", "cursor-style"]
+
+[[example]]
+name = "validation_5"
+required-features = ["gui", "validation", "cursor-style"]
+
+[[example]]
+name = "computed_fields"
+required-features = ["gui", "computed"]
+
+[[example]]
+name = "textarea_vim"
+required-features = ["gui", "cursor-style", "textarea", "textmode-vim"]
+path = "examples/textarea_vim.rs"
+
+[[example]]
+name = "textarea_normal"
+required-features = ["gui", "cursor-style", "textarea", "textmode-normal"]
+path = "examples/textarea_normal.rs"
+
+[[example]]
+name = "textarea_syntax"
+required-features = ["gui", "cursor-style", "textarea", "textmode-normal", "syntect"]
+path = "examples/textarea_syntax.rs"
+
+[[example]]
+name = "canvas_keymap"
+required-features = ["gui", "keymap", "cursor-style"]
+path = "examples/canvas_keymap.rs"

canvas/README.md

@@ -0,0 +1,113 @@
+# Canvas
+
+Canvas is a Rust library for building form‑based and textarea‑driven terminal user interfaces.
+It provides the core logic for text editing, validation, suggestions, and cursor management.
+
+The library does not enforce a specific terminal UI framework:
+- Core functionality works without any rendering backend.
+- Terminal rendering support is available through the `gui` feature, which enables integration with `ratatui` and `crossterm`.
+- Applications may also integrate Canvas with other backends by handling input and rendering independently.
+
+---
+
+## Overview
+
+Canvas is designed for applications that require structured text input in a terminal environment.
+It provides:
+
+- Text editing modes (Vim‑like or normal)
+- Validation (regex, masks, limits, formatting)
+- Suggestions (asynchronous dropdowns)
+- Computed fields (derived values)
+- Textarea widget with cursor management
+- Syntax highlighting (via syntect)
+- Extensible architecture for custom behaviors
+
+---
+
+## Installation
+
+Add the dependency to your `Cargo.toml`:
+
+```toml
+[dependencies]
+canvas = { version = "0.x", features = ["gui", "cursor-style", "textarea", "validation"] }
+```
+
+---
+
+## Features
+
+The library is feature‑gated. Enable only what you need:
+
+- `gui` – terminal rendering support (ratatui + crossterm)
+- `cursor-style` – styled cursor support
+- `validation` – regex, masks, limits, formatting
+- `suggestions` – asynchronous suggestions dropdowns
+- `computed` – derived fields
+- `textarea` – textarea widget
+- `syntect` – syntax highlighting support
+- `textmode-vim` – Vim‑like editing (default)
+- `textmode-normal` – normal editing mode
+
+**Note:** `textmode-vim` and `textmode-normal` are mutually exclusive. Enable exactly one.
+
+The default feature set is `["textmode-vim"]`.
+
+---
+
+## Running Examples
+
+The repository includes several examples. Each requires specific feature flags.
+Use the following commands to run them:
+
+```bash
+# Textarea with Vim mode
+cargo run --example textarea_vim --features "gui cursor-style textarea textmode-vim"
+
+# Textarea with Normal mode
+cargo run --example textarea_normal --features "gui cursor-style textarea textmode-normal"
+
+# Textarea with syntax highlighting
+cargo run --example textarea_syntax --features "gui cursor-style textarea syntect textmode-normal"
+
+# Validation examples
+cargo run --example validation_1 --features "gui validation cursor-style"
+cargo run --example validation_2 --features "gui validation cursor-style"
+cargo run --example validation_3 --features "gui validation cursor-style"
+cargo run --example validation_4 --features "gui validation cursor-style"
+cargo run --example validation_5 --features "gui validation cursor-style"
+
+# Suggestions
+cargo run --example suggestions --features "suggestions gui cursor-style"
+cargo run --example suggestions2 --features "suggestions gui cursor-style"
+
+# Cursor auto movement
+cargo run --example canvas_cursor_auto --features "gui cursor-style"
+
+# Computed fields
+cargo run --example computed_fields --features "gui computed"
+```
+
+---
+
+## Documentation
+
+- API documentation: `cargo doc --open`
+- Migration notes: `CANVAS_MIGRATION.md`
+
+---
+
+## License
+
+Licensed under either of:
+- Apache License, Version 2.0
+- MIT License
+
+at your option.
+
+---
+
+## Contributing
+
+Contributions are welcome. Please follow the existing code structure and feature‑gating conventions.

canvas/aider.md

@@ -0,0 +1,16 @@
+# Aider Instructions
+
+## General Rules
+- Only modify files that I explicitly add with `/add`.
+- If a prompt mentions multiple files, **ignore all files except the ones I have added**.
+- Do not create, edit, or delete any files unless they are explicitly added.
+- Keep all other files exactly as they are, even if the prompt suggests changes.
+- Never move logic into or out of files that are not explicitly added.
+- If a prompt suggests changes to multiple files, apply **only the subset of changes** that belong to the added file(s).
+- If a change requires touching other files, ignore them, if they were not manually added.
+
+## Coding Style
+- Follow Rust 2021 edition idioms.
+- No logic in `mod.rs` files (only exports/routing).
+- Always update or create tests **only if the test file is explicitly added**.
+- Do not think, only apply changes from the prompt

canvas/examples/canvas_cursor_auto.rs

@@ -0,0 +1,865 @@
+// examples/canvas-cursor-auto.rs
+//! Demonstrates automatic cursor management with the canvas library
+//!
+//! This example REQUIRES the `cursor-style` feature to compile.
+//! 
+//! Run with:
+//! cargo run --example canvas_cursor_auto --features "gui,cursor-style"
+//!
+//! This will fail without cursor-style:
+//! cargo run --example canvas-cursor-auto --features "gui"
+
+// REQUIRE cursor-style feature - example won't compile without it
+#[cfg(not(feature = "cursor-style"))]
+compile_error!(
+    "This example requires the 'cursor-style' feature. \
+     Run with: cargo run --example canvas-cursor-auto --features \"gui,cursor-style\""
+);
+
+use std::io;
+use crossterm::{
+    event::{
+        self, DisableMouseCapture, EnableMouseCapture, Event, KeyCode, KeyModifiers,
+    },
+    execute,
+    terminal::{
+        disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen,
+    },
+};
+use ratatui::{
+    backend::{Backend, CrosstermBackend},
+    layout::{Constraint, Direction, Layout},
+    style::{Color, Style},
+    text::{Line, Span},
+    widgets::{Block, Borders, Paragraph},
+    Frame, Terminal,
+};
+
+use canvas::{
+    canvas::{
+        gui::render_canvas_default,
+        modes::AppMode,
+        CursorManager, // This import only exists when cursor-style feature is enabled
+    },
+    DataProvider, FormEditor,
+};
+
+// Enhanced FormEditor that demonstrates automatic cursor management
+struct AutoCursorFormEditor<D: DataProvider> {
+    editor: FormEditor<D>,
+    has_unsaved_changes: bool,
+    debug_message: String,
+    command_buffer: String, // For multi-key vim commands like "gg"
+}
+
+impl<D: DataProvider> AutoCursorFormEditor<D> {
+    fn new(data_provider: D) -> Self {
+        Self {
+            editor: FormEditor::new(data_provider),
+            has_unsaved_changes: false,
+            debug_message: "🎯 Automatic Cursor Demo - cursor-style feature enabled!".to_string(),
+            command_buffer: String::new(),
+        }
+    }
+
+    // === COMMAND BUFFER HANDLING ===
+
+    fn clear_command_buffer(&mut self) {
+        self.command_buffer.clear();
+    }
+
+    fn add_to_command_buffer(&mut self, ch: char) {
+        self.command_buffer.push(ch);
+    }
+
+    fn get_command_buffer(&self) -> &str {
+        &self.command_buffer
+    }
+
+    fn has_pending_command(&self) -> bool {
+        !self.command_buffer.is_empty()
+    }
+
+    // === VISUAL/HIGHLIGHT MODE SUPPORT ===
+
+
+    fn enter_visual_mode(&mut self) {
+        // Use the library method instead of manual state setting
+        self.editor.enter_highlight_mode();
+        self.debug_message = "🔥 VISUAL MODE - Cursor: Blinking Block █".to_string();
+    }
+
+    fn enter_visual_line_mode(&mut self) {
+        // Use the library method instead of manual state setting  
+        self.editor.enter_highlight_line_mode();
+        self.debug_message = "🔥 VISUAL LINE MODE - Cursor: Blinking Block █".to_string();
+    }
+
+    fn exit_visual_mode(&mut self) {
+        // Use the library method
+        self.editor.exit_highlight_mode();
+        self.debug_message = "🔒 NORMAL MODE - Cursor: Steady Block █".to_string();
+    }
+
+    fn update_visual_selection(&mut self) {
+        if self.editor.is_highlight_mode() {
+            use canvas::canvas::state::SelectionState;
+            match self.editor.selection_state() {
+                SelectionState::Characterwise { anchor } => {
+                    self.debug_message = format!(
+                        "🎯 Visual selection: anchor=({},{}) current=({},{}) - Cursor: Blinking Block █",
+                        anchor.0, anchor.1,
+                        self.editor.current_field(),
+                        self.editor.cursor_position()
+                    );
+                }
+                SelectionState::Linewise { anchor_field } => {
+                    self.debug_message = format!(
+                        "🎯 Visual LINE selection: anchor={} current={} - Cursor: Blinking Block █",
+                        anchor_field,
+                        self.editor.current_field()
+                    );
+                }
+                _ => {}
+            }
+        }
+    }
+
+    // === ENHANCED MOVEMENT WITH VISUAL UPDATES ===
+
+    fn move_left(&mut self) {
+        self.editor.move_left();
+        self.update_visual_selection();
+    }
+
+    fn move_right(&mut self) {
+        self.editor.move_right();
+        self.update_visual_selection();
+    }
+
+    fn move_up(&mut self) {
+        self.editor.move_up();
+        self.update_visual_selection();
+    }
+
+    fn move_down(&mut self) {
+        self.editor.move_down();
+        self.update_visual_selection();
+    }
+
+    fn move_word_next(&mut self) {
+        self.editor.move_word_next();
+        self.update_visual_selection();
+    }
+
+    fn move_word_prev(&mut self) {
+        self.editor.move_word_prev();
+        self.update_visual_selection();
+    }
+
+    fn move_word_end(&mut self) {
+        self.editor.move_word_end();
+        self.update_visual_selection();
+    }
+
+    fn move_word_end_prev(&mut self) {
+        self.editor.move_word_end_prev();
+        self.update_visual_selection();
+    }
+
+    fn move_line_start(&mut self) {
+        self.editor.move_line_start();
+        self.update_visual_selection();
+    }
+
+    fn move_line_end(&mut self) {
+        self.editor.move_line_end();
+        self.update_visual_selection();
+    }
+
+    fn move_first_line(&mut self) {
+        self.editor.move_first_line();
+        self.update_visual_selection();
+    }
+
+    fn move_last_line(&mut self) {
+        self.editor.move_last_line();
+        self.update_visual_selection();
+    }
+
+    fn prev_field(&mut self) {
+        self.editor.prev_field();
+        self.update_visual_selection();
+    }
+
+    fn next_field(&mut self) {
+        self.editor.next_field();
+        self.update_visual_selection();
+    }
+
+    // === DELETE OPERATIONS ===
+
+    fn delete_backward(&mut self) -> anyhow::Result<()> {
+        let result = self.editor.delete_backward();
+        if result.is_ok() {
+            self.has_unsaved_changes = true;
+            self.debug_message = "⌫ Deleted character backward".to_string();
+        }
+        result
+    }
+
+    fn delete_forward(&mut self) -> anyhow::Result<()> {
+        let result = self.editor.delete_forward();
+        if result.is_ok() {
+            self.has_unsaved_changes = true;
+            self.debug_message = "⌦ Deleted character forward".to_string();
+        }
+        result
+    }
+
+    // === MODE TRANSITIONS WITH AUTOMATIC CURSOR MANAGEMENT ===
+
+    fn enter_edit_mode(&mut self) {
+        self.editor.enter_edit_mode(); // 🎯 Library automatically sets cursor to bar |
+        self.debug_message = "✏️  INSERT MODE - Cursor: Steady Bar |".to_string();
+    }
+
+    fn enter_append_mode(&mut self) {
+        self.editor.enter_append_mode(); // 🎯 Library automatically positions cursor and sets mode
+        self.debug_message = "✏️  INSERT (append) - Cursor: Steady Bar |".to_string();
+    }
+
+    fn exit_edit_mode(&mut self) {
+        self.editor.exit_edit_mode(); // 🎯 Library automatically sets cursor to block █
+        self.exit_visual_mode();
+        self.debug_message = "🔒 NORMAL MODE - Cursor: Steady Block █".to_string();
+    }
+
+    fn insert_char(&mut self, ch: char) -> anyhow::Result<()> {
+        let result = self.editor.insert_char(ch);
+        if result.is_ok() {
+            self.has_unsaved_changes = true;
+        }
+        result
+    }
+
+    // === MANUAL CURSOR OVERRIDE DEMONSTRATION ===
+    
+    /// Demonstrate manual cursor control (for advanced users)
+    fn demo_manual_cursor_control(&mut self) -> std::io::Result<()> {
+        // Users can still manually control cursor if needed
+        CursorManager::update_for_mode(AppMode::Command)?;
+        self.debug_message = "🔧 Manual override: Command cursor _".to_string();
+        Ok(())
+    }
+
+    fn restore_automatic_cursor(&mut self) -> std::io::Result<()> {
+        // Restore automatic cursor based on current mode
+        CursorManager::update_for_mode(self.editor.mode())?;
+        self.debug_message = "🎯 Restored automatic cursor management".to_string();
+        Ok(())
+    }
+
+    // === DELEGATE TO ORIGINAL EDITOR ===
+
+    fn current_field(&self) -> usize {
+        self.editor.current_field()
+    }
+
+    fn cursor_position(&self) -> usize {
+        self.editor.cursor_position()
+    }
+
+    fn mode(&self) -> AppMode {
+        self.editor.mode()
+    }
+
+    fn current_text(&self) -> &str {
+        let field_index = self.editor.current_field();
+        self.editor.data_provider().field_value(field_index)
+    }
+
+    fn data_provider(&self) -> &D {
+        self.editor.data_provider()
+    }
+
+    fn ui_state(&self) -> &canvas::EditorState {
+        self.editor.ui_state()
+    }
+
+    fn set_mode(&mut self, mode: AppMode) {
+        self.editor.set_mode(mode); // 🎯 Library automatically updates cursor
+        if mode != AppMode::Highlight {
+            self.exit_visual_mode();
+        }
+    }
+
+    // === STATUS AND DEBUG ===
+
+    fn set_debug_message(&mut self, msg: String) {
+        self.debug_message = msg;
+    }
+
+    fn debug_message(&self) -> &str {
+        &self.debug_message
+    }
+
+    fn has_unsaved_changes(&self) -> bool {
+        self.has_unsaved_changes
+    }
+
+    fn open_line_below(&mut self) -> anyhow::Result<()> {
+        let result = self.editor.open_line_below();
+        if result.is_ok() {
+            self.debug_message = "✏️  INSERT (open line below) - Cursor: Steady Bar |".to_string();
+        }
+        result
+    }
+
+    fn open_line_above(&mut self) -> anyhow::Result<()> {
+        let result = self.editor.open_line_above();
+        if result.is_ok() {
+            self.debug_message = "✏️  INSERT (open line above) - Cursor: Steady Bar |".to_string();
+        }
+        result
+    }
+
+    fn move_big_word_next(&mut self) {
+        self.editor.move_big_word_next();
+        self.update_visual_selection();
+    }
+
+    fn move_big_word_prev(&mut self) {
+        self.editor.move_big_word_prev();
+        self.update_visual_selection();
+    }
+
+    fn move_big_word_end(&mut self) {
+        self.editor.move_big_word_end();
+        self.update_visual_selection();
+    }
+
+    fn move_big_word_end_prev(&mut self) {
+        self.editor.move_big_word_end_prev();
+        self.update_visual_selection();
+    }
+}
+
+// Demo form data with interesting text for cursor demonstration
+struct CursorDemoData {
+    fields: Vec<(String, String)>,
+}
+
+impl CursorDemoData {
+    fn new() -> Self {
+        Self {
+            fields: vec![
+                ("👤 Name".to_string(), "John-Paul McDonald".to_string()),
+                ("📧 Email".to_string(), "user@example-domain.com".to_string()),
+                ("📱 Phone".to_string(), "+1 (555) 123-4567".to_string()),
+                ("🏠 Address".to_string(), "123 Main St, Apt 4B".to_string()),
+                ("🏷️  Tags".to_string(), "urgent,important,follow-up".to_string()),
+                ("📝 Notes".to_string(), "Watch the cursor change! Normal=█ Insert=| Visual=blinking█".to_string()),
+                ("🎯 Cursor Demo".to_string(), "Press 'i' for insert, 'v' for visual, 'Esc' for normal".to_string()),
+            ],
+        }
+    }
+}
+
+impl DataProvider for CursorDemoData {
+    fn field_count(&self) -> usize {
+        self.fields.len()
+    }
+
+    fn field_name(&self, index: usize) -> &str {
+        &self.fields[index].0
+    }
+
+    fn field_value(&self, index: usize) -> &str {
+        &self.fields[index].1
+    }
+
+    fn set_field_value(&mut self, index: usize, value: String) {
+        self.fields[index].1 = value;
+    }
+
+    fn supports_suggestions(&self, _field_index: usize) -> bool {
+        false
+    }
+
+    fn display_value(&self, _index: usize) -> Option<&str> {
+        None
+    }
+}
+
+/// Automatic cursor management demonstration
+/// Features the CursorManager directly to show it's working
+fn handle_key_press(
+    key: KeyCode,
+    modifiers: KeyModifiers,
+    editor: &mut AutoCursorFormEditor<CursorDemoData>,
+) -> anyhow::Result<bool> {
+    let mode = editor.mode();
+
+    // Quit handling
+    if (key == KeyCode::Char('q') && modifiers.contains(KeyModifiers::CONTROL))
+        || (key == KeyCode::Char('c') && modifiers.contains(KeyModifiers::CONTROL))
+        || key == KeyCode::F(10)
+    {
+        return Ok(false);
+    }
+
+    match (mode, key, modifiers) {
+        // === MODE TRANSITIONS WITH AUTOMATIC CURSOR MANAGEMENT ===
+        (AppMode::ReadOnly, KeyCode::Char('i'), _) => {
+            editor.enter_edit_mode(); // 🎯 Automatic: cursor becomes bar |
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('a'), _) => {
+            editor.enter_append_mode();
+            editor.set_debug_message("✏️  INSERT (append) - Cursor: Steady Bar |".to_string());
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('A'), _) => {
+            editor.move_line_end();
+            editor.enter_edit_mode(); // 🎯 Automatic: cursor becomes bar |
+            editor.set_debug_message("✏️  INSERT (end of line) - Cursor: Steady Bar |".to_string());
+            editor.clear_command_buffer();
+        }
+
+        (AppMode::ReadOnly, KeyCode::Char('o'), _) => {
+            if let Err(e) = editor.open_line_below() {
+                editor.set_debug_message(format!("Error opening line below: {e}"));
+            }
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('O'), _) => {
+            if let Err(e) = editor.open_line_above() {
+                editor.set_debug_message(format!("Error opening line above: {e}"));
+            }
+            editor.clear_command_buffer();
+        }
+
+        // From Normal Mode: Enter visual modes
+        (AppMode::ReadOnly, KeyCode::Char('v'), _) => {
+            editor.enter_visual_mode();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('V'), _) => {
+            editor.enter_visual_line_mode();
+            editor.clear_command_buffer();
+        }
+        
+        // From Visual Mode: Switch between visual modes or exit
+        (AppMode::Highlight, KeyCode::Char('v'), _) => {
+            use canvas::canvas::state::SelectionState;
+            match editor.editor.selection_state() {
+                SelectionState::Characterwise { .. } => {
+                    // Already in characterwise mode, exit visual mode (vim behavior)
+                    editor.exit_visual_mode();
+                    editor.set_debug_message("🔒 Exited visual mode".to_string());
+                }
+                _ => {
+                    // Switch from linewise to characterwise mode
+                    editor.editor.enter_highlight_mode();
+                    editor.update_visual_selection();
+                    editor.set_debug_message("🔥 Switched to VISUAL mode".to_string());
+                }
+            }
+            editor.clear_command_buffer();
+        }
+        
+        (AppMode::Highlight, KeyCode::Char('V'), _) => {
+            use canvas::canvas::state::SelectionState;
+            match editor.editor.selection_state() {
+                SelectionState::Linewise { .. } => {
+                    // Already in linewise mode, exit visual mode (vim behavior)
+                    editor.exit_visual_mode();
+                    editor.set_debug_message("🔒 Exited visual mode".to_string());
+                }
+                _ => {
+                    // Switch from characterwise to linewise mode
+                    editor.editor.enter_highlight_line_mode();
+                    editor.update_visual_selection();
+                    editor.set_debug_message("🔥 Switched to VISUAL LINE mode".to_string());
+                }
+            }
+            editor.clear_command_buffer();
+        }
+        
+        // Escape: Exit any mode back to normal
+        (_, KeyCode::Esc, _) => {
+            match mode {
+                AppMode::Edit => {
+                    editor.exit_edit_mode(); // Exit insert mode
+                }
+                AppMode::Highlight => {
+                    editor.exit_visual_mode(); // Exit visual mode
+                }
+                _ => {
+                    // Already in normal mode, just clear command buffer
+                    editor.clear_command_buffer();
+                }
+            }
+        }
+
+        // === CURSOR MANAGEMENT DEMONSTRATION ===
+        (AppMode::ReadOnly, KeyCode::F(1), _) => {
+            editor.demo_manual_cursor_control()?;
+        }
+        (AppMode::ReadOnly, KeyCode::F(2), _) => {
+            editor.restore_automatic_cursor()?;
+        }
+
+        // === MOVEMENT: VIM-STYLE NAVIGATION ===
+
+        // Basic movement (hjkl and arrows)
+        (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Char('h'), _)
+        | (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Left, _) => {
+            editor.move_left();
+            editor.set_debug_message("← left".to_string());
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Char('l'), _)
+        | (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Right, _) => {
+            editor.move_right();
+            editor.set_debug_message("→ right".to_string());
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Char('j'), _)
+        | (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Down, _) => {
+            editor.move_down();
+            editor.set_debug_message("↓ next field".to_string());
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Char('k'), _)
+        | (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Up, _) => {
+            editor.move_up();
+            editor.set_debug_message("↑ previous field".to_string());
+            editor.clear_command_buffer();
+        }
+
+        // Word movement
+        (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Char('w'), _) => {
+            editor.move_word_next();
+            editor.set_debug_message("w: next word start".to_string());
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Char('b'), _) => {
+            editor.move_word_prev();
+            editor.set_debug_message("b: previous word start".to_string());
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Char('e'), _) => {
+            // Check if this is 'ge' command
+            if editor.get_command_buffer() == "g" {
+                editor.move_word_end_prev();
+                editor.set_debug_message("ge: previous word end".to_string());
+                editor.clear_command_buffer();
+            } else {
+                editor.move_word_end();
+                editor.set_debug_message("e: word end".to_string());
+                editor.clear_command_buffer();
+            }
+        }
+
+        (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Char('W'), _) => {
+            editor.move_big_word_next();
+            editor.set_debug_message("W: next WORD start".to_string());
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Char('B'), _) => {
+            editor.move_big_word_prev();
+            editor.set_debug_message("B: previous WORD start".to_string());
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Char('E'), _) => {
+            // Check if this is 'gE' command
+            if editor.get_command_buffer() == "g" {
+                editor.move_big_word_end_prev();
+                editor.set_debug_message("gE: previous WORD end".to_string());
+                editor.clear_command_buffer();
+            } else {
+                editor.move_big_word_end();
+                editor.set_debug_message("E: WORD end".to_string());
+                editor.clear_command_buffer();
+            }
+        }
+
+        // Line movement
+        (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Char('0'), _)
+        | (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Home, _) => {
+            editor.move_line_start();
+            editor.set_debug_message("0: line start".to_string());
+        }
+        (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Char('$'), _)
+        | (AppMode::ReadOnly | AppMode::Highlight, KeyCode::End, _) => {
+            editor.move_line_end();
+            editor.set_debug_message("$: line end".to_string());
+        }
+
+        // Field/document movement
+        (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Char('g'), _) => {
+            if editor.get_command_buffer() == "g" {
+                editor.move_first_line();
+                editor.set_debug_message("gg: first field".to_string());
+                editor.clear_command_buffer();
+            } else {
+                editor.clear_command_buffer();
+                editor.add_to_command_buffer('g');
+                editor.set_debug_message("g".to_string());
+            }
+        }
+        (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Char('G'), _) => {
+            editor.move_last_line();
+            editor.set_debug_message("G: last field".to_string());
+            editor.clear_command_buffer();
+        }
+
+        // === EDIT MODE MOVEMENT ===
+        (AppMode::Edit, KeyCode::Left, m) if m.contains(KeyModifiers::CONTROL) => {
+            editor.move_word_prev();
+            editor.set_debug_message("Ctrl+← word back".to_string());
+        }
+        (AppMode::Edit, KeyCode::Right, m) if m.contains(KeyModifiers::CONTROL) => {
+            editor.move_word_next();
+            editor.set_debug_message("Ctrl+→ word forward".to_string());
+        }
+        (AppMode::Edit, KeyCode::Left, _) => {
+            editor.move_left();
+        }
+        (AppMode::Edit, KeyCode::Right, _) => {
+            editor.move_right();
+        }
+        (AppMode::Edit, KeyCode::Up, _) => {
+            editor.move_up();
+        }
+        (AppMode::Edit, KeyCode::Down, _) => {
+            editor.move_down();
+        }
+        (AppMode::Edit, KeyCode::Home, _) => {
+            editor.move_line_start();
+        }
+        (AppMode::Edit, KeyCode::End, _) => {
+            editor.move_line_end();
+        }
+
+        // === DELETE OPERATIONS ===
+        (AppMode::Edit, KeyCode::Backspace, _) => {
+            editor.delete_backward()?;
+        }
+        (AppMode::Edit, KeyCode::Delete, _) => {
+            editor.delete_forward()?;
+        }
+
+        // Delete operations in normal mode (vim x)
+        (AppMode::ReadOnly, KeyCode::Char('x'), _) => {
+            editor.delete_forward()?;
+            editor.set_debug_message("x: deleted character".to_string());
+        }
+        (AppMode::ReadOnly, KeyCode::Char('X'), _) => {
+            editor.delete_backward()?;
+            editor.set_debug_message("X: deleted character backward".to_string());
+        }
+
+        // === TAB NAVIGATION ===
+        (_, KeyCode::Tab, _) => {
+            editor.next_field();
+            editor.set_debug_message("Tab: next field".to_string());
+        }
+        (_, KeyCode::BackTab, _) => {
+            editor.prev_field();
+            editor.set_debug_message("Shift+Tab: previous field".to_string());
+        }
+
+        // === CHARACTER INPUT ===
+        (AppMode::Edit, KeyCode::Char(c), m) if !m.contains(KeyModifiers::CONTROL) => {
+            editor.insert_char(c)?;
+        }
+
+        // === DEBUG/INFO COMMANDS ===
+        (AppMode::ReadOnly, KeyCode::Char('?'), _) => {
+            editor.set_debug_message(format!(
+                "Field {}/{}, Pos {}, Mode: {:?} - Cursor managed automatically!",
+                editor.current_field() + 1,
+                editor.data_provider().field_count(),
+                editor.cursor_position(),
+                editor.mode()
+            ));
+        }
+
+        _ => {
+            if editor.has_pending_command() {
+                editor.clear_command_buffer();
+                editor.set_debug_message("Invalid command sequence".to_string());
+            } else {
+                editor.set_debug_message(format!(
+                    "Unhandled: {key:?} + {modifiers:?} in {mode:?} mode"
+                ));
+            }
+        }
+    }
+
+    Ok(true)
+}
+
+fn run_app<B: Backend>(
+    terminal: &mut Terminal<B>,
+    mut editor: AutoCursorFormEditor<CursorDemoData>,
+) -> io::Result<()> {
+    loop {
+        terminal.draw(|f| ui(f, &editor))?;
+
+        if let Event::Key(key) = event::read()? {
+            match handle_key_press(key.code, key.modifiers, &mut editor) {
+                Ok(should_continue) => {
+                    if !should_continue {
+                        break;
+                    }
+                }
+                Err(e) => {
+                    editor.set_debug_message(format!("Error: {e}"));
+                }
+            }
+        }
+    }
+
+    Ok(())
+}
+
+fn ui(f: &mut Frame, editor: &AutoCursorFormEditor<CursorDemoData>) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Min(8), Constraint::Length(10)])
+        .split(f.area());
+
+    render_enhanced_canvas(f, chunks[0], editor);
+    render_status_and_help(f, chunks[1], editor);
+}
+
+fn render_enhanced_canvas(
+    f: &mut Frame,
+    area: ratatui::layout::Rect,
+    editor: &AutoCursorFormEditor<CursorDemoData>,
+) {
+    render_canvas_default(f, area, &editor.editor);
+}
+
+fn render_status_and_help(
+    f: &mut Frame,
+    area: ratatui::layout::Rect,
+    editor: &AutoCursorFormEditor<CursorDemoData>,
+) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Length(3), Constraint::Length(7)])
+        .split(area);
+
+    // Status bar with cursor information - FIXED VERSION
+    let mode_text = match editor.mode() {
+        AppMode::Edit => "INSERT | (bar cursor)",
+        AppMode::ReadOnly => "NORMAL █ (block cursor)",
+        AppMode::Highlight => {
+            // Use library selection state instead of editor.highlight_state()
+            use canvas::canvas::state::SelectionState;
+            match editor.editor.selection_state() {
+                SelectionState::Characterwise { .. } => "VISUAL █ (blinking block)",
+                SelectionState::Linewise { .. } => "VISUAL LINE █ (blinking block)",
+                _ => "VISUAL █ (blinking block)",
+            }
+        },
+        _ => "NORMAL █ (block cursor)",
+    };
+
+    let status_text = if editor.has_pending_command() {
+        format!("-- {} -- {} [{}]", mode_text, editor.debug_message(), editor.get_command_buffer())
+    } else if editor.has_unsaved_changes() {
+        format!("-- {} -- [Modified] {}", mode_text, editor.debug_message())
+    } else {
+        format!("-- {} -- {}", mode_text, editor.debug_message())
+    };
+
+    let status = Paragraph::new(Line::from(Span::raw(status_text)))
+        .block(Block::default().borders(Borders::ALL).title("🎯 Automatic Cursor Status"));
+
+    f.render_widget(status, chunks[0]);
+
+    // Enhanced help text (no changes needed here)
+    let help_text = match editor.mode() {
+        AppMode::ReadOnly => {
+            if editor.has_pending_command() {
+                match editor.get_command_buffer() {
+                    "g" => "Press 'g' again for first field, or any other key to cancel",
+                    _ => "Pending command... (Esc to cancel)"
+                }
+            } else {
+                "🎯 CURSOR-STYLE DEMO: Normal █ | Insert | | Visual blinking█\n\
+                Normal: hjkl/arrows=move, w/b/e=words, W/B/E=WORDS, 0/$=line, gg/G=first/last\n\
+                i/a/A/o/O=insert, v/V=visual, x/X=delete, ?=info\n\
+                F1=demo manual cursor, F2=restore automatic"
+            }
+        }
+        AppMode::Edit => {
+            "🎯 INSERT MODE - Cursor: | (bar)\n\
+             arrows=move, Ctrl+arrows=words, Backspace/Del=delete\n\
+             Esc=normal, Tab/Shift+Tab=fields"
+        }
+        AppMode::Highlight => {
+            "🎯 VISUAL MODE - Cursor: █ (blinking block)\n\
+             hjkl/arrows=extend selection, w/b/e=word selection\n\
+             Esc=normal"
+        }
+        _ => "🎯 Watch the cursor change automatically!"
+    };
+
+    let help = Paragraph::new(help_text)
+        .block(Block::default().borders(Borders::ALL).title("🚀 Automatic Cursor Management"))
+        .style(Style::default().fg(Color::Gray));
+
+    f.render_widget(help, chunks[1]);
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    // Print feature status
+    println!("🎯 Canvas Cursor Auto Demo");
+    println!("✅ cursor-style feature: ENABLED");
+    println!("🚀 Automatic cursor management: ACTIVE");
+    println!("📖 Watch your terminal cursor change based on mode!");
+    println!();
+
+    enable_raw_mode()?;
+    let mut stdout = io::stdout();
+    execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
+    let backend = CrosstermBackend::new(stdout);
+    let mut terminal = Terminal::new(backend)?;
+
+    let data = CursorDemoData::new();
+    let mut editor = AutoCursorFormEditor::new(data);
+    
+    // Initialize with normal mode - library automatically sets block cursor
+    editor.set_mode(AppMode::ReadOnly);
+
+    // Demonstrate that CursorManager is available and working
+    CursorManager::update_for_mode(AppMode::ReadOnly)?;
+
+    let res = run_app(&mut terminal, editor);
+
+    // Library automatically resets cursor on FormEditor::drop()
+    // But we can also manually reset if needed
+    CursorManager::reset()?;
+
+    disable_raw_mode()?;
+    execute!(
+        terminal.backend_mut(),
+        LeaveAlternateScreen,
+        DisableMouseCapture
+    )?;
+    terminal.show_cursor()?;
+
+    if let Err(err) = res {
+        println!("{err:?}");
+    }
+
+    println!("🎯 Cursor automatically reset to default!");
+    Ok(())
+}

canvas/examples/canvas_keymap.rs

@@ -0,0 +1,376 @@
+// examples/canvas_keymap.rs
+//! Demonstrates the centralized keymap system for canvas interactions
+//!
+//! This example shows how to use the canvas-keymap feature to delegate
+//! all canvas key handling to the library, supporting complex sequences
+//! like "gg", "ge", etc.
+//!
+//! Run with:
+//! cargo run --example canvas_keymap --features "gui,keymap,cursor-style"
+
+#[cfg(not(feature = "keymap"))]
+compile_error!(
+    "This example requires the 'keymap' feature. \
+     Run with: cargo run --example canvas_keymap --features \"gui,keymap,cursor-style\""
+);
+
+use std::collections::HashMap;
+use std::io;
+use crossterm::{
+    event::{self, DisableMouseCapture, EnableMouseCapture, Event, KeyEvent},
+    execute,
+    terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
+};
+use ratatui::{
+    backend::{Backend, CrosstermBackend},
+    layout::{Constraint, Direction, Layout},
+    style::{Color, Style},
+    text::{Line, Span},
+    widgets::{Block, Borders, Paragraph},
+    Frame, Terminal,
+};
+
+use canvas::{
+    canvas::{gui::render_canvas_default, modes::AppMode},
+    keymap::{CanvasKeyMap, KeyEventOutcome},
+    DataProvider, FormEditor,
+};
+
+/// Demo application using centralized keymap system
+struct KeymapDemoApp {
+    editor: FormEditor<DemoData>,
+    message: String,
+    quit: bool,
+}
+
+impl KeymapDemoApp {
+    fn new() -> Self {
+        let data = DemoData::new();
+        let mut editor = FormEditor::new(data);
+        
+        // Build and inject the keymap from our config
+        let keymap = Self::build_demo_keymap();
+        editor.set_keymap(keymap);
+        
+        Self {
+            editor,
+            message: "🎯 Keymap system loaded! Try: gg, ge, hjkl, w/b/e, v, i, etc.".to_string(),
+            quit: false,
+        }
+    }
+
+    /// Build a comprehensive keymap configuration
+    fn build_demo_keymap() -> CanvasKeyMap {
+        let mut read_only = HashMap::new();
+        let mut edit = HashMap::new();
+        let mut highlight = HashMap::new();
+
+        // === READ-ONLY MODE KEYBINDINGS ===
+        
+        // Basic movement
+        read_only.insert("move_left".to_string(), vec!["h".to_string(), "Left".to_string()]);
+        read_only.insert("move_right".to_string(), vec!["l".to_string(), "Right".to_string()]);
+        read_only.insert("move_up".to_string(), vec!["k".to_string(), "Up".to_string()]);
+        read_only.insert("move_down".to_string(), vec!["j".to_string(), "Down".to_string()]);
+
+        // Word movement
+        read_only.insert("move_word_next".to_string(), vec!["w".to_string()]);
+        read_only.insert("move_word_prev".to_string(), vec!["b".to_string()]);
+        read_only.insert("move_word_end".to_string(), vec!["e".to_string()]);
+        read_only.insert("move_word_end_prev".to_string(), vec!["ge".to_string()]); // Multi-key!
+
+        // Big word movement  
+        read_only.insert("move_big_word_next".to_string(), vec!["W".to_string()]);
+        read_only.insert("move_big_word_prev".to_string(), vec!["B".to_string()]);
+        read_only.insert("move_big_word_end".to_string(), vec!["E".to_string()]);
+        read_only.insert("move_big_word_end_prev".to_string(), vec!["gE".to_string()]); // Multi-key!
+
+        // Line movement
+        read_only.insert("move_line_start".to_string(), vec!["0".to_string(), "Home".to_string()]);
+        read_only.insert("move_line_end".to_string(), vec!["$".to_string(), "End".to_string()]);
+        
+        // Field movement
+        read_only.insert("move_first_line".to_string(), vec!["gg".to_string()]); // Multi-key!
+        read_only.insert("move_last_line".to_string(), vec!["G".to_string()]);
+        read_only.insert("next_field".to_string(), vec!["Tab".to_string()]);
+        read_only.insert("prev_field".to_string(), vec!["Shift+Tab".to_string()]);
+
+        // Mode transitions
+        read_only.insert("enter_edit_mode_before".to_string(), vec!["i".to_string()]);
+        read_only.insert("enter_edit_mode_after".to_string(), vec!["a".to_string()]);
+        read_only.insert("enter_highlight_mode".to_string(), vec!["v".to_string()]);
+        read_only.insert("enter_highlight_mode_linewise".to_string(), vec!["V".to_string()]);
+
+        // Editing actions in normal mode
+        read_only.insert("delete_char_forward".to_string(), vec!["x".to_string()]);
+        read_only.insert("delete_char_backward".to_string(), vec!["X".to_string()]);
+        read_only.insert("open_line_below".to_string(), vec!["o".to_string()]);
+        read_only.insert("open_line_above".to_string(), vec!["O".to_string()]);
+
+        // === EDIT MODE KEYBINDINGS ===
+        
+        edit.insert("exit_edit_mode".to_string(), vec!["esc".to_string()]);
+        edit.insert("move_left".to_string(), vec!["Left".to_string()]);
+        edit.insert("move_right".to_string(), vec!["Right".to_string()]);
+        edit.insert("move_up".to_string(), vec!["Up".to_string()]);
+        edit.insert("move_down".to_string(), vec!["Down".to_string()]);
+        edit.insert("move_line_start".to_string(), vec!["Home".to_string()]);
+        edit.insert("move_line_end".to_string(), vec!["End".to_string()]);
+        edit.insert("move_word_next".to_string(), vec!["Ctrl+Right".to_string()]);
+        edit.insert("move_word_prev".to_string(), vec!["Ctrl+Left".to_string()]);
+        edit.insert("next_field".to_string(), vec!["Tab".to_string()]);
+        edit.insert("prev_field".to_string(), vec!["Shift+Tab".to_string()]);
+        edit.insert("delete_char_backward".to_string(), vec!["Backspace".to_string()]);
+        edit.insert("delete_char_forward".to_string(), vec!["Delete".to_string()]);
+
+        // === HIGHLIGHT MODE KEYBINDINGS ===
+        
+        highlight.insert("exit_highlight_mode".to_string(), vec!["esc".to_string()]);
+        highlight.insert("enter_highlight_mode_linewise".to_string(), vec!["V".to_string()]);
+        
+        // Movement (extends selection)
+        highlight.insert("move_left".to_string(), vec!["h".to_string(), "Left".to_string()]);
+        highlight.insert("move_right".to_string(), vec!["l".to_string(), "Right".to_string()]);
+        highlight.insert("move_up".to_string(), vec!["k".to_string(), "Up".to_string()]);
+        highlight.insert("move_down".to_string(), vec!["j".to_string(), "Down".to_string()]);
+        highlight.insert("move_word_next".to_string(), vec!["w".to_string()]);
+        highlight.insert("move_word_prev".to_string(), vec!["b".to_string()]);
+        highlight.insert("move_word_end".to_string(), vec!["e".to_string()]);
+        highlight.insert("move_word_end_prev".to_string(), vec!["ge".to_string()]);
+        highlight.insert("move_line_start".to_string(), vec!["0".to_string()]);
+        highlight.insert("move_line_end".to_string(), vec!["$".to_string()]);
+        highlight.insert("move_first_line".to_string(), vec!["gg".to_string()]);
+        highlight.insert("move_last_line".to_string(), vec!["G".to_string()]);
+
+        CanvasKeyMap::from_mode_maps(&read_only, &edit, &highlight)
+    }
+
+    fn handle_key_event(&mut self, key_event: KeyEvent) -> io::Result<()> {
+        // First, try canvas keymap
+        match self.editor.handle_key_event(key_event) {
+            KeyEventOutcome::Consumed(Some(msg)) => {
+                self.message = format!("🎯 Canvas: {}", msg);
+                return Ok(());
+            }
+            KeyEventOutcome::Consumed(None) => {
+                self.message = "🎯 Canvas action executed".to_string();
+                return Ok(());
+            }
+            KeyEventOutcome::Pending => {
+                self.message = "⏳ Waiting for next key in sequence...".to_string();
+                return Ok(());
+            }
+            KeyEventOutcome::NotMatched => {
+                // Fall through to client actions
+            }
+        }
+
+        // Handle client-specific actions (non-canvas)
+        use crossterm::event::{KeyCode, KeyModifiers};
+        match (key_event.code, key_event.modifiers) {
+            (KeyCode::Char('q'), KeyModifiers::CONTROL) |
+            (KeyCode::Char('c'), KeyModifiers::CONTROL) => {
+                self.quit = true;
+                self.message = "👋 Goodbye!".to_string();
+            }
+            (KeyCode::F(1), _) => {
+                self.message = "ℹ️  F1: This is a client action (not handled by canvas keymap)".to_string();
+            }
+            (KeyCode::F(2), _) => {
+                // Demonstrate saving
+                self.message = "💾 F2: Save action (client-side)".to_string();
+            }
+            (KeyCode::Char('?'), _) if self.editor.mode() == AppMode::ReadOnly => {
+                self.show_help();
+            }
+            _ => {
+                // Unknown key
+                self.message = format!(
+                    "❓ Unhandled key: {:?} (mode: {:?})",
+                    key_event.code,
+                    self.editor.mode()
+                );
+            }
+        }
+
+        Ok(())
+    }
+
+    fn show_help(&mut self) {
+        self.message = "📖 Help: Multi-key sequences work! Try gg, ge, gE. Also: hjkl, w/b/e, v/V, i/a/o".to_string();
+    }
+
+    fn should_quit(&self) -> bool {
+        self.quit
+    }
+
+    fn editor(&self) -> &FormEditor<DemoData> {
+        &self.editor
+    }
+
+    fn message(&self) -> &str {
+        &self.message
+    }
+}
+
+/// Demo form data with interesting examples for keymap testing
+struct DemoData {
+    fields: Vec<(String, String)>,
+}
+
+impl DemoData {
+    fn new() -> Self {
+        Self {
+            fields: vec![
+                ("🎯 Name".to_string(), "John-Paul McDonald-Smith".to_string()),
+                ("📧 Email".to_string(), "user@long-domain-name.example.com".to_string()),
+                ("📱 Phone".to_string(), "+1 (555) 123-4567 ext. 890".to_string()),
+                ("🏠 Address".to_string(), "123 Main Street, Apartment 4B, Suite 100".to_string()),
+                ("🏷️  Tags".to_string(), "urgent,important,follow-up,high-priority".to_string()),
+                ("📝 Notes".to_string(), "Test word movements: w=next-word, b=prev-word, e=word-end, ge=prev-word-end".to_string()),
+                ("🔥 Multi-key".to_string(), "Try multi-key sequences: gg=first-field, ge=prev-word-end, gE=prev-WORD-end".to_string()),
+                ("⚡ Vim Actions".to_string(), "Normal mode: x=delete-char, o=open-line-below, v=visual, i=insert".to_string()),
+            ],
+        }
+    }
+}
+
+impl DataProvider for DemoData {
+    fn field_count(&self) -> usize {
+        self.fields.len()
+    }
+
+    fn field_name(&self, index: usize) -> &str {
+        &self.fields[index].0
+    }
+
+    fn field_value(&self, index: usize) -> &str {
+        &self.fields[index].1
+    }
+
+    fn set_field_value(&mut self, index: usize, value: String) {
+        self.fields[index].1 = value;
+    }
+}
+
+fn run_app<B: Backend>(terminal: &mut Terminal<B>, mut app: KeymapDemoApp) -> io::Result<()> {
+    loop {
+        terminal.draw(|f| ui(f, &app))?;
+
+        if let Event::Key(key) = event::read()? {
+            app.handle_key_event(key)?;
+            if app.should_quit() {
+                break;
+            }
+        }
+    }
+    Ok(())
+}
+
+fn ui(f: &mut Frame, app: &KeymapDemoApp) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Min(8), Constraint::Length(12)])
+        .split(f.area());
+
+    // Render the canvas
+    render_canvas_default(f, chunks[0], app.editor());
+
+    // Render status and help
+    render_status_and_help(f, chunks[1], app);
+}
+
+fn render_status_and_help(f: &mut Frame, area: ratatui::layout::Rect, app: &KeymapDemoApp) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Length(3), Constraint::Min(9)])
+        .split(area);
+
+    // Status message
+    let status_text = format!(
+        "Mode: {:?} | Field: {}/{} | Pos: {} | {}",
+        app.editor().mode(),
+        app.editor().current_field() + 1,
+        app.editor().data_provider().field_count(),
+        app.editor().cursor_position(),
+        app.message()
+    );
+
+    let status = Paragraph::new(Line::from(Span::raw(status_text)))
+        .block(Block::default().borders(Borders::ALL).title("🎯 Keymap Demo Status"));
+
+    f.render_widget(status, chunks[0]);
+
+    // Help text based on current mode
+    let help_text = match app.editor().mode() {
+        AppMode::ReadOnly => {
+            "🎯 KEYMAP DEMO - All keys handled by centralized keymap system!\n\
+             \n\
+             📍 MOVEMENT: hjkl(basic) | w/b/e(words) | W/B/E(WORDS) | 0/$(line) | gg/G(fields)\n\
+             🔥 MULTI-KEY: gg=first-field, ge=prev-word-end, gE=prev-WORD-end\n\
+             ✏️  MODES: i/a(insert) | v/V(visual) | o/O(open-line)\n\
+             🗑️  DELETE: x/X(delete-char)\n\
+             📂 FIELDS: Tab/Shift+Tab\n\
+             \n\
+             💡 Try multi-key sequences like 'gg' or 'ge' - watch the status for 'Waiting...'\n\
+             🚪 Ctrl+C=quit | ?=help | F1/F2=client actions (not canvas)"
+        }
+        AppMode::Edit => {
+            "✏️  INSERT MODE - Keys handled by keymap system\n\
+             \n\
+             🔄 NAVIGATION: arrows | Ctrl+arrows(words) | Home/End(line) | Tab/Shift+Tab(fields)\n\
+             🗑️  DELETE: Backspace/Delete\n\
+             🚪 EXIT: Esc=normal\n\
+             \n\
+             💡 Type text normally - the keymap handles navigation!"
+        }
+        AppMode::Highlight => {
+            "🎯 VISUAL MODE - Selection extended by keymap movements\n\
+             \n\
+             📍 EXTEND: hjkl(basic) | w/b/e(words) | 0/$(line) | gg/G(fields)\n\
+             🔄 SWITCH: V=toggle-line-mode\n\
+             🚪 EXIT: Esc=normal\n\
+             \n\
+             💡 All movements extend the selection automatically!"
+        }
+        _ => "🎯 Keymap system active!"
+    };
+
+    let help = Paragraph::new(help_text)
+        .block(Block::default().borders(Borders::ALL).title("🚀 Centralized Keymap System"))
+        .style(Style::default().fg(Color::Gray));
+
+    f.render_widget(help, chunks[1]);
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    println!("🎯 Canvas Keymap Demo");
+    println!("✅ canvas-keymap feature: ENABLED");
+    println!("🚀 Centralized key handling: ACTIVE");
+    println!("📖 Multi-key sequences: SUPPORTED (gg, ge, gE, etc.)");
+    println!();
+
+    enable_raw_mode()?;
+    let mut stdout = io::stdout();
+    execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
+    let backend = CrosstermBackend::new(stdout);
+    let mut terminal = Terminal::new(backend)?;
+
+    let app = KeymapDemoApp::new();
+    let res = run_app(&mut terminal, app);
+
+    disable_raw_mode()?;
+    execute!(
+        terminal.backend_mut(),
+        LeaveAlternateScreen,
+        DisableMouseCapture
+    )?;
+    terminal.show_cursor()?;
+
+    if let Err(err) = res {
+        println!("{err:?}");
+    }
+
+    println!("🎯 Keymap demo completed!");
+    Ok(())
+}

canvas/examples/computed_fields.rs

@@ -0,0 +1,621 @@
+// examples/computed_fields.rs - COMPLETE WORKING VERSION
+//! Demonstrates computed fields with the canvas library - Invoice Calculator Example
+//!
+//! This example REQUIRES the `computed` feature to compile.
+//!
+//! Run with:
+//! cargo run --example computed_fields --features "gui,computed"
+
+#[cfg(not(feature = "computed"))]
+compile_error!(
+    "This example requires the 'computed' feature. \
+     Run with: cargo run --example computed_fields --features \"gui,computed\""
+);
+
+use std::io;
+use crossterm::{
+    event::{
+        self, DisableMouseCapture, EnableMouseCapture, Event, KeyCode, KeyModifiers,
+    },
+    execute,
+    terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
+};
+use ratatui::{
+    backend::{Backend, CrosstermBackend},
+    layout::{Constraint, Direction, Layout, Rect},
+    style::{Color, Style, Modifier},
+    text::{Line, Span},
+    widgets::{Block, Borders, Paragraph, Wrap},
+    Frame, Terminal,
+};
+
+use canvas::{
+    canvas::{gui::render_canvas_default, modes::AppMode},
+    DataProvider, FormEditor,
+    computed::{ComputedProvider, ComputedContext},
+};
+
+/// Invoice data with computed fields
+struct InvoiceData {
+    fields: Vec<(String, String)>,
+    computed_indices: std::collections::HashSet<usize>,
+}
+
+impl InvoiceData {
+    fn new() -> Self {
+        let mut computed_indices = std::collections::HashSet::new();
+        
+        // Mark computed fields (read-only, calculated)
+        computed_indices.insert(4); // Subtotal
+        computed_indices.insert(5); // Tax Amount
+        computed_indices.insert(6); // Total
+
+        Self {
+            fields: vec![
+                ("📦 Product Name".to_string(), "".to_string()),
+                ("🔢 Quantity".to_string(), "".to_string()),
+                ("💰 Unit Price ($)".to_string(), "".to_string()),
+                ("📊 Tax Rate (%)".to_string(), "".to_string()),
+                ("➕ Subtotal ($)".to_string(), "".to_string()),        // COMPUTED
+                ("🧾 Tax Amount ($)".to_string(), "".to_string()),      // COMPUTED
+                ("💳 Total ($)".to_string(), "".to_string()),           // COMPUTED
+                ("📝 Notes".to_string(), "".to_string()),
+            ],
+            computed_indices,
+        }
+    }
+}
+
+impl DataProvider for InvoiceData {
+    fn field_count(&self) -> usize {
+        self.fields.len()
+    }
+
+    fn field_name(&self, index: usize) -> &str {
+        &self.fields[index].0
+    }
+
+    fn field_value(&self, index: usize) -> &str {
+        &self.fields[index].1
+    }
+
+    fn set_field_value(&mut self, index: usize, value: String) {
+        // 🔥 FIXED: Allow computed fields to be updated for display purposes
+        // The editing protection happens at the editor level, not here
+        self.fields[index].1 = value;
+    }
+
+    fn supports_suggestions(&self, _field_index: usize) -> bool {
+        false
+    }
+
+    fn display_value(&self, _index: usize) -> Option<&str> {
+        None
+    }
+    
+    /// Mark computed fields
+    fn is_computed_field(&self, field_index: usize) -> bool {
+        self.computed_indices.contains(&field_index)
+    }
+
+    /// Get computed field values
+    fn computed_field_value(&self, field_index: usize) -> Option<String> {
+        if self.computed_indices.contains(&field_index) {
+            Some(self.fields[field_index].1.clone())
+        } else {
+            None
+        }
+    }
+}
+
+/// Invoice calculator - computes totals based on input fields
+struct InvoiceCalculator;
+
+impl ComputedProvider for InvoiceCalculator {
+    fn compute_field(&mut self, context: ComputedContext) -> String {
+        // Helper to parse field values safely
+        let parse_field = |index: usize| -> f64 {
+            let value = context.field_values[index].trim();
+            if value.is_empty() {
+                0.0
+            } else {
+                value.parse().unwrap_or(0.0)
+            }
+        };
+
+        match context.target_field {
+            4 => {
+                // Subtotal = Quantity × Unit Price
+                let qty = parse_field(1);
+                let price = parse_field(2);
+                let subtotal = qty * price;
+                
+                if qty == 0.0 || price == 0.0 {
+                    "".to_string()  // Show empty if no meaningful calculation
+                } else {
+                    format!("{subtotal:.2}")
+                }
+            }
+            5 => {
+                // Tax Amount = Subtotal × (Tax Rate / 100)
+                let qty = parse_field(1);
+                let price = parse_field(2);
+                let tax_rate = parse_field(3);
+                let subtotal = qty * price;
+                let tax_amount = subtotal * (tax_rate / 100.0);
+                
+                if subtotal == 0.0 || tax_rate == 0.0 {
+                    "".to_string()
+                } else {
+                    format!("{tax_amount:.2}")
+                }
+            }
+            6 => {
+                // Total = Subtotal + Tax Amount
+                let qty = parse_field(1);
+                let price = parse_field(2);
+                let tax_rate = parse_field(3);
+                let subtotal = qty * price;
+                
+                if subtotal == 0.0 {
+                    "".to_string()
+                } else {
+                    let tax_amount = subtotal * (tax_rate / 100.0);
+                    let total = subtotal + tax_amount;
+                    format!("{total:.2}")
+                }
+            }
+            _ => "".to_string(),
+        }
+    }
+    
+    fn handles_field(&self, field_index: usize) -> bool {
+        matches!(field_index, 4..=6) // Subtotal, Tax Amount, Total
+    }
+    
+    fn field_dependencies(&self, field_index: usize) -> Vec<usize> {
+        match field_index {
+            4 => vec![1, 2],       // Subtotal depends on Quantity, Unit Price
+            5 => vec![1, 2, 3],    // Tax Amount depends on Quantity, Unit Price, Tax Rate
+            6 => vec![1, 2, 3],    // Total depends on Quantity, Unit Price, Tax Rate
+            _ => vec![],
+        }
+    }
+}
+
+/// Enhanced editor with computed fields
+struct ComputedFieldsEditor<D: DataProvider> {
+    editor: FormEditor<D>,
+    calculator: InvoiceCalculator,
+    debug_message: String,
+    last_computed_values: Vec<String>,
+}
+
+impl<D: DataProvider> ComputedFieldsEditor<D> {
+    fn new(data_provider: D) -> Self {
+        let mut editor = FormEditor::new(data_provider);
+        editor.set_computed_provider(InvoiceCalculator);
+
+        let calculator = InvoiceCalculator;
+        let last_computed_values = vec!["".to_string(); 8];
+
+        Self {
+            editor,
+            calculator,
+            debug_message: "💰 Invoice Calculator - Start typing in fields to see calculations!".to_string(),
+            last_computed_values,
+        }
+    }
+
+    fn is_computed_field(&self, field_index: usize) -> bool {
+        self.editor.ui_state().is_computed_field(field_index)
+    }
+
+    fn update_computed_fields(&mut self) {
+        // Trigger recomputation of all computed fields
+        self.editor.recompute_all_fields(&mut self.calculator);
+
+        // 🔥 CRITICAL FIX: Sync computed values to DataProvider so GUI shows them!
+        for i in [4, 5, 6] { // Computed field indices  
+            let computed_value = self.editor.effective_field_value(i);
+            self.editor.data_provider_mut().set_field_value(i, computed_value.clone());
+        }
+
+        // Check if values changed to show feedback
+        let mut changed = false;
+        let mut has_calculations = false;
+        
+        for i in [4, 5, 6] {
+            let new_value = self.editor.effective_field_value(i);
+            if new_value != self.last_computed_values[i] {
+                changed = true;
+                self.last_computed_values[i] = new_value.clone();
+            }
+            if !new_value.is_empty() {
+                has_calculations = true;
+            }
+        }
+
+        if changed {
+            if has_calculations {
+                let subtotal = &self.last_computed_values[4];
+                let tax = &self.last_computed_values[5];
+                let total = &self.last_computed_values[6];
+                
+                let mut parts = Vec::new();
+                if !subtotal.is_empty() {
+                    parts.push(format!("Subtotal=${subtotal}"));
+                }
+                if !tax.is_empty() {
+                    parts.push(format!("Tax=${tax}"));
+                }
+                if !total.is_empty() {
+                    parts.push(format!("Total=${total}"));
+                }
+                
+                if !parts.is_empty() {
+                    self.debug_message = format!("🧮 Calculated: {}", parts.join(", "));
+                } else {
+                    self.debug_message = "💰 Enter Quantity and Unit Price to see calculations".to_string();
+                }
+            } else {
+                self.debug_message = "💰 Enter Quantity and Unit Price to see calculations".to_string();
+            }
+        }
+    }
+
+    fn insert_char(&mut self, ch: char) -> anyhow::Result<()> {
+        let current_field = self.editor.current_field();
+        let result = self.editor.insert_char(ch);
+
+        if result.is_ok() && matches!(current_field, 1..=3) {
+            self.editor.on_field_changed(&mut self.calculator, current_field);
+            self.update_computed_fields();
+        }
+
+        result
+    }
+
+    fn delete_backward(&mut self) -> anyhow::Result<()> {
+        let current_field = self.editor.current_field();
+        let result = self.editor.delete_backward();
+
+        if result.is_ok() && matches!(current_field, 1..=3) {
+            self.editor.on_field_changed(&mut self.calculator, current_field);
+            self.update_computed_fields();
+        }
+
+        result
+    }
+
+    fn delete_forward(&mut self) -> anyhow::Result<()> {
+        let current_field = self.editor.current_field();
+        let result = self.editor.delete_forward();
+
+        if result.is_ok() && matches!(current_field, 1..=3) {
+            self.editor.on_field_changed(&mut self.calculator, current_field);
+            self.update_computed_fields();
+        }
+
+        result
+    }
+
+    fn next_field(&mut self) {
+        let old_field = self.editor.current_field();
+        let _ = self.editor.next_field();
+        let new_field = self.editor.current_field();
+
+        if old_field != new_field {
+            let field_name = self.editor.data_provider().field_name(new_field);
+            let field_type = if self.is_computed_field(new_field) {
+                "computed (read-only)"
+            } else {
+                "editable"
+            };
+            self.debug_message = format!("→ {field_name} - {field_type} field");
+        }
+    }
+
+    fn prev_field(&mut self) {
+        let old_field = self.editor.current_field();
+        let _ = self.editor.prev_field();
+        let new_field = self.editor.current_field();
+
+        if old_field != new_field {
+            let field_name = self.editor.data_provider().field_name(new_field);
+            let field_type = if self.is_computed_field(new_field) {
+                "computed (read-only)"
+            } else {
+                "editable"
+            };
+            self.debug_message = format!("← {field_name} - {field_type} field");
+        }
+    }
+
+    fn enter_edit_mode(&mut self) {
+        let current = self.editor.current_field();
+        
+        // Double protection: check both ways
+        if self.editor.data_provider().is_computed_field(current) || self.is_computed_field(current) {
+            let field_name = self.editor.data_provider().field_name(current);
+            self.debug_message = format!(
+                "🚫 {field_name} is computed (read-only) - Press Tab to move to editable fields"
+            );
+            return;
+        }
+        
+        self.editor.enter_edit_mode();
+        let field_name = self.editor.data_provider().field_name(current);
+        self.debug_message = format!("✏️ Editing {field_name} - Type to see calculations update");
+    }
+
+    fn enter_append_mode(&mut self) {
+        let current = self.editor.current_field();
+        
+        if self.editor.data_provider().is_computed_field(current) || self.is_computed_field(current) {
+            let field_name = self.editor.data_provider().field_name(current);
+            self.debug_message = format!(
+                "🚫 {field_name} is computed (read-only) - Press Tab to move to editable fields"
+            );
+            return;
+        }
+        
+        self.editor.enter_append_mode();
+        let field_name = self.editor.data_provider().field_name(current);
+        self.debug_message = format!("✏️ Appending to {field_name} - Type to see calculations");
+    }
+
+    fn exit_edit_mode(&mut self) {
+        let current_field = self.editor.current_field();
+        self.editor.exit_edit_mode();
+
+        if matches!(current_field, 1..=3) {
+            self.editor.on_field_changed(&mut self.calculator, current_field);
+            self.update_computed_fields();
+        }
+
+        self.debug_message = "🔒 Normal mode - Press 'i' to edit fields".to_string();
+    }
+
+    // Delegate methods
+    fn current_field(&self) -> usize { self.editor.current_field() }
+    fn cursor_position(&self) -> usize { self.editor.cursor_position() }
+    fn mode(&self) -> AppMode { self.editor.mode() }
+    fn current_text(&self) -> &str {
+        let field_index = self.editor.current_field();
+        self.editor.data_provider().field_value(field_index)
+    }
+    fn data_provider(&self) -> &D { self.editor.data_provider() }
+    fn ui_state(&self) -> &canvas::EditorState { self.editor.ui_state() }
+    fn move_left(&mut self) { self.editor.move_left(); }
+    fn move_right(&mut self) { self.editor.move_right(); }
+    fn move_up(&mut self) { let _ = self.editor.move_up(); }
+    fn move_down(&mut self) { let _ = self.editor.move_down(); }
+}
+
+fn handle_key_press(
+    key: KeyCode,
+    modifiers: KeyModifiers,
+    editor: &mut ComputedFieldsEditor<InvoiceData>,
+) -> anyhow::Result<bool> {
+    let mode = editor.mode();
+
+    if (key == KeyCode::Char('q') && modifiers.contains(KeyModifiers::CONTROL))
+        || (key == KeyCode::Char('c') && modifiers.contains(KeyModifiers::CONTROL))
+        || key == KeyCode::F(10)
+    {
+        return Ok(false);
+    }
+
+    match (mode, key, modifiers) {
+        (AppMode::ReadOnly, KeyCode::Char('i'), _) => {
+            editor.enter_edit_mode();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('a'), _) => {
+            editor.enter_append_mode();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('A'), _) => {
+            editor.editor.move_line_end();
+            editor.enter_edit_mode();
+        }
+        (_, KeyCode::Esc, _) => {
+            if mode == AppMode::Edit {
+                editor.exit_edit_mode();
+            }
+        }
+
+        // Movement
+        (AppMode::ReadOnly, KeyCode::Char('h'), _) | (AppMode::ReadOnly, KeyCode::Left, _) => {
+            editor.move_left();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('l'), _) | (AppMode::ReadOnly, KeyCode::Right, _) => {
+            editor.move_right();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('j'), _) | (AppMode::ReadOnly, KeyCode::Down, _) => {
+            editor.move_down();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('k'), _) | (AppMode::ReadOnly, KeyCode::Up, _) => {
+            editor.move_up();
+        }
+
+        // Edit mode movement
+        (AppMode::Edit, KeyCode::Left, _) => { editor.move_left(); }
+        (AppMode::Edit, KeyCode::Right, _) => { editor.move_right(); }
+        (AppMode::Edit, KeyCode::Up, _) => { editor.move_up(); }
+        (AppMode::Edit, KeyCode::Down, _) => { editor.move_down(); }
+
+        // Navigation
+        (_, KeyCode::Tab, _) => {
+            editor.next_field();
+        }
+        (_, KeyCode::BackTab, _) => {
+            editor.prev_field();
+        }
+
+        // Editing
+        (AppMode::Edit, KeyCode::Char(c), m) if !m.contains(KeyModifiers::CONTROL) => {
+            editor.insert_char(c)?;
+        }
+        (AppMode::Edit, KeyCode::Backspace, _) => {
+            editor.delete_backward()?;
+        }
+        (AppMode::Edit, KeyCode::Delete, _) => {
+            editor.delete_forward()?;
+        }
+
+        // Debug info
+        (AppMode::ReadOnly, KeyCode::Char('?'), _) => {
+            let current = editor.current_field();
+            let field_name = editor.data_provider().field_name(current);
+            let field_type = if editor.is_computed_field(current) {
+                "COMPUTED (read-only)"
+            } else {
+                "EDITABLE"
+            };
+            editor.debug_message = format!(
+                "{} - {} - Position {} - Mode: {:?}",
+                field_name, field_type, editor.cursor_position(), mode
+            );
+        }
+
+        _ => {}
+    }
+
+    Ok(true)
+}
+
+fn run_app<B: Backend>(
+    terminal: &mut Terminal<B>,
+    mut editor: ComputedFieldsEditor<InvoiceData>,
+) -> io::Result<()> {
+    editor.update_computed_fields(); // Initial computation
+
+    loop {
+        terminal.draw(|f| ui(f, &editor))?;
+
+        if let Event::Key(key) = event::read()? {
+            match handle_key_press(key.code, key.modifiers, &mut editor) {
+                Ok(should_continue) => {
+                    if !should_continue {
+                        break;
+                    }
+                }
+                Err(e) => {
+                    editor.debug_message = format!("Error: {e}");
+                }
+            }
+        }
+    }
+
+    Ok(())
+}
+
+fn ui(f: &mut Frame, editor: &ComputedFieldsEditor<InvoiceData>) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Min(8), Constraint::Length(10)])
+        .split(f.area());
+
+    render_enhanced_canvas(f, chunks[0], editor);
+    render_computed_status(f, chunks[1], editor);
+}
+
+fn render_enhanced_canvas(f: &mut Frame, area: Rect, editor: &ComputedFieldsEditor<InvoiceData>) {
+    render_canvas_default(f, area, &editor.editor);
+}
+
+fn render_computed_status(f: &mut Frame, area: Rect, editor: &ComputedFieldsEditor<InvoiceData>) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Length(3), Constraint::Length(7)])
+        .split(area);
+
+    let mode_text = match editor.mode() {
+        AppMode::Edit => "INSERT",
+        AppMode::ReadOnly => "NORMAL",
+        _ => "OTHER",
+    };
+
+    let current = editor.current_field();
+    let field_status = if editor.is_computed_field(current) {
+        "📊 COMPUTED FIELD (read-only)"
+    } else {
+        "✏️ EDITABLE FIELD"
+    };
+
+    let status_text = format!("-- {} -- {} | {}", mode_text, field_status, editor.debug_message);
+
+    let status = Paragraph::new(Line::from(Span::raw(status_text)))
+        .block(Block::default().borders(Borders::ALL).title("💰 Invoice Calculator"));
+
+    f.render_widget(status, chunks[0]);
+
+    let help_text = match editor.mode() {
+        AppMode::ReadOnly => {
+            "💰 COMPUTED FIELDS DEMO: Real-time invoice calculations!\n\
+             🔢 EDITABLE: Product, Quantity, Unit Price, Tax Rate, Notes\n\
+             📊 COMPUTED: Subtotal, Tax Amount, Total (calculated automatically)\n\
+             \n\
+             🚀 START: Press 'i' to edit Quantity, type '5', Tab to Unit Price, type '19.99'\n\
+             Watch Subtotal and Total appear! Add Tax Rate to see tax calculations.\n\
+             Navigation: Tab/Shift+Tab skips computed fields automatically"
+        }
+        AppMode::Edit => {
+            "✏️ EDIT MODE: Type numbers to see calculations appear!\n\
+             \n\
+             💡 EXAMPLE: Type '5' in Quantity, then Tab to Unit Price and type '19.99'\n\
+             • Subtotal appears: $99.95\n\
+             • Total appears: $99.95\n\
+             • Add Tax Rate (like '10') to see tax: $9.99, Total: $109.94\n\
+             \n\
+             Esc=normal, Tab=next field (auto-skips computed fields)"
+        }
+        _ => "💰 Invoice Calculator with Computed Fields"
+    };
+
+    let help_style = if editor.is_computed_field(editor.current_field()) {
+        Style::default().fg(Color::Yellow).add_modifier(Modifier::ITALIC)
+    } else {
+        Style::default().fg(Color::Gray)
+    };
+
+    let help = Paragraph::new(help_text)
+        .block(Block::default().borders(Borders::ALL).title("🚀 Try It Now!"))
+        .style(help_style)
+        .wrap(Wrap { trim: true });
+
+    f.render_widget(help, chunks[1]);
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    println!("💰 Canvas Computed Fields Demo - Invoice Calculator");
+    println!("✅ computed feature: ENABLED");
+    println!("🚀 QUICK TEST:");
+    println!("   1. Press 'i' to edit Quantity");
+    println!("   2. Type '5' and press Tab");
+    println!("   3. Type '19.99' in Unit Price");
+    println!("   4. Watch Subtotal ($99.95) and Total ($99.95) appear!");
+    println!();
+
+    enable_raw_mode()?;
+    let mut stdout = io::stdout();
+    execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
+    let backend = CrosstermBackend::new(stdout);
+    let mut terminal = Terminal::new(backend)?;
+
+    let data = InvoiceData::new();
+    let editor = ComputedFieldsEditor::new(data);
+
+    let res = run_app(&mut terminal, editor);
+
+    disable_raw_mode()?;
+    execute!(terminal.backend_mut(), LeaveAlternateScreen, DisableMouseCapture)?;
+    terminal.show_cursor()?;
+
+    if let Err(err) = res {
+        println!("{err:?}");
+    }
+
+    println!("💰 Demo completed! Computed fields should have updated in real-time!");
+    Ok(())
+}

canvas/examples/textarea_normal.rs

@@ -0,0 +1,397 @@
+// examples/textarea_normal.rs
+//! Demonstrates automatic cursor management with the textarea widget
+//!
+//! This example REQUIRES the `cursor-style` and `textarea` features to compile,
+//! and is adapted for `textmode-normal` (always editing, no vim modes).
+//!
+//! Run with:
+//! cargo run --example canvas_textarea_cursor_auto_normal --features "gui,cursor-style,textarea,textmode-normal"
+
+#[cfg(not(feature = "cursor-style"))]
+compile_error!(
+    "This example requires the 'cursor-style' feature. \
+     Run with: cargo run --example canvas_textarea_cursor_auto_normal --features \"gui,cursor-style,textarea,textmode-normal\""
+);
+
+#[cfg(not(feature = "textarea"))]
+compile_error!(
+    "This example requires the 'textarea' feature. \
+     Run with: cargo run --example canvas_textarea_cursor_auto_normal --features \"gui,cursor-style,textarea,textmode-normal\""
+);
+
+use std::io;
+use crossterm::{
+    event::{self, DisableMouseCapture, EnableMouseCapture, Event, KeyCode, KeyEvent, KeyModifiers},
+    execute,
+    terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
+};
+use ratatui::{
+    backend::{Backend, CrosstermBackend},
+    layout::{Constraint, Direction, Layout},
+    style::{Color, Style},
+    text::{Line, Span},
+    widgets::{Block, Borders, Paragraph},
+    Frame, Terminal,
+};
+
+use canvas::{
+    canvas::CursorManager,
+    textarea::{TextArea, TextAreaState},
+};
+
+/// TextArea demo adapted for NORMALMODE (always editing)
+struct AutoCursorTextArea {
+    textarea: TextAreaState,
+    has_unsaved_changes: bool,
+    debug_message: String,
+    command_buffer: String,
+}
+
+impl AutoCursorTextArea {
+    fn new() -> Self {
+        let initial_text = "🎯 Automatic Cursor Management Demo (NORMALMODE)\n\
+Welcome to the textarea cursor demo!\n\
+\n\
+This demo runs in NORMALMODE:\n\
+• Always editing (no insert/normal toggle)\n\
+• Cursor is always underscore _\n\
+\n\
+Navigation commands:\n\
+• hjkl or arrow keys: move cursor\n\
+• w/b/e/W/B/E: word movements\n\
+• 0/$: line start/end\n\
+• g/gG: first/last line\n\
+\n\
+Editing commands:\n\
+• x/X: delete characters\n\
+\n\
+Press ? for help, Ctrl+Q to quit.";
+
+        let mut textarea = TextAreaState::from_text(initial_text);
+        textarea.set_placeholder("Start typing...");
+
+        Self {
+            textarea,
+            has_unsaved_changes: false,
+            debug_message: "🎯 NORMALMODE Demo - always editing".to_string(),
+            command_buffer: String::new(),
+        }
+    }
+
+    fn handle_textarea_input(&mut self, key: KeyEvent) {
+        self.textarea.input(key);
+        self.has_unsaved_changes = true;
+    }
+
+    fn move_left(&mut self) {
+        self.textarea.move_left();
+        self.debug_message = "← left".to_string();
+    }
+    fn move_right(&mut self) {
+        self.textarea.move_right();
+        self.debug_message = "→ right".to_string();
+    }
+    fn move_up(&mut self) {
+        self.textarea.move_up();
+        self.debug_message = "↑ up".to_string();
+    }
+    fn move_down(&mut self) {
+        self.textarea.move_down();
+        self.debug_message = "↓ down".to_string();
+    }
+
+    fn move_word_next(&mut self) {
+        self.textarea.move_word_next();
+        self.debug_message = "w: next word".to_string();
+    }
+    fn move_word_prev(&mut self) {
+        self.textarea.move_word_prev();
+        self.debug_message = "b: previous word".to_string();
+    }
+    fn move_word_end(&mut self) {
+        self.textarea.move_word_end();
+        self.debug_message = "e: word end".to_string();
+    }
+    fn move_word_end_prev(&mut self) {
+        self.textarea.move_word_end_prev();
+        self.debug_message = "ge: previous word end".to_string();
+    }
+
+    fn move_line_start(&mut self) {
+        self.textarea.move_line_start();
+        self.debug_message = "0: line start".to_string();
+    }
+    fn move_line_end(&mut self) {
+        self.textarea.move_line_end();
+        self.debug_message = "$: line end".to_string();
+    }
+    fn move_first_line(&mut self) {
+        self.textarea.move_first_line();
+        self.debug_message = "gg: first line".to_string();
+    }
+    fn move_last_line(&mut self) {
+        self.textarea.move_last_line();
+        self.debug_message = "G: last line".to_string();
+    }
+
+    fn delete_char_forward(&mut self) {
+        if let Ok(_) = self.textarea.delete_forward() {
+            self.has_unsaved_changes = true;
+            self.debug_message = "x: deleted character".to_string();
+        }
+    }
+    fn delete_char_backward(&mut self) {
+        if let Ok(_) = self.textarea.delete_backward() {
+            self.has_unsaved_changes = true;
+            self.debug_message = "X: deleted character backward".to_string();
+        }
+    }
+
+    fn clear_command_buffer(&mut self) {
+        self.command_buffer.clear();
+    }
+    fn add_to_command_buffer(&mut self, ch: char) {
+        self.command_buffer.push(ch);
+    }
+    fn get_command_buffer(&self) -> &str {
+        &self.command_buffer
+    }
+    fn has_pending_command(&self) -> bool {
+        !self.command_buffer.is_empty()
+    }
+
+    fn debug_message(&self) -> &str {
+        &self.debug_message
+    }
+    fn set_debug_message(&mut self, msg: String) {
+        self.debug_message = msg;
+    }
+    fn has_unsaved_changes(&self) -> bool {
+        self.has_unsaved_changes
+    }
+    fn get_cursor_info(&self) -> String {
+        format!(
+            "Line {}, Col {}",
+            self.textarea.current_field() + 1,
+            self.textarea.cursor_position() + 1
+        )
+    }
+
+    // === BIG WORD MOVEMENTS ===
+
+    fn move_big_word_next(&mut self) {
+        self.textarea.move_big_word_next();
+        self.debug_message = "W: next WORD".to_string();
+    }
+
+    fn move_big_word_prev(&mut self) {
+        self.textarea.move_big_word_prev();
+        self.debug_message = "B: previous WORD".to_string();
+    }
+
+    fn move_big_word_end(&mut self) {
+        self.textarea.move_big_word_end();
+        self.debug_message = "E: WORD end".to_string();
+    }
+
+    fn move_big_word_end_prev(&mut self) {
+        self.textarea.move_big_word_end_prev();
+        self.debug_message = "gE: previous WORD end".to_string();
+    }
+}
+
+/// Handle key press in NORMALMODE (always editing, casual editor style)
+fn handle_key_press(
+    key_event: KeyEvent,
+    editor: &mut AutoCursorTextArea,
+) -> anyhow::Result<bool> {
+    let KeyEvent {
+        code: key,
+        modifiers,
+        ..
+    } = key_event;
+
+    // Quit
+    if (key == KeyCode::Char('q') && modifiers.contains(KeyModifiers::CONTROL))
+        || (key == KeyCode::Char('c') && modifiers.contains(KeyModifiers::CONTROL))
+        || key == KeyCode::F(10)
+    {
+        return Ok(false);
+    }
+
+    match (key, modifiers) {
+        // Movement
+        (KeyCode::Left, _) => editor.move_left(),
+        (KeyCode::Right, _) => editor.move_right(),
+        (KeyCode::Up, _) => editor.move_up(),
+        (KeyCode::Down, _) => editor.move_down(),
+
+        // Word movement (Ctrl+Arrows)
+        (KeyCode::Left, m) if m.contains(KeyModifiers::CONTROL) => editor.move_word_prev(),
+        (KeyCode::Right, m) if m.contains(KeyModifiers::CONTROL) => editor.move_word_next(),
+        (KeyCode::Right, m) if m.contains(KeyModifiers::CONTROL | KeyModifiers::SHIFT) => {
+            editor.move_word_end()
+        }
+
+        // Line/document movement
+        (KeyCode::Home, _) => editor.move_line_start(),
+        (KeyCode::End, _) => editor.move_line_end(),
+        (KeyCode::Home, m) if m.contains(KeyModifiers::CONTROL) => editor.move_first_line(),
+        (KeyCode::End, m) if m.contains(KeyModifiers::CONTROL) => editor.move_last_line(),
+
+        // Delete
+        (KeyCode::Delete, _) => editor.delete_char_forward(),
+        (KeyCode::Backspace, _) => editor.delete_char_backward(),
+
+        (KeyCode::F(1), _) => {
+            // Switch to indicator mode
+            editor.textarea.use_overflow_indicator('$');
+            editor.set_debug_message("Overflow: indicator '$' (wrap OFF)".to_string());
+        }
+        (KeyCode::F(2), _) => {
+            // Switch to wrap mode
+            editor.textarea.use_wrap();
+            editor.set_debug_message("Overflow: wrap ON".to_string());
+        }
+
+        (KeyCode::F(3), _) => {
+            editor.textarea.set_wrap_indent_cols(3);
+            editor.set_debug_message("Wrap indent: 3 columns".to_string());
+        }
+        (KeyCode::F(4), _) => {
+            editor.textarea.set_wrap_indent_cols(0);
+            editor.set_debug_message("Wrap indent: 0 columns".to_string());
+        }
+
+        // Debug/info
+        (KeyCode::Char('?'), _) => {
+            editor.set_debug_message(format!(
+                "{}, Mode: NORMALMODE (casual editor, underscore cursor)",
+                editor.get_cursor_info()
+            ));
+            editor.clear_command_buffer();
+        }
+
+        // Default: treat as text input
+        _ => editor.handle_textarea_input(key_event),
+    }
+
+    Ok(true)
+}
+
+fn run_app<B: Backend>(terminal: &mut Terminal<B>, mut editor: AutoCursorTextArea) -> io::Result<()> {
+    loop {
+        terminal.draw(|f| ui(f, &mut editor))?;
+
+        if let Event::Key(key) = event::read()? {
+            match handle_key_press(key, &mut editor) {
+                Ok(should_continue) => {
+                    if !should_continue {
+                        break;
+                    }
+                }
+                Err(e) => {
+                    editor.set_debug_message(format!("Error: {e}"));
+                }
+            }
+        }
+    }
+    Ok(())
+}
+
+fn ui(f: &mut Frame, editor: &mut AutoCursorTextArea) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Min(8), Constraint::Length(8)])
+        .split(f.area());
+
+    render_textarea(f, chunks[0], editor);
+    render_status_and_help(f, chunks[1], editor);
+}
+
+fn render_textarea(f: &mut Frame, area: ratatui::layout::Rect, editor: &mut AutoCursorTextArea) {
+    let block = Block::default()
+        .borders(Borders::ALL)
+        .title("🎯 Textarea with NORMALMODE (always editing)");
+
+    let textarea_widget = TextArea::default().block(block.clone());
+    f.render_stateful_widget(textarea_widget, area, &mut editor.textarea);
+
+    let (cx, cy) = editor.textarea.cursor(area, Some(&block));
+    f.set_cursor_position((cx, cy));
+}
+
+fn render_status_and_help(f: &mut Frame, area: ratatui::layout::Rect, editor: &AutoCursorTextArea) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Length(3), Constraint::Length(5)])
+        .split(area);
+
+    let status_text = if editor.has_pending_command() {
+        format!(
+            "-- NORMALMODE (underscore cursor) -- {} [{}]",
+            editor.debug_message(),
+            editor.get_command_buffer()
+        )
+    } else if editor.has_unsaved_changes() {
+        format!(
+            "-- NORMALMODE (underscore cursor) -- [Modified] {} | {}",
+            editor.debug_message(),
+            editor.get_cursor_info()
+        )
+    } else {
+        format!(
+            "-- NORMALMODE (underscore cursor) -- {} | {}",
+            editor.debug_message(),
+            editor.get_cursor_info()
+        )
+    };
+
+    let status = Paragraph::new(Line::from(Span::raw(status_text)))
+        .block(Block::default().borders(Borders::ALL).title("🎯 Cursor Status"));
+
+    f.render_widget(status, chunks[0]);
+
+    let help_text = "🎯 NORMALMODE (always editing)\n\
+hjkl/arrows=move, w/b/e=words, W/B/E=WORDS, 0/$=line, g/G=first/last\n\
+x/X=delete, typing inserts text\n\
+?=info, Ctrl+Q=quit";
+
+    let help = Paragraph::new(help_text)
+        .block(Block::default().borders(Borders::ALL).title("🚀 Help"))
+        .style(Style::default().fg(Color::Gray));
+
+    f.render_widget(help, chunks[1]);
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    println!("🎯 Canvas Textarea Cursor Auto Demo (NORMALMODE)");
+    println!("✅ cursor-style feature: ENABLED");
+    println!("✅ textarea feature: ENABLED");
+    println!("✅ textmode-normal feature: ENABLED");
+    println!("🚀 Always editing, underscore cursor active");
+    println!();
+
+    enable_raw_mode()?;
+    let mut stdout = io::stdout();
+    execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
+    let backend = CrosstermBackend::new(stdout);
+    let mut terminal = Terminal::new(backend)?;
+
+    let editor = AutoCursorTextArea::new();
+
+    let res = run_app(&mut terminal, editor);
+
+    CursorManager::reset()?;
+
+    disable_raw_mode()?;
+    execute!(terminal.backend_mut(), LeaveAlternateScreen, DisableMouseCapture)?;
+    terminal.show_cursor()?;
+
+    if let Err(err) = res {
+        println!("{err:?}");
+    }
+
+    println!("🎯 Cursor automatically reset to default!");
+    Ok(())
+}

canvas/examples/textarea_syntax.rs

@@ -0,0 +1,413 @@
+// examples/textarea_syntax.rs
+//! Demonstrates syntax highlighting with the textarea widget
+//!
+//! This example REQUIRES the `syntect` feature to compile.
+//!
+//! Run with:
+//! cargo run --example textarea_syntax --features "gui,cursor-style,textarea,syntect,textmode-normal"
+
+#[cfg(not(feature = "syntect"))]
+compile_error!(
+    "This example requires the 'syntect' feature. \
+     Run with: cargo run --example textarea_syntax --features \"gui,cursor-style,textarea,syntect,textmode-normal\""
+);
+
+use std::io;
+use crossterm::{
+    event::{self, DisableMouseCapture, EnableMouseCapture, Event, KeyCode, KeyEvent, KeyModifiers},
+    execute,
+    terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
+};
+use ratatui::{
+    backend::{Backend, CrosstermBackend},
+    layout::{Constraint, Direction, Layout},
+    style::{Color, Style},
+    text::{Line, Span},
+    widgets::{Block, Borders, Paragraph},
+    Frame, Terminal,
+};
+
+use canvas::{
+    canvas::CursorManager,
+    textarea::highlight::{TextAreaSyntax, TextAreaSyntaxState},
+};
+
+/// Syntax highlighting TextArea demo
+struct SyntaxTextAreaDemo {
+    textarea: TextAreaSyntaxState,
+    has_unsaved_changes: bool,
+    debug_message: String,
+    current_language: String,
+    current_theme: String,
+}
+
+impl SyntaxTextAreaDemo {
+    fn new() -> Self {
+        let initial_text = r#"// 🎯 Multi-language Syntax Highlighting Demo
+// ==========================
+// Rust
+// ==========================
+fn main() {
+    println!("Hello, Rust 🦀");
+    let nums = vec![1, 2, 3, 4, 5];
+    for n in nums {
+        println!("n = {}", n);
+    }
+}
+
+// ==========================
+// Python
+// ==========================
+# 🐍 Python example
+def fib(n):
+    if n <= 1:
+        return n
+    return fib(n-1) + fib(n-2)
+
+print([fib(i) for i in range(6)])
+
+# ==========================
+// JavaScript
+// ==========================
+ // 🟨 JavaScript example
+function greet(name) {
+    console.log(`Hello, ${name}!`);
+}
+greet("World");
+
+// ==========================
+// Scheme
+// ==========================
+;; 🎭 Scheme example
+(define (square x) (* x x))
+(display (square 5))
+(newline)
+"#;
+
+        let mut textarea = TextAreaSyntaxState::from_text(initial_text);
+        textarea.set_placeholder("Start typing code...");
+
+        // Pick a colorful default theme
+        let default_theme = "base16-ocean.dark";
+        let _ = textarea.set_syntax_theme(default_theme);
+        // Default to Rust syntax
+        let _ = textarea.set_syntax_by_extension("rs");
+
+        Self {
+            textarea,
+            has_unsaved_changes: false,
+            debug_message: format!("🎯 Syntax highlighting enabled - Rust ({})", default_theme),
+            current_language: "Rust".to_string(),
+            current_theme: default_theme.to_string(),
+        }
+    }
+
+    fn handle_textarea_input(&mut self, key: KeyEvent) {
+        self.textarea.input(key);
+        self.has_unsaved_changes = true;
+    }
+
+    fn switch_to_rust(&mut self) {
+        let _ = self.textarea.set_syntax_by_extension("rs");
+        self.current_language = "Rust".to_string();
+        self.debug_message = format!("🦀 Switched to Rust syntax ({})", self.current_theme);
+        
+        let rust_code = r#"// Rust example
+fn fibonacci(n: u32) -> u32 {
+    match n {
+        0 => 0,
+        1 => 1,
+        _ => fibonacci(n - 1) + fibonacci(n - 2),
+    }
+}
+
+fn main() {
+    for i in 0..10 {
+        println!("fib({}) = {}", i, fibonacci(i));
+    }
+}"#;
+        self.textarea.set_text(rust_code);
+        self.has_unsaved_changes = false;
+    }
+
+    fn switch_to_python(&mut self) {
+        let _ = self.textarea.set_syntax_by_extension("py");
+        self.current_language = "Python".to_string();
+        self.debug_message = format!("🐍 Switched to Python syntax ({})", self.current_theme);
+        
+        let python_code = r#"# Python example
+def fibonacci(n):
+    if n <= 1:
+        return n
+    return fibonacci(n - 1) + fibonacci(n - 2)
+
+def main():
+    for i in range(10):
+        print(f"fib({i}) = {fibonacci(i)}")
+
+if __name__ == "__main__":
+    main()"#;
+        self.textarea.set_text(python_code);
+        self.has_unsaved_changes = false;
+    }
+
+    fn switch_to_javascript(&mut self) {
+        let _ = self.textarea.set_syntax_by_extension("js");
+        self.current_language = "JavaScript".to_string();
+        self.debug_message = format!("🟨 Switched to JavaScript syntax ({})", self.current_theme);
+        
+        let js_code = r#"// JavaScript example
+function fibonacci(n) {
+    if (n <= 1) return n;
+    return fibonacci(n - 1) + fibonacci(n - 2);
+}
+
+function main() {
+    for (let i = 0; i < 10; i++) {
+        console.log(`fib(${i}) = ${fibonacci(i)}`);
+    }
+}
+
+main();"#;
+        self.textarea.set_text(js_code);
+        self.has_unsaved_changes = false;
+    }
+
+    fn switch_to_scheme(&mut self) {
+        let _ = self.textarea.set_syntax_by_name("Scheme");
+        self.current_language = "Scheme".to_string();
+        self.debug_message = format!("🎭 Switched to Scheme syntax ({})", self.current_theme);
+        
+        let scheme_code = r#";; Scheme example
+(define (fibonacci n)
+  (cond ((= n 0) 0)
+        ((= n 1) 1)
+        (else (+ (fibonacci (- n 1))
+                 (fibonacci (- n 2))))))
+
+(define (main)
+  (do ((i 0 (+ i 1)))
+      ((= i 10))
+    (display (format "fib(~a) = ~a~n" i (fibonacci i)))))
+
+(main)"#;
+        self.textarea.set_text(scheme_code);
+        self.has_unsaved_changes = false;
+    }
+
+    fn cycle_theme(&mut self) {
+        let themes = [
+            "InspiredGitHub",
+            "base16-ocean.dark",
+            "base16-eighties.dark",
+            "Solarized (dark)",
+            "Monokai Extended",
+        ];
+        let current_pos = themes.iter().position(|t| *t == self.current_theme);
+        let next_pos = match current_pos {
+            Some(p) => (p + 1) % themes.len(),
+            None => 0,
+        };
+        let next_theme = themes[next_pos];
+        let _ = self.textarea.set_syntax_theme(next_theme);
+        self.current_theme = next_theme.to_string();
+        self.debug_message = format!("🎨 Theme switched to {}", next_theme);
+    }
+
+    fn get_cursor_info(&self) -> String {
+        format!(
+            "Line {}, Col {} | Lang: {} | Theme: {}",
+            self.textarea.current_field() + 1,
+            self.textarea.cursor_position() + 1,
+            self.current_language,
+            self.current_theme
+        )
+    }
+
+    fn debug_message(&self) -> &str {
+        &self.debug_message
+    }
+
+    fn set_debug_message(&mut self, msg: String) {
+        self.debug_message = msg;
+    }
+
+    fn has_unsaved_changes(&self) -> bool {
+        self.has_unsaved_changes
+    }
+}
+
+fn handle_key_press(
+    key_event: KeyEvent,
+    editor: &mut SyntaxTextAreaDemo,
+) -> anyhow::Result<bool> {
+    let KeyEvent {
+        code: key,
+        modifiers,
+        ..
+    } = key_event;
+
+    // Quit
+    if (key == KeyCode::Char('q') && modifiers.contains(KeyModifiers::CONTROL))
+        || (key == KeyCode::Char('c') && modifiers.contains(KeyModifiers::CONTROL))
+        || key == KeyCode::F(10)
+    {
+        return Ok(false);
+    }
+
+    match (key, modifiers) {
+        // Language switching
+        (KeyCode::F(5), _) => editor.switch_to_rust(),
+        (KeyCode::F(6), _) => editor.switch_to_python(),
+        (KeyCode::F(7), _) => editor.switch_to_javascript(),
+        (KeyCode::F(8), _) => editor.switch_to_scheme(),
+
+        // Theme cycling
+        (KeyCode::F(9), _) => editor.cycle_theme(),
+
+        // Overflow modes
+        (KeyCode::F(1), _) => {
+            editor.textarea.use_overflow_indicator('$');
+            editor.set_debug_message(format!("Overflow: indicator '$' (wrap OFF) | Theme: {}", editor.current_theme));
+        }
+        (KeyCode::F(2), _) => {
+            editor.textarea.use_wrap();
+            editor.set_debug_message(format!("Overflow: wrap ON | Theme: {}", editor.current_theme));
+        }
+
+        // Wrap indent
+        (KeyCode::F(3), _) => {
+            editor.textarea.set_wrap_indent_cols(4);
+            editor.set_debug_message(format!("Wrap indent: 4 columns | Theme: {}", editor.current_theme));
+        }
+        (KeyCode::F(4), _) => {
+            editor.textarea.set_wrap_indent_cols(0);
+            editor.set_debug_message(format!("Wrap indent: 0 columns | Theme: {}", editor.current_theme));
+        }
+
+        // Info
+        (KeyCode::Char('?'), _) => {
+            editor.set_debug_message(format!(
+                "{} | Syntax highlighting enabled",
+                editor.get_cursor_info()
+            ));
+        }
+
+        // Default: pass to textarea
+        _ => editor.handle_textarea_input(key_event),
+    }
+
+    Ok(true)
+}
+
+fn run_app<B: Backend>(terminal: &mut Terminal<B>, mut editor: SyntaxTextAreaDemo) -> io::Result<()> {
+    loop {
+        terminal.draw(|f| ui(f, &mut editor))?;
+
+        if let Event::Key(key) = event::read()? {
+            match handle_key_press(key, &mut editor) {
+                Ok(should_continue) => {
+                    if !should_continue {
+                        break;
+                    }
+                }
+                Err(e) => {
+                    editor.set_debug_message(format!("Error: {e}"));
+                }
+            }
+        }
+    }
+    Ok(())
+}
+
+fn ui(f: &mut Frame, editor: &mut SyntaxTextAreaDemo) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Min(8), Constraint::Length(8)])
+        .split(f.area());
+
+    render_textarea(f, chunks[0], editor);
+    render_status_and_help(f, chunks[1], editor);
+}
+
+fn render_textarea(f: &mut Frame, area: ratatui::layout::Rect, editor: &mut SyntaxTextAreaDemo) {
+    let block = Block::default()
+        .borders(Borders::ALL)
+        .title("🎨 Syntax Highlighted Code Editor");
+
+    let textarea_widget = TextAreaSyntax::default().block(block.clone());
+    f.render_stateful_widget(textarea_widget, area, &mut editor.textarea);
+
+    // Reuse cursor calculation from the wrapped textarea
+    let (cx, cy) = editor.textarea.cursor(area, Some(&block));
+    f.set_cursor_position((cx, cy));
+}
+
+fn render_status_and_help(f: &mut Frame, area: ratatui::layout::Rect, editor: &SyntaxTextAreaDemo) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Length(3), Constraint::Length(5)])
+        .split(area);
+
+    let status_text = if editor.has_unsaved_changes() {
+        format!(
+            "-- SYNTAX MODE (highlighting enabled) -- [Modified] {} | {}",
+            editor.debug_message(),
+            editor.get_cursor_info()
+        )
+    } else {
+        format!(
+            "-- SYNTAX MODE (highlighting enabled) -- {} | {}",
+            editor.debug_message(),
+            editor.get_cursor_info()
+        )
+    };
+
+    let status = Paragraph::new(Line::from(Span::raw(status_text)))
+        .block(Block::default().borders(Borders::ALL).title("🎨 Syntax Status"));
+
+    f.render_widget(status, chunks[0]);
+
+    let help_text = "🎨 SYNTAX HIGHLIGHTING DEMO\n\
+F5=Rust, F6=Python, F7=JavaScript, F8=Scheme\n\
+F1/F2=overflow modes, F3/F4=wrap indent\n\
+F9=cycle themes, ?=info, Ctrl+Q=quit";
+
+    let help = Paragraph::new(help_text)
+        .block(Block::default().borders(Borders::ALL).title("🚀 Help"))
+        .style(Style::default().fg(Color::Cyan));
+
+    f.render_widget(help, chunks[1]);
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    println!("🎨 Canvas Textarea Syntax Highlighting Demo");
+    println!("✅ cursor-style feature: ENABLED");
+    println!("✅ textarea feature: ENABLED");
+    println!("✅ syntect feature: ENABLED");
+    println!("🎨 Syntax highlighting active");
+    println!();
+
+    enable_raw_mode()?;
+    let mut stdout = io::stdout();
+    execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
+    let backend = CrosstermBackend::new(stdout);
+    let mut terminal = Terminal::new(backend)?;
+
+    let editor = SyntaxTextAreaDemo::new();
+
+    let res = run_app(&mut terminal, editor);
+
+    CursorManager::reset()?;
+
+    disable_raw_mode()?;
+    execute!(terminal.backend_mut(), LeaveAlternateScreen, DisableMouseCapture)?;
+    terminal.show_cursor()?;
+
+    if let Err(err) = res {
+        println!("{err:?}");
+    }
+
+    println!("🎨 Syntax highlighting demo complete!");
+    Ok(())
+}

canvas/examples/textarea_vim.rs

@@ -0,0 +1,652 @@
+// examples/textarea_vim.rs
+//! Demonstrates automatic cursor management with the textarea widget
+//!
+//! This example REQUIRES the `cursor-style` and `textarea` features to compile.
+//!
+//! Run with:
+//! cargo run --example canvas_textarea_cursor_auto --features "gui,cursor-style,textarea"
+
+// REQUIRE cursor-style and textarea features
+#[cfg(not(feature = "cursor-style"))]
+compile_error!(
+    "This example requires the 'cursor-style' feature. \
+     Run with: cargo run --example canvas_textarea_cursor_auto --features \"gui,cursor-style,textarea\""
+);
+
+#[cfg(not(feature = "textarea"))]
+compile_error!(
+    "This example requires the 'textarea' feature. \
+     Run with: cargo run --example canvas_textarea_cursor_auto --features \"gui,cursor-style,textarea\""
+);
+
+use std::io;
+use crossterm::{
+    event::{
+        self, DisableMouseCapture, EnableMouseCapture, Event, KeyCode, KeyEvent, KeyModifiers,
+    },
+    execute,
+    terminal::{
+        disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen,
+    },
+};
+use ratatui::{
+    backend::{Backend, CrosstermBackend},
+    layout::{Constraint, Direction, Layout},
+    style::{Color, Style},
+    text::{Line, Span},
+    widgets::{Block, Borders, Paragraph},
+    Frame, Terminal,
+};
+
+use canvas::{
+    canvas::{
+        modes::AppMode,
+        CursorManager, // This import only exists when cursor-style feature is enabled
+    },
+    textarea::{TextArea, TextAreaState},
+};
+
+/// Enhanced TextArea that demonstrates automatic cursor management
+/// Now uses direct FormEditor method calls via Deref!
+struct AutoCursorTextArea {
+    textarea: TextAreaState,
+    has_unsaved_changes: bool,
+    debug_message: String,
+    command_buffer: String,
+}
+
+impl AutoCursorTextArea {
+    fn new() -> Self {
+        let initial_text = "🎯 Automatic Cursor Management Demo\n\
+Welcome to the textarea cursor demo!\n\
+\n\
+Try different modes:\n\
+• Normal mode: Block cursor █\n\
+• Insert mode: Bar cursor |\n\
+\n\
+Navigation commands:\n\
+• hjkl or arrow keys: move cursor\n\
+• i/a/A/o/O: enter insert mode\n\
+• w/b/e/W/B/E: word movements\n\
+• Esc: return to normal mode\n\
+\n\
+Watch how the terminal cursor changes automatically!\n\
+This text can be edited when in insert mode.\n\
+\n\
+Press ? for help, F1/F2 for manual cursor control demo.";
+
+        let mut textarea = TextAreaState::from_text(initial_text);
+        textarea.set_placeholder("Start typing...");
+        textarea.use_wrap();
+        
+        Self {
+            textarea,
+            has_unsaved_changes: false,
+            debug_message: "🎯 Automatic Cursor Demo - cursor-style feature enabled!".to_string(),
+            command_buffer: String::new(),
+        }
+    }
+
+    // === MODE TRANSITIONS WITH AUTOMATIC CURSOR MANAGEMENT ===
+
+    fn enter_insert_mode(&mut self) -> std::io::Result<()> {
+        self.textarea.enter_edit_mode(); // 🎯 Direct FormEditor method call via Deref!
+        CursorManager::update_for_mode(AppMode::Edit)?; // 🎯 Automatic: cursor becomes bar |
+        self.debug_message = "✏️  INSERT MODE - Cursor: Steady Bar |".to_string();
+        Ok(())
+    }
+
+    fn enter_append_mode(&mut self) -> std::io::Result<()> {
+        self.textarea.enter_append_mode(); // 🎯 Direct FormEditor method call!
+        CursorManager::update_for_mode(AppMode::Edit)?;
+        self.debug_message = "✏️  INSERT (append) - Cursor: Steady Bar |".to_string();
+        Ok(())
+    }
+
+    fn exit_to_normal_mode(&mut self) -> std::io::Result<()> {
+        self.textarea.exit_edit_mode(); // 🎯 Direct FormEditor method call!
+        CursorManager::update_for_mode(AppMode::ReadOnly)?; // 🎯 Automatic: cursor becomes steady block
+        self.debug_message = "🔒 NORMAL MODE - Cursor: Steady Block █".to_string();
+        Ok(())
+    }
+
+    // === MANUAL CURSOR OVERRIDE DEMONSTRATION ===
+
+    fn demo_manual_cursor_control(&mut self) -> std::io::Result<()> {
+        // Users can still manually control cursor if needed
+        CursorManager::update_for_mode(AppMode::Command)?;
+        self.debug_message = "🔧 Manual override: Command cursor _".to_string();
+        Ok(())
+    }
+
+    fn restore_automatic_cursor(&mut self) -> std::io::Result<()> {
+        // Restore automatic cursor based on current mode
+        CursorManager::update_for_mode(self.textarea.mode())?; // 🎯 Direct method call!
+        self.debug_message = "🎯 Restored automatic cursor management".to_string();
+        Ok(())
+    }
+
+    // === TEXTAREA OPERATIONS ===
+
+    fn handle_textarea_input(&mut self, key: KeyEvent) {
+        self.textarea.input(key);
+        self.has_unsaved_changes = true;
+    }
+
+    // === MOVEMENT OPERATIONS (using direct FormEditor methods!) ===
+
+    fn move_left(&mut self) {
+        self.textarea.move_left(); // 🎯 Direct FormEditor method call!
+        self.update_debug_for_movement("← left");
+    }
+
+    fn move_right(&mut self) {
+        self.textarea.move_right(); // 🎯 Direct FormEditor method call!
+        self.update_debug_for_movement("→ right");
+    }
+
+    fn move_up(&mut self) {
+        self.textarea.move_up(); // 🎯 Direct FormEditor method call!
+        self.update_debug_for_movement("↑ up");
+    }
+
+    fn move_down(&mut self) {
+        self.textarea.move_down(); // 🎯 Direct FormEditor method call!
+        self.update_debug_for_movement("↓ down");
+    }
+
+    fn move_word_next(&mut self) {
+        self.textarea.move_word_next(); // 🎯 Direct FormEditor method call!
+        self.update_debug_for_movement("w: next word");
+    }
+
+    fn move_word_prev(&mut self) {
+        self.textarea.move_word_prev(); // 🎯 Direct FormEditor method call!
+        self.update_debug_for_movement("b: previous word");
+    }
+
+    fn move_word_end(&mut self) {
+        self.textarea.move_word_end(); // 🎯 Direct FormEditor method call!
+        self.update_debug_for_movement("e: word end");
+    }
+
+    fn move_word_end_prev(&mut self) {
+        self.textarea.move_word_end_prev(); // 🎯 Direct FormEditor method call!
+        self.update_debug_for_movement("ge: previous word end");
+    }
+
+    fn move_line_start(&mut self) {
+        self.textarea.move_line_start(); // 🎯 Direct FormEditor method call!
+        self.update_debug_for_movement("0: line start");
+    }
+
+    fn move_line_end(&mut self) {
+        self.textarea.move_line_end(); // 🎯 Direct FormEditor method call!
+        self.update_debug_for_movement("$: line end");
+    }
+
+    fn move_first_line(&mut self) {
+        self.textarea.move_first_line(); // 🎯 Direct FormEditor method call!
+        self.update_debug_for_movement("gg: first line");
+    }
+
+    fn move_last_line(&mut self) {
+        self.textarea.move_last_line(); // 🎯 Direct FormEditor method call!
+        self.update_debug_for_movement("G: last line");
+    }
+
+    // === BIG WORD MOVEMENTS ===
+
+    fn move_big_word_next(&mut self) {
+        self.textarea.move_big_word_next(); // 🎯 Direct FormEditor method call!
+        self.update_debug_for_movement("W: next WORD");
+    }
+
+    fn move_big_word_prev(&mut self) {
+        self.textarea.move_big_word_prev(); // 🎯 Direct FormEditor method call!
+        self.update_debug_for_movement("B: previous WORD");
+    }
+
+    fn move_big_word_end(&mut self) {
+        self.textarea.move_big_word_end(); // 🎯 Direct FormEditor method call!
+        self.update_debug_for_movement("E: WORD end");
+    }
+
+    fn move_big_word_end_prev(&mut self) {
+        self.textarea.move_big_word_end_prev(); // 🎯 Direct FormEditor method call!
+        self.update_debug_for_movement("gE: previous WORD end");
+    }
+
+    fn update_debug_for_movement(&mut self, action: &str) {
+        self.debug_message = action.to_string();
+    }
+
+    // === DELETE OPERATIONS ===
+
+    fn delete_char_forward(&mut self) {
+        if let Ok(_) = self.textarea.delete_forward() { // 🎯 Direct FormEditor method call!
+            self.has_unsaved_changes = true;
+            self.debug_message = "x: deleted character".to_string();
+        }
+    }
+
+    fn delete_char_backward(&mut self) {
+        if let Ok(_) = self.textarea.delete_backward() { // 🎯 Direct FormEditor method call!
+            self.has_unsaved_changes = true;
+            self.debug_message = "X: deleted character backward".to_string();
+        }
+    }
+
+    // === VIM-STYLE EDITING ===
+
+    fn open_line_below(&mut self) -> anyhow::Result<()> {
+        let result = self.textarea.open_line_below(); // 🎯 Textarea-specific override!
+        if result.is_ok() {
+            CursorManager::update_for_mode(AppMode::Edit)?;
+            self.debug_message = "✏️  INSERT (open line below) - Cursor: Steady Bar |".to_string();
+            self.has_unsaved_changes = true;
+        }
+        result
+    }
+
+    fn open_line_above(&mut self) -> anyhow::Result<()> {
+        let result = self.textarea.open_line_above(); // 🎯 Textarea-specific override!
+        if result.is_ok() {
+            CursorManager::update_for_mode(AppMode::Edit)?;
+            self.debug_message = "✏️  INSERT (open line above) - Cursor: Steady Bar |".to_string();
+            self.has_unsaved_changes = true;
+        }
+        result
+    }
+
+    // === COMMAND BUFFER HANDLING ===
+
+    fn clear_command_buffer(&mut self) {
+        self.command_buffer.clear();
+    }
+
+    fn add_to_command_buffer(&mut self, ch: char) {
+        self.command_buffer.push(ch);
+    }
+
+    fn get_command_buffer(&self) -> &str {
+        &self.command_buffer
+    }
+
+    fn has_pending_command(&self) -> bool {
+        !self.command_buffer.is_empty()
+    }
+
+    // === GETTERS ===
+
+    fn mode(&self) -> AppMode {
+        self.textarea.mode() // 🎯 Direct FormEditor method call!
+    }
+
+    fn debug_message(&self) -> &str {
+        &self.debug_message
+    }
+
+    fn has_unsaved_changes(&self) -> bool {
+        self.has_unsaved_changes
+    }
+
+    fn set_debug_message(&mut self, msg: String) {
+        self.debug_message = msg;
+    }
+
+    fn get_cursor_info(&self) -> String {
+        format!(
+            "Line {}, Col {}",
+            self.textarea.current_field() + 1, // 🎯 Direct FormEditor method call!
+            self.textarea.cursor_position() + 1 // 🎯 Direct FormEditor method call!
+        )
+    }
+}
+
+/// Handle key press with automatic cursor management
+fn handle_key_press(
+    key_event: KeyEvent,
+    editor: &mut AutoCursorTextArea,
+) -> anyhow::Result<bool> {
+    let KeyEvent { code: key, modifiers, .. } = key_event;
+    let mode = editor.mode();
+
+    // Quit handling
+    if (key == KeyCode::Char('q') && modifiers.contains(KeyModifiers::CONTROL))
+        || (key == KeyCode::Char('c') && modifiers.contains(KeyModifiers::CONTROL))
+        || key == KeyCode::F(10)
+    {
+        return Ok(false);
+    }
+
+    match (mode, key, modifiers) {
+        // === MODE TRANSITIONS WITH AUTOMATIC CURSOR MANAGEMENT ===
+        (AppMode::ReadOnly, KeyCode::Char('i'), _) => {
+            editor.enter_insert_mode()?;
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('a'), _) => {
+            editor.enter_append_mode()?;
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('A'), _) => {
+            editor.move_line_end();
+            editor.enter_insert_mode()?;
+            editor.clear_command_buffer();
+        }
+
+        // Vim o/O commands
+        (AppMode::ReadOnly, KeyCode::Char('o'), _) => {
+            if let Err(e) = editor.open_line_below() {
+                editor.set_debug_message(format!("Error opening line below: {e}"));
+            }
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('O'), _) => {
+            if let Err(e) = editor.open_line_above() {
+                editor.set_debug_message(format!("Error opening line above: {e}"));
+            }
+            editor.clear_command_buffer();
+        }
+
+        // Escape: Exit any mode back to normal
+        (AppMode::Edit, KeyCode::Esc, _) => {
+            editor.exit_to_normal_mode()?;
+        }
+
+        // === INSERT MODE: Pass to textarea ===
+        (AppMode::Edit, _, _) => {
+            editor.handle_textarea_input(key_event);
+        }
+
+        // === CURSOR MANAGEMENT DEMONSTRATION ===
+        (AppMode::ReadOnly, KeyCode::F(1), _) => {
+            editor.demo_manual_cursor_control()?;
+        }
+        (AppMode::ReadOnly, KeyCode::F(2), _) => {
+            editor.restore_automatic_cursor()?;
+        }
+
+        // === MOVEMENT: VIM-STYLE NAVIGATION (Normal mode) ===
+        (AppMode::ReadOnly, KeyCode::Char('h'), _)
+        | (AppMode::ReadOnly, KeyCode::Left, _) => {
+            editor.move_left();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('l'), _)
+        | (AppMode::ReadOnly, KeyCode::Right, _) => {
+            editor.move_right();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('j'), _)
+        | (AppMode::ReadOnly, KeyCode::Down, _) => {
+            editor.move_down();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('k'), _)
+        | (AppMode::ReadOnly, KeyCode::Up, _) => {
+            editor.move_up();
+            editor.clear_command_buffer();
+        }
+
+        // Word movement
+        (AppMode::ReadOnly, KeyCode::Char('w'), _) => {
+            editor.move_word_next();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('b'), _) => {
+            editor.move_word_prev();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('e'), _) => {
+            if editor.get_command_buffer() == "g" {
+                editor.move_word_end_prev();
+                editor.clear_command_buffer();
+            } else {
+                editor.move_word_end();
+                editor.clear_command_buffer();
+            }
+        }
+
+        // Big word movement (vim W/B/E commands)
+        (AppMode::ReadOnly, KeyCode::Char('W'), _) => {
+            editor.move_big_word_next();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('B'), _) => {
+            editor.move_big_word_prev();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('E'), _) => {
+            if editor.get_command_buffer() == "g" {
+                editor.move_big_word_end_prev();
+                editor.clear_command_buffer();
+            } else {
+                editor.move_big_word_end();
+                editor.clear_command_buffer();
+            }
+        }
+
+        // Line movement
+        (AppMode::ReadOnly, KeyCode::Char('0'), _)
+        | (AppMode::ReadOnly, KeyCode::Home, _) => {
+            editor.move_line_start();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('$'), _)
+        | (AppMode::ReadOnly, KeyCode::End, _) => {
+            editor.move_line_end();
+            editor.clear_command_buffer();
+        }
+
+        // Document movement with command buffer
+        (AppMode::ReadOnly, KeyCode::Char('g'), _) => {
+            if editor.get_command_buffer() == "g" {
+                editor.move_first_line();
+                editor.clear_command_buffer();
+            } else {
+                editor.clear_command_buffer();
+                editor.add_to_command_buffer('g');
+                editor.set_debug_message("g".to_string());
+            }
+        }
+        (AppMode::ReadOnly, KeyCode::Char('G'), _) => {
+            editor.move_last_line();
+            editor.clear_command_buffer();
+        }
+
+        // === DELETE OPERATIONS (Normal mode) ===
+        (AppMode::ReadOnly, KeyCode::Char('x'), _) => {
+            editor.delete_char_forward();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('X'), _) => {
+            editor.delete_char_backward();
+            editor.clear_command_buffer();
+        }
+
+        // === DEBUG/INFO COMMANDS ===
+        (AppMode::ReadOnly, KeyCode::Char('?'), _) => {
+            editor.set_debug_message(format!(
+                "{}, Mode: {:?} - Cursor managed automatically!",
+                editor.get_cursor_info(),
+                mode
+            ));
+            editor.clear_command_buffer();
+        }
+
+        _ => {
+            if editor.has_pending_command() {
+                editor.clear_command_buffer();
+                editor.set_debug_message("Invalid command sequence".to_string());
+            } else {
+                editor.set_debug_message(format!(
+                    "Unhandled: {key:?} + {modifiers:?} in {mode:?} mode"
+                ));
+            }
+        }
+    }
+
+    Ok(true)
+}
+
+fn run_app<B: Backend>(
+    terminal: &mut Terminal<B>,
+    mut editor: AutoCursorTextArea,
+) -> io::Result<()> {
+    loop {
+        terminal.draw(|f| ui(f, &mut editor))?;
+
+        if let Event::Key(key) = event::read()? {
+            match handle_key_press(key, &mut editor) {
+                Ok(should_continue) => {
+                    if !should_continue {
+                        break;
+                    }
+                }
+                Err(e) => {
+                    editor.set_debug_message(format!("Error: {e}"));
+                }
+            }
+        }
+    }
+
+    Ok(())
+}
+
+fn ui(f: &mut Frame, editor: &mut AutoCursorTextArea) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Min(8), Constraint::Length(8)])
+        .split(f.area());
+
+    render_textarea(f, chunks[0], editor);
+    render_status_and_help(f, chunks[1], editor);
+}
+
+fn render_textarea(
+    f: &mut Frame,
+    area: ratatui::layout::Rect,
+    editor: &mut AutoCursorTextArea,
+) {
+    let block = Block::default()
+        .borders(Borders::ALL)
+        .title("🎯 Textarea with Automatic Cursor Management");
+
+    let textarea_widget = TextArea::default().block(block.clone());
+
+    f.render_stateful_widget(textarea_widget, area, &mut editor.textarea);
+
+    // Set cursor position for terminal cursor
+    // Always show cursor - CursorManager handles the style (block/bar/blinking)
+    let (cx, cy) = editor.textarea.cursor(area, Some(&block));
+    f.set_cursor_position((cx, cy));
+}
+
+fn render_status_and_help(
+    f: &mut Frame,
+    area: ratatui::layout::Rect,
+    editor: &AutoCursorTextArea,
+) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Length(3), Constraint::Length(5)])
+        .split(area);
+
+    // Status bar with cursor information
+    let mode_text = match editor.mode() {
+        AppMode::Edit => "INSERT | (bar cursor)",
+        AppMode::ReadOnly => "NORMAL █ (block cursor)",
+        AppMode::Highlight => "VISUAL █ (blinking block)",
+        _ => "NORMAL █ (block cursor)",
+    };
+
+    let status_text = if editor.has_pending_command() {
+        format!("-- {} -- {} [{}]", mode_text, editor.debug_message(), editor.get_command_buffer())
+    } else if editor.has_unsaved_changes() {
+        format!("-- {} -- [Modified] {} | {}", mode_text, editor.debug_message(), editor.get_cursor_info())
+    } else {
+        format!("-- {} -- {} | {}", mode_text, editor.debug_message(), editor.get_cursor_info())
+    };
+
+    let status = Paragraph::new(Line::from(Span::raw(status_text)))
+        .block(Block::default().borders(Borders::ALL).title("🎯 Automatic Cursor Status"));
+
+    f.render_widget(status, chunks[0]);
+
+    // Help text
+    let help_text = match editor.mode() {
+        AppMode::ReadOnly => {
+            if editor.has_pending_command() {
+                match editor.get_command_buffer() {
+                    "g" => "Press 'g' again for first line, or any other key to cancel",
+                    _ => "Pending command... (Esc to cancel)"
+                }
+            } else {
+                "🎯 CURSOR-STYLE DEMO: Normal █ | Insert | \n\
+                Normal: hjkl/arrows=move, w/b/e=words, W/B/E=WORDS, 0/$=line, g/G=first/last\n\
+                i/a/A/o/O=insert, x/X=delete, ?=info\n\
+                F1=demo manual cursor, F2=restore automatic, Ctrl+Q=quit"
+            }
+        }
+        AppMode::Edit => {
+            "🎯 INSERT MODE - Cursor: | (bar)\n\
+            Type to edit text, arrows=move, Enter=new line\n\
+            Esc=normal mode"
+        }
+        AppMode::Highlight => {
+            "🎯 VISUAL MODE - Cursor: █ (blinking block)\n\
+            hjkl/arrows=extend selection\n\
+            Esc=normal mode"
+        }
+        _ => "🎯 Watch the cursor change automatically!"
+    };
+
+    let help = Paragraph::new(help_text)
+        .block(Block::default().borders(Borders::ALL).title("🚀 Automatic Cursor Management"))
+        .style(Style::default().fg(Color::Gray));
+
+    f.render_widget(help, chunks[1]);
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    // Print feature status
+    println!("🎯 Canvas Textarea Cursor Auto Demo");
+    println!("✅ cursor-style feature: ENABLED");
+    println!("✅ textarea feature: ENABLED");
+    println!("🚀 Automatic cursor management: ACTIVE");
+    println!("📖 Watch your terminal cursor change based on mode!");
+    println!();
+
+    enable_raw_mode()?;
+    let mut stdout = io::stdout();
+    execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
+    let backend = CrosstermBackend::new(stdout);
+    let mut terminal = Terminal::new(backend)?;
+
+    let mut editor = AutoCursorTextArea::new();
+
+    // Initialize with normal mode - library automatically sets block cursor
+    editor.exit_to_normal_mode()?;
+
+    let res = run_app(&mut terminal, editor);
+
+    // Reset cursor on exit
+    CursorManager::reset()?;
+
+    disable_raw_mode()?;
+    execute!(
+        terminal.backend_mut(),
+        LeaveAlternateScreen,
+        DisableMouseCapture
+    )?;
+    terminal.show_cursor()?;
+
+    if let Err(err) = res {
+        println!("{err:?}");
+    }
+
+    println!("🎯 Cursor automatically reset to default!");
+    Ok(())
+}

canvas/examples/validation_1.rs

@@ -0,0 +1,831 @@
+// examples/validation_1.rs
+//! Demonstrates field validation with the canvas library
+//!
+//! This example REQUIRES the `validation` and `cursor-style` features to compile.
+//!
+//! Run with:
+//! cargo run --example validation_1 --features "gui,validation"
+//!
+//! This will fail without validation:
+//! cargo run --example validation_1 --features "gui"
+
+// REQUIRE validation feature - example won't compile without it
+#[cfg(not(all(feature = "validation", feature = "cursor-style")))]
+compile_error!(
+    "This example requires the 'validation' and 'cursor-style' features. \
+     Run with: cargo run --example validation_1 --features \"gui,validation,cursor-style\""
+);
+
+use std::io;
+use crossterm::{
+    event::{
+        self, DisableMouseCapture, EnableMouseCapture, Event, KeyCode, KeyModifiers,
+    },
+    execute,
+    terminal::{
+        disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen,
+    },
+};
+use ratatui::{
+    backend::{Backend, CrosstermBackend},
+    layout::{Constraint, Direction, Layout, Rect},
+    style::{Color, Style},
+    text::{Line, Span},
+    widgets::{Block, Borders, Paragraph, Wrap},
+    Frame, Terminal,
+};
+use canvas::{
+    canvas::{
+        gui::render_canvas_default,
+        modes::AppMode,
+        CursorManager,
+    },
+    DataProvider, FormEditor,
+    ValidationConfig, ValidationConfigBuilder, CharacterLimits, ValidationResult,
+};
+
+// Import CountMode from the validation module directly
+use canvas::validation::limits::CountMode;
+
+// Enhanced FormEditor that demonstrates validation functionality
+struct ValidationFormEditor<D: DataProvider> {
+    editor: FormEditor<D>,
+    has_unsaved_changes: bool,
+    debug_message: String,
+    command_buffer: String,
+    validation_enabled: bool,
+    field_switch_blocked: bool,
+    block_reason: Option<String>,
+}
+
+impl<D: DataProvider> ValidationFormEditor<D> {
+    fn new(data_provider: D) -> Self {
+        let mut editor = FormEditor::new(data_provider);
+        // Enable validation by default
+        editor.set_validation_enabled(true);
+        Self {
+            editor,
+            has_unsaved_changes: false,
+            debug_message: "🔍 Validation Demo - Try typing in different fields!".to_string(),
+            command_buffer: String::new(),
+            validation_enabled: true,
+            field_switch_blocked: false,
+            block_reason: None,
+        }
+    }
+
+    // === COMMAND BUFFER HANDLING ===
+    fn clear_command_buffer(&mut self) {
+        self.command_buffer.clear();
+    }
+
+    fn add_to_command_buffer(&mut self, ch: char) {
+        self.command_buffer.push(ch);
+    }
+
+    fn get_command_buffer(&self) -> &str {
+        &self.command_buffer
+    }
+
+    fn has_pending_command(&self) -> bool {
+        !self.command_buffer.is_empty()
+    }
+
+    // === VALIDATION CONTROL ===
+    fn toggle_validation(&mut self) {
+        self.validation_enabled = !self.validation_enabled;
+        self.editor.set_validation_enabled(self.validation_enabled);
+        if self.validation_enabled {
+            self.debug_message = "✅ Validation ENABLED - Try exceeding limits!".to_string();
+        } else {
+            self.debug_message = "❌ Validation DISABLED - No limits enforced".to_string();
+        }
+    }
+
+    fn check_field_switch_allowed(&self) -> (bool, Option<String>) {
+        if !self.validation_enabled {
+            return (true, None);
+        }
+        let can_switch = self.editor.can_switch_fields();
+        let reason = if !can_switch {
+            self.editor.field_switch_block_reason()
+        } else {
+            None
+        };
+        (can_switch, reason)
+    }
+
+    fn get_validation_status(&self) -> String {
+        if !self.validation_enabled {
+            return "❌ DISABLED".to_string();
+        }
+        if self.field_switch_blocked {
+            return "🚫 SWITCH BLOCKED".to_string();
+        }
+        let summary = self.editor.validation_summary();
+        if summary.has_errors() {
+            format!("❌ {} ERRORS", summary.error_fields)
+        } else if summary.has_warnings() {
+            format!("⚠️  {} WARNINGS", summary.warning_fields)
+        } else if summary.validated_fields > 0 {
+            format!("✅ {} VALID", summary.valid_fields)
+        } else {
+            "🔍 READY".to_string()
+        }
+    }
+
+    fn validate_current_field(&mut self) {
+        let result = self.editor.validate_current_field();
+        match result {
+            ValidationResult::Valid => {
+                self.debug_message = "✅ Current field is valid!".to_string();
+            }
+            ValidationResult::Warning { message } => {
+                self.debug_message = format!("⚠️  Warning: {message}");
+            }
+            ValidationResult::Error { message } => {
+                self.debug_message = format!("❌ Error: {message}");
+            }
+        }
+    }
+
+    fn validate_all_fields(&mut self) {
+        let field_count = self.editor.data_provider().field_count();
+        for i in 0..field_count {
+            self.editor.validate_field(i);
+        }
+        let summary = self.editor.validation_summary();
+        self.debug_message = format!(
+            "🔍 Validated all fields: {} valid, {} warnings, {} errors",
+            summary.valid_fields, summary.warning_fields, summary.error_fields
+        );
+    }
+
+    fn clear_validation_results(&mut self) {
+        self.editor.clear_validation_results();
+        self.debug_message = "🧹 Cleared all validation results".to_string();
+    }
+
+    // === ENHANCED MOVEMENT WITH VALIDATION ===
+    fn move_left(&mut self) {
+        self.editor.move_left();
+        self.field_switch_blocked = false;
+        self.block_reason = None;
+    }
+
+    fn move_right(&mut self) {
+        self.editor.move_right();
+        self.field_switch_blocked = false;
+        self.block_reason = None;
+    }
+
+    fn move_up(&mut self) {
+        match self.editor.move_up() {
+            Ok(()) => {
+                self.update_field_validation_status();
+                self.field_switch_blocked = false;
+                self.block_reason = None;
+            }
+            Err(e) => {
+                self.field_switch_blocked = true;
+                self.block_reason = Some(e.to_string());
+                self.debug_message = format!("🚫 Field switch blocked: {e}");
+            }
+        }
+    }
+
+    fn move_down(&mut self) {
+        match self.editor.move_down() {
+            Ok(()) => {
+                self.update_field_validation_status();
+                self.field_switch_blocked = false;
+                self.block_reason = None;
+            }
+            Err(e) => {
+                self.field_switch_blocked = true;
+                self.block_reason = Some(e.to_string());
+                self.debug_message = format!("🚫 Field switch blocked: {e}");
+            }
+        }
+    }
+
+    fn move_line_start(&mut self) {
+        self.editor.move_line_start();
+    }
+
+    fn move_line_end(&mut self) {
+        self.editor.move_line_end();
+    }
+
+    fn move_word_next(&mut self) {
+        self.editor.move_word_next();
+    }
+
+    fn move_word_prev(&mut self) {
+        self.editor.move_word_prev();
+    }
+
+    fn move_word_end(&mut self) {
+        self.editor.move_word_end();
+    }
+
+    fn move_first_line(&mut self) {
+        self.editor.move_first_line();
+    }
+
+    fn move_last_line(&mut self) {
+        self.editor.move_last_line();
+    }
+
+    fn update_field_validation_status(&mut self) {
+        if !self.validation_enabled {
+            return;
+        }
+        let result = self.editor.validate_current_field();
+        match result {
+            ValidationResult::Valid => {
+                self.debug_message = format!("Field {}: ✅ Valid", self.editor.current_field() + 1);
+            }
+            ValidationResult::Warning { message } => {
+                self.debug_message = format!("Field {}: ⚠️  {}", self.editor.current_field() + 1, message);
+            }
+            ValidationResult::Error { message } => {
+                self.debug_message = format!("Field {}: ❌ {}", self.editor.current_field() + 1, message);
+            }
+        }
+    }
+
+    // === MODE TRANSITIONS ===
+    fn enter_edit_mode(&mut self) {
+        // Library will automatically update cursor to bar | in insert mode
+        self.editor.enter_edit_mode();
+        self.debug_message = "✏️  INSERT MODE - Cursor: Steady Bar | - Type to test validation".to_string();
+    }
+
+    fn enter_append_mode(&mut self) {
+        // Library will automatically update cursor to bar | in insert mode
+        self.editor.enter_append_mode();
+        self.debug_message = "✏️  INSERT (append) - Cursor: Steady Bar | - Validation active".to_string();
+    }
+
+    fn exit_edit_mode(&mut self) {
+        // Library will automatically update cursor to block █ in normal mode
+        self.editor.exit_edit_mode();
+        self.debug_message = "🔒 NORMAL MODE - Cursor: Steady Block █ - Press 'v' to validate current field".to_string();
+        self.update_field_validation_status();
+    }
+
+    fn insert_char(&mut self, ch: char) -> anyhow::Result<()> {
+        let result = self.editor.insert_char(ch);
+        if result.is_ok() {
+            self.has_unsaved_changes = true;
+            // Show real-time validation feedback
+            let validation_result = self.editor.validate_current_field();
+            match validation_result {
+                ValidationResult::Valid => {
+                    // Don't spam with valid messages, just show character count if applicable
+                    if let Some(limits) = self.get_current_field_limits() {
+                        let field_index = self.editor.current_field();
+                        if let Some(status) = limits.status_text(
+                            self.editor.data_provider().field_value(field_index)
+                        ) {
+                            self.debug_message = format!("✏️  {status}");
+                        }
+                    }
+                }
+                ValidationResult::Warning { message } => {
+                    self.debug_message = format!("⚠️  {message}");
+                }
+                ValidationResult::Error { message } => {
+                    self.debug_message = format!("❌ {message}");
+                }
+            }
+        }
+        result
+    }
+
+    fn get_current_field_limits(&self) -> Option<&CharacterLimits> {
+        let validation_state = self.editor.validation_state();
+        let config = validation_state.get_field_config(self.editor.current_field())?;
+        config.character_limits.as_ref()
+    }
+
+    // === DELETE OPERATIONS ===
+    fn delete_backward(&mut self) -> anyhow::Result<()> {
+        let result = self.editor.delete_backward();
+        if result.is_ok() {
+            self.has_unsaved_changes = true;
+            self.debug_message = "⌫ Deleted character".to_string();
+        }
+        result
+    }
+
+    fn delete_forward(&mut self) -> anyhow::Result<()> {
+        let result = self.editor.delete_forward();
+        if result.is_ok() {
+            self.has_unsaved_changes = true;
+            self.debug_message = "⌦ Deleted character".to_string();
+        }
+        result
+    }
+
+    // === DELEGATE TO ORIGINAL EDITOR ===
+    fn current_field(&self) -> usize {
+        self.editor.current_field()
+    }
+
+    fn cursor_position(&self) -> usize {
+        self.editor.cursor_position()
+    }
+
+    fn mode(&self) -> AppMode {
+        self.editor.mode()
+    }
+
+    fn current_text(&self) -> &str {
+        let field_index = self.editor.current_field();
+        self.editor.data_provider().field_value(field_index)
+    }
+
+    fn data_provider(&self) -> &D {
+        self.editor.data_provider()
+    }
+
+    fn ui_state(&self) -> &canvas::EditorState {
+        self.editor.ui_state()
+    }
+
+    fn set_mode(&mut self, mode: AppMode) {
+        // Library automatically updates cursor for the mode
+        self.editor.set_mode(mode);
+    }
+
+    fn next_field(&mut self) {
+        match self.editor.next_field() {
+            Ok(()) => {
+                self.update_field_validation_status();
+                self.field_switch_blocked = false;
+                self.block_reason = None;
+            }
+            Err(e) => {
+                self.field_switch_blocked = true;
+                self.block_reason = Some(e.to_string());
+                self.debug_message = format!("🚫 Cannot move to next field: {e}");
+            }
+        }
+    }
+
+    fn prev_field(&mut self) {
+        match self.editor.prev_field() {
+            Ok(()) => {
+                self.update_field_validation_status();
+                self.field_switch_blocked = false;
+                self.block_reason = None;
+            }
+            Err(e) => {
+                self.field_switch_blocked = true;
+                self.block_reason = Some(e.to_string());
+                self.debug_message = format!("🚫 Cannot move to previous field: {e}");
+            }
+        }
+    }
+
+    // === STATUS AND DEBUG ===
+    fn set_debug_message(&mut self, msg: String) {
+        self.debug_message = msg;
+    }
+
+    fn debug_message(&self) -> &str {
+        &self.debug_message
+    }
+
+    fn has_unsaved_changes(&self) -> bool {
+        self.has_unsaved_changes
+    }
+}
+
+// Demo form data with different validation rules
+struct ValidationDemoData {
+    fields: Vec<(String, String)>,
+}
+
+impl ValidationDemoData {
+    fn new() -> Self {
+        Self {
+            fields: vec![
+                ("👤 Name (max 20)".to_string(), "".to_string()),
+                ("📧 Email (max 50, warn@40)".to_string(), "".to_string()),
+                ("🔑 Password (5-20 chars)".to_string(), "".to_string()),
+                ("🔢 ID (min 3, max 10)".to_string(), "".to_string()),
+                ("📝 Comment (min 10, max 100)".to_string(), "".to_string()),
+                ("🏷️  Tag (max 30, bytes)".to_string(), "".to_string()),
+                ("🌍 Unicode (width, min 2)".to_string(), "".to_string()),
+            ],
+        }
+    }
+}
+
+impl DataProvider for ValidationDemoData {
+    fn field_count(&self) -> usize {
+        self.fields.len()
+    }
+
+    fn field_name(&self, index: usize) -> &str {
+        &self.fields[index].0
+    }
+
+    fn field_value(&self, index: usize) -> &str {
+        &self.fields[index].1
+    }
+
+    fn set_field_value(&mut self, index: usize, value: String) {
+        self.fields[index].1 = value;
+    }
+
+    fn supports_suggestions(&self, _field_index: usize) -> bool {
+        false
+    }
+
+    fn display_value(&self, _index: usize) -> Option<&str> {
+        None
+    }
+
+    // 🎯 NEW: Validation configuration per field
+    fn validation_config(&self, field_index: usize) -> Option<ValidationConfig> {
+        match field_index {
+            0 => Some(ValidationConfig::with_max_length(20)), // Name: simple 20 char limit
+            1 => Some(
+                ValidationConfigBuilder::new()
+                    .with_character_limits(
+                        CharacterLimits::new(50).with_warning_threshold(40)
+                    )
+                    .build()
+            ), // Email: 50 chars with warning at 40
+            2 => Some(
+                ValidationConfigBuilder::new()
+                    .with_character_limits(CharacterLimits::new_range(5, 20))
+                    .build()
+            ), // Password: must be 5-20 characters (blocks field switching if 1-4 chars)
+            3 => Some(
+                ValidationConfigBuilder::new()
+                    .with_character_limits(CharacterLimits::new_range(3, 10))
+                    .build()
+            ), // ID: must be 3-10 characters (blocks field switching if 1-2 chars)
+            4 => Some(
+                ValidationConfigBuilder::new()
+                    .with_character_limits(CharacterLimits::new_range(10, 100))
+                    .build()
+            ), // Comment: must be 10-100 characters (blocks field switching if 1-9 chars)
+            5 => Some(
+                ValidationConfigBuilder::new()
+                    .with_character_limits(
+                        CharacterLimits::new(30).with_count_mode(CountMode::Bytes)
+                    )
+                    .build()
+            ), // Tag: 30 bytes (useful for UTF-8)
+            6 => Some(
+                ValidationConfigBuilder::new()
+                    .with_character_limits(
+                        CharacterLimits::new_range(2, 20).with_count_mode(CountMode::DisplayWidth)
+                    )
+                    .build()
+            ), // Unicode: 2-20 display width (useful for CJK characters, blocks if 1 char)
+            _ => None,
+        }
+    }
+}
+
+/// Handle key presses with validation-focused commands
+fn handle_key_press(
+    key: KeyCode,
+    modifiers: KeyModifiers,
+    editor: &mut ValidationFormEditor<ValidationDemoData>,
+) -> anyhow::Result<bool> {
+    let mode = editor.mode();
+
+    // Quit handling
+    if (key == KeyCode::Char('q') && modifiers.contains(KeyModifiers::CONTROL))
+        || (key == KeyCode::Char('c') && modifiers.contains(KeyModifiers::CONTROL))
+        || key == KeyCode::F(10)
+    {
+        return Ok(false);
+    }
+
+    match (mode, key, modifiers) {
+        // === MODE TRANSITIONS ===
+        (AppMode::ReadOnly, KeyCode::Char('i'), _) => {
+            editor.enter_edit_mode();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('a'), _) => {
+            editor.enter_append_mode();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('A'), _) => {
+            editor.move_line_end();
+            editor.enter_edit_mode();
+            editor.clear_command_buffer();
+        }
+        // Escape: Exit edit mode
+        (_, KeyCode::Esc, _) => {
+            if mode == AppMode::Edit {
+                editor.exit_edit_mode();
+            } else {
+                editor.clear_command_buffer();
+            }
+        }
+
+        // === VALIDATION COMMANDS ===
+        (AppMode::ReadOnly, KeyCode::Char('v'), _) => {
+            editor.validate_current_field();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('V'), _) => {
+            editor.validate_all_fields();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('c'), _) => {
+            editor.clear_validation_results();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::F(1), _) => {
+            editor.toggle_validation();
+        }
+
+        // === MOVEMENT ===
+        (AppMode::ReadOnly, KeyCode::Char('h'), _) | (AppMode::ReadOnly, KeyCode::Left, _) => {
+            editor.move_left();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('l'), _) | (AppMode::ReadOnly, KeyCode::Right, _) => {
+            editor.move_right();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('j'), _) | (AppMode::ReadOnly, KeyCode::Down, _) => {
+            editor.move_down();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('k'), _) | (AppMode::ReadOnly, KeyCode::Up, _) => {
+            editor.move_up();
+            editor.clear_command_buffer();
+        }
+
+        // === EDIT MODE MOVEMENT ===
+        (AppMode::Edit, KeyCode::Left, _) => {
+            editor.move_left();
+        }
+        (AppMode::Edit, KeyCode::Right, _) => {
+            editor.move_right();
+        }
+        (AppMode::Edit, KeyCode::Up, _) => {
+            editor.move_up();
+        }
+        (AppMode::Edit, KeyCode::Down, _) => {
+            editor.move_down();
+        }
+
+        // === DELETE OPERATIONS ===
+        (AppMode::Edit, KeyCode::Backspace, _) => {
+            editor.delete_backward()?;
+        }
+        (AppMode::Edit, KeyCode::Delete, _) => {
+            editor.delete_forward()?;
+        }
+
+        // === TAB NAVIGATION ===
+        (_, KeyCode::Tab, _) => {
+            editor.next_field();
+        }
+        (_, KeyCode::BackTab, _) => {
+            editor.prev_field();
+        }
+
+        // === CHARACTER INPUT ===
+        (AppMode::Edit, KeyCode::Char(c), m) if !m.contains(KeyModifiers::CONTROL) => {
+            editor.insert_char(c)?;
+        }
+
+        // === DEBUG/INFO COMMANDS ===
+        (AppMode::ReadOnly, KeyCode::Char('?'), _) => {
+            let summary = editor.editor.validation_summary();
+            editor.set_debug_message(format!(
+                "Field {}/{}, Pos {}, Mode: {:?}, Validation: {} fields configured, {} validated",
+                editor.current_field() + 1,
+                editor.data_provider().field_count(),
+                editor.cursor_position(),
+                editor.mode(),
+                summary.total_fields,
+                summary.validated_fields
+            ));
+        }
+        _ => {
+            if editor.has_pending_command() {
+                editor.clear_command_buffer();
+                editor.set_debug_message("Invalid command sequence".to_string());
+            }
+        }
+    }
+
+    Ok(true)
+}
+
+fn run_app<B: Backend>(
+    terminal: &mut Terminal<B>,
+    mut editor: ValidationFormEditor<ValidationDemoData>,
+) -> io::Result<()> {
+    loop {
+        terminal.draw(|f| ui(f, &editor))?;
+
+        if let Event::Key(key) = event::read()? {
+            match handle_key_press(key.code, key.modifiers, &mut editor) {
+                Ok(should_continue) => {
+                    if !should_continue {
+                        break;
+                    }
+                }
+                Err(e) => {
+                    editor.set_debug_message(format!("Error: {e}"));
+                }
+            }
+        }
+    }
+    Ok(())
+}
+
+fn ui(f: &mut Frame, editor: &ValidationFormEditor<ValidationDemoData>) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Min(8), Constraint::Length(12)])
+        .split(f.area());
+
+    render_enhanced_canvas(f, chunks[0], editor);
+    render_validation_status(f, chunks[1], editor);
+}
+
+fn render_enhanced_canvas(
+    f: &mut Frame,
+    area: Rect,
+    editor: &ValidationFormEditor<ValidationDemoData>,
+) {
+    render_canvas_default(f, area, &editor.editor);
+}
+
+fn render_validation_status(
+    f: &mut Frame,
+    area: Rect,
+    editor: &ValidationFormEditor<ValidationDemoData>,
+) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([
+            Constraint::Length(3), // Status bar
+            Constraint::Length(4), // Validation summary
+            Constraint::Length(5), // Help
+        ])
+        .split(area);
+
+    // Status bar with validation information
+    let mode_text = match editor.mode() {
+        AppMode::Edit => "INSERT | (bar cursor)",
+        AppMode::ReadOnly => "NORMAL █ (block cursor)",
+        _ => "NORMAL █ (block cursor)",
+    };
+
+    let validation_status = editor.get_validation_status();
+
+    let status_text = if editor.has_pending_command() {
+        format!("-- {} -- {} [{}] | Validation: {}",
+                mode_text, editor.debug_message(), editor.get_command_buffer(), validation_status)
+    } else if editor.has_unsaved_changes() {
+        format!("-- {} -- [Modified] {} | Validation: {}",
+                mode_text, editor.debug_message(), validation_status)
+    } else {
+        format!("-- {} -- {} | Validation: {}",
+                mode_text, editor.debug_message(), validation_status)
+    };
+
+    let status = Paragraph::new(Line::from(Span::raw(status_text)))
+        .block(Block::default().borders(Borders::ALL).title("🔍 Validation Status"));
+    f.render_widget(status, chunks[0]);
+
+    // Validation summary with field switching info
+    let summary = editor.editor.validation_summary();
+    let summary_text = if editor.validation_enabled {
+        let switch_info = if editor.field_switch_blocked {
+            format!("\n🚫 Field switching blocked: {}",
+                   editor.block_reason.as_deref().unwrap_or("Unknown reason"))
+        } else {
+            let (can_switch, reason) = editor.check_field_switch_allowed();
+            if !can_switch {
+                format!("\n⚠️  Field switching will be blocked: {}",
+                       reason.as_deref().unwrap_or("Unknown reason"))
+            } else {
+                "\n✅ Field switching allowed".to_string()
+            }
+        };
+        
+        format!(
+            "📊 Validation Summary: {} fields configured, {} validated{}\n\
+             ✅ Valid: {}  ⚠️  Warnings: {}  ❌ Errors: {}  📈 Progress: {:.0}%",
+            summary.total_fields,
+            summary.validated_fields,
+            switch_info,
+            summary.valid_fields,
+            summary.warning_fields,
+            summary.error_fields,
+            summary.completion_percentage() * 100.0
+        )
+    } else {
+        "❌ Validation is currently DISABLED\nPress F1 to enable validation".to_string()
+    };
+
+    let summary_style = if summary.has_errors() {
+        Style::default().fg(Color::Red)
+    } else if summary.has_warnings() {
+        Style::default().fg(Color::Yellow)
+    } else {
+        Style::default().fg(Color::Green)
+    };
+
+    let validation_summary = Paragraph::new(summary_text)
+        .block(Block::default().borders(Borders::ALL).title("📈 Validation Overview"))
+        .style(summary_style)
+        .wrap(Wrap { trim: true });
+    f.render_widget(validation_summary, chunks[1]);
+
+    // Enhanced help text
+    let help_text = match editor.mode() {
+        AppMode::ReadOnly => {
+            "🎯 CURSOR-STYLE: Normal █ | Insert |\n\
+             🔍 VALIDATION: Different fields have different limits (some block field switching)!\n\
+             Movement: hjkl/arrows=move, Tab/Shift+Tab=fields\n\
+             Edit: i/a/A=insert modes, Esc=normal\n\
+             Validation: v=validate current, V=validate all, c=clear results, F1=toggle\n\
+             ?=info, Ctrl+C/Ctrl+Q=quit"
+        }
+        AppMode::Edit => {
+            "🎯 INSERT MODE - Cursor: | (bar)\n\
+             🔍 Type to test validation limits (some fields have MIN requirements)!\n\
+             Try typing 1-2 chars in Password/ID/Comment fields, then try to switch!\n\
+             arrows=move, Backspace/Del=delete, Esc=normal, Tab=next field\n\
+             Field switching may be BLOCKED if minimum requirements not met!"
+        }
+        _ => "🎯 Watch the cursor change automatically while validating!"
+    };
+
+    let help = Paragraph::new(help_text)
+        .block(Block::default().borders(Borders::ALL).title("🚀 Validation Commands"))
+        .style(Style::default().fg(Color::Gray))
+        .wrap(Wrap { trim: true });
+    f.render_widget(help, chunks[2]);
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    // Print feature status
+    println!("🔍 Canvas Validation Demo");
+    println!("✅ validation feature: ENABLED");
+    println!("🚀 Field validation: ACTIVE");
+    println!("🚫 Field switching validation: ACTIVE");
+    println!("📊 Try typing in fields with minimum requirements!");
+    println!("   - Password (min 5): Type 1-4 chars, then try to switch fields");
+    println!("   - ID (min 3): Type 1-2 chars, then try to switch fields");
+    println!("   - Comment (min 10): Type 1-9 chars, then try to switch fields");
+    println!("   - Unicode (min 2): Type 1 char, then try to switch fields");
+    println!();
+
+    enable_raw_mode()?;
+    let mut stdout = io::stdout();
+    execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
+    let backend = CrosstermBackend::new(stdout);
+    let mut terminal = Terminal::new(backend)?;
+
+    let data = ValidationDemoData::new();
+    let mut editor = ValidationFormEditor::new(data);
+    
+    // Initialize with normal mode - library automatically sets block cursor
+    editor.set_mode(AppMode::ReadOnly);
+    
+    // Demonstrate that CursorManager is available and working
+    CursorManager::update_for_mode(AppMode::ReadOnly)?;
+
+    let res = run_app(&mut terminal, editor);
+
+    // Library automatically resets cursor on FormEditor::drop()
+    // But we can also manually reset if needed
+    CursorManager::reset()?;
+
+    disable_raw_mode()?;
+    execute!(
+        terminal.backend_mut(),
+        LeaveAlternateScreen,
+        DisableMouseCapture
+    )?;
+    terminal.show_cursor()?;
+
+    if let Err(err) = res {
+        println!("{err:?}");
+    }
+
+    println!("🔍 Validation demo completed!");
+    Ok(())
+}

canvas/examples/validation_2.rs

@@ -0,0 +1,663 @@
+// examples/validation_2.rs
+//! Advanced TUI Example demonstrating complex pattern filtering edge cases
+//!
+//! This example showcases the full potential of the pattern validation system
+//! with creative real-world scenarios and edge cases.
+//!
+//! Run with: cargo run --example validation_advanced_patterns --features "validation,gui,cursor-style"
+
+// REQUIRE validation, gui and cursor-style features
+#[cfg(not(all(feature = "validation", feature = "gui", feature = "cursor-style")))]
+compile_error!(
+    "This example requires the 'validation', 'gui' and 'cursor-style' features. \
+     Run with: cargo run --example validation_advanced_patterns --features \"validation,gui,cursor-style\""
+);
+
+use std::io;
+use std::sync::Arc;
+use canvas::ValidationResult;
+use crossterm::{
+    event::{
+        self, DisableMouseCapture, EnableMouseCapture, Event, KeyCode, KeyModifiers,
+    },
+    execute,
+    terminal::{
+        disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen,
+    },
+};
+use ratatui::{
+    backend::{Backend, CrosstermBackend},
+    layout::{Constraint, Direction, Layout, Rect},
+    style::{Color, Style},
+    text::{Line, Span},
+    widgets::{Block, Borders, Paragraph, Wrap},
+    Frame, Terminal,
+};
+
+use canvas::{
+    canvas::{
+        gui::render_canvas_default,
+        modes::AppMode,
+        CursorManager,
+    },
+    DataProvider, FormEditor,
+    ValidationConfig, ValidationConfigBuilder, PatternFilters, PositionFilter, PositionRange, CharacterFilter,
+};
+
+// Enhanced FormEditor wrapper (keeping the same structure as before)
+struct AdvancedPatternFormEditor<D: DataProvider> {
+    editor: FormEditor<D>,
+    debug_message: String,
+    command_buffer: String,
+    validation_enabled: bool,
+    field_switch_blocked: bool,
+    block_reason: Option<String>,
+}
+
+impl<D: DataProvider> AdvancedPatternFormEditor<D> {
+    fn new(data_provider: D) -> Self {
+        let mut editor = FormEditor::new(data_provider);
+        editor.set_validation_enabled(true);
+
+        Self {
+            editor,
+            debug_message: "🚀 Advanced Pattern Validation - Showcasing edge cases and complex patterns!".to_string(),
+            command_buffer: String::new(),
+            validation_enabled: true,
+            field_switch_blocked: false,
+            block_reason: None,
+        }
+    }
+
+    // ... (keeping all the same methods as before for brevity)
+    // [All the previous methods: clear_command_buffer, add_to_command_buffer, etc.]
+
+    fn clear_command_buffer(&mut self) { self.command_buffer.clear(); }
+    fn add_to_command_buffer(&mut self, ch: char) { self.command_buffer.push(ch); }
+    fn get_command_buffer(&self) -> &str { &self.command_buffer }
+    fn has_pending_command(&self) -> bool { !self.command_buffer.is_empty() }
+
+    fn toggle_validation(&mut self) {
+        self.validation_enabled = !self.validation_enabled;
+        self.editor.set_validation_enabled(self.validation_enabled);
+        if self.validation_enabled {
+            self.debug_message = "✅ Advanced Pattern Validation ENABLED".to_string();
+        } else {
+            self.debug_message = "❌ Advanced Pattern Validation DISABLED".to_string();
+        }
+    }
+
+    fn move_left(&mut self) { self.editor.move_left(); self.field_switch_blocked = false; self.block_reason = None; }
+    fn move_right(&mut self) { self.editor.move_right(); self.field_switch_blocked = false; self.block_reason = None; }
+
+    fn move_up(&mut self) {
+        match self.editor.move_up() {
+            Ok(()) => { self.update_field_validation_status(); self.field_switch_blocked = false; self.block_reason = None; }
+            Err(e) => { self.field_switch_blocked = true; self.block_reason = Some(e.to_string()); self.debug_message = format!("🚫 Field switch blocked: {e}"); }
+        }
+    }
+
+    fn move_down(&mut self) {
+        match self.editor.move_down() {
+            Ok(()) => { self.update_field_validation_status(); self.field_switch_blocked = false; self.block_reason = None; }
+            Err(e) => { self.field_switch_blocked = true; self.block_reason = Some(e.to_string()); self.debug_message = format!("🚫 Field switch blocked: {e}"); }
+        }
+    }
+
+    fn move_line_start(&mut self) { self.editor.move_line_start(); }
+    fn move_line_end(&mut self) { self.editor.move_line_end(); }
+
+    fn enter_edit_mode(&mut self) {
+        // Library will automatically update cursor to bar | in insert mode
+        self.editor.enter_edit_mode();
+        self.debug_message = "✏️  INSERT MODE - Cursor: Steady Bar | - Testing advanced pattern validation".to_string();
+    }
+
+    fn enter_append_mode(&mut self) {
+        // Library will automatically update cursor to bar | in insert mode
+        self.editor.enter_append_mode();
+        self.debug_message = "✏️  INSERT (append) - Cursor: Steady Bar | - Advanced patterns active".to_string();
+    }
+
+    fn exit_edit_mode(&mut self) {
+        // Library will automatically update cursor to block █ in normal mode
+        self.editor.exit_edit_mode();
+        self.debug_message = "🔒 NORMAL MODE - Cursor: Steady Block █".to_string();
+        self.update_field_validation_status();
+    }
+
+    fn insert_char(&mut self, ch: char) -> anyhow::Result<()> {
+        let result = self.editor.insert_char(ch);
+        if result.is_ok() {
+            let validation_result = self.editor.validate_current_field();
+            match validation_result {
+                ValidationResult::Valid => { self.debug_message = "✅ Character accepted".to_string(); }
+                ValidationResult::Warning { message } => { self.debug_message = format!("⚠️  Warning: {message}"); }
+                ValidationResult::Error { message } => { self.debug_message = format!("❌ Pattern violation: {message}"); }
+            }
+        }
+        result
+    }
+
+    fn delete_backward(&mut self) -> anyhow::Result<()> {
+        let result = self.editor.delete_backward();
+        if result.is_ok() { self.debug_message = "⌫ Character deleted".to_string(); }
+        result
+    }
+
+    fn delete_forward(&mut self) -> anyhow::Result<()> {
+        let result = self.editor.delete_forward();
+        if result.is_ok() { self.debug_message = "⌦ Character deleted".to_string(); }
+        result
+    }
+
+    // Delegate methods
+    fn current_field(&self) -> usize { self.editor.current_field() }
+    fn cursor_position(&self) -> usize { self.editor.cursor_position() }
+    fn mode(&self) -> AppMode { self.editor.mode() }
+    fn current_text(&self) -> &str {
+        let field_index = self.editor.current_field();
+        self.editor.data_provider().field_value(field_index)
+    }
+    fn data_provider(&self) -> &D { self.editor.data_provider() }
+    fn ui_state(&self) -> &canvas::EditorState { self.editor.ui_state() }
+    fn set_mode(&mut self, mode: AppMode) { self.editor.set_mode(mode); }
+
+    fn next_field(&mut self) {
+        match self.editor.next_field() {
+            Ok(()) => { self.update_field_validation_status(); self.field_switch_blocked = false; self.block_reason = None; }
+            Err(e) => { self.field_switch_blocked = true; self.block_reason = Some(e.to_string()); self.debug_message = format!("🚫 Cannot move to next field: {e}"); }
+        }
+    }
+
+    fn prev_field(&mut self) {
+        match self.editor.prev_field() {
+            Ok(()) => { self.update_field_validation_status(); self.field_switch_blocked = false; self.block_reason = None; }
+            Err(e) => { self.field_switch_blocked = true; self.block_reason = Some(e.to_string()); self.debug_message = format!("🚫 Cannot move to previous field: {e}"); }
+        }
+    }
+
+    fn set_debug_message(&mut self, msg: String) { self.debug_message = msg; }
+    fn debug_message(&self) -> &str { &self.debug_message }
+
+    fn update_field_validation_status(&mut self) {
+        if !self.validation_enabled { return; }
+        let result = self.editor.validate_current_field();
+        match result {
+            ValidationResult::Valid => { self.debug_message = format!("Field {}: ✅ Pattern valid", self.editor.current_field() + 1); }
+            ValidationResult::Warning { message } => { self.debug_message = format!("Field {}: ⚠️  {}", self.editor.current_field() + 1, message); }
+            ValidationResult::Error { message } => { self.debug_message = format!("Field {}: ❌ {}", self.editor.current_field() + 1, message); }
+        }
+    }
+
+    fn get_validation_status(&self) -> String {
+        if !self.validation_enabled { return "❌ DISABLED".to_string(); }
+        if self.field_switch_blocked { return "🚫 SWITCH BLOCKED".to_string(); }
+        let summary = self.editor.validation_summary();
+        if summary.has_errors() { format!("❌ {} ERRORS", summary.error_fields) }
+        else if summary.has_warnings() { format!("⚠️  {} WARNINGS", summary.warning_fields) }
+        else if summary.validated_fields > 0 { format!("✅ {} VALID", summary.valid_fields) }
+        else { "🔍 READY".to_string() }
+    }
+}
+
+// Advanced demo form with creative and edge-case-heavy validation patterns
+struct AdvancedPatternData {
+    fields: Vec<(String, String)>,
+}
+
+impl AdvancedPatternData {
+    fn new() -> Self {
+        Self {
+            fields: vec![
+                ("🕐 Time (HH:MM) - 24hr format".to_string(), "".to_string()),
+                ("🎨 Hex Color (#RRGGBB) - Web colors".to_string(), "".to_string()),
+                ("🌐 IPv4 (XXX.XXX.XXX.XXX) - Network address".to_string(), "".to_string()),
+                ("🏷️  Product Code (ABC-123-XYZ) - Mixed format".to_string(), "".to_string()),
+                ("📅 Date Code (2024W15) - Year + Week".to_string(), "".to_string()),
+                ("🔢 Binary (101010) - Only 0s and 1s".to_string(), "".to_string()),
+                ("🎯 Complex ID (A1-B2C-3D4E) - Multi-rule".to_string(), "".to_string()),
+                ("🚀 Custom Pattern - Advanced logic".to_string(), "".to_string()),
+            ],
+        }
+    }
+}
+
+impl DataProvider for AdvancedPatternData {
+    fn field_count(&self) -> usize { self.fields.len() }
+    fn field_name(&self, index: usize) -> &str { &self.fields[index].0 }
+    fn field_value(&self, index: usize) -> &str { &self.fields[index].1 }
+    fn set_field_value(&mut self, index: usize, value: String) { self.fields[index].1 = value; }
+
+    fn validation_config(&self, field_index: usize) -> Option<ValidationConfig> {
+        match field_index {
+            0 => {
+                // 🕐 Time (HH:MM) - Hours 00-23, Minutes 00-59
+                // This showcases: Multiple position ranges, exact character matching, custom validation
+                let time_pattern = PatternFilters::new()
+                    .add_filter(PositionFilter::new(
+                        PositionRange::Multiple(vec![0, 1, 3, 4]), // Hours and minutes positions
+                        CharacterFilter::Numeric,
+                    ))
+                    .add_filter(PositionFilter::new(
+                        PositionRange::Single(2), // Colon separator
+                        CharacterFilter::Exact(':'),
+                    ));
+
+                Some(ValidationConfigBuilder::new()
+                    .with_pattern_filters(time_pattern)
+                    .with_max_length(5) // HH:MM = 5 characters
+                    .build())
+            }
+            1 => {
+                // 🎨 Hex Color (#RRGGBB) - Web color format
+                // This showcases: OneOf filter with hex digits, exact character at start
+                let hex_digits = vec!['0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F','a','b','c','d','e','f'];
+                let hex_color_pattern = PatternFilters::new()
+                    .add_filter(PositionFilter::new(
+                        PositionRange::Single(0), // Hash symbol
+                        CharacterFilter::Exact('#'),
+                    ))
+                    .add_filter(PositionFilter::new(
+                        PositionRange::Range(1, 6), // 6 hex digits for RGB
+                        CharacterFilter::OneOf(hex_digits),
+                    ));
+
+                Some(ValidationConfigBuilder::new()
+                    .with_pattern_filters(hex_color_pattern)
+                    .with_max_length(7) // #RRGGBB = 7 characters
+                    .build())
+            }
+            2 => {
+                // 🌐 IPv4 Address (XXX.XXX.XXX.XXX) - Network address
+                // This showcases: Complex pattern with dots at specific positions
+                let ipv4_pattern = PatternFilters::new()
+                    .add_filter(PositionFilter::new(
+                        PositionRange::Multiple(vec![3, 7, 11]), // Dots at specific positions
+                        CharacterFilter::Exact('.'),
+                    ))
+                    .add_filter(PositionFilter::new(
+                        PositionRange::Multiple(vec![0,1,2,4,5,6,8,9,10,12,13,14]), // Number positions
+                        CharacterFilter::Numeric,
+                    ));
+
+                Some(ValidationConfigBuilder::new()
+                    .with_pattern_filters(ipv4_pattern)
+                    .with_max_length(15) // XXX.XXX.XXX.XXX = up to 15 chars
+                    .build())
+            }
+            3 => {
+                // 🏷️ Product Code (ABC-123-XYZ) - Mixed format sections
+                // This showcases: Different rules for different sections
+                let product_code_pattern = PatternFilters::new()
+                    .add_filter(PositionFilter::new(
+                        PositionRange::Range(0, 2), // First 3 positions: letters
+                        CharacterFilter::Alphabetic,
+                    ))
+                    .add_filter(PositionFilter::new(
+                        PositionRange::Multiple(vec![3, 7]), // Dashes
+                        CharacterFilter::Exact('-'),
+                    ))
+                    .add_filter(PositionFilter::new(
+                        PositionRange::Range(4, 6), // Middle 3 positions: numbers
+                        CharacterFilter::Numeric,
+                    ))
+                    .add_filter(PositionFilter::new(
+                        PositionRange::Range(8, 10), // Last 3 positions: letters
+                        CharacterFilter::Alphabetic,
+                    ));
+
+                Some(ValidationConfigBuilder::new()
+                    .with_pattern_filters(product_code_pattern)
+                    .with_max_length(11) // ABC-123-XYZ = 11 characters
+                    .build())
+            }
+            4 => {
+                // 📅 Date Code (2024W15) - Year + Week format
+                // This showcases: From position filtering and mixed patterns
+                let date_code_pattern = PatternFilters::new()
+                    .add_filter(PositionFilter::new(
+                        PositionRange::Range(0, 3), // Year: 4 digits
+                        CharacterFilter::Numeric,
+                    ))
+                    .add_filter(PositionFilter::new(
+                        PositionRange::Single(4), // Week indicator
+                        CharacterFilter::Exact('W'),
+                    ))
+                    .add_filter(PositionFilter::new(
+                        PositionRange::From(5), // Week number: rest are digits
+                        CharacterFilter::Numeric,
+                    ));
+
+                Some(ValidationConfigBuilder::new()
+                    .with_pattern_filters(date_code_pattern)
+                    .with_max_length(7) // 2024W15 = 7 characters
+                    .build())
+            }
+            5 => {
+                // 🔢 Binary (101010) - Only 0s and 1s
+                // This showcases: OneOf filter with limited character set
+                let binary_pattern = PatternFilters::new()
+                    .add_filter(PositionFilter::new(
+                        PositionRange::From(0), // All positions
+                        CharacterFilter::OneOf(vec!['0', '1']),
+                    ));
+
+                Some(ValidationConfigBuilder::new()
+                    .with_pattern_filters(binary_pattern)
+                    .with_max_length(16) // Allow up to 16 binary digits
+                    .build())
+            }
+            6 => {
+                // 🎯 Complex ID (A1-B2C-3D4E) - Multiple overlapping rules
+                // This showcases: Complex overlapping patterns and edge cases
+                let complex_id_pattern = PatternFilters::new()
+                    .add_filter(PositionFilter::new(
+                        PositionRange::Multiple(vec![0, 3, 6, 8]), // Letter positions
+                        CharacterFilter::Alphabetic,
+                    ))
+                    .add_filter(PositionFilter::new(
+                        PositionRange::Multiple(vec![1, 4, 7, 9]), // Number positions
+                        CharacterFilter::Numeric,
+                    ))
+                    .add_filter(PositionFilter::new(
+                        PositionRange::Multiple(vec![2, 5]), // Dashes
+                        CharacterFilter::Exact('-'),
+                    ))
+                    .add_filter(PositionFilter::new(
+                        PositionRange::Single(5), // Special case: override dash with letter C
+                        CharacterFilter::Alphabetic, // This creates an interesting edge case
+                    ));
+
+                Some(ValidationConfigBuilder::new()
+                    .with_pattern_filters(complex_id_pattern)
+                    .with_max_length(10) // A1-B2C-3D4E = 10 characters
+                    .build())
+            }
+            7 => {
+                // 🚀 Custom Pattern - Advanced logic with custom function
+                // This showcases: Custom validation function for complex rules
+                let custom_pattern = PatternFilters::new()
+                    .add_filter(PositionFilter::new(
+                        PositionRange::From(0),
+                        CharacterFilter::Custom(Arc::new(|c| {
+                            // Advanced rule: Alternating vowels and consonants!
+                            // Even positions (0,2,4...): vowels (a,e,i,o,u)
+                            // Odd positions (1,3,5...): consonants
+                            let vowels = ['a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'];
+
+                            // For demo purposes, we'll just accept alphabetic characters
+                            // In real usage, you'd implement the alternating logic based on position
+                            c.is_alphabetic()
+                        })),
+                    ));
+
+                Some(ValidationConfigBuilder::new()
+                    .with_pattern_filters(custom_pattern)
+                    .with_max_length(12) // Allow up to 12 characters
+                    .build())
+            }
+            _ => None,
+        }
+    }
+}
+
+// Key handling (same structure as before)
+fn handle_key_press(
+    key: KeyCode,
+    modifiers: KeyModifiers,
+    editor: &mut AdvancedPatternFormEditor<AdvancedPatternData>,
+) -> anyhow::Result<bool> {
+    let mode = editor.mode();
+
+    // Quit handling
+    if (key == KeyCode::Char('q') && modifiers.contains(KeyModifiers::CONTROL))
+        || (key == KeyCode::Char('c') && modifiers.contains(KeyModifiers::CONTROL))
+        || key == KeyCode::F(10)
+    {
+        return Ok(false);
+    }
+
+    match (mode, key, modifiers) {
+        // Mode transitions
+        (AppMode::ReadOnly, KeyCode::Char('i'), _) => { editor.enter_edit_mode(); editor.clear_command_buffer(); }
+        (AppMode::ReadOnly, KeyCode::Char('a'), _) => { editor.enter_append_mode(); editor.clear_command_buffer(); }
+        (AppMode::ReadOnly, KeyCode::Char('A'), _) => { editor.move_line_end(); editor.enter_edit_mode(); editor.clear_command_buffer(); }
+        (_, KeyCode::Esc, _) => { if mode == AppMode::Edit { editor.exit_edit_mode(); } else { editor.clear_command_buffer(); } }
+
+        // Validation commands
+        (AppMode::ReadOnly, KeyCode::F(1), _) => { editor.toggle_validation(); }
+
+        // Movement in ReadOnly mode
+        (AppMode::ReadOnly, KeyCode::Char('h'), _) | (AppMode::ReadOnly, KeyCode::Left, _) => { editor.move_left(); editor.clear_command_buffer(); }
+        (AppMode::ReadOnly, KeyCode::Char('l'), _) | (AppMode::ReadOnly, KeyCode::Right, _) => { editor.move_right(); editor.clear_command_buffer(); }
+        (AppMode::ReadOnly, KeyCode::Char('j'), _) | (AppMode::ReadOnly, KeyCode::Down, _) => { editor.move_down(); editor.clear_command_buffer(); }
+        (AppMode::ReadOnly, KeyCode::Char('k'), _) | (AppMode::ReadOnly, KeyCode::Up, _) => { editor.move_up(); editor.clear_command_buffer(); }
+
+        // Movement in Edit mode
+        (AppMode::Edit, KeyCode::Left, _) => { editor.move_left(); }
+        (AppMode::Edit, KeyCode::Right, _) => { editor.move_right(); }
+        (AppMode::Edit, KeyCode::Up, _) => { editor.move_up(); }
+        (AppMode::Edit, KeyCode::Down, _) => { editor.move_down(); }
+
+        // Delete operations
+        (AppMode::Edit, KeyCode::Backspace, _) => { editor.delete_backward()?; }
+        (AppMode::Edit, KeyCode::Delete, _) => { editor.delete_forward()?; }
+
+        // Tab navigation
+        (_, KeyCode::Tab, _) => { editor.next_field(); }
+        (_, KeyCode::BackTab, _) => { editor.prev_field(); }
+
+        // Character input
+        (AppMode::Edit, KeyCode::Char(c), m) if !m.contains(KeyModifiers::CONTROL) => {
+            editor.insert_char(c)?;
+        }
+
+        // Debug info
+        (AppMode::ReadOnly, KeyCode::Char('?'), _) => {
+            let summary = editor.editor.validation_summary();
+            editor.set_debug_message(format!(
+                "Field {}/{}, Pos {}, Mode: {:?}, Advanced patterns: {} configured",
+                editor.current_field() + 1,
+                editor.data_provider().field_count(),
+                editor.cursor_position(),
+                editor.mode(),
+                summary.total_fields
+            ));
+        }
+
+        _ => {
+            if editor.has_pending_command() {
+                editor.clear_command_buffer();
+                editor.set_debug_message("Invalid command sequence".to_string());
+            }
+        }
+    }
+
+    Ok(true)
+}
+
+fn run_app<B: Backend>(
+    terminal: &mut Terminal<B>,
+    mut editor: AdvancedPatternFormEditor<AdvancedPatternData>,
+) -> io::Result<()> {
+    loop {
+        terminal.draw(|f| ui(f, &editor))?;
+
+        if let Event::Key(key) = event::read()? {
+            match handle_key_press(key.code, key.modifiers, &mut editor) {
+                Ok(should_continue) => {
+                    if !should_continue {
+                        break;
+                    }
+                }
+                Err(e) => {
+                    editor.set_debug_message(format!("Error: {e}"));
+                }
+            }
+        }
+    }
+
+    Ok(())
+}
+
+fn ui(f: &mut Frame, editor: &AdvancedPatternFormEditor<AdvancedPatternData>) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Min(8), Constraint::Length(15)])
+        .split(f.area());
+
+    render_canvas_default(f, chunks[0], &editor.editor);
+    render_advanced_validation_status(f, chunks[1], editor);
+}
+
+fn render_advanced_validation_status(
+    f: &mut Frame,
+    area: Rect,
+    editor: &AdvancedPatternFormEditor<AdvancedPatternData>,
+) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([
+            Constraint::Length(3), // Status bar
+            Constraint::Length(5), // Validation summary
+            Constraint::Length(7), // Help
+        ])
+        .split(area);
+
+    // Status bar
+    let mode_text = match editor.mode() {
+        AppMode::Edit => "INSERT | (bar cursor)",
+        AppMode::ReadOnly => "NORMAL █ (block cursor)",
+        _ => "NORMAL █ (block cursor)",
+    };
+
+    let validation_status = editor.get_validation_status();
+    let status_text = format!("-- {} -- {} | Advanced Patterns: {}", mode_text, editor.debug_message(), validation_status);
+
+    let status = Paragraph::new(Line::from(Span::raw(status_text)))
+        .block(Block::default().borders(Borders::ALL).title("🚀 Advanced Pattern Validation"));
+
+    f.render_widget(status, chunks[0]);
+
+    // Enhanced validation summary
+    let summary = editor.editor.validation_summary();
+    let field_info = match editor.current_field() {
+        0 => "Time format (HH:MM) - Tests exact chars + numeric ranges",
+        1 => "Hex color (#RRGGBB) - Tests OneOf filter with case insensitive",
+        2 => "IPv4 address - Tests complex dot positioning",
+        3 => "Product code (ABC-123-XYZ) - Tests section-based patterns",
+        4 => "Date code (2024W15) - Tests From position filtering",
+        5 => "Binary input - Tests limited character set (0,1 only)",
+        6 => "Complex ID - Tests overlapping/conflicting rules",
+        7 => "Custom pattern - Tests advanced custom validation logic",
+        _ => "Unknown field",
+    };
+
+    let summary_text = if editor.validation_enabled {
+        format!(
+            "📊 Advanced Pattern Summary: {} fields with complex rules\n\
+             Current Field: {}\n\
+             ✅ Valid: {}  ⚠️  Warnings: {}  ❌ Errors: {}  📈 Progress: {:.0}%\n\
+             🎯 Pattern Focus: {}",
+            summary.total_fields,
+            editor.current_field() + 1,
+            summary.valid_fields,
+            summary.warning_fields,
+            summary.error_fields,
+            summary.completion_percentage() * 100.0,
+            field_info
+        )
+    } else {
+        "❌ Advanced pattern validation is DISABLED\nPress F1 to enable and see the magic!".to_string()
+    };
+
+    let summary_style = if summary.has_errors() {
+        Style::default().fg(Color::Red)
+    } else if summary.has_warnings() {
+        Style::default().fg(Color::Yellow)
+    } else {
+        Style::default().fg(Color::Green)
+    };
+
+    let validation_summary = Paragraph::new(summary_text)
+        .block(Block::default().borders(Borders::ALL).title("🎯 Advanced Pattern Analysis"))
+        .style(summary_style)
+        .wrap(Wrap { trim: true });
+
+    f.render_widget(validation_summary, chunks[1]);
+
+    // Enhanced help text
+    let help_text = match editor.mode() {
+        AppMode::ReadOnly => {
+            "🚀 ADVANCED PATTERN SHOWCASE - Each field demonstrates different edge cases!\n\
+             🕐 Time: Numeric+exact chars  🎨 Hex: OneOf with case-insensitive  🌐 IPv4: Complex positioning\n\
+             🏷️  Product: Multi-section rules  📅 Date: From-position filtering  🔢 Binary: Limited charset\n\
+             🎯 Complex: Overlapping rules  🚀 Custom: Advanced logic functions\n\
+             \n\
+             Movement: hjkl/arrows=move, Tab/Shift+Tab=fields, i/a=insert, F1=toggle, ?=info"
+        }
+        AppMode::Edit => {
+            "✏️  INSERT MODE - Testing advanced pattern validation!\n\
+             Each character is validated against complex rules in real-time\n\
+             Try entering invalid characters to see detailed error messages\n\
+             arrows=move, Backspace/Del=delete, Esc=normal, Tab=next field"
+        }
+        _ => "🚀 Advanced Pattern Validation Active!"
+    };
+
+    let help = Paragraph::new(help_text)
+        .block(Block::default().borders(Borders::ALL).title("🎯 Advanced Pattern Commands & Info"))
+        .style(Style::default().fg(Color::Gray))
+        .wrap(Wrap { trim: true });
+
+    f.render_widget(help, chunks[2]);
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    println!("🚀 Canvas Advanced Pattern Validation Demo");
+    println!("✅ validation feature: ENABLED");
+    println!("✅ gui feature: ENABLED");
+    println!("✅ cursor-style feature: ENABLED");
+    println!("🎯 Advanced pattern filtering: ACTIVE");
+    println!("🧪 Edge cases and complex patterns: READY");
+    println!("💡 Each field showcases different validation capabilities!");
+    println!();
+
+    enable_raw_mode()?;
+    let mut stdout = io::stdout();
+    execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
+    let backend = CrosstermBackend::new(stdout);
+    let mut terminal = Terminal::new(backend)?;
+
+    let data = AdvancedPatternData::new();
+    let mut editor = AdvancedPatternFormEditor::new(data);
+
+    // Initialize with normal mode - library automatically sets block cursor
+    editor.set_mode(AppMode::ReadOnly);
+
+    // Demonstrate that CursorManager is available and working
+    CursorManager::update_for_mode(AppMode::ReadOnly)?;
+
+    let res = run_app(&mut terminal, editor);
+
+    // Library automatically resets cursor on FormEditor::drop()
+    // But we can also manually reset if needed
+    CursorManager::reset()?;
+
+    disable_raw_mode()?;
+    execute!(
+        terminal.backend_mut(),
+        LeaveAlternateScreen,
+        DisableMouseCapture
+    )?;
+    terminal.show_cursor()?;
+
+    if let Err(err) = res {
+        println!("{err:?}");
+    }
+
+    println!("🚀 Advanced pattern validation demo completed!");
+    println!("🎯 Hope you enjoyed seeing all the edge cases in action!");
+    Ok(())
+}

canvas/examples/validation_3.rs

@@ -0,0 +1,734 @@
+// examples/validation_3.rs
+//! Comprehensive Display Mask Features Demo
+//!
+//! This example showcases the full power of the display mask system (Feature 3)
+//! demonstrating visual formatting that keeps business logic clean.
+//!
+//! Key Features Demonstrated:
+//! - Dynamic vs Template display modes
+//! - Custom patterns for different data types
+//! - Custom input characters and separators
+//! - Custom placeholder characters
+//! - Real-time visual formatting with clean raw data
+//! - Cursor movement through formatted displays
+//! - 🔥 CRITICAL: Perfect mask/character-limit coordination to prevent invisible character bugs
+//!
+//! ⚠️  IMPORTANT BUG PREVENTION:
+//! This example demonstrates the CORRECT way to configure masks with character limits.
+//! Each mask's input position count EXACTLY matches its character limit to prevent
+//! the critical bug where users can type more characters than they can see.
+//!
+//! Run with: cargo run --example validation_3 --features "gui,validation,cursor-style"
+
+// REQUIRE validation, gui and cursor-style features for mask functionality
+#[cfg(not(all(feature = "validation", feature = "gui", feature = "cursor-style")))]
+compile_error!(
+    "This example requires the 'validation', 'gui' and 'cursor-style' features. \
+     Run with: cargo run --example validation_3 --features \"gui,validation,cursor-style\""
+);
+
+use std::io;
+use crossterm::{
+    event::{
+        self, DisableMouseCapture, EnableMouseCapture, Event, KeyCode, KeyModifiers,
+    },
+    execute,
+    terminal::{
+        disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen,
+    },
+};
+use ratatui::{
+    backend::{Backend, CrosstermBackend},
+    layout::{Constraint, Direction, Layout, Rect},
+    style::{Color, Style},
+    text::{Line, Span},
+    widgets::{Block, Borders, Paragraph, Wrap},
+    Frame, Terminal,
+};
+
+use canvas::{
+    canvas::{
+        gui::render_canvas_default,
+        modes::AppMode,
+        CursorManager,
+    },
+    DataProvider, FormEditor,
+    ValidationConfig, ValidationConfigBuilder, DisplayMask,
+};
+
+// Enhanced FormEditor wrapper for mask demonstration
+struct MaskDemoFormEditor<D: DataProvider> {
+    editor: FormEditor<D>,
+    debug_message: String,
+    command_buffer: String,
+    validation_enabled: bool,
+    show_raw_data: bool,
+}
+
+impl<D: DataProvider> MaskDemoFormEditor<D> {
+    fn new(data_provider: D) -> Self {
+        let mut editor = FormEditor::new(data_provider);
+        editor.set_validation_enabled(true);
+
+        Self {
+            editor,
+            debug_message: "🎭 Display Mask Demo - Visual formatting with clean business logic!".to_string(),
+            command_buffer: String::new(),
+            validation_enabled: true,
+            show_raw_data: false,
+        }
+    }
+
+    // === COMMAND BUFFER HANDLING ===
+    fn clear_command_buffer(&mut self) { self.command_buffer.clear(); }
+    fn add_to_command_buffer(&mut self, ch: char) { self.command_buffer.push(ch); }
+    fn get_command_buffer(&self) -> &str { &self.command_buffer }
+    fn has_pending_command(&self) -> bool { !self.command_buffer.is_empty() }
+
+    // === MASK CONTROL ===
+    fn toggle_validation(&mut self) {
+        self.validation_enabled = !self.validation_enabled;
+        self.editor.set_validation_enabled(self.validation_enabled);
+        if self.validation_enabled {
+            self.debug_message = "✅ Display Masks ENABLED - See visual formatting in action!".to_string();
+        } else {
+            self.debug_message = "❌ Display Masks DISABLED - Raw text only".to_string();
+        }
+    }
+
+    fn toggle_raw_data_view(&mut self) {
+        self.show_raw_data = !self.show_raw_data;
+        if self.show_raw_data {
+            self.debug_message = "👁️ Showing RAW business data (what's actually stored)".to_string();
+        } else {
+            self.debug_message = "🎭 Showing FORMATTED display (what users see)".to_string();
+        }
+    }
+
+    fn get_current_field_info(&self) -> (String, String, String) {
+        let field_index = self.editor.current_field();
+        let raw_data = self.editor.data_provider().field_value(field_index);
+        let display_data = if self.validation_enabled {
+            self.editor.current_display_text()
+        } else {
+            raw_data.to_string()
+        };
+
+        let mask_info = if let Some(config) = self.editor.validation_state().get_field_config(field_index) {
+            if let Some(mask) = &config.display_mask {
+                format!("Pattern: '{}', Mode: {:?}",
+                       mask.pattern(),
+                       mask.display_mode())
+            } else {
+                "No mask configured".to_string()
+            }
+        } else {
+            "No validation config".to_string()
+        };
+
+        (raw_data.to_string(), display_data, mask_info)
+    }
+
+    // === ENHANCED MOVEMENT WITH MASK AWARENESS ===
+    fn move_left(&mut self) {
+        self.editor.move_left();
+        self.update_cursor_info();
+    }
+
+    fn move_right(&mut self) {
+        self.editor.move_right();
+        self.update_cursor_info();
+    }
+
+    fn move_up(&mut self) {
+        match self.editor.move_up() {
+            Ok(()) => { self.update_field_info(); }
+            Err(e) => { self.debug_message = format!("🚫 Field switch blocked: {e}"); }
+        }
+    }
+
+    fn move_down(&mut self) {
+        match self.editor.move_down() {
+            Ok(()) => { self.update_field_info(); }
+            Err(e) => { self.debug_message = format!("🚫 Field switch blocked: {e}"); }
+        }
+    }
+
+    fn move_line_start(&mut self) {
+        self.editor.move_line_start();
+        self.update_cursor_info();
+    }
+
+    fn move_line_end(&mut self) {
+        self.editor.move_line_end();
+        self.update_cursor_info();
+    }
+
+    fn update_cursor_info(&mut self) {
+        if self.validation_enabled {
+            let raw_pos = self.editor.cursor_position();
+            let display_pos = self.editor.display_cursor_position();
+            if raw_pos != display_pos {
+                self.debug_message = format!("📍 Cursor: Raw pos {raw_pos} → Display pos {display_pos} (mask active)");
+            } else {
+                self.debug_message = format!("📍 Cursor at position {raw_pos} (no mask offset)");
+            }
+        }
+    }
+
+    fn update_field_info(&mut self) {
+        let field_name = self.editor.data_provider().field_name(self.editor.current_field());
+        self.debug_message = format!("📝 Switched to: {field_name}");
+    }
+
+    // === MODE TRANSITIONS ===
+    fn enter_edit_mode(&mut self) {
+        // Library will automatically update cursor to bar | in insert mode
+        self.editor.enter_edit_mode();
+        self.debug_message = "✏️ INSERT MODE - Cursor: Steady Bar | - Type to see mask formatting in real-time".to_string();
+    }
+
+    fn enter_append_mode(&mut self) {
+        // Library will automatically update cursor to bar | in insert mode
+        self.editor.enter_append_mode();
+        self.debug_message = "✏️ INSERT (append) - Cursor: Steady Bar | - Mask formatting active".to_string();
+    }
+
+    fn exit_edit_mode(&mut self) {
+        // Library will automatically update cursor to block █ in normal mode
+        self.editor.exit_edit_mode();
+        self.debug_message = "🔒 NORMAL MODE - Cursor: Steady Block █ - Press 'r' to see raw data, 'm' for mask info".to_string();
+    }
+
+    fn insert_char(&mut self, ch: char) -> anyhow::Result<()> {
+        let result = self.editor.insert_char(ch);
+        if result.is_ok() {
+            let (raw, display, _) = self.get_current_field_info();
+            if raw != display {
+                self.debug_message = format!("✏️ Added '{ch}': Raw='{raw}' Display='{display}'");
+            } else {
+                self.debug_message = format!("✏️ Added '{ch}': '{raw}'");
+            }
+        }
+        result
+    }
+
+    // === DELETE OPERATIONS ===
+    fn delete_backward(&mut self) -> anyhow::Result<()> {
+        let result = self.editor.delete_backward();
+        if result.is_ok() {
+            self.debug_message = "⌫ Character deleted".to_string();
+            self.update_cursor_info();
+        }
+        result
+    }
+
+    fn delete_forward(&mut self) -> anyhow::Result<()> {
+        let result = self.editor.delete_forward();
+        if result.is_ok() {
+            self.debug_message = "⌦ Character deleted".to_string();
+            self.update_cursor_info();
+        }
+        result
+    }
+
+    // === DELEGATE TO ORIGINAL EDITOR ===
+    fn current_field(&self) -> usize { self.editor.current_field() }
+    fn cursor_position(&self) -> usize { self.editor.cursor_position() }
+    fn mode(&self) -> AppMode { self.editor.mode() }
+    fn current_text(&self) -> &str {
+        let field_index = self.editor.current_field();
+        self.editor.data_provider().field_value(field_index)
+    }
+    fn data_provider(&self) -> &D { self.editor.data_provider() }
+    fn ui_state(&self) -> &canvas::EditorState { self.editor.ui_state() }
+    fn set_mode(&mut self, mode: AppMode) {
+        // Library automatically updates cursor for the mode
+        self.editor.set_mode(mode);
+    }
+
+    fn next_field(&mut self) {
+        match self.editor.next_field() {
+            Ok(()) => { self.update_field_info(); }
+            Err(e) => { self.debug_message = format!("🚫 Cannot move to next field: {e}"); }
+        }
+    }
+
+    fn prev_field(&mut self) {
+        match self.editor.prev_field() {
+            Ok(()) => { self.update_field_info(); }
+            Err(e) => { self.debug_message = format!("🚫 Cannot move to previous field: {e}"); }
+        }
+    }
+
+    // === STATUS AND DEBUG ===
+    fn set_debug_message(&mut self, msg: String) { self.debug_message = msg; }
+    fn debug_message(&self) -> &str { &self.debug_message }
+
+    fn show_mask_details(&mut self) {
+        let (raw, display, mask_info) = self.get_current_field_info();
+        self.debug_message = format!("🔍 Field {}: {} | Raw: '{}' Display: '{}'",
+                                   self.current_field() + 1, mask_info, raw, display);
+    }
+
+    fn get_mask_status(&self) -> String {
+        if !self.validation_enabled {
+            return "❌ DISABLED".to_string();
+        }
+
+        let field_count = self.editor.data_provider().field_count();
+        let mut mask_count = 0;
+        for i in 0..field_count {
+            if let Some(config) = self.editor.validation_state().get_field_config(i) {
+                if config.display_mask.is_some() {
+                    mask_count += 1;
+                }
+            }
+        }
+
+        format!("🎭 {mask_count} MASKS")
+    }
+}
+
+// Demo data with comprehensive mask examples
+struct MaskDemoData {
+    fields: Vec<(String, String)>,
+}
+
+impl MaskDemoData {
+    fn new() -> Self {
+        Self {
+            fields: vec![
+                ("📞 Phone (Dynamic)".to_string(), "".to_string()),
+                ("📞 Phone (Template)".to_string(), "".to_string()),
+                ("📅 Date US (MM/DD/YYYY)".to_string(), "".to_string()),
+                ("📅 Date EU (DD.MM.YYYY)".to_string(), "".to_string()),
+                ("📅 Date ISO (YYYY-MM-DD)".to_string(), "".to_string()),
+                ("🏛️ SSN (XXX-XX-XXXX)".to_string(), "".to_string()),
+                ("💳 Credit Card".to_string(), "".to_string()),
+                ("🏢 Employee ID (EMP-####)".to_string(), "".to_string()),
+                ("📦 Product Code (ABC###XYZ)".to_string(), "".to_string()),
+                ("🌈 Custom Separators".to_string(), "".to_string()),
+                ("⭐ Custom Placeholders".to_string(), "".to_string()),
+                ("🎯 Mixed Input Chars".to_string(), "".to_string()),
+            ],
+        }
+    }
+}
+
+impl DataProvider for MaskDemoData {
+    fn field_count(&self) -> usize { self.fields.len() }
+    fn field_name(&self, index: usize) -> &str { &self.fields[index].0 }
+    fn field_value(&self, index: usize) -> &str { &self.fields[index].1 }
+    fn set_field_value(&mut self, index: usize, value: String) { self.fields[index].1 = value; }
+
+    fn validation_config(&self, field_index: usize) -> Option<ValidationConfig> {
+        match field_index {
+            0 => {
+                // 📞 Phone (Dynamic) - FIXED: Perfect mask/limit coordination
+                let phone_mask = DisplayMask::new("(###) ###-####", '#');
+                Some(ValidationConfigBuilder::new()
+                    .with_display_mask(phone_mask)
+                    .with_max_length(10)  // ✅ CRITICAL: Exactly matches 10 input positions
+                    .build())
+            }
+            1 => {
+                // 📞 Phone (Template) - FIXED: Perfect mask/limit coordination
+                let phone_template = DisplayMask::new("(###) ###-####", '#')
+                    .with_template('_');
+                Some(ValidationConfigBuilder::new()
+                    .with_display_mask(phone_template)
+                    .with_max_length(10)  // ✅ CRITICAL: Exactly matches 10 input positions
+                    .build())
+            }
+            2 => {
+                // 📅 Date US (MM/DD/YYYY) - American date format
+                let us_date = DisplayMask::new("##/##/####", '#');
+                Some(ValidationConfig::with_mask(us_date))
+            }
+            3 => {
+                // 📅 Date EU (DD.MM.YYYY) - European date format with dots
+                let eu_date = DisplayMask::new("##.##.####", '#')
+                    .with_template('•');
+                Some(ValidationConfig::with_mask(eu_date))
+            }
+            4 => {
+                // 📅 Date ISO (YYYY-MM-DD) - ISO date format
+                let iso_date = DisplayMask::new("####-##-##", '#')
+                    .with_template('-');
+                Some(ValidationConfig::with_mask(iso_date))
+            }
+            5 => {
+                // 🏛️ SSN using custom input character 'X' - FIXED: Perfect coordination
+                let ssn_mask = DisplayMask::new("XXX-XX-XXXX", 'X');
+                Some(ValidationConfigBuilder::new()
+                    .with_display_mask(ssn_mask)
+                    .with_max_length(9)  // ✅ CRITICAL: Exactly matches 9 input positions
+                    .build())
+            }
+            6 => {
+                // 💳 Credit Card (16 digits with spaces) - FIXED: Perfect coordination
+                let cc_mask = DisplayMask::new("#### #### #### ####", '#')
+                    .with_template('•');
+                Some(ValidationConfigBuilder::new()
+                    .with_display_mask(cc_mask)
+                    .with_max_length(16)  // ✅ CRITICAL: Exactly matches 16 input positions
+                    .build())
+            }
+            7 => {
+                // 🏢 Employee ID with business prefix
+                let emp_id = DisplayMask::new("EMP-####", '#');
+                Some(ValidationConfig::with_mask(emp_id))
+            }
+            8 => {
+                // 📦 Product Code with mixed letters and numbers
+                let product_code = DisplayMask::new("ABC###XYZ", '#');
+                Some(ValidationConfig::with_mask(product_code))
+            }
+            9 => {
+                // 🌈 Custom Separators - Using | and ~ as separators
+                let custom_sep = DisplayMask::new("##|##~####", '#')
+                    .with_template('?');
+                Some(ValidationConfig::with_mask(custom_sep))
+            }
+            10 => {
+                // ⭐ Custom Placeholders - Using different placeholder characters
+                let custom_placeholder = DisplayMask::new("##-##-##", '#')
+                    .with_template('★');
+                Some(ValidationConfig::with_mask(custom_placeholder))
+            }
+            11 => {
+                // 🎯 Mixed Input Characters - Using 'N' for numbers
+                let mixed_input = DisplayMask::new("ID:NNN-NNN", 'N');
+                Some(ValidationConfig::with_mask(mixed_input))
+            }
+            _ => None,
+        }
+    }
+}
+
+// Enhanced key handling with mask-specific commands
+fn handle_key_press(
+    key: KeyCode,
+    modifiers: KeyModifiers,
+    editor: &mut MaskDemoFormEditor<MaskDemoData>,
+) -> anyhow::Result<bool> {
+    let mode = editor.mode();
+
+    // Quit handling
+    if (key == KeyCode::Char('q') && modifiers.contains(KeyModifiers::CONTROL))
+        || (key == KeyCode::Char('c') && modifiers.contains(KeyModifiers::CONTROL))
+        || key == KeyCode::F(10)
+    {
+        return Ok(false);
+    }
+
+    match (mode, key, modifiers) {
+        // === MODE TRANSITIONS ===
+        (AppMode::ReadOnly, KeyCode::Char('i'), _) => {
+            editor.enter_edit_mode();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('a'), _) => {
+            editor.enter_append_mode();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('A'), _) => {
+            editor.move_line_end();
+            editor.enter_edit_mode();
+            editor.clear_command_buffer();
+        }
+
+        // Escape: Exit edit mode
+        (_, KeyCode::Esc, _) => {
+            if mode == AppMode::Edit {
+                editor.exit_edit_mode();
+            } else {
+                editor.clear_command_buffer();
+            }
+        }
+
+        // === MASK SPECIFIC COMMANDS ===
+        (AppMode::ReadOnly, KeyCode::Char('m'), _) => {
+            editor.show_mask_details();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('r'), _) => {
+            editor.toggle_raw_data_view();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::F(1), _) => {
+            editor.toggle_validation();
+        }
+
+        // === MOVEMENT ===
+        (AppMode::ReadOnly, KeyCode::Char('h'), _) | (AppMode::ReadOnly, KeyCode::Left, _) => {
+            editor.move_left();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('l'), _) | (AppMode::ReadOnly, KeyCode::Right, _) => {
+            editor.move_right();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('j'), _) | (AppMode::ReadOnly, KeyCode::Down, _) => {
+            editor.move_down();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('k'), _) | (AppMode::ReadOnly, KeyCode::Up, _) => {
+            editor.move_up();
+            editor.clear_command_buffer();
+        }
+
+        // Line movement
+        (AppMode::ReadOnly, KeyCode::Char('0'), _) => {
+            editor.move_line_start();
+            editor.clear_command_buffer();
+        }
+        (AppMode::ReadOnly, KeyCode::Char('$'), _) => {
+            editor.move_line_end();
+            editor.clear_command_buffer();
+        }
+
+        // === EDIT MODE MOVEMENT ===
+        (AppMode::Edit, KeyCode::Left, _) => { editor.move_left(); }
+        (AppMode::Edit, KeyCode::Right, _) => { editor.move_right(); }
+        (AppMode::Edit, KeyCode::Up, _) => { editor.move_up(); }
+        (AppMode::Edit, KeyCode::Down, _) => { editor.move_down(); }
+
+        // === DELETE OPERATIONS ===
+        (AppMode::Edit, KeyCode::Backspace, _) => { editor.delete_backward()?; }
+        (AppMode::Edit, KeyCode::Delete, _) => { editor.delete_forward()?; }
+
+        // === TAB NAVIGATION ===
+        (_, KeyCode::Tab, _) => { editor.next_field(); }
+        (_, KeyCode::BackTab, _) => { editor.prev_field(); }
+
+        // === CHARACTER INPUT ===
+        (AppMode::Edit, KeyCode::Char(c), m) if !m.contains(KeyModifiers::CONTROL) => {
+            editor.insert_char(c)?;
+        }
+
+        // === DEBUG/INFO COMMANDS ===
+        (AppMode::ReadOnly, KeyCode::Char('?'), _) => {
+            let (raw, display, mask_info) = editor.get_current_field_info();
+            editor.set_debug_message(format!(
+                "Field {}/{}, Cursor {}, {}, Raw: '{}', Display: '{}'",
+                editor.current_field() + 1,
+                editor.data_provider().field_count(),
+                editor.cursor_position(),
+                mask_info,
+                raw,
+                display
+            ));
+        }
+
+        _ => {
+            if editor.has_pending_command() {
+                editor.clear_command_buffer();
+                editor.set_debug_message("Invalid command sequence".to_string());
+            }
+        }
+    }
+
+    Ok(true)
+}
+
+fn run_app<B: Backend>(
+    terminal: &mut Terminal<B>,
+    mut editor: MaskDemoFormEditor<MaskDemoData>,
+) -> io::Result<()> {
+    loop {
+        terminal.draw(|f| ui(f, &editor))?;
+
+        if let Event::Key(key) = event::read()? {
+            match handle_key_press(key.code, key.modifiers, &mut editor) {
+                Ok(should_continue) => {
+                    if !should_continue {
+                        break;
+                    }
+                }
+                Err(e) => {
+                    editor.set_debug_message(format!("Error: {e}"));
+                }
+            }
+        }
+    }
+
+    Ok(())
+}
+
+fn ui(f: &mut Frame, editor: &MaskDemoFormEditor<MaskDemoData>) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Min(8), Constraint::Length(16)])
+        .split(f.area());
+
+    render_enhanced_canvas(f, chunks[0], editor);
+    render_mask_status(f, chunks[1], editor);
+}
+
+fn render_enhanced_canvas(
+    f: &mut Frame,
+    area: Rect,
+    editor: &MaskDemoFormEditor<MaskDemoData>,
+) {
+    render_canvas_default(f, area, &editor.editor);
+}
+
+fn render_mask_status(
+    f: &mut Frame,
+    area: Rect,
+    editor: &MaskDemoFormEditor<MaskDemoData>,
+) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([
+            Constraint::Length(3), // Status bar
+            Constraint::Length(6), // Data comparison
+            Constraint::Length(7), // Help
+        ])
+        .split(area);
+
+    // Status bar with mask information
+    let mode_text = match editor.mode() {
+        AppMode::Edit => "INSERT | (bar cursor)",
+        AppMode::ReadOnly => "NORMAL █ (block cursor)",
+        _ => "NORMAL █ (block cursor)",
+    };
+
+    let mask_status = editor.get_mask_status();
+    let status_text = format!("-- {} -- {} | Masks: {} | View: {}",
+                             mode_text,
+                             editor.debug_message(),
+                             mask_status,
+                             if editor.show_raw_data { "RAW" } else { "FORMATTED" });
+
+    let status = Paragraph::new(Line::from(Span::raw(status_text)))
+        .block(Block::default().borders(Borders::ALL).title("🎭 Display Mask Demo"));
+
+    f.render_widget(status, chunks[0]);
+
+    // Data comparison showing raw vs display
+    let (raw_data, display_data, mask_info) = editor.get_current_field_info();
+    let field_name = editor.data_provider().field_name(editor.current_field());
+
+    let comparison_text = format!(
+        "📝 Current Field: {}\n\
+         🔧 Mask Config: {}\n\
+         \n\
+         💾 Raw Business Data: '{}' ← What's actually stored in your database\n\
+         🎭 Formatted Display: '{}' ← What users see in the interface\n\
+         📍 Cursor: Raw pos {} → Display pos {}",
+        field_name,
+        mask_info,
+        raw_data,
+        display_data,
+        editor.cursor_position(),
+        editor.editor.display_cursor_position()
+    );
+
+    let comparison_style = if raw_data != display_data {
+        Style::default().fg(Color::Green) // Green when mask is active
+    } else {
+        Style::default().fg(Color::Gray) // Gray when no formatting
+    };
+
+    let data_comparison = Paragraph::new(comparison_text)
+        .block(Block::default().borders(Borders::ALL).title("📊 Raw Data vs Display Formatting"))
+        .style(comparison_style)
+        .wrap(Wrap { trim: true });
+
+    f.render_widget(data_comparison, chunks[1]);
+
+    // Enhanced help text
+    let help_text = match editor.mode() {
+        AppMode::ReadOnly => {
+            "🎯 CURSOR-STYLE: Normal █ | Insert |\n\
+             🎭 MASK DEMO: Visual formatting keeps business logic clean!\n\
+             \n\
+             📱 Try different fields to see various mask patterns:\n\
+             • Dynamic vs Template modes  • Custom separators  • Different input chars\n\
+             \n\
+             Commands: i/a=insert, m=mask details, r=toggle raw/display view\n\
+             Movement: hjkl/arrows=move, 0/$=line start/end, Tab=next field, F1=toggle masks\n\
+             ?=detailed info, Ctrl+C=quit"
+        }
+        AppMode::Edit => {
+            "🎯 INSERT MODE - Cursor: | (bar)\n\
+             ✏️ Type to see real-time mask formatting!\n\
+             \n\
+             🔥 Key Features in Action:\n\
+             • Separators auto-appear as you type  • Cursor skips over separators\n\
+             • Template fields show placeholders  • Raw data stays clean for business logic\n\
+             \n\
+             arrows=move through mask, Backspace/Del=delete, Esc=normal, Tab=next field\n\
+             Notice how cursor position maps between raw data and display!"
+        }
+        _ => "🎭 Display Mask Demo Active!"
+    };
+
+    let help = Paragraph::new(help_text)
+        .block(Block::default().borders(Borders::ALL).title("🚀 Mask Features & Commands"))
+        .style(Style::default().fg(Color::Gray))
+        .wrap(Wrap { trim: true });
+
+    f.render_widget(help, chunks[2]);
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    // Print feature status
+    println!("🎭 Canvas Display Mask Demo (Feature 3)");
+    println!("✅ validation feature: ENABLED");
+    println!("✅ gui feature: ENABLED");
+    println!("🎭 Display masks: ACTIVE");
+    println!("✅ cursor-style feature: ENABLED");
+    println!("🔥 Key Benefits Demonstrated:");
+    println!("   • Clean separation: Visual formatting ≠ Business logic");
+    println!("   • User-friendly: Pretty displays with automatic cursor handling");
+    println!("   • Flexible: Custom patterns, separators, and placeholders");
+    println!("   • Transparent: Library handles all complexity, API stays simple");
+    println!();
+    println!("💡 Try typing in different fields to see mask magic!");
+    println!("   📞 Phone fields show dynamic vs template modes");
+    println!("   📅 Date fields show different regional formats");
+    println!("   💳 Credit card shows spaced formatting");
+    println!("   ⭐ Custom fields show advanced separator/placeholder options");
+    println!();
+
+    enable_raw_mode()?;
+    let mut stdout = io::stdout();
+    execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
+    let backend = CrosstermBackend::new(stdout);
+    let mut terminal = Terminal::new(backend)?;
+
+    let data = MaskDemoData::new();
+    let mut editor = MaskDemoFormEditor::new(data);
+
+    // Initialize with normal mode - library automatically sets block cursor
+    editor.set_mode(AppMode::ReadOnly);
+
+    // Demonstrate that CursorManager is available and working
+    CursorManager::update_for_mode(AppMode::ReadOnly)?;
+
+    let res = run_app(&mut terminal, editor);
+
+    disable_raw_mode()?;
+    execute!(
+        terminal.backend_mut(),
+        LeaveAlternateScreen,
+        DisableMouseCapture
+    )?;
+    terminal.show_cursor()?;
+
+    // Library automatically resets cursor on FormEditor::drop()
+    // But we can also manually reset if needed
+    CursorManager::reset()?;
+
+    if let Err(err) = res {
+        println!("{err:?}");
+    }
+
+    println!("🎭 Display mask demo completed!");
+    println!("🏆 You've seen how masks provide beautiful UX while keeping business logic clean!");
+    Ok(())
+}

canvas/examples/validation_4.rs

@@ -0,0 +1,755 @@
+/* examples/validation_4.rs
+   Enhanced Feature 4 Demo: Multiple custom formatters with comprehensive edge cases
+
+   Demonstrates:
+   - Multiple formatter types: PSC, Phone, Credit Card, Date
+   - Edge case handling: incomplete input, invalid chars, overflow
+   - Real-time validation feedback and format preview
+   - Advanced cursor position mapping
+   - Raw vs formatted data separation
+   - Error handling and fallback behavior
+
+*/
+
+#![allow(clippy::needless_return)]
+
+#[cfg(not(all(feature = "validation", feature = "gui", feature = "cursor-style")))]
+compile_error!(
+    "This example requires the 'validation', 'gui' and 'cursor-style' features. \
+     Run with: cargo run --example validation_4 --features \"gui,validation,cursor-style\""
+);
+
+use std::io;
+use std::sync::Arc;
+
+use crossterm::{
+    event::{
+        self, DisableMouseCapture, EnableMouseCapture, Event, KeyCode, KeyModifiers,
+    },
+    execute,
+    terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
+};
+use ratatui::{
+    backend::{Backend, CrosstermBackend},
+    layout::{Constraint, Direction, Layout, Rect},
+    style::{Color, Style},
+    text::{Line, Span},
+    widgets::{Block, Borders, Paragraph, Wrap},
+    Frame, Terminal,
+};
+
+use canvas::{
+    canvas::{gui::render_canvas_default, modes::AppMode, CursorManager},
+    DataProvider, FormEditor,
+    ValidationConfig, ValidationConfigBuilder,
+    CustomFormatter, FormattingResult,
+};
+
+/// PSC (Postal Code) Formatter: "01001" -> "010 01"
+struct PSCFormatter;
+
+impl CustomFormatter for PSCFormatter {
+    fn format(&self, raw: &str) -> FormattingResult {
+        if raw.is_empty() {
+            return FormattingResult::success("");
+        }
+
+        // Validate: only digits allowed
+        if !raw.chars().all(|c| c.is_ascii_digit()) {
+            return FormattingResult::error("PSC must contain only digits");
+        }
+
+        let len = raw.chars().count();
+        match len {
+            0 => FormattingResult::success(""),
+            1..=3 => FormattingResult::success(raw),
+            4 => FormattingResult::warning(
+                format!("{} ", &raw[..3]),
+                "PSC incomplete (4/5 digits)"
+            ),
+            5 => {
+                let formatted = format!("{} {}", &raw[..3], &raw[3..]);
+                if raw == "00000" {
+                    FormattingResult::warning(formatted, "Invalid PSC: 00000")
+                } else {
+                    FormattingResult::success(formatted)
+                }
+            },
+            _ => FormattingResult::error("PSC too long (max 5 digits)"),
+        }
+    }
+}
+
+/// Phone Number Formatter: "1234567890" -> "(123) 456-7890"
+struct PhoneFormatter;
+
+impl CustomFormatter for PhoneFormatter {
+    fn format(&self, raw: &str) -> FormattingResult {
+        if raw.is_empty() {
+            return FormattingResult::success("");
+        }
+
+        // Only digits allowed
+        if !raw.chars().all(|c| c.is_ascii_digit()) {
+            return FormattingResult::error("Phone must contain only digits");
+        }
+
+        let len = raw.chars().count();
+        match len {
+            0 => FormattingResult::success(""),
+            1..=3 => FormattingResult::success(format!("({raw})")),
+            4..=6 => FormattingResult::success(format!("({}) {}", &raw[..3], &raw[3..])),
+            7..=10 => FormattingResult::success(format!("({}) {}-{}", &raw[..3], &raw[3..6], &raw[6..])),
+            10 => {
+                let formatted = format!("({}) {}-{}", &raw[..3], &raw[3..6], &raw[6..]);
+                FormattingResult::success(formatted)
+            },
+            _ => FormattingResult::warning(
+                format!("({}) {}-{}", &raw[..3], &raw[3..6], &raw[6..10]),
+                "Phone too long (extra digits ignored)"
+            ),
+        }
+    }
+}
+
+/// Credit Card Formatter: "1234567890123456" -> "1234 5678 9012 3456"
+struct CreditCardFormatter;
+
+impl CustomFormatter for CreditCardFormatter {
+    fn format(&self, raw: &str) -> FormattingResult {
+        if raw.is_empty() {
+            return FormattingResult::success("");
+        }
+
+        if !raw.chars().all(|c| c.is_ascii_digit()) {
+            return FormattingResult::error("Card number must contain only digits");
+        }
+
+        let mut formatted = String::new();
+        for (i, ch) in raw.chars().enumerate() {
+            if i > 0 && i % 4 == 0 {
+                formatted.push(' ');
+            }
+            formatted.push(ch);
+        }
+
+        let len = raw.chars().count();
+        match len {
+            0..=15 => FormattingResult::warning(formatted, format!("Card incomplete ({len}/16 digits)")),
+            16 => FormattingResult::success(formatted),
+            _ => FormattingResult::warning(formatted, "Card too long (extra digits shown)"),
+        }
+    }
+}
+
+
+
+
+
+
+/// Date Formatter: "12012024" -> "12/01/2024"
+struct DateFormatter;
+
+impl CustomFormatter for DateFormatter {
+    fn format(&self, raw: &str) -> FormattingResult {
+        if raw.is_empty() {
+            return FormattingResult::success("");
+        }
+
+        if !raw.chars().all(|c| c.is_ascii_digit()) {
+            return FormattingResult::error("Date must contain only digits");
+        }
+
+        let len = raw.len();
+        match len {
+            0 => FormattingResult::success(""),
+            1..=2 => FormattingResult::success(raw.to_string()),
+            3..=4 => FormattingResult::success(format!("{}/{}", &raw[..2], &raw[2..])),
+            5..=8 => FormattingResult::success(format!("{}/{}/{}", &raw[..2], &raw[2..4], &raw[4..])),
+            8 => {
+                let month = &raw[..2];
+                let day = &raw[2..4];
+                let year = &raw[4..];
+
+                // Basic validation
+                let m: u32 = month.parse().unwrap_or(0);
+                let d: u32 = day.parse().unwrap_or(0);
+
+                if m == 0 || m > 12 {
+                    FormattingResult::warning(
+                        format!("{month}/{day}/{year}"),
+                        "Invalid month (01-12)"
+                    )
+                } else if d == 0 || d > 31 {
+                    FormattingResult::warning(
+                        format!("{month}/{day}/{year}"),
+                        "Invalid day (01-31)"
+                    )
+                } else {
+                    FormattingResult::success(format!("{month}/{day}/{year}"))
+                }
+            },
+            _ => FormattingResult::error("Date too long (MMDDYYYY format)"),
+        }
+    }
+}
+
+// Enhanced demo data with multiple formatter types
+struct MultiFormatterDemoData {
+    fields: Vec<(String, String)>,
+}
+
+impl MultiFormatterDemoData {
+    fn new() -> Self {
+        Self {
+            fields: vec![
+                ("🏁 PSC (01001)".to_string(), "".to_string()),
+                ("📞 Phone (1234567890)".to_string(), "".to_string()),
+                ("💳 Credit Card (16 digits)".to_string(), "".to_string()),
+                ("📅 Date (12012024)".to_string(), "".to_string()),
+                ("📝 Plain Text".to_string(), "".to_string()),
+            ],
+        }
+    }
+}
+
+impl DataProvider for MultiFormatterDemoData {
+    fn field_count(&self) -> usize {
+        self.fields.len()
+    }
+
+    fn field_name(&self, index: usize) -> &str {
+        &self.fields[index].0
+    }
+
+    fn field_value(&self, index: usize) -> &str {
+        &self.fields[index].1
+    }
+
+    fn set_field_value(&mut self, index: usize, value: String) {
+        self.fields[index].1 = value;
+    }
+
+    #[cfg(feature = "validation")]
+    fn validation_config(&self, field_index: usize) -> Option<ValidationConfig> {
+        match field_index {
+            0 => Some(ValidationConfigBuilder::new()
+                .with_custom_formatter(Arc::new(PSCFormatter))
+                .with_max_length(5)
+                .build()),
+            1 => Some(ValidationConfigBuilder::new()
+                .with_custom_formatter(Arc::new(PhoneFormatter))
+                .with_max_length(12)
+                .build()),
+            2 => Some(ValidationConfigBuilder::new()
+                .with_custom_formatter(Arc::new(CreditCardFormatter))
+                .with_max_length(20)
+                .build()),
+            3 => Some(ValidationConfigBuilder::new()
+                .with_custom_formatter(Arc::new(DateFormatter))
+                .with_max_length(8)
+                .build()),
+            4 => Some(ValidationConfigBuilder::new()
+                .with_custom_formatter(Arc::new(DateFormatter))
+                .with_max_length(8)
+                .build()),
+            _ => None, // Plain text field - no formatter
+        }
+    }
+}
+
+// Enhanced demo editor with comprehensive status tracking
+struct EnhancedDemoEditor<D: DataProvider> {
+    editor: FormEditor<D>,
+    debug_message: String,
+    validation_enabled: bool,
+    show_raw_data: bool,
+    show_cursor_details: bool,
+    example_mode: usize,
+}
+
+impl<D: DataProvider> EnhancedDemoEditor<D> {
+    fn new(data_provider: D) -> Self {
+        let mut editor = FormEditor::new(data_provider);
+        editor.set_validation_enabled(true);
+
+        Self {
+            editor,
+            debug_message: "🧩 Enhanced Custom Formatter Demo - Multiple formatters with rich edge cases!".to_string(),
+            validation_enabled: true,
+            show_raw_data: false,
+            show_cursor_details: false,
+            example_mode: 0,
+        }
+    }
+
+    // Field type detection
+    fn current_field_type(&self) -> &'static str {
+        match self.editor.current_field() {
+            0 => "PSC",
+            1 => "Phone",
+            2 => "Credit Card",
+            3 => "Date",
+            _ => "Plain Text",
+        }
+    }
+
+    fn has_formatter(&self) -> bool {
+        self.editor.current_field() < 5 // First 5 fields have formatters
+    }
+
+    fn get_input_rules(&self) -> &'static str {
+        match self.editor.current_field() {
+            0 => "5 digits only (PSC format)",
+            1 => "10+ digits (US phone format)",
+            2 => "16+ digits (credit card)",
+            3 => "Digits as cents (12345 = $123.45)",
+            4 => "8 digits MMDDYYYY (date format)",
+            _ => "Any text (no formatting)",
+        }
+    }
+
+    fn cycle_example_data(&mut self) {
+        let examples = [
+            // PSC examples
+            vec!["01001", "1234567890", "1234567890123456", "12345", "12012024", "Plain text here"],
+            // Incomplete examples
+            vec!["010", "123", "1234", "123", "1201", "More text"],
+            // Invalid examples (will show error handling)
+            vec!["0abc1", "12a45", "123abc", "abc", "ab01cd", "Special chars!"],
+            // Edge cases
+            vec!["00000", "0000000000", "0000000000000000", "99", "13012024", ""],
+        ];
+
+        self.example_mode = (self.example_mode + 1) % examples.len();
+        let current_examples = &examples[self.example_mode];
+
+        for (i, example) in current_examples.iter().enumerate() {
+            if i < self.editor.data_provider().field_count() {
+                self.editor.data_provider_mut().set_field_value(i, example.to_string());
+            }
+        }
+
+        let mode_names = ["Valid Examples", "Incomplete Input", "Invalid Characters", "Edge Cases"];
+        self.debug_message = format!("📋 Loaded: {}", mode_names[self.example_mode]);
+    }
+
+    // Enhanced status methods
+    fn toggle_validation(&mut self) {
+        self.validation_enabled = !self.validation_enabled;
+        self.editor.set_validation_enabled(self.validation_enabled);
+        self.debug_message = if self.validation_enabled {
+            "✅ Custom Formatters ENABLED".to_string()
+        } else {
+            "❌ Custom Formatters DISABLED".to_string()
+        };
+    }
+
+    fn toggle_raw_data_view(&mut self) {
+        self.show_raw_data = !self.show_raw_data;
+        self.debug_message = if self.show_raw_data {
+            "👁️ Showing RAW data focus".to_string()
+        } else {
+            "✨ Showing FORMATTED display focus".to_string()
+        };
+    }
+
+    fn toggle_cursor_details(&mut self) {
+        self.show_cursor_details = !self.show_cursor_details;
+        self.debug_message = if self.show_cursor_details {
+            "📍 Detailed cursor mapping info ON".to_string()
+        } else {
+            "📍 Detailed cursor mapping info OFF".to_string()
+        };
+    }
+
+    fn get_current_field_analysis(&self) -> (String, String, String, Option<String>) {
+        let field_index = self.editor.current_field();
+        let raw = self.editor.data_provider().field_value(field_index);
+        let display = self.editor.current_display_text();
+
+        let status = if raw == display {
+            if self.has_formatter() {
+                if self.mode() == AppMode::Edit {
+                    "Raw (editing)".to_string()
+                } else {
+                    "No formatting needed".to_string()
+                }
+            } else {
+                "No formatter".to_string()
+            }
+        } else {
+            "Custom formatted".to_string()
+        };
+
+        let warning = if self.validation_enabled && self.has_formatter() {
+            // Check if there are any formatting warnings
+            if !raw.is_empty() {
+                match self.editor.current_field() {
+                    0 if raw.len() < 5 => Some(format!("PSC incomplete: {}/5", raw.len())),
+                    1 if raw.len() < 10 => Some(format!("Phone incomplete: {}/10", raw.len())),
+                    2 if raw.len() < 16 => Some(format!("Card incomplete: {}/16", raw.len())),
+                    4 if raw.len() < 8 => Some(format!("Date incomplete: {}/8", raw.len())),
+                    _ => None,
+                }
+            } else {
+                None
+            }
+        } else {
+            None
+        };
+
+        (raw.to_string(), display, status, warning)
+    }
+
+    // Delegate methods with enhanced feedback
+    fn enter_edit_mode(&mut self) {
+        // Library will automatically update cursor to bar | in insert mode
+        self.editor.enter_edit_mode();
+        let field_type = self.current_field_type();
+        let rules = self.get_input_rules();
+        self.debug_message = format!("✏️ INSERT MODE - Cursor: Steady Bar | - {field_type} - {rules}");
+    }
+
+    fn exit_edit_mode(&mut self) {
+        // Library will automatically update cursor to block █ in normal mode
+        self.editor.exit_edit_mode();
+        let (raw, display, _, warning) = self.get_current_field_analysis();
+        if let Some(warn) = warning {
+            self.debug_message = format!("🔒 NORMAL - Cursor: Steady Block █ - {} | ⚠️ {}", self.current_field_type(), warn);
+        } else if raw != display {
+            self.debug_message = format!("🔒 NORMAL - Cursor: Steady Block █ - {} formatted successfully", self.current_field_type());
+        } else {
+            self.debug_message = "🔒 NORMAL MODE - Cursor: Steady Block █".to_string();
+        }
+    }
+
+    fn insert_char(&mut self, ch: char) -> anyhow::Result<()> {
+        let result = self.editor.insert_char(ch);
+        if result.is_ok() {
+            let (raw, display, _, _) = self.get_current_field_analysis();
+            if raw != display && self.validation_enabled {
+                self.debug_message = format!("✏️ '{ch}' added - Real-time formatting active");
+            } else {
+                self.debug_message = format!("✏️ '{ch}' added");
+            }
+        }
+        result
+    }
+
+    // Position mapping demo
+    fn show_position_mapping(&mut self) {
+        if !self.has_formatter() {
+            self.debug_message = "📍 No position mapping (plain text field)".to_string();
+            return;
+        }
+
+        let raw_pos = self.editor.cursor_position();
+        let display_pos = self.editor.display_cursor_position();
+        let field_index = self.editor.current_field();
+        let raw = self.editor.data_provider().field_value(field_index);
+        let display = self.editor.current_display_text();
+
+        if raw_pos != display_pos {
+            self.debug_message = format!(
+                "🗺️ Position mapping: Raw[{}]='{}' ↔ Display[{}]='{}'",
+                raw_pos,
+                raw.chars().nth(raw_pos).unwrap_or('∅'),
+                display_pos,
+                display.chars().nth(display_pos).unwrap_or('∅')
+            );
+        } else {
+            self.debug_message = format!("📍 Cursor at position {raw_pos} (no mapping needed)");
+        }
+    }
+
+    // Delegate remaining methods
+    fn mode(&self) -> AppMode { self.editor.mode() }
+    fn current_field(&self) -> usize { self.editor.current_field() }
+    fn cursor_position(&self) -> usize { self.editor.cursor_position() }
+    fn data_provider(&self) -> &D { self.editor.data_provider() }
+    fn data_provider_mut(&mut self) -> &mut D { self.editor.data_provider_mut() }
+    fn ui_state(&self) -> &canvas::EditorState { self.editor.ui_state() }
+
+    fn move_up(&mut self) { let _ = self.editor.move_up(); }
+    fn move_down(&mut self) { let _ = self.editor.move_down(); }
+    fn move_left(&mut self) { let _ = self.editor.move_left(); }
+    fn move_right(&mut self) { let _ = self.editor.move_right(); }
+    fn delete_backward(&mut self) -> anyhow::Result<()> { self.editor.delete_backward() }
+    fn delete_forward(&mut self) -> anyhow::Result<()> { self.editor.delete_forward() }
+    fn next_field(&mut self) { let _ = self.editor.next_field(); }
+    fn prev_field(&mut self) { let _ = self.editor.prev_field(); }
+}
+
+// Enhanced key handling
+fn handle_key_press(
+    key: KeyCode,
+    modifiers: KeyModifiers,
+    editor: &mut EnhancedDemoEditor<MultiFormatterDemoData>,
+) -> anyhow::Result<bool> {
+    let mode = editor.mode();
+
+    // Quit
+    if matches!(key, KeyCode::F(10)) ||
+       (key == KeyCode::Char('q') && modifiers.contains(KeyModifiers::CONTROL)) ||
+       (key == KeyCode::Char('c') && modifiers.contains(KeyModifiers::CONTROL)) {
+        return Ok(false);
+    }
+
+    match (mode, key, modifiers) {
+        // Mode transitions
+        (AppMode::ReadOnly, KeyCode::Char('i'), _) => editor.enter_edit_mode(),
+        (AppMode::ReadOnly, KeyCode::Char('a'), _) => {
+            editor.editor.enter_append_mode();
+            editor.debug_message = format!("✏️ APPEND {} - {}", editor.current_field_type(), editor.get_input_rules());
+        },
+        (_, KeyCode::Esc, _) => editor.exit_edit_mode(),
+
+        // Enhanced demo features
+        (AppMode::ReadOnly, KeyCode::Char('e'), _) => editor.cycle_example_data(),
+        (AppMode::ReadOnly, KeyCode::Char('r'), _) => editor.toggle_raw_data_view(),
+        (AppMode::ReadOnly, KeyCode::Char('c'), _) => editor.toggle_cursor_details(),
+        (AppMode::ReadOnly, KeyCode::Char('m'), _) => editor.show_position_mapping(),
+        (AppMode::ReadOnly, KeyCode::F(1), _) => editor.toggle_validation(),
+
+        // Movement
+        (_, KeyCode::Up, _) | (AppMode::ReadOnly, KeyCode::Char('k'), _) => editor.move_up(),
+        (_, KeyCode::Down, _) | (AppMode::ReadOnly, KeyCode::Char('j'), _) => editor.move_down(),
+        (_, KeyCode::Left, _) | (AppMode::ReadOnly, KeyCode::Char('h'), _) => editor.move_left(),
+        (_, KeyCode::Right, _) | (AppMode::ReadOnly, KeyCode::Char('l'), _) => editor.move_right(),
+        (_, KeyCode::Tab, _) => editor.next_field(),
+        (_, KeyCode::BackTab, _) => editor.prev_field(),
+
+        // Editing
+        (AppMode::Edit, KeyCode::Char(c), m) if !m.contains(KeyModifiers::CONTROL) => {
+            editor.insert_char(c)?;
+        },
+        (AppMode::Edit, KeyCode::Backspace, _) => { editor.delete_backward()?; },
+        (AppMode::Edit, KeyCode::Delete, _) => { editor.delete_forward()?; },
+
+        // Field analysis
+        (AppMode::ReadOnly, KeyCode::Char('?'), _) => {
+            let (raw, display, status, warning) = editor.get_current_field_analysis();
+            let warning_text = warning.map(|w| format!(" ⚠️ {w}")).unwrap_or_default();
+            editor.debug_message = format!(
+                "🔍 Field {}: {} | Raw: '{}' | Display: '{}'{}",
+                editor.current_field() + 1, status, raw, display, warning_text
+            );
+        },
+
+        _ => {}
+    }
+
+    Ok(true)
+}
+
+fn run_app<B: Backend>(
+    terminal: &mut Terminal<B>,
+    mut editor: EnhancedDemoEditor<MultiFormatterDemoData>,
+) -> io::Result<()> {
+    loop {
+        terminal.draw(|f| ui(f, &editor))?;
+
+        if let Event::Key(key) = event::read()? {
+            match handle_key_press(key.code, key.modifiers, &mut editor) {
+                Ok(should_continue) => {
+                    if !should_continue {
+                        break;
+                    }
+                }
+                Err(e) => {
+                    editor.debug_message = format!("❌ Error: {e}");
+                }
+            }
+        }
+    }
+    Ok(())
+}
+
+fn ui(f: &mut Frame, editor: &EnhancedDemoEditor<MultiFormatterDemoData>) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Min(8), Constraint::Length(18)])
+        .split(f.area());
+
+    render_canvas_default(f, chunks[0], &editor.editor);
+    render_enhanced_status(f, chunks[1], editor);
+}
+
+fn render_enhanced_status(
+    f: &mut Frame,
+    area: Rect,
+    editor: &EnhancedDemoEditor<MultiFormatterDemoData>,
+) {
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([
+            Constraint::Length(3),  // Status bar
+            Constraint::Length(6),  // Current field analysis
+            Constraint::Length(9),  // Help
+        ])
+        .split(area);
+
+    // Status bar
+    let mode_text = match editor.mode() {
+        AppMode::Edit => "INSERT | (bar cursor)",
+        AppMode::ReadOnly => "NORMAL █ (block cursor)",
+        _ => "NORMAL █ (block cursor)",
+    };
+
+    let formatter_count = (0..editor.data_provider().field_count())
+        .filter(|&i| editor.data_provider().validation_config(i).is_some())
+        .count();
+
+    let status_text = format!(
+        "-- {} -- {} | Formatters: {}/{} active | View: {}{}",
+        mode_text,
+        editor.debug_message,
+        formatter_count,
+        editor.data_provider().field_count(),
+        if editor.show_raw_data { "RAW" } else { "DISPLAY" },
+        if editor.show_cursor_details { " | CURSOR+" } else { "" }
+    );
+
+    let status = Paragraph::new(Line::from(Span::raw(status_text)))
+        .block(Block::default().borders(Borders::ALL).title("🧩 Enhanced Custom Formatter Demo"));
+
+    f.render_widget(status, chunks[0]);
+
+    // Current field analysis
+    let (raw, display, status, warning) = editor.get_current_field_analysis();
+    let field_name = editor.data_provider().field_name(editor.current_field());
+    let field_type = editor.current_field_type();
+
+    let mut analysis_lines = vec![
+        format!("📝 Current: {} ({})", field_name, field_type),
+        format!("🔧 Status: {}", status),
+    ];
+
+    if editor.show_raw_data || editor.mode() == AppMode::Edit {
+        analysis_lines.push(format!("💾 Raw Data: '{raw}'"));
+        analysis_lines.push(format!("✨ Display: '{display}'"));
+    } else {
+        analysis_lines.push(format!("✨ User Sees: '{display}'"));
+        analysis_lines.push(format!("💾 Stored As: '{raw}'"));
+    }
+
+    if editor.show_cursor_details {
+        analysis_lines.push(format!(
+            "📍 Cursor: Raw[{}] → Display[{}]",
+            editor.cursor_position(),
+            editor.editor.display_cursor_position()
+        ));
+    }
+
+    if let Some(ref warn) = warning {
+        analysis_lines.push(format!("⚠️ Warning: {warn}"));
+    }
+
+    let analysis_color = if warning.is_some() {
+        Color::Yellow
+    } else if raw != display && editor.validation_enabled {
+        Color::Green
+    } else {
+        Color::Gray
+    };
+
+    let analysis = Paragraph::new(analysis_lines.join("\n"))
+        .block(Block::default().borders(Borders::ALL).title("🔍 Field Analysis"))
+        .style(Style::default().fg(analysis_color))
+        .wrap(Wrap { trim: true });
+
+    f.render_widget(analysis, chunks[1]);
+
+    // Enhanced help
+    let help_text = match editor.mode() {
+        AppMode::ReadOnly => {
+            "🎯 CURSOR-STYLE: Normal █ | Insert |\n\
+             🧩 ENHANCED CUSTOM FORMATTER DEMO\n\
+             \n\
+             Try these formatters:
+             • PSC: 01001 → 010 01 | Phone: 1234567890 → (123) 456-7890 | Card: 1234567890123456 → 1234 5678 9012 3456
+             • Date: 12012024 → 12/01/2024 | Plain: no formatting
+             \n\
+             Commands: i=insert, e=cycle examples, r=toggle raw/display, c=cursor details, m=position mapping\n\
+             Movement: hjkl/arrows, Tab=next field, ?=analyze current field, F1=toggle formatters\n\
+             Ctrl+C/F10=quit"
+        }
+        AppMode::Edit => {
+            "🎯 INSERT MODE - Cursor: | (bar)\n\
+             ✏️ Real-time formatting as you type!\n\
+             \n\
+             Current field rules: {}\n\
+             • Raw input is authoritative (what gets stored)\n\
+             • Display formatting updates in real-time (what users see)\n\
+             • Cursor position is mapped between raw and display\n\
+             \n\
+             Esc=normal mode, arrows=navigate, Backspace/Del=delete"
+        }
+        _ => "🧩 Enhanced Custom Formatter Demo"
+    };
+
+    let formatted_help = if editor.mode() == AppMode::Edit {
+        help_text.replace("{}", editor.get_input_rules())
+    } else {
+        help_text.to_string()
+    };
+
+    let help = Paragraph::new(formatted_help)
+        .block(Block::default().borders(Borders::ALL).title("🚀 Enhanced Features & Commands"))
+        .style(Style::default().fg(Color::Gray))
+        .wrap(Wrap { trim: true });
+
+    f.render_widget(help, chunks[2]);
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    println!("🧩 Enhanced Canvas Custom Formatter Demo (Feature 4)");
+    println!("✅ validation feature: ENABLED");
+    println!("✅ gui feature: ENABLED");
+    println!("✅ cursor-style feature: ENABLED");
+    println!("🧩 Enhanced features:");
+    println!("   • 5 different custom formatters with edge cases");
+    println!("   • Real-time format preview and validation");
+    println!("   • Advanced cursor position mapping");
+    println!("   • Comprehensive error handling and warnings");
+    println!("   • Raw vs formatted data separation demos");
+    println!();
+
+    enable_raw_mode()?;
+    let mut stdout = io::stdout();
+    execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
+    let backend = CrosstermBackend::new(stdout);
+    let mut terminal = Terminal::new(backend)?;
+
+    let data = MultiFormatterDemoData::new();
+    let mut editor = EnhancedDemoEditor::new(data);
+
+    // Initialize with normal mode - library automatically sets block cursor
+    editor.editor.set_mode(AppMode::ReadOnly);
+
+    // Demonstrate that CursorManager is available and working
+    CursorManager::update_for_mode(AppMode::ReadOnly)?;
+
+    let res = run_app(&mut terminal, editor);
+
+    disable_raw_mode()?;
+    execute!(terminal.backend_mut(), LeaveAlternateScreen, DisableMouseCapture)?;
+    terminal.show_cursor()?;
+
+    // Library automatically resets cursor on FormEditor::drop()
+    // But we can also manually reset if needed
+    CursorManager::reset()?;
+
+    if let Err(err) = res {
+        println!("{err:?}");
+    }
+
+    println!("🧩 Enhanced custom formatter demo completed!");
+    println!("🏆 You experienced comprehensive custom formatting with:");
+    println!("   • Multiple formatter types (PSC, Phone, Credit Card, Date)");
+    println!("   • Edge case handling (incomplete, invalid, overflow)");
+    println!("   • Real-time format preview and cursor mapping");
+    println!("   • Clear separation between raw business data and display formatting");
+    Ok(())
+}

canvas/integration_patterns.rs

@@ -0,0 +1,620 @@
+// examples/integration_patterns.rs
+//! Advanced integration patterns showing how Canvas works with:
+//! - State management patterns
+//! - Event-driven architectures
+//! - Validation systems
+//! - Custom rendering
+//!
+//! Run with: cargo run --example integration_patterns
+
+use canvas::prelude::*;
+use std::collections::HashMap;
+
+#[tokio::main]
+async fn main() {
+    println!("🔧 Canvas Integration Patterns");
+    println!("==============================\n");
+
+    // Pattern 1: State machine integration
+    state_machine_example().await;
+
+    // Pattern 2: Event-driven architecture
+    event_driven_example().await;
+
+    // Pattern 3: Validation pipeline
+    validation_pipeline_example().await;
+
+    // Pattern 4: Multi-form orchestration
+    multi_form_example().await;
+}
+
+// Pattern 1: Canvas with state machine
+async fn state_machine_example() {
+    println!("🔄 Pattern 1: State Machine Integration");
+
+    #[derive(Debug, Clone, PartialEq)]
+    enum FormState {
+        Initial,
+        Editing,
+        Validating,
+        Submitting,
+        Success,
+        Error(String),
+    }
+
+    #[derive(Debug)]
+    struct StateMachineForm {
+        // Canvas state
+        current_field: usize,
+        cursor_pos: usize,
+        username: String,
+        password: String,
+        has_changes: bool,
+
+        // State machine
+        state: FormState,
+    }
+
+    impl StateMachineForm {
+        fn new() -> Self {
+            Self {
+                current_field: 0,
+                cursor_pos: 0,
+                username: String::new(),
+                password: String::new(),
+                has_changes: false,
+                state: FormState::Initial,
+            }
+        }
+
+        fn transition_to(&mut self, new_state: FormState) -> String {
+            let old_state = self.state.clone();
+            self.state = new_state;
+            format!("State transition: {:?} -> {:?}", old_state, self.state)
+        }
+
+        fn can_submit(&self) -> bool {
+            matches!(self.state, FormState::Editing) &&
+            !self.username.trim().is_empty() &&
+            !self.password.trim().is_empty()
+        }
+    }
+
+    impl CanvasState for StateMachineForm {
+        fn current_field(&self) -> usize { self.current_field }
+        fn current_cursor_pos(&self) -> usize { self.cursor_pos }
+        fn set_current_field(&mut self, index: usize) { self.current_field = index.min(1); }
+        fn set_current_cursor_pos(&mut self, pos: usize) { self.cursor_pos = pos; }
+
+        fn get_current_input(&self) -> &str {
+            match self.current_field {
+                0 => &self.username,
+                1 => &self.password,
+                _ => "",
+            }
+        }
+
+        fn get_current_input_mut(&mut self) -> &mut String {
+            match self.current_field {
+                0 => &mut self.username,
+                1 => &mut self.password,
+                _ => unreachable!(),
+            }
+        }
+
+        fn inputs(&self) -> Vec<&String> { vec![&self.username, &self.password] }
+        fn fields(&self) -> Vec<&str> { vec!["Username", "Password"] }
+        fn has_unsaved_changes(&self) -> bool { self.has_changes }
+
+        fn set_has_unsaved_changes(&mut self, changed: bool) {
+            self.has_changes = changed;
+            // Transition to editing state when user starts typing
+            if changed && self.state == FormState::Initial {
+                self.state = FormState::Editing;
+            }
+        }
+
+        fn handle_feature_action(&mut self, action: &CanvasAction, context: &ActionContext) -> Option<String> {
+            match action {
+                CanvasAction::Custom(cmd) => match cmd.as_str() {
+                    "submit" => {
+                        if self.can_submit() {
+                            let msg = self.transition_to(FormState::Submitting);
+                            // Simulate submission
+                            self.state = FormState::Success;
+                            Some(format!("{} -> Form submitted successfully", msg))
+                        } else {
+                            let msg = self.transition_to(FormState::Error("Invalid form data".to_string()));
+                            Some(msg)
+                        }
+                    }
+                    "reset" => {
+                        self.username.clear();
+                        self.password.clear();
+                        self.has_changes = false;
+                        Some(self.transition_to(FormState::Initial))
+                    }
+                    _ => None,
+                },
+                _ => None,
+            }
+        }
+    }
+
+    let mut form = StateMachineForm::new();
+    let mut ideal_cursor = 0;
+
+    println!("  Initial state: {:?}", form.state);
+
+    // Type some text to trigger state change
+    let result = ActionDispatcher::dispatch(
+        CanvasAction::InsertChar('u'),
+        &mut form,
+        &mut ideal_cursor,
+    ).await.unwrap();
+    println!("  After typing: {:?}", form.state);
+
+    // Try to submit (should fail)
+    let result = ActionDispatcher::dispatch(
+        CanvasAction::Custom("submit".to_string()),
+        &mut form,
+        &mut ideal_cursor,
+    ).await.unwrap();
+    println!("  Submit result: {}", result.message().unwrap_or(""));
+    println!("  ✅ State machine integration works!\n");
+}
+
+// Pattern 2: Event-driven architecture
+async fn event_driven_example() {
+    println!("📡 Pattern 2: Event-Driven Architecture");
+
+    #[derive(Debug, Clone)]
+    enum FormEvent {
+        FieldChanged { field: usize, old_value: String, new_value: String },
+        ValidationTriggered { field: usize, is_valid: bool },
+        ActionExecuted { action: String, success: bool },
+    }
+
+    #[derive(Debug)]
+    struct EventDrivenForm {
+        current_field: usize,
+        cursor_pos: usize,
+        email: String,
+        has_changes: bool,
+        events: Vec<FormEvent>,
+    }
+
+    impl EventDrivenForm {
+        fn new() -> Self {
+            Self {
+                current_field: 0,
+                cursor_pos: 0,
+                email: String::new(),
+                has_changes: false,
+                events: Vec::new(),
+            }
+        }
+
+        fn emit_event(&mut self, event: FormEvent) {
+            println!("  📡 Event: {:?}", event);
+            self.events.push(event);
+        }
+
+        fn validate_email(&self) -> bool {
+            self.email.contains('@') && self.email.contains('.')
+        }
+    }
+
+    impl CanvasState for EventDrivenForm {
+        fn current_field(&self) -> usize { self.current_field }
+        fn current_cursor_pos(&self) -> usize { self.cursor_pos }
+        fn set_current_field(&mut self, index: usize) { self.current_field = index; }
+        fn set_current_cursor_pos(&mut self, pos: usize) { self.cursor_pos = pos; }
+
+        fn get_current_input(&self) -> &str { &self.email }
+        fn get_current_input_mut(&mut self) -> &mut String { &mut self.email }
+        fn inputs(&self) -> Vec<&String> { vec![&self.email] }
+        fn fields(&self) -> Vec<&str> { vec!["Email"] }
+        fn has_unsaved_changes(&self) -> bool { self.has_changes }
+
+        fn set_has_unsaved_changes(&mut self, changed: bool) {
+            if changed != self.has_changes {
+                let old_value = if self.has_changes { "modified" } else { "unmodified" };
+                let new_value = if changed { "modified" } else { "unmodified" };
+
+                self.emit_event(FormEvent::FieldChanged {
+                    field: self.current_field,
+                    old_value: old_value.to_string(),
+                    new_value: new_value.to_string(),
+                });
+            }
+            self.has_changes = changed;
+        }
+
+        fn handle_feature_action(&mut self, action: &CanvasAction, context: &ActionContext) -> Option<String> {
+            match action {
+                CanvasAction::Custom(cmd) => match cmd.as_str() {
+                    "validate" => {
+                        let is_valid = self.validate_email();
+                        self.emit_event(FormEvent::ValidationTriggered {
+                            field: self.current_field,
+                            is_valid,
+                        });
+
+                        self.emit_event(FormEvent::ActionExecuted {
+                            action: "validate".to_string(),
+                            success: true,
+                        });
+
+                        if is_valid {
+                            Some("Email is valid!".to_string())
+                        } else {
+                            Some("Email is invalid".to_string())
+                        }
+                    }
+                    _ => None,
+                },
+                _ => None,
+            }
+        }
+    }
+
+    let mut form = EventDrivenForm::new();
+    let mut ideal_cursor = 0;
+
+    // Type an email address
+    let email = "user@example.com";
+    for c in email.chars() {
+        ActionDispatcher::dispatch(
+            CanvasAction::InsertChar(c),
+            &mut form,
+            &mut ideal_cursor,
+        ).await.unwrap();
+    }
+
+    // Validate the email
+    let result = ActionDispatcher::dispatch(
+        CanvasAction::Custom("validate".to_string()),
+        &mut form,
+        &mut ideal_cursor,
+    ).await.unwrap();
+
+    println!("  Final email: {}", form.email);
+    println!("  Validation result: {}", result.message().unwrap_or(""));
+    println!("  Total events captured: {}", form.events.len());
+    println!("  ✅ Event-driven architecture works!\n");
+}
+
+// Pattern 3: Validation pipeline
+async fn validation_pipeline_example() {
+    println!("✅ Pattern 3: Validation Pipeline");
+
+    type ValidationRule = Box<dyn Fn(&str) -> Result<(), String>>;
+
+    // Custom Debug implementation since function pointers don't implement Debug
+    struct ValidatedForm {
+        current_field: usize,
+        cursor_pos: usize,
+        password: String,
+        has_changes: bool,
+        validators: HashMap<usize, Vec<ValidationRule>>,
+    }
+
+    impl std::fmt::Debug for ValidatedForm {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            f.debug_struct("ValidatedForm")
+                .field("current_field", &self.current_field)
+                .field("cursor_pos", &self.cursor_pos)
+                .field("password", &self.password)
+                .field("has_changes", &self.has_changes)
+                .field("validators", &format!("HashMap with {} entries", self.validators.len()))
+                .finish()
+        }
+    }
+
+    impl ValidatedForm {
+        fn new() -> Self {
+            let mut validators: HashMap<usize, Vec<ValidationRule>> = HashMap::new();
+
+            // Password validators
+            let mut password_validators: Vec<ValidationRule> = Vec::new();
+            password_validators.push(Box::new(|value| {
+                if value.len() < 8 {
+                    Err("Password must be at least 8 characters".to_string())
+                } else {
+                    Ok(())
+                }
+            }));
+            password_validators.push(Box::new(|value| {
+                if !value.chars().any(|c| c.is_uppercase()) {
+                    Err("Password must contain at least one uppercase letter".to_string())
+                } else {
+                    Ok(())
+                }
+            }));
+            password_validators.push(Box::new(|value| {
+                if !value.chars().any(|c| c.is_numeric()) {
+                    Err("Password must contain at least one number".to_string())
+                } else {
+                    Ok(())
+                }
+            }));
+
+            validators.insert(0, password_validators);
+
+            Self {
+                current_field: 0,
+                cursor_pos: 0,
+                password: String::new(),
+                has_changes: false,
+                validators,
+            }
+        }
+
+        fn validate_field(&self, field_index: usize) -> Vec<String> {
+            let mut errors = Vec::new();
+
+            if let Some(validators) = self.validators.get(&field_index) {
+                let value = match field_index {
+                    0 => &self.password,
+                    _ => return errors,
+                };
+
+                for validator in validators {
+                    if let Err(error) = validator(value) {
+                        errors.push(error);
+                    }
+                }
+            }
+
+            errors
+        }
+    }
+
+    impl CanvasState for ValidatedForm {
+        fn current_field(&self) -> usize { self.current_field }
+        fn current_cursor_pos(&self) -> usize { self.cursor_pos }
+        fn set_current_field(&mut self, index: usize) { self.current_field = index; }
+        fn set_current_cursor_pos(&mut self, pos: usize) { self.cursor_pos = pos; }
+
+        fn get_current_input(&self) -> &str { &self.password }
+        fn get_current_input_mut(&mut self) -> &mut String { &mut self.password }
+        fn inputs(&self) -> Vec<&String> { vec![&self.password] }
+        fn fields(&self) -> Vec<&str> { vec!["Password"] }
+        fn has_unsaved_changes(&self) -> bool { self.has_changes }
+        fn set_has_unsaved_changes(&mut self, changed: bool) { self.has_changes = changed; }
+
+        fn handle_feature_action(&mut self, action: &CanvasAction, context: &ActionContext) -> Option<String> {
+            match action {
+                CanvasAction::Custom(cmd) => match cmd.as_str() {
+                    "validate" => {
+                        let errors = self.validate_field(self.current_field);
+                        if errors.is_empty() {
+                            Some("Password meets all requirements!".to_string())
+                        } else {
+                            Some(format!("Validation errors: {}", errors.join(", ")))
+                        }
+                    }
+                    _ => None,
+                },
+                _ => None,
+            }
+        }
+    }
+
+    let mut form = ValidatedForm::new();
+    let mut ideal_cursor = 0;
+
+    // Test with weak password
+    let weak_password = "abc";
+    for c in weak_password.chars() {
+        ActionDispatcher::dispatch(
+            CanvasAction::InsertChar(c),
+            &mut form,
+            &mut ideal_cursor,
+        ).await.unwrap();
+    }
+
+    let result = ActionDispatcher::dispatch(
+        CanvasAction::Custom("validate".to_string()),
+        &mut form,
+        &mut ideal_cursor,
+    ).await.unwrap();
+    println!("  Weak password '{}': {}", form.password, result.message().unwrap_or(""));
+
+    // Clear and test with strong password
+    form.password.clear();
+    form.cursor_pos = 0;
+
+    let strong_password = "StrongPass123";
+    for c in strong_password.chars() {
+        ActionDispatcher::dispatch(
+            CanvasAction::InsertChar(c),
+            &mut form,
+            &mut ideal_cursor,
+        ).await.unwrap();
+    }
+
+    let result = ActionDispatcher::dispatch(
+        CanvasAction::Custom("validate".to_string()),
+        &mut form,
+        &mut ideal_cursor,
+    ).await.unwrap();
+    println!("  Strong password '{}': {}", form.password, result.message().unwrap_or(""));
+    println!("  ✅ Validation pipeline works!\n");
+}
+
+// Pattern 4: Multi-form orchestration
+async fn multi_form_example() {
+    println!("🎭 Pattern 4: Multi-Form Orchestration");
+
+    #[derive(Debug)]
+    struct PersonalInfoForm {
+        current_field: usize,
+        cursor_pos: usize,
+        name: String,
+        age: String,
+        has_changes: bool,
+    }
+
+    #[derive(Debug)]
+    struct ContactInfoForm {
+        current_field: usize,
+        cursor_pos: usize,
+        email: String,
+        phone: String,
+        has_changes: bool,
+    }
+
+    // Implement CanvasState for both forms
+    impl CanvasState for PersonalInfoForm {
+        fn current_field(&self) -> usize { self.current_field }
+        fn current_cursor_pos(&self) -> usize { self.cursor_pos }
+        fn set_current_field(&mut self, index: usize) { self.current_field = index.min(1); }
+        fn set_current_cursor_pos(&mut self, pos: usize) { self.cursor_pos = pos; }
+
+        fn get_current_input(&self) -> &str {
+            match self.current_field {
+                0 => &self.name,
+                1 => &self.age,
+                _ => "",
+            }
+        }
+
+        fn get_current_input_mut(&mut self) -> &mut String {
+            match self.current_field {
+                0 => &mut self.name,
+                1 => &mut self.age,
+                _ => unreachable!(),
+            }
+        }
+
+        fn inputs(&self) -> Vec<&String> { vec![&self.name, &self.age] }
+        fn fields(&self) -> Vec<&str> { vec!["Name", "Age"] }
+        fn has_unsaved_changes(&self) -> bool { self.has_changes }
+        fn set_has_unsaved_changes(&mut self, changed: bool) { self.has_changes = changed; }
+    }
+
+    impl CanvasState for ContactInfoForm {
+        fn current_field(&self) -> usize { self.current_field }
+        fn current_cursor_pos(&self) -> usize { self.cursor_pos }
+        fn set_current_field(&mut self, index: usize) { self.current_field = index.min(1); }
+        fn set_current_cursor_pos(&mut self, pos: usize) { self.cursor_pos = pos; }
+
+        fn get_current_input(&self) -> &str {
+            match self.current_field {
+                0 => &self.email,
+                1 => &self.phone,
+                _ => "",
+            }
+        }
+
+        fn get_current_input_mut(&mut self) -> &mut String {
+            match self.current_field {
+                0 => &mut self.email,
+                1 => &mut self.phone,
+                _ => unreachable!(),
+            }
+        }
+
+        fn inputs(&self) -> Vec<&String> { vec![&self.email, &self.phone] }
+        fn fields(&self) -> Vec<&str> { vec!["Email", "Phone"] }
+        fn has_unsaved_changes(&self) -> bool { self.has_changes }
+        fn set_has_unsaved_changes(&mut self, changed: bool) { self.has_changes = changed; }
+    }
+
+    // Form orchestrator
+    #[derive(Debug)]
+    struct FormOrchestrator {
+        personal_form: PersonalInfoForm,
+        contact_form: ContactInfoForm,
+        current_form: usize, // 0 = personal, 1 = contact
+    }
+
+    impl FormOrchestrator {
+        fn new() -> Self {
+            Self {
+                personal_form: PersonalInfoForm {
+                    current_field: 0,
+                    cursor_pos: 0,
+                    name: String::new(),
+                    age: String::new(),
+                    has_changes: false,
+                },
+                contact_form: ContactInfoForm {
+                    current_field: 0,
+                    cursor_pos: 0,
+                    email: String::new(),
+                    phone: String::new(),
+                    has_changes: false,
+                },
+                current_form: 0,
+            }
+        }
+
+        async fn execute_action(&mut self, action: CanvasAction) -> ActionResult {
+            let mut ideal_cursor = 0;
+
+            match self.current_form {
+                0 => ActionDispatcher::dispatch(action, &mut self.personal_form, &mut ideal_cursor).await.unwrap(),
+                1 => ActionDispatcher::dispatch(action, &mut self.contact_form, &mut ideal_cursor).await.unwrap(),
+                _ => ActionResult::error("Invalid form index"),
+            }
+        }
+
+        fn switch_form(&mut self) -> String {
+            self.current_form = (self.current_form + 1) % 2;
+            match self.current_form {
+                0 => "Switched to Personal Info form".to_string(),
+                1 => "Switched to Contact Info form".to_string(),
+                _ => "Unknown form".to_string(),
+            }
+        }
+
+        fn current_form_name(&self) -> &str {
+            match self.current_form {
+                0 => "Personal Info",
+                1 => "Contact Info",
+                _ => "Unknown",
+            }
+        }
+    }
+
+    let mut orchestrator = FormOrchestrator::new();
+
+    println!("  Current form: {}", orchestrator.current_form_name());
+
+    // Fill personal info
+    for &c in &['J', 'o', 'h', 'n'] {
+        orchestrator.execute_action(CanvasAction::InsertChar(c)).await;
+    }
+
+    orchestrator.execute_action(CanvasAction::NextField).await;
+
+    for &c in &['2', '5'] {
+        orchestrator.execute_action(CanvasAction::InsertChar(c)).await;
+    }
+
+    println!("  Personal form - Name: '{}', Age: '{}'",
+             orchestrator.personal_form.name,
+             orchestrator.personal_form.age);
+
+    // Switch to contact form
+    let switch_msg = orchestrator.switch_form();
+    println!("  {}", switch_msg);
+
+    // Fill contact info
+    for &c in &['j', 'o', 'h', 'n', '@', 'e', 'x', 'a', 'm', 'p', 'l', 'e', '.', 'c', 'o', 'm'] {
+        orchestrator.execute_action(CanvasAction::InsertChar(c)).await;
+    }
+
+    orchestrator.execute_action(CanvasAction::NextField).await;
+
+    for &c in &['5', '5', '5', '-', '1', '2', '3', '4'] {
+        orchestrator.execute_action(CanvasAction::InsertChar(c)).await;
+    }
+
+    println!("  Contact form - Email: '{}', Phone: '{}'",
+             orchestrator.contact_form.email,
+             orchestrator.contact_form.phone);
+}

canvas/src/canvas/actions/mod.rs

@@ -0,0 +1,8 @@
+// src/canvas/actions/mod.rs
+//! Canvas action definitions and movement utilities
+
+pub mod types;
+pub mod movement;
+
+// Re-export the main API
+pub use types::{CanvasAction, ActionResult};

canvas/src/canvas/actions/movement/char.rs

@@ -0,0 +1,50 @@
+// src/canvas/actions/movement/char.rs
+//! Character-level cursor movement functions
+
+/// Calculate new position when moving left
+pub fn move_left(current_pos: usize) -> usize {
+    current_pos.saturating_sub(1)
+}
+
+/// Calculate new position when moving right
+pub fn move_right(current_pos: usize, text: &str, for_edit_mode: bool) -> usize {
+    if text.is_empty() {
+        return current_pos;
+    }
+
+    if for_edit_mode {
+        // Edit mode: can move past end of text
+        (current_pos + 1).min(text.len())
+    } else {
+        // Read-only/highlight mode: stays within text bounds
+        if current_pos < text.len().saturating_sub(1) {
+            current_pos + 1
+        } else {
+            current_pos
+        }
+    }
+}
+
+/// Check if cursor position is valid for the given mode
+pub fn is_valid_cursor_position(pos: usize, text: &str, for_edit_mode: bool) -> bool {
+    if text.is_empty() {
+        return pos == 0;
+    }
+
+    if for_edit_mode {
+        pos <= text.len()
+    } else {
+        pos < text.len()
+    }
+}
+
+/// Clamp cursor position to valid bounds for the given mode
+pub fn clamp_cursor_position(pos: usize, text: &str, for_edit_mode: bool) -> usize {
+    if text.is_empty() {
+        0
+    } else if for_edit_mode {
+        pos.min(text.len())
+    } else {
+        pos.min(text.len().saturating_sub(1))
+    }
+}

canvas/src/canvas/actions/movement/line.rs

@@ -0,0 +1,33 @@
+// src/canvas/actions/movement/line.rs
+//! Line-level cursor movement and positioning
+
+/// Calculate cursor position for line start
+pub fn line_start_position() -> usize {
+    0
+}
+
+/// Calculate cursor position for line end
+pub fn line_end_position(text: &str, for_edit_mode: bool) -> usize {
+    if text.is_empty() {
+        0
+    } else if for_edit_mode {
+        // Edit mode: cursor can go past end of text
+        text.len()
+    } else {
+        // Read-only/highlight mode: cursor stays on last character
+        text.len().saturating_sub(1)
+    }
+}
+
+/// Calculate safe cursor position when switching fields
+pub fn safe_cursor_position(text: &str, ideal_column: usize, for_edit_mode: bool) -> usize {
+    if text.is_empty() {
+        0
+    } else if for_edit_mode {
+        // Edit mode: cursor can go past end
+        ideal_column.min(text.len())
+    } else {
+        // Read-only/highlight mode: cursor stays within text
+        ideal_column.min(text.len().saturating_sub(1))
+    }
+}

canvas/src/canvas/actions/movement/mod.rs

@@ -0,0 +1,17 @@
+// src/canvas/actions/movement/mod.rs
+//! Movement utilities for character, word, and line navigation
+
+pub mod word;
+pub mod line;
+pub mod char;
+
+// Re-export commonly used functions
+pub use word::{
+    find_next_word_start, find_word_end, find_prev_word_start, find_prev_word_end,
+    find_next_big_word_start, find_prev_big_word_start, find_big_word_end, find_prev_big_word_end,
+    // Add these new exports:
+    find_last_word_start_in_field, find_last_word_end_in_field,
+    find_last_big_word_start_in_field, find_last_big_word_end_in_field,
+};
+pub use line::{line_start_position, line_end_position, safe_cursor_position};
+pub use char::{move_left, move_right, is_valid_cursor_position, clamp_cursor_position};

canvas/src/canvas/actions/movement/word.rs

@@ -0,0 +1,403 @@
+// src/canvas/actions/movement/word.rs
+//! Word-based cursor movement with vim-like semantics
+
+#[derive(PartialEq, Copy, Clone)]
+enum CharType {
+    Whitespace,
+    Alphanumeric,
+    Punctuation,
+}
+
+fn get_char_type(c: char) -> CharType {
+    if c.is_whitespace() {
+        CharType::Whitespace
+    } else if c.is_alphanumeric() {
+        CharType::Alphanumeric
+    } else {
+        CharType::Punctuation
+    }
+}
+
+/// Find the start of the next word from the current position
+pub fn find_next_word_start(text: &str, current_pos: usize) -> usize {
+    let chars: Vec<char> = text.chars().collect();
+    if chars.is_empty() {
+        return 0;
+    }
+    let current_pos = current_pos.min(chars.len());
+
+    if current_pos == chars.len() {
+        return current_pos;
+    }
+
+    let mut pos = current_pos;
+    let initial_type = get_char_type(chars[pos]);
+
+    // Skip current word/token
+    while pos < chars.len() && get_char_type(chars[pos]) == initial_type {
+        pos += 1;
+    }
+
+    // Skip whitespace
+    while pos < chars.len() && get_char_type(chars[pos]) == CharType::Whitespace {
+        pos += 1;
+    }
+
+    pos
+}
+
+/// Find the end of the current or next word
+pub fn find_word_end(text: &str, current_pos: usize) -> usize {
+    let chars: Vec<char> = text.chars().collect();
+    let len = chars.len();
+    if len == 0 {
+        return 0;
+    }
+
+    let mut pos = current_pos.min(len - 1);
+    let current_type = get_char_type(chars[pos]);
+
+    // If we're not on whitespace, move to end of current word
+    if current_type != CharType::Whitespace {
+        while pos < len && get_char_type(chars[pos]) == current_type {
+            pos += 1;
+        }
+        return pos.saturating_sub(1);
+    }
+
+    // If we're on whitespace, find next word and go to its end
+    pos = find_next_word_start(text, pos);
+    if pos >= len {
+        return len.saturating_sub(1);
+    }
+
+    let word_type = get_char_type(chars[pos]);
+    while pos < len && get_char_type(chars[pos]) == word_type {
+        pos += 1;
+    }
+
+    pos.saturating_sub(1).min(len.saturating_sub(1))
+}
+
+/// Find the start of the previous word
+pub fn find_prev_word_start(text: &str, current_pos: usize) -> usize {
+    let chars: Vec<char> = text.chars().collect();
+    if chars.is_empty() || current_pos == 0 {
+        return 0;
+    }
+
+    let mut pos = current_pos.saturating_sub(1);
+
+    // Skip whitespace backwards
+    while pos > 0 && get_char_type(chars[pos]) == CharType::Whitespace {
+        pos -= 1;
+    }
+
+    // Move to start of word
+    if get_char_type(chars[pos]) != CharType::Whitespace {
+        let word_type = get_char_type(chars[pos]);
+        while pos > 0 && get_char_type(chars[pos - 1]) == word_type {
+            pos -= 1;
+        }
+    }
+
+    if pos == 0 && get_char_type(chars[0]) == CharType::Whitespace {
+        0
+    } else {
+        pos
+    }
+}
+
+/// Find the end of the previous word (CORRECTED VERSION for vim's ge command)
+pub fn find_prev_word_end(text: &str, current_pos: usize) -> usize {
+    let chars: Vec<char> = text.chars().collect();
+    if chars.is_empty() || current_pos == 0 {
+        return 0;
+    }
+
+    // Find all word end positions using boundary detection
+    let mut word_ends = Vec::new();
+    let mut in_word = false;
+    let mut current_word_type: Option<CharType> = None;
+
+    for (i, &ch) in chars.iter().enumerate() {
+        let char_type = get_char_type(ch);
+        
+        match char_type {
+            CharType::Whitespace => {
+                if in_word {
+                    // End of a word
+                    word_ends.push(i - 1);
+                    in_word = false;
+                    current_word_type = None;
+                }
+            }
+            _ => {
+                if !in_word || current_word_type != Some(char_type) {
+                    // Start of a new word (or word type change)
+                    if in_word {
+                        // End the previous word first
+                        word_ends.push(i - 1);
+                    }
+                    in_word = true;
+                    current_word_type = Some(char_type);
+                }
+            }
+        }
+    }
+
+    // Add the final word end if text doesn't end with whitespace
+    if in_word && !chars.is_empty() {
+        word_ends.push(chars.len() - 1);
+    }
+
+    // Find the largest word end position that's before current_pos
+    for &end_pos in word_ends.iter().rev() {
+        if end_pos < current_pos {
+            return end_pos;
+        }
+    }
+
+    0
+}
+
+/// Find the start of the next big_word (whitespace-separated)
+pub fn find_next_big_word_start(text: &str, current_pos: usize) -> usize {
+    let chars: Vec<char> = text.chars().collect();
+    if chars.is_empty() || current_pos >= chars.len() {
+        return text.chars().count();
+    }
+
+    let mut pos = current_pos;
+
+    // If we're on non-whitespace, skip to end of current big_word
+    while pos < chars.len() && !chars[pos].is_whitespace() {
+        pos += 1;
+    }
+
+    // Skip whitespace to find start of next big_word
+    while pos < chars.len() && chars[pos].is_whitespace() {
+        pos += 1;
+    }
+
+    pos
+}
+
+/// Find the start of the previous big_word (whitespace-separated)
+pub fn find_prev_big_word_start(text: &str, current_pos: usize) -> usize {
+    let chars: Vec<char> = text.chars().collect();
+    if chars.is_empty() || current_pos == 0 {
+        return 0;
+    }
+
+    let mut pos = current_pos.saturating_sub(1);
+
+    // Skip whitespace backwards
+    while pos > 0 && chars[pos].is_whitespace() {
+        pos -= 1;
+    }
+
+    // Find start of current big_word by going back while non-whitespace
+    while pos > 0 && !chars[pos - 1].is_whitespace() {
+        pos -= 1;
+    }
+
+    pos
+}
+
+/// Find the end of the current/next big_word (whitespace-separated)
+pub fn find_big_word_end(text: &str, current_pos: usize) -> usize {
+    let chars: Vec<char> = text.chars().collect();
+    if chars.is_empty() {
+        return 0;
+    }
+
+    let mut pos = current_pos;
+
+    // If we're on whitespace, skip to start of next big_word
+    while pos < chars.len() && chars[pos].is_whitespace() {
+        pos += 1;
+    }
+
+    // If we reached end, return it
+    if pos >= chars.len() {
+        return chars.len();
+    }
+
+    // Find end of current big_word (last non-whitespace char)
+    while pos < chars.len() && !chars[pos].is_whitespace() {
+        pos += 1;
+    }
+
+    // Return position of last character in big_word
+    pos.saturating_sub(1)
+}
+
+/// Find the end of the previous big_word (whitespace-separated)
+pub fn find_prev_big_word_end(text: &str, current_pos: usize) -> usize {
+    let chars: Vec<char> = text.chars().collect();
+    if chars.is_empty() || current_pos == 0 {
+        return 0;
+    }
+
+    let mut pos = current_pos.saturating_sub(1);
+
+    // Skip whitespace backwards
+    while pos > 0 && chars[pos].is_whitespace() {
+        pos -= 1;
+    }
+
+    // If we hit start of text and it's whitespace, return 0
+    if pos == 0 && chars[0].is_whitespace() {
+        return 0;
+    }
+
+    // Skip back to start of current big_word, then forward to end
+    while pos > 0 && !chars[pos - 1].is_whitespace() {
+        pos -= 1;
+    }
+
+    // Now find end of this big_word
+    while pos < chars.len() && !chars[pos].is_whitespace() {
+        pos += 1;
+    }
+
+    // Return position of last character in big_word
+    pos.saturating_sub(1)
+}
+
+// ============================================================================
+// FIELD BOUNDARY HELPER FUNCTIONS (for cross-field movement)
+// ============================================================================
+
+/// Find the start of the last word in a field (for cross-field 'b' movement)
+pub fn find_last_word_start_in_field(text: &str) -> usize {
+    if text.is_empty() {
+        return 0;
+    }
+
+    let chars: Vec<char> = text.chars().collect();
+    if chars.is_empty() {
+        return 0;
+    }
+
+    let mut pos = chars.len().saturating_sub(1);
+
+    // Skip trailing whitespace
+    while pos > 0 && chars[pos].is_whitespace() {
+        pos -= 1;
+    }
+
+    // If the whole field is whitespace, return 0
+    if pos == 0 && chars[0].is_whitespace() {
+        return 0;
+    }
+
+    // Now we're on a non-whitespace character
+    // Find the start of this word by going backwards while chars are the same type
+    let char_type = if chars[pos].is_alphanumeric() { "alnum" } else { "punct" };
+
+    while pos > 0 {
+        let prev_char = chars[pos - 1];
+        let prev_type = if prev_char.is_alphanumeric() {
+            "alnum"
+        } else if prev_char.is_whitespace() {
+            "space"
+        } else {
+            "punct"
+        };
+
+        // Stop if we hit whitespace or different word type
+        if prev_type == "space" || prev_type != char_type {
+            break;
+        }
+        pos -= 1;
+    }
+
+    pos
+}
+
+/// Find the end of the last word in a field (for cross-field 'ge' movement)
+pub fn find_last_word_end_in_field(text: &str) -> usize {
+    let chars: Vec<char> = text.chars().collect();
+    if chars.is_empty() {
+        return 0;
+    }
+
+    // Start from the end and find the last non-whitespace character
+    let mut pos = chars.len() - 1;
+    
+    // Skip trailing whitespace
+    while pos > 0 && chars[pos].is_whitespace() {
+        pos -= 1;
+    }
+
+    // If the whole field is whitespace, return 0
+    if chars[pos].is_whitespace() {
+        return 0;
+    }
+
+    // We're now at the end of the last word
+    pos
+}
+
+/// Find the start of the last big_word in a field (for cross-field 'B' movement)
+pub fn find_last_big_word_start_in_field(text: &str) -> usize {
+    if text.is_empty() {
+        return 0;
+    }
+
+    let chars: Vec<char> = text.chars().collect();
+    if chars.is_empty() {
+        return 0;
+    }
+
+    let mut pos = chars.len().saturating_sub(1);
+
+    // Skip trailing whitespace
+    while pos > 0 && chars[pos].is_whitespace() {
+        pos -= 1;
+    }
+
+    // If the whole field is whitespace, return 0
+    if pos == 0 && chars[0].is_whitespace() {
+        return 0;
+    }
+
+    // Now we're on a non-whitespace character
+    // Find the start of this big_word by going backwards while chars are non-whitespace
+    while pos > 0 {
+        let prev_char = chars[pos - 1];
+
+        // Stop if we hit whitespace (big_word boundary)
+        if prev_char.is_whitespace() {
+            break;
+        }
+        pos -= 1;
+    }
+
+    pos
+}
+
+/// Find the end of the last big_word in a field (for cross-field 'gE' movement)
+pub fn find_last_big_word_end_in_field(text: &str) -> usize {
+    let chars: Vec<char> = text.chars().collect();
+    if chars.is_empty() {
+        return 0;
+    }
+
+    let mut pos = chars.len().saturating_sub(1);
+
+    // Skip trailing whitespace
+    while pos > 0 && chars[pos].is_whitespace() {
+        pos -= 1;
+    }
+
+    // If the whole field is whitespace, return 0
+    if pos == 0 && chars[0].is_whitespace() {
+        return 0;
+    }
+
+    // We're now at the end of the last big_word
+    pos
+}

canvas/src/canvas/actions/types.rs

@@ -0,0 +1,215 @@
+// src/canvas/actions/types.rs
+//! Core action types and result handling for canvas operations.
+
+/// All available canvas actions.
+///
+/// This enum lists high-level actions that can be performed on the canvas.
+/// Consumers can match on variants to implement custom handling or map input
+/// events to these canonical actions.
+#[non_exhaustive]
+#[derive(Debug, Clone, PartialEq)]
+pub enum CanvasAction {
+    // Movement actions
+    /// Move the cursor left by one character (or logical unit).
+    MoveLeft,
+    /// Move the cursor right by one character (or logical unit).
+    MoveRight,
+    /// Move the cursor up a visual line/field.
+    MoveUp,
+    /// Move the cursor down a visual line/field.
+    MoveDown,
+
+    // Word movement
+    /// Move to the start of the next word.
+    MoveWordNext,
+    /// Move to the start of the previous word.
+    MoveWordPrev,
+    /// Move to the end of the current/next word.
+    MoveWordEnd,
+    /// Move to the previous word end (vim `ge`).
+    MoveWordEndPrev,
+
+    // Line movement
+    /// Move to the start of the current line.
+    MoveLineStart,
+    /// Move to the end of the current line.
+    MoveLineEnd,
+
+    // Field movement
+    /// Move to the next field.
+    NextField,
+    /// Move to the previous field.
+    PrevField,
+    /// Move to the first field.
+    MoveFirstLine,
+    /// Move to the last field.
+    MoveLastLine,
+
+    // Editing actions
+    /// Insert a character at the cursor.
+    InsertChar(char),
+    /// Delete character before the cursor.
+    DeleteBackward,
+    /// Delete character under/after the cursor.
+    DeleteForward,
+
+    // Suggestions actions
+    /// Trigger suggestions dropdown (e.g. Tab).
+    TriggerSuggestions,
+    /// Move selection up in suggestions dropdown.
+    SuggestionUp,
+    /// Move selection down in suggestions dropdown.
+    SuggestionDown,
+    /// Accept the selected suggestion.
+    SelectSuggestion,
+    /// Exit suggestions UI.
+    ExitSuggestions,
+
+    // Custom actions
+    /// Custom named action for application-specific behavior.
+    Custom(String),
+}
+
+/// Result type for canvas actions.
+///
+/// Action handlers return an ActionResult to indicate success, user-facing
+/// messages, or errors. The enum is non-exhaustive to allow extension.
+#[non_exhaustive]
+#[derive(Debug, Clone)]
+pub enum ActionResult {
+    /// Action completed successfully.
+    Success,
+    /// Action completed with a user-facing message.
+    Message(String),
+    /// Action was handled by the application with an associated message.
+    HandledByApp(String),
+    /// Action was handled by a feature with an associated message.
+    HandledByFeature(String), // Keep for compatibility
+    /// An error occurred while handling the action.
+    Error(String),
+}
+
+impl ActionResult {
+    /// Convenience constructor for Success.
+    pub fn success() -> Self {
+        Self::Success
+    }
+
+    /// Convenience constructor for Message.
+    pub fn success_with_message(msg: &str) -> Self {
+        Self::Message(msg.to_string())
+    }
+
+    /// Convenience constructor for HandledByApp.
+    pub fn handled_by_app(msg: &str) -> Self {
+        Self::HandledByApp(msg.to_string())
+    }
+
+    /// Convenience constructor for Error.
+    pub fn error(msg: &str) -> Self {
+        Self::Error(msg.to_string())
+    }
+
+    /// Returns true for any variant representing a success-like outcome.
+    pub fn is_success(&self) -> bool {
+        matches!(self, Self::Success | Self::Message(_) | Self::HandledByApp(_) | Self::HandledByFeature(_))
+    }
+
+    /// Extract a message from the result when present.
+    pub fn message(&self) -> Option<&str> {
+        match self {
+            Self::Message(msg) | Self::HandledByApp(msg) | Self::HandledByFeature(msg) | Self::Error(msg) => Some(msg),
+            Self::Success => None,
+        }
+    }
+}
+
+impl CanvasAction {
+    /// Get a human-readable description of this action.
+    pub fn description(&self) -> &'static str {
+        match self {
+            Self::MoveLeft => "move left",
+            Self::MoveRight => "move right",
+            Self::MoveUp => "move up",
+            Self::MoveDown => "move down",
+            Self::MoveWordNext => "next word",
+            Self::MoveWordPrev => "previous word",
+            Self::MoveWordEnd => "word end",
+            Self::MoveWordEndPrev => "previous word end",
+            Self::MoveLineStart => "line start",
+            Self::MoveLineEnd => "line end",
+            Self::NextField => "next field",
+            Self::PrevField => "previous field",
+            Self::MoveFirstLine => "first field",
+            Self::MoveLastLine => "last field",
+            Self::InsertChar(_c) => "insert character",
+            Self::DeleteBackward => "delete backward",
+            Self::DeleteForward => "delete forward",
+            Self::TriggerSuggestions => "trigger suggestions",
+            Self::SuggestionUp => "suggestion up",
+            Self::SuggestionDown => "suggestion down",
+            Self::SelectSuggestion => "select suggestion",
+            Self::ExitSuggestions => "exit suggestions",
+            Self::Custom(_name) => "custom action",
+        }
+    }
+
+    /// Get all movement-related actions.
+    pub fn movement_actions() -> Vec<CanvasAction> {
+        vec![
+            Self::MoveLeft,
+            Self::MoveRight,
+            Self::MoveUp,
+            Self::MoveDown,
+            Self::MoveWordNext,
+            Self::MoveWordPrev,
+            Self::MoveWordEnd,
+            Self::MoveWordEndPrev,
+            Self::MoveLineStart,
+            Self::MoveLineEnd,
+            Self::NextField,
+            Self::PrevField,
+            Self::MoveFirstLine,
+            Self::MoveLastLine,
+        ]
+    }
+
+    /// Get all editing-related actions.
+    pub fn editing_actions() -> Vec<CanvasAction> {
+        vec![
+            Self::InsertChar(' '), // Example char
+            Self::DeleteBackward,
+            Self::DeleteForward,
+        ]
+    }
+
+    /// Get all suggestions-related actions.
+    pub fn suggestions_actions() -> Vec<CanvasAction> {
+        vec![
+            Self::TriggerSuggestions,
+            Self::SuggestionUp,
+            Self::SuggestionDown,
+            Self::SelectSuggestion,
+            Self::ExitSuggestions,
+        ]
+    }
+
+    /// Check if this action modifies text content.
+    pub fn is_editing_action(&self) -> bool {
+        matches!(self,
+            Self::InsertChar(_) |
+            Self::DeleteBackward |
+            Self::DeleteForward
+        )
+    }
+
+    /// Check if this action moves the cursor.
+    pub fn is_movement_action(&self) -> bool {
+        matches!(self,
+            Self::MoveLeft | Self::MoveRight | Self::MoveUp | Self::MoveDown |
+            Self::MoveWordNext | Self::MoveWordPrev | Self::MoveWordEnd | Self::MoveWordEndPrev |
+            Self::MoveLineStart | Self::MoveLineEnd | Self::NextField | Self::PrevField |
+            Self::MoveFirstLine | Self::MoveLastLine
+        )
+    }
+}

canvas/src/canvas/cursor.rs

@@ -0,0 +1,64 @@
+// src/canvas/cursor.rs
+//! Cursor style management for different canvas modes
+//!
+//! Provides helpers to update and reset terminal cursor style when the
+//! `cursor-style` feature is enabled. When the feature is disabled the
+//! functions are no-ops.
+
+#[cfg(feature = "cursor-style")]
+use crossterm::{cursor::SetCursorStyle, execute};
+#[cfg(feature = "cursor-style")]
+use std::io;
+
+use crate::canvas::modes::AppMode;
+
+/// Manages cursor styles based on canvas modes
+pub struct CursorManager;
+
+impl CursorManager {
+    /// Update cursor style based on current mode.
+    ///
+    /// When the `textmode-normal` feature is enabled a fixed style is applied.
+    /// Otherwise, the cursor style is mapped to the provided AppMode.
+    #[cfg(feature = "cursor-style")]
+    pub fn update_for_mode(mode: AppMode) -> io::Result<()> {
+        // NORMALMODE: force underscore for every mode
+        #[cfg(feature = "textmode-normal")]
+        {
+            let style = SetCursorStyle::SteadyBar;
+            execute!(io::stdout(), style)
+        }
+
+        // Default (not normal): original mapping
+        #[cfg(not(feature = "textmode-normal"))]
+        {
+            let style = match mode {
+                AppMode::Edit => SetCursorStyle::SteadyBar,           // Thin line for insert
+                AppMode::ReadOnly => SetCursorStyle::SteadyBlock,     // Block for normal
+                AppMode::Highlight => SetCursorStyle::BlinkingBlock,  // Blinking for visual
+                AppMode::General => SetCursorStyle::SteadyBlock,      // Block for general
+                AppMode::Command => SetCursorStyle::SteadyUnderScore, // Underscore for command
+            };
+
+            return execute!(io::stdout(), style);
+        }
+    }
+
+    /// No-op when cursor-style feature is disabled.
+    #[cfg(not(feature = "cursor-style"))]
+    pub fn update_for_mode(_mode: AppMode) -> io::Result<()> {
+        Ok(())
+    }
+
+    /// Reset cursor to default on cleanup.
+    #[cfg(feature = "cursor-style")]
+    pub fn reset() -> io::Result<()> {
+        execute!(io::stdout(), SetCursorStyle::DefaultUserShape)
+    }
+
+    /// Reset is a no-op when the cursor-style feature is disabled.
+    #[cfg(not(feature = "cursor-style"))]
+    pub fn reset() -> io::Result<()> {
+        Ok(())
+    }
+}

canvas/src/canvas/gui.rs

@@ -0,0 +1,729 @@
+// src/canvas/gui.rs
+//! Canvas GUI updated to work with FormEditor
+//!
+//! This module provides rendering helpers for the canvas UI when the `gui`
+//! feature is enabled. It exposes high-level functions to render the canvas
+//! and convenience types for display options.
+
+#[cfg(feature = "gui")]
+use ratatui::{
+    layout::{Alignment, Constraint, Direction, Layout, Rect},
+    style::{Modifier, Style},
+    text::{Line, Span},
+    widgets::{Block, Borders, BorderType, Paragraph, Wrap},
+    Frame,
+};
+
+#[cfg(feature = "gui")]
+use crate::canvas::theme::{CanvasTheme, DefaultCanvasTheme};
+use crate::canvas::modes::HighlightState;
+use crate::data_provider::DataProvider;
+use crate::editor::FormEditor;
+use unicode_width::UnicodeWidthChar;
+
+#[cfg(feature = "gui")]
+use std::cmp::{max, min};
+
+#[cfg(feature = "gui")]
+#[derive(Debug, Clone, Copy)]
+/// How to handle overflow when rendering a field's content.
+pub enum OverflowMode {
+    /// Show an indicator character at the left/right when text is truncated.
+    /// Common default is '$'.
+    Indicator(char),
+    /// Wrap content into multiple visual lines.
+    Wrap,
+}
+
+#[cfg(feature = "gui")]
+#[derive(Debug, Clone, Copy)]
+/// Display options controlling canvas rendering behavior.
+pub struct CanvasDisplayOptions {
+    /// How to handle horizontal overflow for fields.
+    pub overflow: OverflowMode,
+}
+
+#[cfg(feature = "gui")]
+impl Default for CanvasDisplayOptions {
+    fn default() -> Self {
+        Self {
+            overflow: OverflowMode::Indicator('$'),
+        }
+    }
+}
+
+/// Utility: measure display width of a string
+#[cfg(feature = "gui")]
+fn display_width(s: &str) -> u16 {
+    s.chars()
+        .map(|c| UnicodeWidthChar::width(c).unwrap_or(0) as u16)
+        .sum()
+}
+
+/// Utility: clip a string to fit width, append indicator if overflow
+#[cfg(feature = "gui")]
+fn clip_with_indicator_line<'a>(s: &'a str, width: u16, indicator: char) -> Line<'a> {
+    if width == 0 {
+        return Line::from("");
+    }
+    if display_width(s) <= width {
+        return Line::from(Span::raw(s));
+    }
+    let budget = width.saturating_sub(1);
+    let mut out = String::new();
+    let mut used: u16 = 0;
+    for ch in s.chars() {
+        let w = UnicodeWidthChar::width(ch).unwrap_or(0) as u16;
+        if used + w > budget {
+            break;
+        }
+        out.push(ch);
+        used = used.saturating_add(w);
+    }
+    Line::from(vec![Span::raw(out), Span::raw(indicator.to_string())])
+}
+
+#[cfg(feature = "gui")]
+const RIGHT_PAD: u16 = 3;
+
+#[cfg(feature = "gui")]
+fn slice_by_display_cols(s: &str, start_cols: u16, max_cols: u16) -> String {
+    if max_cols == 0 {
+        return String::new();
+    }
+    let mut cols: u16 = 0;
+    let mut out = String::new();
+    let mut taken: u16 = 0;
+    let mut started = false;
+
+    for ch in s.chars() {
+        let w = UnicodeWidthChar::width(ch).unwrap_or(0) as u16;
+        let next = cols.saturating_add(w);
+
+        if !started {
+            if next <= start_cols {
+                cols = next;
+                continue;
+            } else {
+                started = true;
+            }
+        }
+
+        if taken.saturating_add(w) > max_cols {
+            break;
+        }
+        out.push(ch);
+        taken = taken.saturating_add(w);
+        cols = next;
+    }
+
+    out
+}
+
+#[cfg(feature = "gui")]
+fn compute_h_scroll_with_padding(cursor_cols: u16, width: u16) -> (u16, u16) {
+    let mut h = 0u16;
+    for _ in 0..2 {
+        let left_cols = if h > 0 { 1 } else { 0 };
+        let max_x_visible = width.saturating_sub(1 + RIGHT_PAD + left_cols);
+        let needed = cursor_cols.saturating_sub(max_x_visible);
+        if needed <= h {
+            return (h, left_cols);
+        }
+        h = needed;
+    }
+    let left_cols = if h > 0 { 1 } else { 0 };
+    (h, left_cols)
+}
+
+#[cfg(feature = "gui")]
+fn render_active_line_with_indicator<T: CanvasTheme>(
+    typed_text: &str,
+    completion: Option<&str>,
+    width: u16,
+    indicator: char,
+    cursor_chars: usize,
+    theme: &T,
+) -> (Line<'static>, u16, u16) {
+    if width == 0 {
+        return (Line::from(""), 0, 0);
+    }
+
+    // Cursor display column
+    let mut cursor_cols: u16 = 0;
+    for (i, ch) in typed_text.chars().enumerate() {
+        if i >= cursor_chars {
+            break;
+        }
+        cursor_cols = cursor_cols
+            .saturating_add(UnicodeWidthChar::width(ch).unwrap_or(0) as u16);
+    }
+
+    let (h_scroll, left_cols) = compute_h_scroll_with_padding(cursor_cols, width);
+
+    let total_cols = display_width(typed_text);
+    let content_budget = width.saturating_sub(left_cols);
+    let show_right = total_cols.saturating_sub(h_scroll) > content_budget;
+    let right_cols: u16 = if show_right { 1 } else { 0 };
+
+    let visible_cols = width.saturating_sub(left_cols + right_cols);
+    let visible_typed = slice_by_display_cols(typed_text, h_scroll, visible_cols);
+
+    let used_typed_cols = display_width(&visible_typed);
+    let mut remaining_cols = visible_cols.saturating_sub(used_typed_cols);
+    let mut visible_completion = String::new();
+
+    if let Some(comp) = completion {
+        if !comp.is_empty() && remaining_cols > 0 {
+            visible_completion = slice_by_display_cols(comp, 0, remaining_cols);
+        }
+    }
+
+    let mut spans: Vec<Span> = Vec::with_capacity(3);
+    if left_cols == 1 {
+        spans.push(Span::raw(indicator.to_string()));
+    }
+    spans.push(Span::styled(
+        visible_typed,
+        Style::default().fg(theme.fg()),
+    ));
+    if !visible_completion.is_empty() {
+        spans.push(Span::styled(
+            visible_completion,
+            Style::default().fg(theme.suggestion_gray()),
+        ));
+    }
+    if show_right {
+        spans.push(Span::raw(indicator.to_string()));
+    }
+
+    (Line::from(spans), h_scroll, left_cols)
+}
+
+#[cfg(feature = "gui")]
+/// Render the canvas into the provided frame using default display options.
+///
+/// Returns the rectangle of the active input field if present.
+pub fn render_canvas<T: CanvasTheme, D: DataProvider>(
+    f: &mut Frame,
+    area: Rect,
+    editor: &FormEditor<D>,
+    theme: &T,
+) -> Option<Rect> {
+    let opts = CanvasDisplayOptions::default();
+    render_canvas_with_options(f, area, editor, theme, opts)
+}
+
+#[cfg(feature = "gui")]
+/// Render the canvas into the provided frame with explicit display options.
+///
+/// This is the more configurable entrypoint for rendering and is useful for
+/// tests or when callers need to override overflow handling.
+pub fn render_canvas_with_options<T: CanvasTheme, D: DataProvider>(
+    f: &mut Frame,
+    area: Rect,
+    editor: &FormEditor<D>,
+    theme: &T,
+    opts: CanvasDisplayOptions,
+) -> Option<Rect> {
+    let highlight_state =
+        convert_selection_to_highlight(editor.ui_state().selection_state());
+
+    #[cfg(feature = "suggestions")]
+    let active_completion = if editor.ui_state().is_suggestions_active()
+        && editor.ui_state().suggestions.active_field
+            == Some(editor.ui_state().current_field())
+    {
+        editor.ui_state().suggestions.completion_text.clone()
+    } else {
+        None
+    };
+    #[cfg(not(feature = "suggestions"))]
+    let active_completion: Option<String> = None;
+
+    render_canvas_with_highlight_and_options(
+        f,
+        area,
+        editor,
+        theme,
+        &highlight_state,
+        active_completion,
+        opts,
+    )
+}
+
+#[cfg(feature = "gui")]
+fn render_canvas_with_highlight_and_options<T: CanvasTheme, D: DataProvider>(
+    f: &mut Frame,
+    area: Rect,
+    editor: &FormEditor<D>,
+    theme: &T,
+    highlight_state: &HighlightState,
+    active_completion: Option<String>,
+    opts: CanvasDisplayOptions,
+) -> Option<Rect> {
+    let ui_state = editor.ui_state();
+    let data_provider = editor.data_provider();
+
+    let field_count = data_provider.field_count();
+    let mut fields: Vec<&str> = Vec::with_capacity(field_count);
+    let mut inputs: Vec<String> = Vec::with_capacity(field_count);
+
+    for i in 0..field_count {
+        fields.push(data_provider.field_name(i));
+        #[cfg(feature = "validation")]
+        {
+            inputs.push(editor.display_text_for_field(i));
+        }
+        #[cfg(not(feature = "validation"))]
+        {
+            inputs.push(data_provider.field_value(i).to_string());
+        }
+    }
+
+    let current_field_idx = ui_state.current_field();
+    let is_edit_mode = matches!(ui_state.mode(), crate::canvas::modes::AppMode::Edit);
+
+    render_canvas_fields_with_options(
+        f,
+        area,
+        &fields,
+        &current_field_idx,
+        &inputs,
+        theme,
+        is_edit_mode,
+        highlight_state,
+        editor.display_cursor_position(),
+        false,
+        #[cfg(feature = "validation")]
+        |field_idx| editor.display_text_for_field(field_idx),
+        #[cfg(not(feature = "validation"))]
+        |field_idx| data_provider.field_value(field_idx).to_string(),
+        #[cfg(feature = "validation")]
+        |field_idx| {
+            editor
+                .ui_state()
+                .validation_state()
+                .get_field_config(field_idx)
+                .map(|cfg| cfg.custom_formatter.is_some() || cfg.display_mask.is_some())
+                .unwrap_or(false)
+        },
+        #[cfg(not(feature = "validation"))]
+        |_field_idx| false,
+        active_completion,
+        opts,
+    )
+}
+
+#[cfg(feature = "gui")]
+fn convert_selection_to_highlight(
+    selection: &crate::canvas::state::SelectionState,
+) -> HighlightState {
+    use crate::canvas::state::SelectionState;
+
+    match selection {
+        SelectionState::None => HighlightState::Off,
+        SelectionState::Characterwise { anchor } => {
+            HighlightState::Characterwise { anchor: *anchor }
+        }
+        SelectionState::Linewise { anchor_field } => {
+            HighlightState::Linewise {
+                anchor_line: *anchor_field,
+            }
+        }
+    }
+}
+
+/// Core canvas field rendering with options
+#[cfg(feature = "gui")]
+fn render_canvas_fields_with_options<T: CanvasTheme, F1, F2>(
+    f: &mut Frame,
+    area: Rect,
+    fields: &[&str],
+    current_field_idx: &usize,
+    inputs: &[String],
+    theme: &T,
+    is_edit_mode: bool,
+    highlight_state: &HighlightState,
+    current_cursor_pos: usize,
+    has_unsaved_changes: bool,
+    get_display_value: F1,
+    has_display_override: F2,
+    active_completion: Option<String>,
+    opts: CanvasDisplayOptions,
+) -> Option<Rect>
+where
+    F1: Fn(usize) -> String,
+    F2: Fn(usize) -> bool,
+{
+    let columns = Layout::default()
+        .direction(Direction::Horizontal)
+        .constraints([Constraint::Percentage(30), Constraint::Percentage(70)])
+        .split(area);
+
+    let border_style = if has_unsaved_changes {
+        Style::default().fg(theme.warning())
+    } else if is_edit_mode {
+        Style::default().fg(theme.accent())
+    } else {
+        Style::default().fg(theme.secondary())
+    };
+
+    let input_container = Block::default()
+        .borders(Borders::ALL)
+        .border_type(BorderType::Rounded)
+        .border_style(border_style)
+        .style(Style::default().bg(theme.bg()));
+
+    let input_block = Rect {
+        x: columns[1].x,
+        y: columns[1].y,
+        width: columns[1].width,
+        height: fields.len() as u16 + 2,
+    };
+
+    f.render_widget(&input_container, input_block);
+
+    let input_area = input_container.inner(input_block);
+
+    let input_rows = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints(vec![Constraint::Length(1); fields.len()])
+        .split(input_area);
+
+    render_field_labels(f, columns[0], input_block, fields, theme);
+
+    let mut active_field_input_rect = None;
+
+    for i in 0..inputs.len() {
+        let is_active = i == *current_field_idx;
+        let typed_text = get_display_value(i);
+        let inner_width = input_rows[i].width;
+
+        // ---- BEGIN MODIFIED SECTION ----
+        let mut h_scroll_for_cursor: u16 = 0;
+        let mut left_offset_for_cursor: u16 = 0;
+
+        let line = match highlight_state {
+            // Selection highlighting active: always use highlighting, even for the active field
+            HighlightState::Characterwise { .. } | HighlightState::Linewise { .. } => {
+                apply_highlighting(
+                    &typed_text,
+                    i,
+                    current_field_idx,
+                    current_cursor_pos,
+                    highlight_state,
+                    theme,
+                    is_active,
+                )
+            }
+
+            // No selection highlighting
+            HighlightState::Off => match opts.overflow {
+                // Indicator mode: special-case the active field to preserve h-scroll + indicators
+                OverflowMode::Indicator(ind) => {
+                    if is_active {
+                        let (l, hs, left_cols) = render_active_line_with_indicator(
+                            &typed_text,
+                            active_completion.as_deref(),
+                            inner_width,
+                            ind,
+                            current_cursor_pos,
+                            theme,
+                        );
+                        h_scroll_for_cursor = hs;
+                        left_offset_for_cursor = left_cols;
+                        l
+                    } else if display_width(&typed_text) <= inner_width {
+                        Line::from(Span::raw(typed_text.clone()))
+                    } else {
+                        clip_with_indicator_line(&typed_text, inner_width, ind)
+                    }
+                }
+
+                // Wrap mode: keep active completion for active line
+                OverflowMode::Wrap => {
+                    if is_active {
+                        let mut spans: Vec<Span> = Vec::new();
+                        spans.push(Span::styled(
+                                typed_text.clone(),
+                                Style::default().fg(theme.fg()),
+                        ));
+                        if let Some(completion) = &active_completion {
+                            if !completion.is_empty() {
+                                spans.push(Span::styled(
+                                        completion.clone(),
+                                        Style::default().fg(theme.suggestion_gray()),
+                                ));
+                            }
+                        }
+                        Line::from(spans)
+                    } else {
+                        Line::from(Span::raw(typed_text.clone()))
+                    }
+                }
+            },
+        };        
+        // ---- END MODIFIED SECTION ----
+
+        let mut p = Paragraph::new(line).alignment(Alignment::Left);
+
+        if matches!(opts.overflow, OverflowMode::Wrap) {
+            p = p.wrap(Wrap { trim: false });
+        }
+
+        f.render_widget(p, input_rows[i]);
+
+        if is_active {
+            active_field_input_rect = Some(input_rows[i]);
+            set_cursor_position_scrolled(
+                f,
+                input_rows[i],
+                &typed_text,
+                current_cursor_pos,
+                has_display_override(i),
+                h_scroll_for_cursor,
+                left_offset_for_cursor,
+            );
+        }
+    }
+
+    active_field_input_rect
+}
+
+/// Render field labels
+#[cfg(feature = "gui")]
+fn render_field_labels<T: CanvasTheme>(
+    f: &mut Frame,
+    label_area: Rect,
+    input_block: Rect,
+    fields: &[&str],
+    theme: &T,
+) {
+    for (i, field) in fields.iter().enumerate() {
+        let label = Paragraph::new(Line::from(Span::styled(
+            format!("{field}:"),
+            Style::default().fg(theme.fg()),
+        )));
+        f.render_widget(
+            label,
+            Rect {
+                x: label_area.x,
+                y: input_block.y + 1 + i as u16,
+                width: label_area.width,
+                height: 1,
+            },
+        );
+    }
+}
+
+/// Apply highlighting based on highlight state
+#[cfg(feature = "gui")]
+fn apply_highlighting<'a, T: CanvasTheme>(
+    text: &'a str,
+    field_index: usize,
+    current_field_idx: &usize,
+    current_cursor_pos: usize,
+    highlight_state: &HighlightState,
+    theme: &T,
+    is_active: bool,
+) -> Line<'a> {
+    let text_len = text.chars().count();
+
+    match highlight_state {
+        HighlightState::Off => {
+            Line::from(Span::styled(text, Style::default().fg(theme.fg())))
+        }
+        HighlightState::Characterwise { anchor } => {
+            apply_characterwise_highlighting(
+                text,
+                text_len,
+                field_index,
+                current_field_idx,
+                current_cursor_pos,
+                anchor,
+                theme,
+                is_active,
+            )
+        }
+        HighlightState::Linewise { anchor_line } => {
+            apply_linewise_highlighting(
+                text,
+                field_index,
+                current_field_idx,
+                anchor_line,
+                theme,
+                is_active,
+            )
+        }
+    }
+}
+
+/// Apply characterwise highlighting (unchanged)
+#[cfg(feature = "gui")]
+fn apply_characterwise_highlighting<'a, T: CanvasTheme>(
+    text: &'a str,
+    text_len: usize,
+    field_index: usize,
+    current_field_idx: &usize,
+    current_cursor_pos: usize,
+    anchor: &(usize, usize),
+    theme: &T,
+    _is_active: bool,
+) -> Line<'a> {
+    let (anchor_field, anchor_char) = *anchor;
+    let start_field = min(anchor_field, *current_field_idx);
+    let end_field = max(anchor_field, *current_field_idx);
+
+    let highlight_style = Style::default()
+        .fg(theme.highlight())
+        .bg(theme.highlight_bg())
+        .add_modifier(Modifier::BOLD);
+
+    let normal_style = Style::default().fg(theme.fg());
+
+    if field_index >= start_field && field_index <= end_field {
+        if start_field == end_field {
+            let (start_char, end_char) = if anchor_field == *current_field_idx {
+                (
+                    min(anchor_char, current_cursor_pos),
+                    max(anchor_char, current_cursor_pos),
+                )
+            } else if anchor_field < *current_field_idx {
+                (anchor_char, current_cursor_pos)
+            } else {
+                (current_cursor_pos, anchor_char)
+            };
+
+            let clamped_start = start_char.min(text_len);
+            let clamped_end = end_char.min(text_len);
+
+            let before: String = text.chars().take(clamped_start).collect();
+            let highlighted: String = text
+                .chars()
+                .skip(clamped_start)
+                .take(clamped_end.saturating_sub(clamped_start) + 1)
+                .collect();
+            let after: String = text.chars().skip(clamped_end + 1).collect();
+
+            Line::from(vec![
+                Span::styled(before, normal_style),
+                Span::styled(highlighted, highlight_style),
+                Span::styled(after, normal_style),
+            ])
+        } else if field_index == anchor_field {
+            if anchor_field < *current_field_idx {
+                let clamped_start = anchor_char.min(text_len);
+                let before: String = text.chars().take(clamped_start).collect();
+                let highlighted: String = text.chars().skip(clamped_start).collect();
+
+                Line::from(vec![
+                    Span::styled(before, normal_style),
+                    Span::styled(highlighted, highlight_style),
+                ])
+            } else {
+                let clamped_end = anchor_char.min(text_len);
+                let highlighted: String = text.chars().take(clamped_end + 1).collect();
+                let after: String = text.chars().skip(clamped_end + 1).collect();
+
+                Line::from(vec![
+                    Span::styled(highlighted, highlight_style),
+                    Span::styled(after, normal_style),
+                ])
+            }
+        } else if field_index == *current_field_idx {
+            if anchor_field < *current_field_idx {
+                let clamped_end = current_cursor_pos.min(text_len);
+                let highlighted: String = text.chars().take(clamped_end + 1).collect();
+                let after: String = text.chars().skip(clamped_end + 1).collect();
+
+                Line::from(vec![
+                    Span::styled(highlighted, highlight_style),
+                    Span::styled(after, normal_style),
+                ])
+            } else {
+                let clamped_start = current_cursor_pos.min(text_len);
+                let before: String = text.chars().take(clamped_start).collect();
+                let highlighted: String = text.chars().skip(clamped_start).collect();
+
+                Line::from(vec![
+                    Span::styled(before, normal_style),
+                    Span::styled(highlighted, highlight_style),
+                ])
+            }
+        } else {
+            Line::from(Span::styled(text, highlight_style))
+        }
+    } else {
+        Line::from(Span::styled(text, normal_style))
+    }
+}
+
+/// Apply linewise highlighting (unchanged)
+#[cfg(feature = "gui")]
+fn apply_linewise_highlighting<'a, T: CanvasTheme>(
+    text: &'a str,
+    field_index: usize,
+    current_field_idx: &usize,
+    anchor_line: &usize,
+    theme: &T,
+    _is_active: bool,
+) -> Line<'a> {
+    let start_field = min(*anchor_line, *current_field_idx);
+    let end_field = max(*anchor_line, *current_field_idx);
+
+    let highlight_style = Style::default()
+        .fg(theme.highlight())
+        .bg(theme.highlight_bg())
+        .add_modifier(Modifier::BOLD);
+
+    let normal_style = Style::default().fg(theme.fg());
+
+    if field_index >= start_field && field_index <= end_field {
+        Line::from(Span::styled(text, highlight_style))
+    } else {
+        Line::from(Span::styled(text, normal_style))
+    }
+}
+
+/// Set cursor position (x clamp only; no Y offset with wrap in this version)
+#[cfg(feature = "gui")]
+fn set_cursor_position_scrolled(
+    f: &mut Frame,
+    field_rect: Rect,
+    text: &str,
+    current_cursor_pos: usize,
+    _has_display_override: bool,
+    h_scroll: u16,
+    left_offset: u16,
+) {
+    let mut cols: u16 = 0;
+    for (i, ch) in text.chars().enumerate() {
+        if i >= current_cursor_pos {
+            break;
+        }
+        cols = cols.saturating_add(UnicodeWidthChar::width(ch).unwrap_or(0) as u16);
+    }
+
+    let mut visible_x = cols.saturating_sub(h_scroll).saturating_add(left_offset);
+
+    let limit = field_rect.width.saturating_sub(1 + RIGHT_PAD);
+    if visible_x > limit {
+        visible_x = limit;
+    }
+
+    let cursor_x = field_rect.x.saturating_add(visible_x);
+    let cursor_y = field_rect.y;
+    f.set_cursor_position((cursor_x, cursor_y));
+}
+
+/// Default theme
+#[cfg(feature = "gui")]
+pub fn render_canvas_default<D: DataProvider>(
+    f: &mut Frame,
+    area: Rect,
+    editor: &FormEditor<D>,
+) -> Option<Rect> {
+    let theme = DefaultCanvasTheme;
+    render_canvas(f, area, editor, &theme)
+}

canvas/src/canvas/mod.rs

@@ -0,0 +1,23 @@
+// src/canvas/mod.rs
+//! Top-level canvas module.
+//!
+//! Re-exports commonly used canvas types and modules so that downstream
+//! consumers can import them from `crate::canvas`.
+
+pub mod actions;
+pub mod state;
+pub mod modes;
+
+#[cfg(feature = "gui")]
+pub mod gui;
+#[cfg(feature = "gui")]
+pub mod theme;
+
+#[cfg(feature = "cursor-style")]
+pub mod cursor;
+
+// Keep these exports for current functionality
+pub use modes::{AppMode, ModeManager, HighlightState};
+
+#[cfg(feature = "cursor-style")]
+pub use cursor::CursorManager;

canvas/src/canvas/modes/highlight.rs

@@ -0,0 +1,18 @@
+// src/canvas/modes/highlight.rs
+//! Highlight state definitions for canvas visual/selection modes.
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Default)]
+/// Represents the current highlight/visual selection state.
+///
+/// This enum is used by the GUI and selection logic to track whether a visual
+/// selection is active and its anchor position.
+pub enum HighlightState {
+    /// No highlighting active.
+    #[default]
+    Off,
+    /// Characterwise selection with an anchor (field_index, char_position).
+    Characterwise { anchor: (usize, usize) }, // (field_index, char_position)
+    /// Linewise selection anchored at a field index.
+    Linewise { anchor_line: usize },          // field_index
+}

canvas/src/canvas/modes/manager.rs

@@ -0,0 +1,106 @@
+// src/modes/handlers/mode_manager.rs
+// canvas/src/modes/manager.rs
+//! Mode manager utilities and the AppMode enum.
+//!
+//! This module defines the available canvas modes and provides helper
+//! functions to validate mode transitions and perform required side-effects
+//! such as updating cursor style when enabled.
+
+#[cfg(feature = "cursor-style")]
+use crate::canvas::CursorManager;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+/// Top-level application modes used by the canvas UI.
+///
+/// These modes control input handling, cursor behavior, and how the UI should
+/// respond to user actions.
+pub enum AppMode {
+    /// For intro and admin screens
+    General,
+    /// Canvas read-only mode (navigation)
+    ReadOnly,
+    /// Canvas edit mode (insertion/modification)
+    Edit,
+    /// Canvas highlight/visual mode (selection)
+    Highlight,
+    /// Command mode overlay (for commands)
+    Command,
+}
+
+pub struct ModeManager;
+
+impl ModeManager {
+    // Mode transition rules
+
+    /// Return true if the system can enter Command mode from the given current mode.
+    pub fn can_enter_command_mode(current_mode: AppMode) -> bool {
+        !matches!(current_mode, AppMode::Edit)
+    }
+
+    /// Return true if the system can enter Edit mode from the given current mode.
+    pub fn can_enter_edit_mode(current_mode: AppMode) -> bool {
+        matches!(current_mode, AppMode::ReadOnly)
+    }
+
+    /// Return true if the system can enter ReadOnly mode from the given current mode.
+    pub fn can_enter_read_only_mode(current_mode: AppMode) -> bool {
+        matches!(current_mode, AppMode::Edit | AppMode::Command | AppMode::Highlight)
+    }
+
+    /// Return true if the system can enter Highlight mode from the given current mode.
+    pub fn can_enter_highlight_mode(current_mode: AppMode) -> bool {
+        matches!(current_mode, AppMode::ReadOnly)
+    }
+
+
+    /// Transition to new mode with automatic cursor update (when cursor-style feature enabled).
+    ///
+    /// Returns the resulting mode or an I/O error if cursor style update fails.
+    pub fn transition_to_mode(current_mode: AppMode, new_mode: AppMode) -> std::io::Result<AppMode> {
+        #[cfg(feature = "textmode-normal")]
+        {
+            // Always force Edit in normalmode
+            Ok(AppMode::Edit)
+        }
+
+        #[cfg(not(feature = "textmode-normal"))]
+        {
+            if current_mode != new_mode {
+                #[cfg(feature = "cursor-style")]
+                {
+                    let _ = CursorManager::update_for_mode(new_mode);
+                }
+            }
+            Ok(new_mode)
+        }
+    }
+
+    /// Enter highlight mode with cursor styling.
+    ///
+    /// Returns Ok(true) if the transition succeeded (and cursor style was updated
+    /// when enabled), otherwise Ok(false) if the transition is not allowed.
+    pub fn enter_highlight_mode_with_cursor(current_mode: AppMode) -> std::io::Result<bool> {
+        if Self::can_enter_highlight_mode(current_mode) {
+            #[cfg(feature = "cursor-style")]
+            {
+                let _ = CursorManager::update_for_mode(AppMode::Highlight);
+            }
+            Ok(true)
+        } else {
+            Ok(false)
+        }
+    }
+
+    /// Exit highlight mode with cursor styling and return the next mode.
+    ///
+    /// This helper returns the mode to switch to (ReadOnly) and updates cursor
+    /// style if the feature is enabled.
+    pub fn exit_highlight_mode_with_cursor() -> std::io::Result<AppMode> {
+        let new_mode = AppMode::ReadOnly;
+        #[cfg(feature = "cursor-style")]
+        {
+            let _ = CursorManager::update_for_mode(new_mode);
+        }
+        Ok(new_mode)
+    }
+}

canvas/src/canvas/modes/mod.rs

@@ -0,0 +1,7 @@
+// canvas/src/modes/mod.rs
+
+pub mod highlight;
+pub mod manager;
+
+pub use highlight::HighlightState;
+pub use manager::{AppMode, ModeManager};

canvas/src/canvas/state.rs

@@ -0,0 +1,219 @@
+// src/canvas/state.rs
+//! Library-owned UI state - user never directly modifies this
+//!
+//! This module exposes the EditorState type (and related selection and
+//! suggestions types) which represent the internal UI state maintained by the
+//! canvas library. These types are intended for read-only access by callers
+//! and are mutated only through the library's APIs.
+
+use crate::canvas::modes::AppMode;
+
+/// Library-owned UI state - user never directly modifies this
+#[derive(Debug, Clone)]
+/// Internal editor UI state managed by the canvas library.
+///
+/// The fields are `pub(crate)` because they should only be modified by the
+/// library's internal action handlers. Consumers can use the provided getter
+/// methods to observe the state.
+pub struct EditorState {
+    // Navigation state
+    pub(crate) current_field: usize,
+    pub(crate) cursor_pos: usize,
+    pub(crate) ideal_cursor_column: usize,
+
+    // Mode state
+    pub(crate) current_mode: AppMode,
+
+    // Suggestions dropdown state (only available with suggestions feature)
+    #[cfg(feature = "suggestions")]
+    pub(crate) suggestions: SuggestionsUIState,
+
+    // Selection state (for vim visual mode)
+    pub(crate) selection: SelectionState,
+
+    // Validation state (only available with validation feature)
+    #[cfg(feature = "validation")]
+    pub(crate) validation: crate::validation::ValidationState,
+
+    /// Computed fields state (only when computed feature is enabled)
+    #[cfg(feature = "computed")]
+    pub(crate) computed: Option<crate::computed::ComputedState>,
+}
+
+#[cfg(feature = "suggestions")]
+#[derive(Debug, Clone)]
+/// Internal suggestions UI state used to manage the suggestions dropdown.
+pub struct SuggestionsUIState {
+    pub(crate) is_active: bool,
+    pub(crate) is_loading: bool,
+    pub(crate) selected_index: Option<usize>,
+    pub(crate) active_field: Option<usize>,
+    pub(crate) active_query: Option<String>,
+    pub(crate) completion_text: Option<String>,
+}
+
+#[derive(Debug, Clone)]
+/// SelectionState represents the current selection/visual mode state used by
+/// the canvas (for example, Vim-like visual modes).
+pub enum SelectionState {
+    /// No selection is active.
+    None,
+    /// Characterwise selection: (field_index, char_position)
+    Characterwise { anchor: (usize, usize) },
+    /// Linewise selection anchored at a field (field index).
+    Linewise { anchor_field: usize },
+}
+
+impl EditorState {
+    /// Create a new EditorState with default initial values.
+    pub fn new() -> Self {
+        Self {
+            current_field: 0,
+            cursor_pos: 0,
+            ideal_cursor_column: 0,
+            // NORMALMODE: always start in Edit
+            #[cfg(feature = "textmode-normal")]
+            current_mode: AppMode::Edit,
+            // Default (vim): start in ReadOnly
+            #[cfg(not(feature = "textmode-normal"))]
+            current_mode: AppMode::ReadOnly,
+
+            #[cfg(feature = "suggestions")]
+            suggestions: SuggestionsUIState {
+                is_active: false,
+                is_loading: false,
+                selected_index: None,
+                active_field: None,
+                active_query: None,
+                completion_text: None,
+            },
+            selection: SelectionState::None,
+            #[cfg(feature = "validation")]
+            validation: crate::validation::ValidationState::new(),
+            #[cfg(feature = "computed")]
+            computed: None,
+        }
+    }
+
+    // ===================================================================
+    // READ-ONLY ACCESS: User can fetch UI state for compatibility
+    // ===================================================================
+
+    /// Get current field index (for user's business logic)
+    pub fn current_field(&self) -> usize {
+        self.current_field
+    }
+
+    /// Check if field is computed
+    #[cfg(feature = "computed")]
+    pub fn is_computed_field(&self, field_index: usize) -> bool {
+        self.computed
+            .as_ref()
+            .map(|state| state.is_computed_field(field_index))
+            .unwrap_or(false)
+    }
+
+    /// Get current cursor position (for user's business logic)
+    pub fn cursor_position(&self) -> usize {
+        self.cursor_pos
+    }
+
+    /// Get ideal cursor column (for vim-like behavior)
+    pub fn ideal_cursor_column(&self) -> usize {
+        self.ideal_cursor_column
+    }
+
+    /// Get current mode (for user's business logic)
+    pub fn mode(&self) -> AppMode {
+        self.current_mode
+    }
+
+    /// Check if suggestions dropdown is active (for user's business logic)
+    #[cfg(feature = "suggestions")]
+    pub fn is_suggestions_active(&self) -> bool {
+        self.suggestions.is_active
+    }
+
+    /// Check if suggestions dropdown is loading (for user's business logic)
+    #[cfg(feature = "suggestions")]
+    pub fn is_suggestions_loading(&self) -> bool {
+        self.suggestions.is_loading
+    }
+
+    /// Get selection state (for user's business logic)
+    pub fn selection_state(&self) -> &SelectionState {
+        &self.selection
+    }
+
+    /// Get validation state (for user's business logic)
+    /// Only available when the 'validation' feature is enabled
+    #[cfg(feature = "validation")]
+    pub fn validation_state(&self) -> &crate::validation::ValidationState {
+        &self.validation
+    }
+
+    // ===================================================================
+    // INTERNAL MUTATIONS: Only library modifies these
+    // ===================================================================
+
+    /// Move internal pointer to another field index.
+    ///
+    /// This method is intended for internal library use to change the current
+    /// field and reset the cursor to a safe value.
+    pub(crate) fn move_to_field(&mut self, field_index: usize, field_count: usize) {
+        if field_index < field_count {
+            self.current_field = field_index;
+            // Reset cursor to safe position - will be clamped by movement logic
+            self.cursor_pos = 0;
+        }
+    }
+
+    /// Set the cursor position with appropriate clamping depending on mode.
+    ///
+    /// If `for_edit_mode` is true the cursor may be positioned at the end of
+    /// the text (allowing insertion); otherwise it will be kept within the
+    /// bounds of the existing text for read-only/highlight modes.
+    pub(crate) fn set_cursor(
+        &mut self,
+        position: usize,
+        max_position: usize,
+        for_edit_mode: bool,
+    ) {
+        if for_edit_mode {
+            // Edit mode: can go past end for insertion
+            self.cursor_pos = position.min(max_position);
+        } else {
+            // ReadOnly/Highlight: stay within text bounds
+            self.cursor_pos = position.min(max_position.saturating_sub(1));
+        }
+        self.ideal_cursor_column = self.cursor_pos;
+    }
+
+    /// Explicitly open suggestions — should only be called on Tab
+    #[cfg(feature = "suggestions")]
+    pub(crate) fn open_suggestions(&mut self, field_index: usize) {
+        self.suggestions.is_active = true;
+        self.suggestions.is_loading = true;
+        self.suggestions.active_field = Some(field_index);
+        self.suggestions.active_query = None;
+        self.suggestions.selected_index = None;
+        self.suggestions.completion_text = None;
+    }
+
+    /// Explicitly close suggestions — should be called on Esc or field change
+    #[cfg(feature = "suggestions")]
+    pub(crate) fn close_suggestions(&mut self) {
+        self.suggestions.is_active = false;
+        self.suggestions.is_loading = false;
+        self.suggestions.active_field = None;
+        self.suggestions.active_query = None;
+        self.suggestions.selected_index = None;
+        self.suggestions.completion_text = None;
+    }
+}
+
+impl Default for EditorState {
+    fn default() -> Self {
+        Self::new()
+    }
+}

canvas/src/canvas/theme.rs

@@ -0,0 +1,54 @@
+// canvas/src/gui/theme.rs
+
+#[cfg(feature = "gui")]
+use ratatui::style::Color;
+
+/// Theme trait that must be implemented by applications using the canvas GUI
+#[cfg(feature = "gui")]
+pub trait CanvasTheme {
+    fn bg(&self) -> Color;
+    fn fg(&self) -> Color;
+    fn border(&self) -> Color;
+    fn accent(&self) -> Color;
+    fn secondary(&self) -> Color;
+    fn highlight(&self) -> Color;
+    fn highlight_bg(&self) -> Color;
+    fn warning(&self) -> Color;
+    fn suggestion_gray(&self) -> Color;
+}
+
+
+#[cfg(feature = "gui")]
+#[derive(Debug, Clone, Default)]
+pub struct DefaultCanvasTheme;
+
+#[cfg(feature = "gui")]
+impl CanvasTheme for DefaultCanvasTheme {
+    fn bg(&self) -> Color {
+        Color::Black
+    }
+    fn fg(&self) -> Color {
+        Color::White
+    }
+    fn border(&self) -> Color {
+        Color::DarkGray
+    }
+    fn accent(&self) -> Color {
+        Color::Cyan
+    }
+    fn secondary(&self) -> Color {
+        Color::Gray
+    }
+    fn highlight(&self) -> Color {
+        Color::Yellow
+    }
+    fn highlight_bg(&self) -> Color {
+        Color::Blue
+    }
+    fn warning(&self) -> Color {
+        Color::Red
+    }
+    fn suggestion_gray(&self) -> Color {
+        Color::DarkGray
+    }
+}

canvas/src/computed/mod.rs

@@ -0,0 +1,11 @@
+//! Computed fields subsystem.
+//!
+//! This module exposes the provider trait and the internal state management
+//! for computed (display-only) fields. Computed fields are values derived
+//! from other fields in the form and are not directly editable by the user.
+
+pub mod provider;
+pub mod state;
+
+pub use provider::{ComputedContext, ComputedProvider};
+pub use state::ComputedState;

canvas/src/computed/provider.rs

@@ -0,0 +1,32 @@
+//! Provider interface and context for computed/display-only fields.
+//!
+//! Implementors provide logic to compute a field's display value from the
+//! other field values in the form.
+
+/// Context information provided to computed field calculations
+#[derive(Debug, Clone)]
+pub struct ComputedContext<'a> {
+    /// All field values in the form (index -> value)
+    pub field_values: &'a [&'a str],
+    /// The field index being computed
+    pub target_field: usize,
+    /// Current field that user is editing (if any)
+    pub current_field: Option<usize>,
+}
+
+/// User implements this to provide computed field logic
+pub trait ComputedProvider {
+    /// Compute value for a field based on other field values.
+    /// Called automatically when any field changes.
+    fn compute_field(&mut self, context: ComputedContext) -> String;
+
+    /// Check if this provider handles the given field.
+    fn handles_field(&self, field_index: usize) -> bool;
+
+    /// Get list of field dependencies for optimization.
+    /// If field A depends on fields [1, 3], only recompute A when fields 1 or 3 change.
+    /// Default: depend on all fields (always recompute) with a reasonable upper bound.
+    fn field_dependencies(&self, _field_index: usize) -> Vec<usize> {
+        (0..100).collect()
+    }
+}

canvas/src/computed/state.rs

@@ -0,0 +1,87 @@
+// src/computed/state.rs
+//! Computed field state: caching and dependency graph.
+//!
+//! This module holds the internal state necessary to track which fields are
+//! computed, their dependencies, and cached computed values. It is used by the
+//! editor to avoid unnecessary recomputation and to present computed fields as
+//! read-only.
+
+use std::collections::{HashMap, HashSet};
+
+/// Internal state for computed field management
+#[derive(Debug, Clone)]
+pub struct ComputedState {
+    /// Cached computed values (field_index -> computed_value)
+    computed_values: HashMap<usize, String>,
+    /// Field dependency graph (field_index -> depends_on_fields)
+    dependencies: HashMap<usize, Vec<usize>>,
+    /// Track which fields are computed (display-only)
+    computed_fields: HashSet<usize>,
+}
+
+impl ComputedState {
+    /// Create a new, empty computed state
+    pub fn new() -> Self {
+        Self {
+            computed_values: HashMap::new(),
+            dependencies: HashMap::new(),
+            computed_fields: HashSet::new(),
+        }
+    }
+
+    /// Register a field as computed with its dependencies
+    ///
+    /// - `field_index`: the field that is computed (display-only)
+    /// - `dependencies`: indices of fields this computed field depends on
+    pub fn register_computed_field(&mut self, field_index: usize, mut dependencies: Vec<usize>) {
+        // Deduplicate dependencies to keep graph lean
+        dependencies.sort_unstable();
+        dependencies.dedup();
+
+        self.computed_fields.insert(field_index);
+        self.dependencies.insert(field_index, dependencies);
+    }
+
+    /// Check if a field is computed (read-only, skip editing/navigation)
+    pub fn is_computed_field(&self, field_index: usize) -> bool {
+        self.computed_fields.contains(&field_index)
+    }
+
+    /// Get cached computed value for a field, if available
+    pub fn get_computed_value(&self, field_index: usize) -> Option<&String> {
+        self.computed_values.get(&field_index)
+    }
+
+    /// Update cached computed value for a field
+    pub fn set_computed_value(&mut self, field_index: usize, value: String) {
+        self.computed_values.insert(field_index, value);
+    }
+
+    /// Get fields that should be recomputed when `changed_field` changed
+    ///
+    /// This scans the dependency graph and returns all computed fields
+    /// that list `changed_field` as a dependency.
+    pub fn fields_to_recompute(&self, changed_field: usize) -> Vec<usize> {
+        self.dependencies
+            .iter()
+            .filter_map(|(field, deps)| {
+                if deps.contains(&changed_field) {
+                    Some(*field)
+                } else {
+                    None
+                }
+            })
+            .collect()
+    }
+
+    /// Iterator over all computed field indices
+    pub fn computed_fields(&self) -> impl Iterator<Item = usize> + '_ {
+        self.computed_fields.iter().copied()
+    }
+}
+
+impl Default for ComputedState {
+    fn default() -> Self {
+        Self::new()
+    }
+}

canvas/src/data_provider.rs

@@ -0,0 +1,69 @@
+// src/data_provider.rs
+//! Simplified user interface - only business data, no UI state
+
+#[cfg(feature = "suggestions")]
+use anyhow::Result;
+#[cfg(feature = "suggestions")]
+use async_trait::async_trait;
+
+/// User implements this - only business data, no UI state
+pub trait DataProvider {
+    /// How many fields in the form
+    fn field_count(&self) -> usize;
+
+    /// Get field label/name
+    fn field_name(&self, index: usize) -> &str;
+
+    /// Get field value
+    fn field_value(&self, index: usize) -> &str;
+
+    /// Set field value (library calls this when text changes)
+    fn set_field_value(&mut self, index: usize, value: String);
+
+    /// Check if field supports suggestions (optional)
+    fn supports_suggestions(&self, _field_index: usize) -> bool {
+        false
+    }
+
+    /// Get display value (for password masking, etc.) - optional
+    fn display_value(&self, _index: usize) -> Option<&str> {
+        None // Default: use actual value
+    }
+
+    /// Get validation configuration for a field (optional)
+    /// Only available when the 'validation' feature is enabled
+    #[cfg(feature = "validation")]
+    fn validation_config(&self, _field_index: usize) -> Option<crate::validation::ValidationConfig> {
+        None
+    }
+
+    /// Check if field is computed (display-only, skip in navigation)
+    /// Default: not computed
+    #[cfg(feature = "computed")]
+    fn is_computed_field(&self, _field_index: usize) -> bool {
+        false
+    }
+
+    /// Get computed field value if this is a computed field.
+    /// Returns None for regular fields. Default: not computed.
+    #[cfg(feature = "computed")]
+    fn computed_field_value(&self, _field_index: usize) -> Option<String> {
+        None
+    }
+}
+
+/// Optional: User implements this for suggestions data
+#[cfg(feature = "suggestions")]
+#[async_trait]
+pub trait SuggestionsProvider {
+    /// Fetch suggestions (user's business logic)
+    async fn fetch_suggestions(&mut self, field_index: usize, query: &str)
+        -> Result<Vec<SuggestionItem>>;
+}
+
+#[cfg(feature = "suggestions")]
+#[derive(Debug, Clone)]
+pub struct SuggestionItem {
+    pub display_text: String,
+    pub value_to_store: String,
+}

canvas/src/editor/computed_helpers.rs

@@ -0,0 +1,111 @@
+// src/editor/computed_helpers.rs
+
+use crate::computed::{ComputedContext, ComputedProvider, ComputedState};
+use crate::editor::FormEditor;
+use crate::DataProvider;
+
+impl<D: DataProvider> FormEditor<D> {
+    #[cfg(feature = "computed")]
+    pub fn set_computed_provider<C>(&mut self, mut provider: C)
+    where
+        C: ComputedProvider,
+    {
+        self.ui_state.computed = Some(ComputedState::new());
+
+        let field_count = self.data_provider.field_count();
+        for field_index in 0..field_count {
+            if provider.handles_field(field_index) {
+                let deps = provider.field_dependencies(field_index);
+                if let Some(computed_state) = &mut self.ui_state.computed {
+                    computed_state.register_computed_field(field_index, deps);
+                }
+            }
+        }
+
+        self.recompute_all_fields(&mut provider);
+    }
+
+    #[cfg(feature = "computed")]
+    pub fn recompute_fields<C>(
+        &mut self,
+        provider: &mut C,
+        field_indices: &[usize],
+    ) where
+        C: ComputedProvider,
+    {
+        if let Some(computed_state) = &mut self.ui_state.computed {
+            let field_values: Vec<String> = (0..self.data_provider.field_count())
+                .map(|i| {
+                    if computed_state.is_computed_field(i) {
+                        computed_state
+                            .get_computed_value(i)
+                            .cloned()
+                            .unwrap_or_default()
+                    } else {
+                        self.data_provider.field_value(i).to_string()
+                    }
+                })
+                .collect();
+
+            let field_refs: Vec<&str> =
+                field_values.iter().map(|s| s.as_str()).collect();
+
+            for &field_index in field_indices {
+                if provider.handles_field(field_index) {
+                    let context = ComputedContext {
+                        field_values: &field_refs,
+                        target_field: field_index,
+                        current_field: Some(self.ui_state.current_field),
+                    };
+
+                    let computed_value = provider.compute_field(context);
+                    computed_state.set_computed_value(
+                        field_index,
+                        computed_value,
+                    );
+                }
+            }
+        }
+    }
+
+    #[cfg(feature = "computed")]
+    pub fn recompute_all_fields<C>(&mut self, provider: &mut C)
+    where
+        C: ComputedProvider,
+    {
+        if let Some(computed_state) = &self.ui_state.computed {
+            let computed_fields: Vec<usize> =
+                computed_state.computed_fields().collect();
+            self.recompute_fields(provider, &computed_fields);
+        }
+    }
+
+    #[cfg(feature = "computed")]
+    pub fn on_field_changed<C>(
+        &mut self,
+        provider: &mut C,
+        changed_field: usize,
+    ) where
+        C: ComputedProvider,
+    {
+        if let Some(computed_state) = &self.ui_state.computed {
+            let fields_to_update =
+                computed_state.fields_to_recompute(changed_field);
+            if !fields_to_update.is_empty() {
+                self.recompute_fields(provider, &fields_to_update);
+            }
+        }
+    }
+
+    #[cfg(feature = "computed")]
+    pub fn effective_field_value(&self, field_index: usize) -> String {
+        if let Some(computed_state) = &self.ui_state.computed {
+            if let Some(computed_value) =
+                computed_state.get_computed_value(field_index)
+            {
+                return computed_value.clone();
+            }
+        }
+        self.data_provider.field_value(field_index).to_string()
+    }
+}

canvas/src/editor/core.rs

@@ -0,0 +1,166 @@
+// src/editor/core.rs
+
+#[cfg(feature = "cursor-style")]
+use crate::canvas::CursorManager;
+
+use crate::canvas::modes::AppMode;
+use crate::canvas::state::EditorState;
+use crate::DataProvider;
+#[cfg(feature = "suggestions")]
+use crate::SuggestionItem;
+
+// NEW: Import keymap types when keymap feature is enabled
+#[cfg(feature = "keymap")]
+use crate::keymap::{CanvasKeyMap, KeySequenceTracker};
+
+pub struct FormEditor<D: DataProvider> {
+    pub(crate) ui_state: EditorState,
+    pub(crate) data_provider: D,
+    #[cfg(feature = "suggestions")]
+    pub(crate) suggestions: Vec<SuggestionItem>,
+
+    #[cfg(feature = "validation")]
+    pub(crate) external_validation_callback: Option<
+        Box<
+            dyn FnMut(usize, &str) -> crate::validation::ExternalValidationState
+                + Send
+                + Sync,
+        >,
+    >,
+
+    // NEW: Injected keymap and sequence tracker (keymap feature only)
+    #[cfg(feature = "keymap")]
+    pub(crate) keymap: Option<CanvasKeyMap>,
+    #[cfg(feature = "keymap")]
+    pub(crate) seq_tracker: KeySequenceTracker,
+}
+
+impl<D: DataProvider> FormEditor<D> {
+    // Make helpers visible to sibling modules in this crate
+    pub(crate) fn char_to_byte_index(s: &str, char_idx: usize) -> usize {
+        s.char_indices()
+            .nth(char_idx)
+            .map(|(byte_idx, _)| byte_idx)
+            .unwrap_or_else(|| s.len())
+    }
+
+    #[allow(dead_code)]
+    pub(crate) fn byte_to_char_index(s: &str, byte_idx: usize) -> usize {
+        s[..byte_idx].chars().count()
+    }
+
+    pub fn new(data_provider: D) -> Self {
+        let editor = Self {
+            ui_state: EditorState::new(),
+            data_provider,
+            #[cfg(feature = "suggestions")]
+            suggestions: Vec::new(),
+            #[cfg(feature = "validation")]
+            external_validation_callback: None,
+            // NEW: Initialize keymap fields
+            #[cfg(feature = "keymap")]
+            keymap: None,
+            #[cfg(feature = "keymap")]
+            seq_tracker: KeySequenceTracker::new(400), // 400ms default timeout
+        };
+
+        #[cfg(feature = "validation")]
+        {
+            let mut editor = editor;
+            editor.initialize_validation();
+
+            #[cfg(feature = "cursor-style")]
+            {
+                let _ = CursorManager::update_for_mode(editor.ui_state.current_mode);
+            }
+            editor
+        }
+        #[cfg(not(feature = "validation"))]
+        {
+            #[cfg(feature = "cursor-style")]
+            {
+                let _ = CursorManager::update_for_mode(editor.ui_state.current_mode);
+            }
+            editor
+        }
+    }
+
+    // NEW: Keymap management methods (keymap feature only)
+    
+    /// Set the keymap for this editor instance
+    #[cfg(feature = "keymap")]
+    pub fn set_keymap(&mut self, keymap: CanvasKeyMap) {
+        self.keymap = Some(keymap);
+    }
+
+    /// Check if this editor has a keymap configured
+    #[cfg(feature = "keymap")]
+    pub fn has_keymap(&self) -> bool {
+        self.keymap.is_some()
+    }
+
+    /// Set the timeout for multi-key sequences (in milliseconds)
+    #[cfg(feature = "keymap")]
+    pub fn set_key_sequence_timeout_ms(&mut self, timeout_ms: u64) {
+        self.seq_tracker = KeySequenceTracker::new(timeout_ms);
+    }
+
+    // Library-internal, used by multiple modules
+    pub(crate) fn current_text(&self) -> &str {
+        let field_index = self.ui_state.current_field;
+        if field_index < self.data_provider.field_count() {
+            self.data_provider.field_value(field_index)
+        } else {
+            ""
+        }
+    }
+
+    // Read-only getters
+    pub fn current_field(&self) -> usize {
+        self.ui_state.current_field()
+    }
+    pub fn cursor_position(&self) -> usize {
+        self.ui_state.cursor_position()
+    }
+    pub fn mode(&self) -> AppMode {
+        self.ui_state.mode()
+    }
+    #[cfg(feature = "suggestions")]
+    pub fn is_suggestions_active(&self) -> bool {
+        self.ui_state.is_suggestions_active()
+    }
+    pub fn ui_state(&self) -> &EditorState {
+        &self.ui_state
+    }
+    pub fn data_provider(&self) -> &D {
+        &self.data_provider
+    }
+    pub fn data_provider_mut(&mut self) -> &mut D {
+        &mut self.data_provider
+    }
+    #[cfg(feature = "suggestions")]
+    pub fn suggestions(&self) -> &[SuggestionItem] {
+        &self.suggestions
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn validation_state(&self) -> &crate::validation::ValidationState {
+        self.ui_state.validation_state()
+    }
+
+    // Cursor cleanup
+    #[cfg(feature = "cursor-style")]
+    pub fn cleanup_cursor(&self) -> std::io::Result<()> {
+        CursorManager::reset()
+    }
+    #[cfg(not(feature = "cursor-style"))]
+    pub fn cleanup_cursor(&self) -> std::io::Result<()> {
+        Ok(())
+    }
+}
+
+impl<D: DataProvider> Drop for FormEditor<D> {
+    fn drop(&mut self) {
+        let _ = self.cleanup_cursor();
+    }
+}

canvas/src/editor/display.rs

@@ -0,0 +1,123 @@
+// src/editor/display.rs
+
+use crate::canvas::modes::AppMode;
+use crate::editor::FormEditor;
+use crate::DataProvider;
+
+impl<D: DataProvider> FormEditor<D> {
+    /// Get current field text for display.
+    /// Policies documented in original file.
+    #[cfg(feature = "validation")]
+    pub fn current_display_text(&self) -> String {
+        let field_index = self.ui_state.current_field;
+        let raw = if field_index < self.data_provider.field_count() {
+            self.data_provider.field_value(field_index)
+        } else {
+            ""
+        };
+
+        if let Some(cfg) = self.ui_state.validation.get_field_config(field_index) {
+            if cfg.custom_formatter.is_none() {
+                if let Some(mask) = &cfg.display_mask {
+                    return mask.apply_to_display(raw);
+                }
+            }
+
+            if cfg.custom_formatter.is_some() {
+                if matches!(self.ui_state.current_mode, AppMode::Edit) {
+                    return raw.to_string();
+                }
+                if let Some((formatted, _mapper, _warning)) =
+                    cfg.run_custom_formatter(raw)
+                {
+                    return formatted;
+                }
+            }
+
+            if let Some(mask) = &cfg.display_mask {
+                return mask.apply_to_display(raw);
+            }
+        }
+
+        raw.to_string()
+    }
+
+    /// Get effective display text for any field index (Feature 4 + masks).
+    #[cfg(feature = "validation")]
+    pub fn display_text_for_field(&self, field_index: usize) -> String {
+        let raw = if field_index < self.data_provider.field_count() {
+            self.data_provider.field_value(field_index)
+        } else {
+            ""
+        };
+
+        if let Some(cfg) = self.ui_state.validation.get_field_config(field_index) {
+            if cfg.custom_formatter.is_none() {
+                if let Some(mask) = &cfg.display_mask {
+                    return mask.apply_to_display(raw);
+                }
+            }
+
+            if cfg.custom_formatter.is_some() {
+                if field_index == self.ui_state.current_field
+                    && matches!(self.ui_state.current_mode, AppMode::Edit)
+                {
+                    return raw.to_string();
+                }
+                if let Some((formatted, _mapper, _warning)) =
+                    cfg.run_custom_formatter(raw)
+                {
+                    return formatted;
+                }
+            }
+
+            if let Some(mask) = &cfg.display_mask {
+                return mask.apply_to_display(raw);
+            }
+        }
+
+        raw.to_string()
+    }
+
+    /// Map raw cursor to display position (formatter/mask aware).
+    pub fn display_cursor_position(&self) -> usize {
+        let current_text = self.current_text();
+        let char_count = current_text.chars().count();
+
+        let raw_pos = match self.ui_state.current_mode {
+            AppMode::Edit => self.ui_state.cursor_pos.min(char_count),
+            _ => {
+                if char_count == 0 {
+                    0
+                } else {
+                    self.ui_state
+                        .cursor_pos
+                        .min(char_count.saturating_sub(1))
+                }
+            }
+        };
+
+        #[cfg(feature = "validation")]
+        {
+            let field_index = self.ui_state.current_field;
+            if let Some(cfg) = self.ui_state.validation.get_field_config(field_index) {
+                if !matches!(self.ui_state.current_mode, AppMode::Edit) {
+                    if let Some((formatted, mapper, _)) =
+                        cfg.run_custom_formatter(current_text)
+                    {
+                        return mapper.raw_to_formatted(
+                            current_text,
+                            &formatted,
+                            raw_pos,
+                        );
+                    }
+                }
+                if let Some(mask) = &cfg.display_mask {
+                    return mask.raw_pos_to_display_pos(raw_pos);
+                }
+            }
+        }
+
+        raw_pos
+    }
+}

canvas/src/editor/editing.rs

@@ -0,0 +1,348 @@
+// src/editor/editing.rs
+
+use crate::editor::FormEditor;
+use crate::DataProvider;
+
+impl<D: DataProvider> FormEditor<D> {
+    /// Open new line below (vim o)
+    pub fn open_line_below(&mut self) -> anyhow::Result<()> {
+        // paste the method body unchanged from editor.rs
+        // (exact code from your VIM COMMANDS: o and O section)
+        let field_count = self.data_provider.field_count();
+        if field_count == 0 {
+            return Ok(());
+        }
+        let next_field = (self.ui_state.current_field + 1)
+            .min(field_count.saturating_sub(1));
+        self.transition_to_field(next_field)?;
+        self.ui_state.cursor_pos = 0;
+        self.ui_state.ideal_cursor_column = 0;
+        self.enter_edit_mode();
+        Ok(())
+    }
+
+    /// Open new line above (vim O)
+    pub fn open_line_above(&mut self) -> anyhow::Result<()> {
+        let prev_field = self.ui_state.current_field.saturating_sub(1);
+        self.transition_to_field(prev_field)?;
+        self.ui_state.cursor_pos = 0;
+        self.ui_state.ideal_cursor_column = 0;
+        self.enter_edit_mode();
+        Ok(())
+    }
+
+    /// Handle character insertion (mask/limit-aware)
+    pub fn insert_char(&mut self, ch: char) -> anyhow::Result<()> {
+        // paste entire insert_char body unchanged
+        if self.ui_state.current_mode != crate::canvas::modes::AppMode::Edit
+        {
+            return Ok(());
+        }
+
+        #[cfg(feature = "validation")]
+        let field_index = self.ui_state.current_field;
+        #[cfg(feature = "validation")]
+        let raw_cursor_pos = self.ui_state.cursor_pos;
+        #[cfg(feature = "validation")]
+        let current_raw_text = self.data_provider.field_value(field_index);
+
+        #[cfg(not(feature = "validation"))]
+        let field_index = self.ui_state.current_field;
+        #[cfg(not(feature = "validation"))]
+        let raw_cursor_pos = self.ui_state.cursor_pos;
+        #[cfg(not(feature = "validation"))]
+        let current_raw_text = self.data_provider.field_value(field_index);
+
+        #[cfg(feature = "validation")]
+        {
+            if let Some(cfg) = self.ui_state.validation.get_field_config(
+                field_index,
+            ) {
+                if let Some(mask) = &cfg.display_mask {
+                    let display_cursor_pos =
+                        mask.raw_pos_to_display_pos(raw_cursor_pos);
+
+                    let pattern_char_len = mask.pattern().chars().count();
+                    if display_cursor_pos >= pattern_char_len {
+                        return Ok(());
+                    }
+
+                    if !mask.is_input_position(display_cursor_pos) {
+                        return Ok(());
+                    }
+
+                    let input_slots = (0..pattern_char_len)
+                        .filter(|&pos| mask.is_input_position(pos))
+                        .count();
+                    if current_raw_text.chars().count() >= input_slots {
+                        return Ok(());
+                    }
+                }
+            }
+        }
+
+        #[cfg(feature = "validation")]
+        {
+            let vr = self.ui_state.validation.validate_char_insertion(
+                field_index,
+                current_raw_text,
+                raw_cursor_pos,
+                ch,
+            );
+            if !vr.is_acceptable() {
+                return Ok(());
+            }
+        }
+
+        let new_raw_text = {
+            let mut temp = current_raw_text.to_string();
+            let byte_pos = Self::char_to_byte_index(
+                current_raw_text,
+                raw_cursor_pos,
+            );
+            temp.insert(byte_pos, ch);
+            temp
+        };
+
+        #[cfg(feature = "validation")]
+        {
+            if let Some(cfg) = self.ui_state.validation.get_field_config(
+                field_index,
+            ) {
+                if let Some(limits) = &cfg.character_limits {
+                    if let Some(result) = limits.validate_content(&new_raw_text)
+                    {
+                        if !result.is_acceptable() {
+                            return Ok(());
+                        }
+                    }
+                }
+                if let Some(mask) = &cfg.display_mask {
+                    let pattern_char_len = mask.pattern().chars().count();
+                    let input_slots = (0..pattern_char_len)
+                        .filter(|&pos| mask.is_input_position(pos))
+                        .count();
+                    if new_raw_text.chars().count() > input_slots {
+                        return Ok(());
+                    }
+                }
+            }
+        }
+
+        self.data_provider
+            .set_field_value(field_index, new_raw_text.clone());
+
+        #[cfg(feature = "validation")]
+        {
+            if let Some(cfg) = self.ui_state.validation.get_field_config(
+                field_index,
+            ) {
+                if let Some(mask) = &cfg.display_mask {
+                    let new_raw_pos = raw_cursor_pos + 1;
+                    let display_pos = mask.raw_pos_to_display_pos(new_raw_pos);
+                    let next_input_display =
+                        mask.next_input_position(display_pos);
+                    let next_raw_pos =
+                        mask.display_pos_to_raw_pos(next_input_display);
+                    let max_raw = new_raw_text.chars().count();
+
+                    self.ui_state.cursor_pos = next_raw_pos.min(max_raw);
+                    self.ui_state.ideal_cursor_column =
+                        self.ui_state.cursor_pos;
+                    return Ok(());
+                }
+            }
+        }
+
+        self.ui_state.cursor_pos = raw_cursor_pos + 1;
+        self.ui_state.ideal_cursor_column = self.ui_state.cursor_pos;
+        Ok(())
+    }
+
+    /// Delete backward (backspace)
+    pub fn delete_backward(&mut self) -> anyhow::Result<()> {
+        // paste entire delete_backward body unchanged
+        if self.ui_state.current_mode != crate::canvas::modes::AppMode::Edit
+        {
+            return Ok(());
+        }
+        if self.ui_state.cursor_pos == 0 {
+            return Ok(());
+        }
+
+        let field_index = self.ui_state.current_field;
+        let mut current_text =
+            self.data_provider.field_value(field_index).to_string();
+
+        let new_cursor = self.ui_state.cursor_pos.saturating_sub(1);
+
+        let start = Self::char_to_byte_index(
+            &current_text,
+            self.ui_state.cursor_pos - 1,
+        );
+        let end =
+            Self::char_to_byte_index(&current_text, self.ui_state.cursor_pos);
+        current_text.replace_range(start..end, "");
+        self.data_provider
+            .set_field_value(field_index, current_text.clone());
+
+        #[cfg(feature = "validation")]
+        let mut target_cursor = new_cursor;
+        #[cfg(not(feature = "validation"))]
+        let target_cursor = new_cursor;
+
+        #[cfg(feature = "validation")]
+        {
+            if let Some(cfg) = self.ui_state.validation.get_field_config(
+                field_index,
+            ) {
+                if let Some(mask) = &cfg.display_mask {
+                    let display_pos =
+                        mask.raw_pos_to_display_pos(new_cursor);
+                    if let Some(prev_input) =
+                        mask.prev_input_position(display_pos)
+                    {
+                        target_cursor =
+                            mask.display_pos_to_raw_pos(prev_input);
+                    }
+                }
+            }
+        }
+
+        self.ui_state.cursor_pos = target_cursor;
+        self.ui_state.ideal_cursor_column = target_cursor;
+
+        #[cfg(feature = "validation")]
+        {
+            let _ = self.ui_state.validation.validate_field_content(
+                field_index,
+                &current_text,
+            );
+        }
+
+        Ok(())
+    }
+
+    /// Delete forward (Delete key)
+    pub fn delete_forward(&mut self) -> anyhow::Result<()> {
+        // paste entire delete_forward body unchanged
+        if self.ui_state.current_mode != crate::canvas::modes::AppMode::Edit
+        {
+            return Ok(());
+        }
+
+        let field_index = self.ui_state.current_field;
+        let mut current_text =
+            self.data_provider.field_value(field_index).to_string();
+
+        if self.ui_state.cursor_pos < current_text.chars().count() {
+            let start = Self::char_to_byte_index(
+                &current_text,
+                self.ui_state.cursor_pos,
+            );
+            let end = Self::char_to_byte_index(
+                &current_text,
+                self.ui_state.cursor_pos + 1,
+            );
+            current_text.replace_range(start..end, "");
+            self.data_provider
+                .set_field_value(field_index, current_text.clone());
+
+            #[cfg(feature = "validation")]
+            let mut target_cursor = self.ui_state.cursor_pos;
+            #[cfg(not(feature = "validation"))]
+            let target_cursor = self.ui_state.cursor_pos;
+
+            #[cfg(feature = "validation")]
+            {
+                if let Some(cfg) = self.ui_state.validation.get_field_config(
+                    field_index,
+                ) {
+                    if let Some(mask) = &cfg.display_mask {
+                        let display_pos =
+                            mask.raw_pos_to_display_pos(
+                                self.ui_state.cursor_pos,
+                            );
+                        let next_input =
+                            mask.next_input_position(display_pos);
+                        target_cursor = mask
+                            .display_pos_to_raw_pos(next_input)
+                            .min(current_text.chars().count());
+                    }
+                }
+            }
+
+            self.ui_state.cursor_pos = target_cursor;
+            self.ui_state.ideal_cursor_column = target_cursor;
+
+            #[cfg(feature = "validation")]
+            {
+                let _ = self.ui_state.validation.validate_field_content(
+                    field_index,
+                    &current_text,
+                );
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Enter edit mode with cursor positioned for append (vim 'a')
+    pub fn enter_append_mode(&mut self) {
+        // paste body unchanged
+        let current_text = self.current_text();
+
+        let char_len = current_text.chars().count();
+        let append_pos = if current_text.is_empty() {
+            0
+        } else {
+            (self.ui_state.cursor_pos + 1).min(char_len)
+        };
+
+        self.ui_state.cursor_pos = append_pos;
+        self.ui_state.ideal_cursor_column = append_pos;
+
+        self.set_mode(crate::canvas::modes::AppMode::Edit);
+    }
+
+    /// Set current field value (validates under feature flag)
+    pub fn set_current_field_value(&mut self, value: String) {
+        let field_index = self.ui_state.current_field;
+        self.data_provider.set_field_value(field_index, value.clone());
+        self.ui_state.cursor_pos = 0;
+        self.ui_state.ideal_cursor_column = 0;
+
+        #[cfg(feature = "validation")]
+        {
+            let _ = self
+                .ui_state
+                .validation
+                .validate_field_content(field_index, &value);
+        }
+    }
+
+    /// Set specific field value by index (validates under feature flag)
+    pub fn set_field_value(&mut self, field_index: usize, value: String) {
+        if field_index < self.data_provider.field_count() {
+            self.data_provider
+                .set_field_value(field_index, value.clone());
+            if field_index == self.ui_state.current_field {
+                self.ui_state.cursor_pos = 0;
+                self.ui_state.ideal_cursor_column = 0;
+            }
+
+            #[cfg(feature = "validation")]
+            {
+                let _ = self
+                    .ui_state
+                    .validation
+                    .validate_field_content(field_index, &value);
+            }
+        }
+    }
+
+    /// Clear the current field
+    pub fn clear_current_field(&mut self) {
+        self.set_current_field_value(String::new());
+    }
+}

canvas/src/editor/key_input.rs

@@ -0,0 +1,228 @@
+// src/editor/key_input.rs
+use crossterm::event::{KeyCode, KeyEvent, KeyModifiers};
+
+use crate::canvas::modes::AppMode;
+use crate::editor::FormEditor;
+use crate::DataProvider;
+
+#[cfg(feature = "keymap")]
+use crate::keymap::{KeyEventOutcome, KeyStroke};
+
+impl<D: DataProvider> FormEditor<D> {
+    #[cfg(feature = "keymap")]
+    pub fn handle_key_event(&mut self, evt: KeyEvent) -> KeyEventOutcome {
+        // Check if keymap exists first
+        if self.keymap.is_none() {
+            return KeyEventOutcome::NotMatched;
+        }
+
+        let mode = self.ui_state.current_mode;
+
+        // Convert event to normalized stroke
+        let stroke = KeyStroke {
+            code: evt.code,
+            modifiers: evt.modifiers,
+        };
+
+        // Add key to sequence tracker
+        self.seq_tracker.add_key(stroke);
+
+        // Look up the action in keymap
+        let (matched, is_prefix) = {
+            let km = self.keymap.as_ref().unwrap();
+            km.lookup(mode, self.seq_tracker.sequence())
+        };
+
+        if let Some(action) = matched {
+            // Clone the action string to avoid borrow checker issues
+            let action_owned = action.to_string();
+            let msg = self.dispatch_canvas_action(&action_owned);
+            self.seq_tracker.reset();
+            return KeyEventOutcome::Consumed(msg);
+        }
+
+        if is_prefix {
+            // Wait for more keys
+            return KeyEventOutcome::Pending;
+        }
+
+        // No match: reset sequence and try insert-char fallback in Edit
+        self.seq_tracker.reset();
+
+        if mode == AppMode::Edit {
+            if let KeyCode::Char(c) = evt.code {
+                // Skip control/alt combos
+                let m = evt.modifiers;
+                let is_plain =
+                    m.is_empty() || m == KeyModifiers::SHIFT;
+                if is_plain {
+                    if self.insert_char(c).is_ok() {
+                        return KeyEventOutcome::Consumed(None);
+                    }
+                }
+            }
+        }
+
+        KeyEventOutcome::NotMatched
+    }
+
+    #[cfg(feature = "keymap")]
+    fn dispatch_canvas_action(&mut self, action: &str) -> Option<String> {
+        match action {
+            // Movement
+            "move_left" => {
+                let _ = self.move_left();
+                None
+            }
+            "move_right" => {
+                let _ = self.move_right();
+                None
+            }
+            "move_up" => {
+                let _ = self.move_up();
+                None
+            }
+            "move_down" => {
+                let _ = self.move_down();
+                None
+            }
+            "next_field" => {
+                let _ = self.next_field();
+                None
+            }
+            "prev_field" => {
+                let _ = self.prev_field();
+                None
+            }
+            "move_line_start" => {
+                self.move_line_start();
+                None
+            }
+            "move_line_end" => {
+                self.move_line_end();
+                None
+            }
+            "move_first_line" => {
+                let _ = self.move_first_line();
+                None
+            }
+            "move_last_line" => {
+                let _ = self.move_last_line();
+                None
+            }
+
+            // Word/big-word movement (cross-field aware)
+            "move_word_next" => {
+                self.move_word_next();
+                None
+            }
+            "move_word_prev" => {
+                self.move_word_prev();
+                None
+            }
+            "move_word_end" => {
+                self.move_word_end();
+                None
+            }
+            "move_word_end_prev" => {
+                self.move_word_end_prev();
+                None
+            }
+            "move_big_word_next" => {
+                self.move_big_word_next();
+                None
+            }
+            "move_big_word_prev" => {
+                self.move_big_word_prev();
+                None
+            }
+            "move_big_word_end" => {
+                self.move_big_word_end();
+                None
+            }
+            "move_big_word_end_prev" => {
+                self.move_big_word_end_prev();
+                None
+            }
+
+            // Editing
+            "delete_char_backward" => {
+                let _ = self.delete_backward();
+                None
+            }
+            "delete_char_forward" => {
+                let _ = self.delete_forward();
+                None
+            }
+            "open_line_below" => {
+                let _ = self.open_line_below();
+                None
+            }
+            "open_line_above" => {
+                let _ = self.open_line_above();
+                None
+            }
+
+            // Suggestions (only when feature is enabled)
+            #[cfg(feature = "suggestions")]
+            "open_suggestions" => {
+                let idx = self.current_field();
+                self.open_suggestions(idx);
+                None
+            }
+            #[cfg(feature = "suggestions")]
+            "apply_suggestion" | "enter_decider" => {
+                if let Some(_applied) = self.apply_suggestion() {
+                    None
+                } else {
+                    None
+                }
+            }
+            #[cfg(feature = "suggestions")]
+            "suggestion_down" => {
+                self.suggestions_next();
+                None
+            }
+            #[cfg(feature = "suggestions")]
+            "suggestion_up" => {
+                self.suggestions_prev();
+                None
+            }
+
+            // Mode transitions (vim-like)
+            "enter_edit_mode_before" => {
+                self.enter_edit_mode();
+                None
+            }
+            "enter_edit_mode_after" => {
+                // Move forward 1 char if possible (vim 'a'), then enter insert
+                let txt_len = self.current_text().chars().count();
+                let pos = self.ui_state.cursor_pos;
+                if pos < txt_len {
+                    self.ui_state.cursor_pos = pos + 1;
+                    self.ui_state.ideal_cursor_column = self.ui_state.cursor_pos;
+                }
+                self.enter_edit_mode();
+                None
+            }
+            "exit" | "exit_edit_mode" => {
+                let _ = self.exit_edit_mode();
+                None
+            }
+            "enter_highlight_mode" => {
+                self.enter_highlight_mode();
+                None
+            }
+            "enter_highlight_mode_linewise" => {
+                self.enter_highlight_line_mode();
+                None
+            }
+            "exit_highlight_mode" => {
+                self.exit_highlight_mode();
+                None
+            }
+
+            _ => None,
+        }
+    }
+}

canvas/src/editor/mod.rs

@@ -0,0 +1,28 @@
+// src/editor/mod.rs
+//! Editor submodule exports.
+//!
+//! This module exposes the internal editor pieces (core, editing, movement,
+//! navigation, mode, and optional features like suggestions, validation, and
+//! computed field helpers). Only module declarations and re-exports live here.
+
+pub mod core;
+pub mod display;
+pub mod editing;
+pub mod movement;
+pub mod navigation;
+pub mod mode;
+
+#[cfg(feature = "suggestions")]
+pub mod suggestions;
+
+#[cfg(feature = "validation")]
+pub mod validation_helpers;
+
+#[cfg(feature = "computed")]
+pub mod computed_helpers;
+
+#[cfg(feature = "keymap")] 
+pub mod key_input;
+
+// Re-export the main type
+pub use core::FormEditor;

canvas/src/editor/mode.rs

@@ -0,0 +1,305 @@
+// src/editor/mode.rs
+
+#[cfg(feature = "cursor-style")]
+use crate::canvas::CursorManager;
+
+use crate::canvas::modes::AppMode;
+use crate::canvas::state::SelectionState;
+use crate::editor::FormEditor;
+use crate::DataProvider;
+
+impl<D: DataProvider> FormEditor<D> {
+    /// Change mode
+    pub fn set_mode(&mut self, mode: AppMode) {
+        // Avoid unused param warning in normalmode
+        #[cfg(feature = "textmode-normal")]
+        let _ = mode;
+
+        // NORMALMODE: force Edit, ignore requested mode
+        #[cfg(feature = "textmode-normal")]
+        {
+            self.ui_state.current_mode = AppMode::Edit;
+            self.ui_state.selection = SelectionState::None;
+
+            #[cfg(feature = "cursor-style")]
+            {
+                let _ = CursorManager::update_for_mode(AppMode::Edit);
+            }
+        }
+
+        // Default (not normal): original vim behavior
+        #[cfg(not(feature = "textmode-normal"))]
+        match (self.ui_state.current_mode, mode) {
+            (AppMode::ReadOnly, AppMode::Highlight) => {
+                self.enter_highlight_mode();
+            }
+            (AppMode::Highlight, AppMode::ReadOnly) => {
+                self.exit_highlight_mode();
+            }
+            (_, new_mode) => {
+                self.ui_state.current_mode = new_mode;
+                if new_mode != AppMode::Highlight {
+                    self.ui_state.selection = SelectionState::None;
+                }
+                #[cfg(feature = "cursor-style")]
+                {
+                    let _ = CursorManager::update_for_mode(new_mode);
+                }
+            }
+        }
+    }
+
+    /// Exit edit mode to read-only mode
+    pub fn exit_edit_mode(&mut self) -> anyhow::Result<()> {
+        #[cfg(feature = "validation")]
+        {
+            let current_text = self.current_text();
+            if !self.ui_state.validation.allows_field_switch(
+                self.ui_state.current_field,
+                current_text,
+            ) {
+                if let Some(reason) = self
+                    .ui_state
+                    .validation
+                    .field_switch_block_reason(
+                        self.ui_state.current_field,
+                        current_text,
+                    )
+                {
+                    self.ui_state
+                        .validation
+                        .set_last_switch_block(reason.clone());
+                    return Err(anyhow::anyhow!(
+                        "Cannot exit edit mode: {}",
+                        reason
+                    ));
+                }
+            }
+        }
+
+        let current_text = self.current_text();
+        if !current_text.is_empty() {
+            let max_normal_pos =
+                current_text.chars().count().saturating_sub(1);
+            if self.ui_state.cursor_pos > max_normal_pos {
+                self.ui_state.cursor_pos = max_normal_pos;
+                self.ui_state.ideal_cursor_column = self.ui_state.cursor_pos;
+            }
+        }
+
+        #[cfg(feature = "validation")]
+        {
+            let field_index = self.ui_state.current_field;
+            if let Some(cfg) =
+                self.ui_state.validation.get_field_config(field_index)
+            {
+                if cfg.external_validation_enabled {
+                    let text = self.current_text().to_string();
+                    if !text.is_empty() {
+                        self.set_external_validation(
+                            field_index,
+                            crate::validation::ExternalValidationState::Validating,
+                        );
+                        if let Some(cb) =
+                            self.external_validation_callback.as_mut()
+                        {
+                            let final_state = cb(field_index, &text);
+                            self.set_external_validation(field_index, final_state);
+                        }
+                    }
+                }
+            }
+        }
+
+        // NORMALMODE: stay in Edit (do not switch to ReadOnly)
+        #[cfg(feature = "textmode-normal")]
+        {
+            #[cfg(feature = "suggestions")]
+            {
+                self.close_suggestions();
+            }
+            Ok(())
+        }
+
+        // Default (not normal): original vim behavior
+        #[cfg(not(feature = "textmode-normal"))]
+        {
+            self.set_mode(AppMode::ReadOnly);
+            #[cfg(feature = "suggestions")]
+            {
+                self.close_suggestions();
+            }
+            Ok(())
+        }
+    }
+
+    /// Enter edit mode
+    pub fn enter_edit_mode(&mut self) {
+        #[cfg(feature = "computed")]
+        {
+            if let Some(computed_state) = &self.ui_state.computed {
+                if computed_state.is_computed_field(self.ui_state.current_field)
+                {
+                    return;
+                }
+            }
+        }
+
+        // NORMALMODE: already in Edit, but enforce it
+        #[cfg(feature = "textmode-normal")]
+        {
+            self.ui_state.current_mode = AppMode::Edit;
+            self.ui_state.selection = SelectionState::None;
+            #[cfg(feature = "cursor-style")]
+            {
+                let _ = CursorManager::update_for_mode(AppMode::Edit);
+            }
+        }
+
+        // Default (not normal): vim behavior
+        #[cfg(not(feature = "textmode-normal"))]
+        self.set_mode(AppMode::Edit);
+    }
+
+    // -------------------- Highlight/Visual mode -------------------------
+
+    pub fn enter_highlight_mode(&mut self) {
+        // NORMALMODE: ignore request (stay in Edit)
+        #[cfg(feature = "textmode-normal")]
+        {
+        }
+
+        // Default (not normal): original vim
+        #[cfg(not(feature = "textmode-normal"))]
+        {
+            if self.ui_state.current_mode == AppMode::ReadOnly {
+                self.ui_state.current_mode = AppMode::Highlight;
+                self.ui_state.selection = SelectionState::Characterwise {
+                    anchor: (self.ui_state.current_field, self.ui_state.cursor_pos),
+                };
+
+                #[cfg(feature = "cursor-style")]
+                {
+                    let _ = CursorManager::update_for_mode(AppMode::Highlight);
+                }
+            }
+        }
+    }
+
+    pub fn enter_highlight_line_mode(&mut self) {
+        // NORMALMODE: ignore
+        #[cfg(feature = "textmode-normal")]
+        {
+        }
+
+        // Default (not normal): original vim
+        #[cfg(not(feature = "textmode-normal"))]
+        {
+            if self.ui_state.current_mode == AppMode::ReadOnly {
+                self.ui_state.current_mode = AppMode::Highlight;
+                self.ui_state.selection =
+                    SelectionState::Linewise { anchor_field: self.ui_state.current_field };
+
+                #[cfg(feature = "cursor-style")]
+                {
+                    let _ = CursorManager::update_for_mode(AppMode::Highlight);
+                }
+            }
+        }
+    }
+
+    pub fn exit_highlight_mode(&mut self) {
+        // NORMALMODE: ignore
+        #[cfg(feature = "textmode-normal")]
+        {
+        }
+
+        // Default (not normal): original vim
+        #[cfg(not(feature = "textmode-normal"))]
+        {
+            if self.ui_state.current_mode == AppMode::Highlight {
+                self.ui_state.current_mode = AppMode::ReadOnly;
+                self.ui_state.selection = SelectionState::None;
+
+                #[cfg(feature = "cursor-style")]
+                {
+                    let _ = CursorManager::update_for_mode(AppMode::ReadOnly);
+                }
+            }
+        }
+    }
+
+    pub fn is_highlight_mode(&self) -> bool {
+        #[cfg(feature = "textmode-normal")]
+        {
+            false
+        }
+        #[cfg(not(feature = "textmode-normal"))]
+        {
+            return self.ui_state.current_mode == AppMode::Highlight;
+        }
+    }
+
+    pub fn selection_state(&self) -> &SelectionState {
+        &self.ui_state.selection
+    }
+
+    // Visual-mode movements reuse existing movement methods
+    // These keep calling the movement methods; in normalmode selection is never enabled,
+    // so these just move without creating a selection.
+    pub fn move_left_with_selection(&mut self) {
+        let _ = self.move_left();
+    }
+
+    pub fn move_right_with_selection(&mut self) {
+        let _ = self.move_right();
+    }
+
+    pub fn move_up_with_selection(&mut self) {
+        let _ = self.move_up();
+    }
+
+    pub fn move_down_with_selection(&mut self) {
+        let _ = self.move_down();
+    }
+
+    pub fn move_word_next_with_selection(&mut self) {
+        self.move_word_next();
+    }
+
+    pub fn move_word_end_with_selection(&mut self) {
+        self.move_word_end();
+    }
+
+    pub fn move_word_prev_with_selection(&mut self) {
+        self.move_word_prev();
+    }
+
+    pub fn move_word_end_prev_with_selection(&mut self) {
+        self.move_word_end_prev();
+    }
+
+    pub fn move_big_word_next_with_selection(&mut self) {
+        self.move_big_word_next();
+    }
+
+    pub fn move_big_word_end_with_selection(&mut self) {
+        self.move_big_word_end();
+    }
+
+    pub fn move_big_word_prev_with_selection(&mut self) {
+        self.move_big_word_prev();
+    }
+
+    pub fn move_big_word_end_prev_with_selection(&mut self) {
+        self.move_big_word_end_prev();
+    }
+
+    pub fn move_line_start_with_selection(&mut self) {
+        self.move_line_start();
+    }
+
+    pub fn move_line_end_with_selection(&mut self) {
+        self.move_line_end();
+    }
+}

canvas/src/editor/movement.rs

@@ -0,0 +1,687 @@
+// src/editor/movement.rs
+
+use crate::canvas::actions::movement::line::{
+    line_end_position, line_start_position,
+};
+use crate::canvas::modes::AppMode;
+use crate::editor::FormEditor;
+use crate::DataProvider;
+use crate::canvas::actions::movement::word::{
+    find_last_big_word_start_in_field, find_last_word_start_in_field,
+};
+
+impl<D: DataProvider> FormEditor<D> {
+    /// Move cursor left within current field (mask-aware)
+    pub fn move_left(&mut self) -> anyhow::Result<()> {
+        #[cfg(feature = "validation")]
+        let mut moved = false;
+        #[cfg(not(feature = "validation"))]
+        let moved = false;
+
+        #[cfg(feature = "validation")]
+        {
+            let field_index = self.ui_state.current_field;
+            if let Some(cfg) =
+                self.ui_state.validation.get_field_config(field_index)
+            {
+                if let Some(mask) = &cfg.display_mask {
+                    let display_pos =
+                        mask.raw_pos_to_display_pos(self.ui_state.cursor_pos);
+                    if let Some(prev_input) =
+                        mask.prev_input_position(display_pos)
+                    {
+                        let raw_pos =
+                            mask.display_pos_to_raw_pos(prev_input);
+                        let max_pos = self.current_text().chars().count();
+                        self.ui_state.cursor_pos = raw_pos.min(max_pos);
+                        self.ui_state.ideal_cursor_column =
+                            self.ui_state.cursor_pos;
+                        moved = true;
+                    } else {
+                        self.ui_state.cursor_pos = 0;
+                        self.ui_state.ideal_cursor_column = 0;
+                        moved = true;
+                    }
+                }
+            }
+        }
+
+        if !moved
+            && self.ui_state.cursor_pos > 0 {
+                self.ui_state.cursor_pos -= 1;
+                self.ui_state.ideal_cursor_column = self.ui_state.cursor_pos;
+            }
+        Ok(())
+    }
+
+    /// Move cursor right within current field (mask-aware)
+    pub fn move_right(&mut self) -> anyhow::Result<()> {
+        #[cfg(feature = "validation")]
+        let mut moved = false;
+        #[cfg(not(feature = "validation"))]
+        let moved = false;
+
+        #[cfg(feature = "validation")]
+        {
+            let field_index = self.ui_state.current_field;
+            if let Some(cfg) =
+                self.ui_state.validation.get_field_config(field_index)
+            {
+                if let Some(mask) = &cfg.display_mask {
+                    let display_pos =
+                        mask.raw_pos_to_display_pos(self.ui_state.cursor_pos);
+                    let next_display_pos = mask.next_input_position(display_pos);
+                    let next_pos =
+                        mask.display_pos_to_raw_pos(next_display_pos);
+                    let max_pos = self.current_text().chars().count();
+                    self.ui_state.cursor_pos = next_pos.min(max_pos);
+                    self.ui_state.ideal_cursor_column =
+                        self.ui_state.cursor_pos;
+                    moved = true;
+                }
+            }
+        }
+
+        if !moved {
+            let max_pos = self.current_text().chars().count();
+            if self.ui_state.cursor_pos < max_pos {
+                self.ui_state.cursor_pos += 1;
+                self.ui_state.ideal_cursor_column = self.ui_state.cursor_pos;
+            }
+        }
+        Ok(())
+    }
+
+    /// Move to start of current field (vim 0)
+    pub fn move_line_start(&mut self) {
+        let new_pos = line_start_position();
+        self.ui_state.cursor_pos = new_pos;
+        self.ui_state.ideal_cursor_column = new_pos;
+    }
+
+    /// Move to end of current field (vim $)
+    pub fn move_line_end(&mut self) {
+        let current_text = self.current_text();
+        let is_edit_mode = self.ui_state.current_mode == AppMode::Edit;
+
+        let new_pos = line_end_position(current_text, is_edit_mode);
+        self.ui_state.cursor_pos = new_pos;
+        self.ui_state.ideal_cursor_column = new_pos;
+    }
+
+    /// Set cursor to exact position (for f/F/t/T etc.)
+    pub fn set_cursor_position(&mut self, position: usize) {
+        let current_text = self.current_text();
+        let is_edit_mode = self.ui_state.current_mode == AppMode::Edit;
+
+        let char_len = current_text.chars().count();
+        let max_pos = if is_edit_mode {
+            char_len
+        } else {
+            char_len.saturating_sub(1)
+        };
+
+        let clamped_pos = position.min(max_pos);
+        self.ui_state.cursor_pos = clamped_pos;
+        self.ui_state.ideal_cursor_column = clamped_pos;
+    }
+}
+
+
+impl<D: DataProvider> FormEditor<D> {
+    /// Move to start of next word (vim w) - can cross field boundaries
+    pub fn move_word_next(&mut self) {
+        use crate::canvas::actions::movement::word::find_next_word_start;
+        let current_text = self.current_text();
+
+        if current_text.is_empty() {
+            // Empty field - try to move to next field
+            if self.move_down().is_ok() {
+                // Successfully moved to next field, try to find first word
+                let new_text = self.current_text();
+                if !new_text.is_empty() {
+                    let first_word_pos = if new_text.chars().next().is_some_and(|c| !c.is_whitespace()) {
+                        // Field starts with non-whitespace, go to position 0
+                        0
+                    } else {
+                        // Field starts with whitespace, find first word
+                        find_next_word_start(new_text, 0)
+                    };
+                    let is_edit_mode = self.ui_state.current_mode == AppMode::Edit;
+                    let char_len = new_text.chars().count();
+                    let final_pos = if is_edit_mode {
+                        first_word_pos.min(char_len)
+                    } else {
+                        first_word_pos.min(char_len.saturating_sub(1))
+                    };
+                    self.ui_state.cursor_pos = final_pos;
+                    self.ui_state.ideal_cursor_column = final_pos;
+                }
+            }
+            return;
+        }
+
+        let current_pos = self.ui_state.cursor_pos;
+        let new_pos = find_next_word_start(current_text, current_pos);
+        
+        // Check if we've hit the end of the current field
+        if new_pos >= current_text.chars().count() {
+            // At end of field - jump to next field and start from beginning
+            if self.move_down().is_ok() {
+                // Successfully moved to next field
+                let new_text = self.current_text();
+                if new_text.is_empty() {
+                    // New field is empty, cursor stays at 0
+                    self.ui_state.cursor_pos = 0;
+                    self.ui_state.ideal_cursor_column = 0;
+                } else {
+                    // Find first word in new field
+                    let first_word_pos = if new_text.chars().next().is_some_and(|c| !c.is_whitespace()) {
+                        // Field starts with non-whitespace, go to position 0
+                        0
+                    } else {
+                        // Field starts with whitespace, find first word
+                        find_next_word_start(new_text, 0)
+                    };
+                    let is_edit_mode = self.ui_state.current_mode == AppMode::Edit;
+                    let char_len = new_text.chars().count();
+                    let final_pos = if is_edit_mode {
+                        first_word_pos.min(char_len)
+                    } else {
+                        first_word_pos.min(char_len.saturating_sub(1))
+                    };
+                    self.ui_state.cursor_pos = final_pos;
+                    self.ui_state.ideal_cursor_column = final_pos;
+                }
+            }
+            // If move_down() failed, we stay where we are (at end of last field)
+        } else {
+            // Normal word movement within current field
+            let is_edit_mode = self.ui_state.current_mode == AppMode::Edit;
+            let char_len = current_text.chars().count();
+            let final_pos = if is_edit_mode {
+                new_pos.min(char_len)
+            } else {
+                new_pos.min(char_len.saturating_sub(1))
+            };
+
+            self.ui_state.cursor_pos = final_pos;
+            self.ui_state.ideal_cursor_column = final_pos;
+        }
+    }
+
+    /// Move to start of previous word (vim b) - can cross field boundaries
+    pub fn move_word_prev(&mut self) {
+        use crate::canvas::actions::movement::word::find_prev_word_start;
+        let current_text = self.current_text();
+
+        if current_text.is_empty() {
+            // Empty field - try to move to previous field and find last word
+            let current_field = self.ui_state.current_field;
+            if self.move_up().is_ok() {
+                // Check if we actually moved to a different field
+                if self.ui_state.current_field != current_field {
+                    let new_text = self.current_text();
+                    if !new_text.is_empty() {
+                        let last_word_start = find_last_word_start_in_field(new_text);
+                        self.ui_state.cursor_pos = last_word_start;
+                        self.ui_state.ideal_cursor_column = last_word_start;
+                    }
+                }
+            }
+            return;
+        }
+
+        let current_pos = self.ui_state.cursor_pos;
+
+        // Special case: if we're at position 0, jump to previous field
+        if current_pos == 0 {
+            let current_field = self.ui_state.current_field;
+            if self.move_up().is_ok() {
+                // Check if we actually moved to a different field
+                if self.ui_state.current_field != current_field {
+                    let new_text = self.current_text();
+                    if !new_text.is_empty() {
+                        let last_word_start = find_last_word_start_in_field(new_text);
+                        self.ui_state.cursor_pos = last_word_start;
+                        self.ui_state.ideal_cursor_column = last_word_start;
+                    }
+                }
+            }
+            return;
+        }
+
+        // Try to find previous word in current field
+        let new_pos = find_prev_word_start(current_text, current_pos);
+
+        // Check if we actually moved
+        if new_pos < current_pos {
+            // Normal word movement within current field - we found a previous word
+            self.ui_state.cursor_pos = new_pos;
+            self.ui_state.ideal_cursor_column = new_pos;
+        } else {
+            // We didn't move (probably at start of first word), try previous field
+            let current_field = self.ui_state.current_field;
+            if self.move_up().is_ok() {
+                // Check if we actually moved to a different field
+                if self.ui_state.current_field != current_field {
+                    let new_text = self.current_text();
+                    if !new_text.is_empty() {
+                        let last_word_start = find_last_word_start_in_field(new_text);
+                        self.ui_state.cursor_pos = last_word_start;
+                        self.ui_state.ideal_cursor_column = last_word_start;
+                    }
+                }
+            }
+        }
+    }
+
+    /// Move to end of current/next word (vim e) - can cross field boundaries
+    pub fn move_word_end(&mut self) {
+        use crate::canvas::actions::movement::word::find_word_end;
+        let current_text = self.current_text();
+
+        if current_text.is_empty() {
+            // Empty field - try to move to next field
+            if self.move_down().is_ok() {
+                // Recursively call move_word_end in the new field
+                self.move_word_end();
+            }
+            return;
+        }
+
+        let current_pos = self.ui_state.cursor_pos;
+        let char_len = current_text.chars().count();
+        let new_pos = find_word_end(current_text, current_pos);
+
+        // Check if we didn't move or hit the end of the field
+        if new_pos == current_pos && current_pos + 1 < char_len {
+            // Try next character and find word end from there
+            let next_pos = find_word_end(current_text, current_pos + 1);
+            if next_pos < char_len {
+                let is_edit_mode = self.ui_state.current_mode == AppMode::Edit;
+                let final_pos = if is_edit_mode {
+                    next_pos.min(char_len)
+                } else {
+                    next_pos.min(char_len.saturating_sub(1))
+                };
+                self.ui_state.cursor_pos = final_pos;
+                self.ui_state.ideal_cursor_column = final_pos;
+                return;
+            }
+        }
+
+        // If we're at or near the end of the field, try next field
+        if new_pos >= char_len.saturating_sub(1) {
+            if self.move_down().is_ok() {
+                // Position at start and find first word end
+                self.ui_state.cursor_pos = 0;
+                self.ui_state.ideal_cursor_column = 0;
+                self.move_word_end();
+            }
+        } else {
+            // Normal word end movement within current field
+            let is_edit_mode = self.ui_state.current_mode == AppMode::Edit;
+            let final_pos = if is_edit_mode {
+                new_pos.min(char_len)
+            } else {
+                new_pos.min(char_len.saturating_sub(1))
+            };
+
+            self.ui_state.cursor_pos = final_pos;
+            self.ui_state.ideal_cursor_column = final_pos;
+        }
+    }
+
+    /// Move to end of previous word (vim ge) - can cross field boundaries
+    pub fn move_word_end_prev(&mut self) {
+        use crate::canvas::actions::movement::word::{find_prev_word_end, find_last_word_end_in_field};
+        let current_text = self.current_text();
+
+        if current_text.is_empty() {
+            // Empty field - try to move to previous field (but don't recurse)
+            let current_field = self.ui_state.current_field;
+            if self.move_up().is_ok() {
+                // Check if we actually moved to a different field
+                if self.ui_state.current_field != current_field {
+                    let new_text = self.current_text();
+                    if !new_text.is_empty() {
+                        // Find end of last word in the field
+                        let last_word_end = find_last_word_end_in_field(new_text);
+                        self.ui_state.cursor_pos = last_word_end;
+                        self.ui_state.ideal_cursor_column = last_word_end;
+                    }
+                }
+            }
+            return;
+        }
+
+        let current_pos = self.ui_state.cursor_pos;
+
+        // Special case: if we're at position 0, jump to previous field (but don't recurse)
+        if current_pos == 0 {
+            let current_field = self.ui_state.current_field;
+            if self.move_up().is_ok() {
+                // Check if we actually moved to a different field
+                if self.ui_state.current_field != current_field {
+                    let new_text = self.current_text();
+                    if !new_text.is_empty() {
+                        let last_word_end = find_last_word_end_in_field(new_text);
+                        self.ui_state.cursor_pos = last_word_end;
+                        self.ui_state.ideal_cursor_column = last_word_end;
+                    }
+                }
+            }
+            return;
+        }
+
+        let new_pos = find_prev_word_end(current_text, current_pos);
+
+        // Only try to cross fields if we didn't move at all (stayed at same position)
+        if new_pos == current_pos {
+            // We didn't move within the current field, try previous field
+            let current_field = self.ui_state.current_field;
+            if self.move_up().is_ok() {
+                // Check if we actually moved to a different field
+                if self.ui_state.current_field != current_field {
+                    let new_text = self.current_text();
+                    if !new_text.is_empty() {
+                        let last_word_end = find_last_word_end_in_field(new_text);
+                        self.ui_state.cursor_pos = last_word_end;
+                        self.ui_state.ideal_cursor_column = last_word_end;
+                    }
+                }
+            }
+        } else {
+            // Normal word movement within current field
+            let is_edit_mode = self.ui_state.current_mode == AppMode::Edit;
+            let char_len = current_text.chars().count();
+            let final_pos = if is_edit_mode {
+                new_pos.min(char_len)
+            } else {
+                new_pos.min(char_len.saturating_sub(1))
+            };
+
+            self.ui_state.cursor_pos = final_pos;
+            self.ui_state.ideal_cursor_column = final_pos;
+        }
+    }
+
+    /// Move to start of next big_word (vim W) - can cross field boundaries
+    pub fn move_big_word_next(&mut self) {
+        use crate::canvas::actions::movement::word::find_next_big_word_start;
+        let current_text = self.current_text();
+
+        if current_text.is_empty() {
+            // Empty field - try to move to next field
+            if self.move_down().is_ok() {
+                // Successfully moved to next field, try to find first big_word
+                let new_text = self.current_text();
+                if !new_text.is_empty() {
+                    let first_big_word_pos = if new_text.chars().next().is_some_and(|c| !c.is_whitespace()) {
+                        // Field starts with non-whitespace, go to position 0
+                        0
+                    } else {
+                        // Field starts with whitespace, find first big_word
+                        find_next_big_word_start(new_text, 0)
+                    };
+                    let is_edit_mode = self.ui_state.current_mode == AppMode::Edit;
+                    let char_len = new_text.chars().count();
+                    let final_pos = if is_edit_mode {
+                        first_big_word_pos.min(char_len)
+                    } else {
+                        first_big_word_pos.min(char_len.saturating_sub(1))
+                    };
+                    self.ui_state.cursor_pos = final_pos;
+                    self.ui_state.ideal_cursor_column = final_pos;
+                }
+            }
+            return;
+        }
+
+        let current_pos = self.ui_state.cursor_pos;
+        let new_pos = find_next_big_word_start(current_text, current_pos);
+
+        // Check if we've hit the end of the current field
+        if new_pos >= current_text.chars().count() {
+            // At end of field - jump to next field and start from beginning
+            if self.move_down().is_ok() {
+                // Successfully moved to next field
+                let new_text = self.current_text();
+                if new_text.is_empty() {
+                    // New field is empty, cursor stays at 0
+                    self.ui_state.cursor_pos = 0;
+                    self.ui_state.ideal_cursor_column = 0;
+                } else {
+                    // Find first big_word in new field
+                    let first_big_word_pos = if new_text.chars().next().is_some_and(|c| !c.is_whitespace()) {
+                        // Field starts with non-whitespace, go to position 0
+                        0
+                    } else {
+                        // Field starts with whitespace, find first big_word
+                        find_next_big_word_start(new_text, 0)
+                    };
+                    let is_edit_mode = self.ui_state.current_mode == AppMode::Edit;
+                    let char_len = new_text.chars().count();
+                    let final_pos = if is_edit_mode {
+                        first_big_word_pos.min(char_len)
+                    } else {
+                        first_big_word_pos.min(char_len.saturating_sub(1))
+                    };
+                    self.ui_state.cursor_pos = final_pos;
+                    self.ui_state.ideal_cursor_column = final_pos;
+                }
+            }
+            // If move_down() failed, we stay where we are (at end of last field)
+        } else {
+            // Normal big_word movement within current field
+            let is_edit_mode = self.ui_state.current_mode == AppMode::Edit;
+            let char_len = current_text.chars().count();
+            let final_pos = if is_edit_mode {
+                new_pos.min(char_len)
+            } else {
+                new_pos.min(char_len.saturating_sub(1))
+            };
+
+            self.ui_state.cursor_pos = final_pos;
+            self.ui_state.ideal_cursor_column = final_pos;
+        }
+    }
+
+    /// Move to start of previous big_word (vim B) - can cross field boundaries
+    pub fn move_big_word_prev(&mut self) {
+        use crate::canvas::actions::movement::word::find_prev_big_word_start;
+        let current_text = self.current_text();
+
+        if current_text.is_empty() {
+            // Empty field - try to move to previous field and find last big_word
+            let current_field = self.ui_state.current_field;
+            if self.move_up().is_ok() {
+                // Check if we actually moved to a different field
+                if self.ui_state.current_field != current_field {
+                    let new_text = self.current_text();
+                    if !new_text.is_empty() {
+                        let last_big_word_start = find_last_big_word_start_in_field(new_text);
+                        self.ui_state.cursor_pos = last_big_word_start;
+                        self.ui_state.ideal_cursor_column = last_big_word_start;
+                    }
+                }
+            }
+            return;
+        }
+
+        let current_pos = self.ui_state.cursor_pos;
+
+        // Special case: if we're at position 0, jump to previous field
+        if current_pos == 0 {
+            let current_field = self.ui_state.current_field;
+            if self.move_up().is_ok() {
+                // Check if we actually moved to a different field
+                if self.ui_state.current_field != current_field {
+                    let new_text = self.current_text();
+                    if !new_text.is_empty() {
+                        let last_big_word_start = find_last_big_word_start_in_field(new_text);
+                        self.ui_state.cursor_pos = last_big_word_start;
+                        self.ui_state.ideal_cursor_column = last_big_word_start;
+                    }
+                }
+            }
+            return;
+        }
+
+        // Try to find previous big_word in current field
+        let new_pos = find_prev_big_word_start(current_text, current_pos);
+
+        // Check if we actually moved
+        if new_pos < current_pos {
+            // Normal big_word movement within current field - we found a previous big_word
+            self.ui_state.cursor_pos = new_pos;
+            self.ui_state.ideal_cursor_column = new_pos;
+        } else {
+            // We didn't move (probably at start of first big_word), try previous field
+            let current_field = self.ui_state.current_field;
+            if self.move_up().is_ok() {
+                // Check if we actually moved to a different field
+                if self.ui_state.current_field != current_field {
+                    let new_text = self.current_text();
+                    if !new_text.is_empty() {
+                        let last_big_word_start = find_last_big_word_start_in_field(new_text);
+                        self.ui_state.cursor_pos = last_big_word_start;
+                        self.ui_state.ideal_cursor_column = last_big_word_start;
+                    }
+                }
+            }
+        }
+    }
+
+    /// Move to end of current/next big_word (vim E) - can cross field boundaries
+    pub fn move_big_word_end(&mut self) {
+        use crate::canvas::actions::movement::word::find_big_word_end;
+        let current_text = self.current_text();
+
+        if current_text.is_empty() {
+            // Empty field - try to move to next field (but don't recurse)
+            if self.move_down().is_ok() {
+                let new_text = self.current_text();
+                if !new_text.is_empty() {
+                    // Find first big_word end in new field
+                    let first_big_word_end = find_big_word_end(new_text, 0);
+                    let is_edit_mode = self.ui_state.current_mode == AppMode::Edit;
+                    let char_len = new_text.chars().count();
+                    let final_pos = if is_edit_mode {
+                        first_big_word_end.min(char_len)
+                    } else {
+                        first_big_word_end.min(char_len.saturating_sub(1))
+                    };
+                    self.ui_state.cursor_pos = final_pos;
+                    self.ui_state.ideal_cursor_column = final_pos;
+                }
+            }
+            return;
+        }
+
+        let current_pos = self.ui_state.cursor_pos;
+        let char_len = current_text.chars().count();
+        let new_pos = find_big_word_end(current_text, current_pos);
+
+        // Check if we didn't move or hit the end of the field
+        if new_pos == current_pos && current_pos + 1 < char_len {
+            // Try next character and find big_word end from there
+            let next_pos = find_big_word_end(current_text, current_pos + 1);
+            if next_pos < char_len {
+                let is_edit_mode = self.ui_state.current_mode == AppMode::Edit;
+                let final_pos = if is_edit_mode {
+                    next_pos.min(char_len)
+                } else {
+                    next_pos.min(char_len.saturating_sub(1))
+                };
+                self.ui_state.cursor_pos = final_pos;
+                self.ui_state.ideal_cursor_column = final_pos;
+                return;
+            }
+        }
+
+        // If we're at or near the end of the field, try next field (but don't recurse)
+        if new_pos >= char_len.saturating_sub(1) {
+            if self.move_down().is_ok() {
+                // Find first big_word end in new field
+                let new_text = self.current_text();
+                if !new_text.is_empty() {
+                    let first_big_word_end = find_big_word_end(new_text, 0);
+                    let is_edit_mode = self.ui_state.current_mode == AppMode::Edit;
+                    let new_char_len = new_text.chars().count();
+                    let final_pos = if is_edit_mode {
+                        first_big_word_end.min(new_char_len)
+                    } else {
+                        first_big_word_end.min(new_char_len.saturating_sub(1))
+                    };
+                    self.ui_state.cursor_pos = final_pos;
+                    self.ui_state.ideal_cursor_column = final_pos;
+                }
+            }
+        } else {
+            // Normal big_word end movement within current field
+            let is_edit_mode = self.ui_state.current_mode == AppMode::Edit;
+            let final_pos = if is_edit_mode {
+                new_pos.min(char_len)
+            } else {
+                new_pos.min(char_len.saturating_sub(1))
+            };
+
+            self.ui_state.cursor_pos = final_pos;
+            self.ui_state.ideal_cursor_column = final_pos;
+        }
+    }
+
+    /// Move to end of previous big_word (vim gE) - can cross field boundaries
+    pub fn move_big_word_end_prev(&mut self) {
+        use crate::canvas::actions::movement::word::{
+            find_prev_big_word_end, find_big_word_end,
+        };
+
+        let current_text = self.current_text();
+
+        if current_text.is_empty() {
+            let current_field = self.ui_state.current_field;
+            if self.move_up().is_ok()
+                && self.ui_state.current_field != current_field {
+                    let new_text = self.current_text();
+                    if !new_text.is_empty() {
+                        // Find first big_word end in new field
+                        let last_big_word_end = find_big_word_end(new_text, 0);
+                        self.ui_state.cursor_pos = last_big_word_end;
+                        self.ui_state.ideal_cursor_column = last_big_word_end;
+                    }
+                }
+            return;
+        }
+
+        let current_pos = self.ui_state.cursor_pos;
+        let new_pos = find_prev_big_word_end(current_text, current_pos);
+
+        // Only try to cross fields if we didn't move at all (stayed at same position)
+        if new_pos == current_pos {
+            let current_field = self.ui_state.current_field;
+            if self.move_up().is_ok()
+                && self.ui_state.current_field != current_field {
+                    let new_text = self.current_text();
+                    if !new_text.is_empty() {
+                        let last_big_word_end = find_big_word_end(new_text, 0);
+                        self.ui_state.cursor_pos = last_big_word_end;
+                        self.ui_state.ideal_cursor_column = last_big_word_end;
+                    }
+                }
+        } else {
+            // Normal big_word movement within current field
+            let is_edit_mode = self.ui_state.current_mode == AppMode::Edit;
+            let char_len = current_text.chars().count();
+            let final_pos = if is_edit_mode {
+                new_pos.min(char_len)
+            } else {
+                new_pos.min(char_len.saturating_sub(1))
+            };
+            self.ui_state.cursor_pos = final_pos;
+            self.ui_state.ideal_cursor_column = final_pos;
+        }
+    }
+}

canvas/src/editor/navigation.rs

@@ -0,0 +1,177 @@
+// src/editor/navigation.rs
+
+use crate::canvas::modes::AppMode;
+use crate::editor::FormEditor;
+use crate::DataProvider;
+
+impl<D: DataProvider> FormEditor<D> {
+    /// Centralized field transition logic (unchanged).
+    pub fn transition_to_field(&mut self, new_field: usize) -> anyhow::Result<()> {
+        let field_count = self.data_provider.field_count();
+        if field_count == 0 {
+            return Ok(());
+        }
+
+        let prev_field = self.ui_state.current_field;
+
+        #[cfg(feature = "computed")]
+        let mut target_field = new_field.min(field_count - 1);
+        #[cfg(not(feature = "computed"))]
+        let target_field = new_field.min(field_count - 1);
+
+        #[cfg(feature = "computed")]
+        {
+            if let Some(computed_state) = &self.ui_state.computed {
+                if computed_state.is_computed_field(target_field) {
+                    if target_field >= prev_field {
+                        for i in (target_field + 1)..field_count {
+                            if !computed_state.is_computed_field(i) {
+                                target_field = i;
+                                break;
+                            }
+                        }
+                    } else {
+                        let mut i = target_field;
+                        loop {
+                            if !computed_state.is_computed_field(i) {
+                                target_field = i;
+                                break;
+                            }
+                            if i == 0 {
+                                break;
+                            }
+                            i -= 1;
+                        }
+                    }
+                }
+            }
+        }
+
+        if target_field == prev_field {
+            return Ok(());
+        }
+
+        #[cfg(feature = "validation")]
+        self.ui_state.validation.clear_last_switch_block();
+
+        #[cfg(feature = "validation")]
+        {
+            let current_text = self.current_text();
+            if !self
+                .ui_state
+                .validation
+                .allows_field_switch(prev_field, current_text)
+            {
+                if let Some(reason) = self
+                    .ui_state
+                    .validation
+                    .field_switch_block_reason(prev_field, current_text)
+                {
+                    self.ui_state
+                        .validation
+                        .set_last_switch_block(reason.clone());
+                    tracing::debug!("Field switch blocked: {}", reason);
+                    return Err(anyhow::anyhow!(
+                        "Cannot switch fields: {}",
+                        reason
+                    ));
+                }
+            }
+        }
+
+        #[cfg(feature = "validation")]
+        {
+            let text =
+                self.data_provider.field_value(prev_field).to_string();
+            let _ = self
+                .ui_state
+                .validation
+                .validate_field_content(prev_field, &text);
+
+            if let Some(cfg) =
+                self.ui_state.validation.get_field_config(prev_field)
+            {
+                if cfg.external_validation_enabled && !text.is_empty() {
+                    self.set_external_validation(
+                        prev_field,
+                        crate::validation::ExternalValidationState::Validating,
+                    );
+
+                    if let Some(cb) =
+                        self.external_validation_callback.as_mut()
+                    {
+                        let final_state = cb(prev_field, &text);
+                        self.set_external_validation(prev_field, final_state);
+                    }
+                }
+            }
+        }
+
+        #[cfg(feature = "computed")]
+        {
+            // Placeholder for recompute hook if needed later
+        }
+
+        self.ui_state.move_to_field(target_field, field_count);
+
+        let current_text = self.current_text();
+        let max_pos = current_text.chars().count();
+        self.ui_state.set_cursor(
+            self.ui_state.ideal_cursor_column,
+            max_pos,
+            self.ui_state.current_mode == AppMode::Edit,
+        );
+
+        // Automatically close suggestions on field switch
+        #[cfg(feature = "suggestions")]
+        {
+            self.close_suggestions();
+        }
+
+        Ok(())
+    }
+
+    /// Move to first line (vim gg)
+    pub fn move_first_line(&mut self) -> anyhow::Result<()> {
+        self.transition_to_field(0)
+    }
+
+    /// Move to last line (vim G)
+    pub fn move_last_line(&mut self) -> anyhow::Result<()> {
+        let last_field =
+            self.data_provider.field_count().saturating_sub(1);
+        self.transition_to_field(last_field)
+    }
+
+    /// Move to previous field (vim k / up)
+    pub fn move_up(&mut self) -> anyhow::Result<()> {
+        let new_field = self.ui_state.current_field.saturating_sub(1);
+        self.transition_to_field(new_field)
+    }
+
+    /// Move to next field (vim j / down)
+    pub fn move_down(&mut self) -> anyhow::Result<()> {
+        let new_field = (self.ui_state.current_field + 1)
+            .min(self.data_provider.field_count().saturating_sub(1));
+        self.transition_to_field(new_field)
+    }
+
+    /// Move to next field cyclic
+    pub fn move_to_next_field(&mut self) -> anyhow::Result<()> {
+        let field_count = self.data_provider.field_count();
+        if field_count == 0 {
+            return Ok(());
+        }
+        let new_field = (self.ui_state.current_field + 1) % field_count;
+        self.transition_to_field(new_field)
+    }
+
+    /// Aliases
+    pub fn prev_field(&mut self) -> anyhow::Result<()> {
+        self.move_up()
+    }
+
+    pub fn next_field(&mut self) -> anyhow::Result<()> {
+        self.move_down()
+    }
+}

canvas/src/editor/suggestions.rs

@@ -0,0 +1,181 @@
+// src/editor/suggestions.rs
+
+use crate::editor::FormEditor;
+use crate::{DataProvider, SuggestionItem};
+
+impl<D: DataProvider> FormEditor<D> {
+    /// Compute inline completion for current selection and text
+    fn compute_current_completion(&self) -> Option<String> {
+        let typed = self.current_text();
+        let idx = self.ui_state.suggestions.selected_index?;
+        let sugg = self.suggestions.get(idx)?;
+        if let Some(rest) = sugg.value_to_store.strip_prefix(typed) {
+            if !rest.is_empty() {
+                return Some(rest.to_string());
+            }
+        }
+        None
+    }
+
+    /// Update UI state's completion text from current selection
+    pub fn update_inline_completion(&mut self) {
+        self.ui_state.suggestions.completion_text =
+            self.compute_current_completion();
+    }
+
+    /// Open the suggestions UI for `field_index`
+    pub fn open_suggestions(&mut self, field_index: usize) {
+        self.ui_state.open_suggestions(field_index);
+    }
+
+    /// Close suggestions UI and clear current suggestion results
+    pub fn close_suggestions(&mut self) {
+        self.ui_state.close_suggestions();
+        self.suggestions.clear();
+    }
+
+    /// Handle Escape key in ReadOnly mode (closes suggestions if active)
+    pub fn handle_escape_readonly(&mut self) {
+        if self.ui_state.suggestions.is_active {
+            self.close_suggestions();
+        }
+    }
+
+    // ----------------- Non-blocking suggestions API --------------------
+
+    #[cfg(feature = "suggestions")]
+    pub fn start_suggestions(&mut self, field_index: usize) -> Option<String> {
+        if !self.data_provider.supports_suggestions(field_index) {
+            return None;
+        }
+
+        let query = self.current_text().to_string();
+        self.ui_state.open_suggestions(field_index);
+        self.ui_state.suggestions.is_loading = true;
+        self.ui_state.suggestions.active_query = Some(query.clone());
+        self.suggestions.clear();
+        Some(query)
+    }
+
+    #[cfg(not(feature = "suggestions"))]
+    pub fn start_suggestions(&mut self, _field_index: usize) -> Option<String> {
+        None
+    }
+
+    #[cfg(feature = "suggestions")]
+    pub fn apply_suggestions_result(
+        &mut self,
+        field_index: usize,
+        query: &str,
+        results: Vec<SuggestionItem>,
+    ) -> bool {
+        if self.ui_state.suggestions.active_field != Some(field_index) {
+            return false;
+        }
+        if self.ui_state.suggestions.active_query.as_deref() != Some(query) {
+            return false;
+        }
+
+        self.ui_state.suggestions.is_loading = false;
+        self.suggestions = results;
+
+        if !self.suggestions.is_empty() {
+            self.ui_state.suggestions.selected_index = Some(0);
+            self.update_inline_completion();
+        } else {
+            self.ui_state.suggestions.selected_index = None;
+            self.ui_state.suggestions.completion_text = None;
+        }
+        true
+    }
+
+    #[cfg(not(feature = "suggestions"))]
+    pub fn apply_suggestions_result(
+        &mut self,
+        _field_index: usize,
+        _query: &str,
+        _results: Vec<SuggestionItem>,
+    ) -> bool {
+        false
+    }
+
+    #[cfg(feature = "suggestions")]
+    pub fn pending_suggestions_query(&self) -> Option<(usize, String)> {
+        if self.ui_state.suggestions.is_loading {
+            if let (Some(field), Some(query)) = (
+                self.ui_state.suggestions.active_field,
+                &self.ui_state.suggestions.active_query,
+            ) {
+                return Some((field, query.clone()));
+            }
+        }
+        None
+    }
+
+    #[cfg(not(feature = "suggestions"))]
+    pub fn pending_suggestions_query(&self) -> Option<(usize, String)> {
+        None
+    }
+
+    pub fn cancel_suggestions(&mut self) {
+        self.close_suggestions();
+    }
+
+    pub fn suggestions_next(&mut self) {
+        if !self.ui_state.suggestions.is_active || self.suggestions.is_empty()
+        {
+            return;
+        }
+
+        let current = self.ui_state.suggestions.selected_index.unwrap_or(0);
+        let next = (current + 1) % self.suggestions.len();
+        self.ui_state.suggestions.selected_index = Some(next);
+        self.update_inline_completion();
+    }
+
+    pub fn suggestions_prev(&mut self) {
+        if !self.ui_state.suggestions.is_active || self.suggestions.is_empty() {
+            return;
+        }
+
+        let current = self.ui_state.suggestions.selected_index.unwrap_or(0);
+        let prev = if current == 0 {
+            self.suggestions.len() - 1
+        } else {
+            current - 1
+        };
+        self.ui_state.suggestions.selected_index = Some(prev);
+        self.update_inline_completion();
+    }
+
+    pub fn apply_suggestion(&mut self) -> Option<String> {
+        if let Some(selected_index) = self.ui_state.suggestions.selected_index {
+            if let Some(suggestion) = self.suggestions.get(selected_index).cloned()
+            {
+                let field_index = self.ui_state.current_field;
+
+                self.data_provider.set_field_value(
+                    field_index,
+                    suggestion.value_to_store.clone(),
+                );
+
+                self.ui_state.cursor_pos = suggestion.value_to_store.len();
+                self.ui_state.ideal_cursor_column = self.ui_state.cursor_pos;
+
+                self.close_suggestions();
+                self.suggestions.clear();
+
+                #[cfg(feature = "validation")]
+                {
+                    let _ = self.ui_state.validation.validate_field_content(
+                        field_index,
+                        &suggestion.value_to_store,
+                    );
+                }
+
+                return Some(suggestion.display_text);
+            }
+        }
+        None
+    }
+}

canvas/src/editor/suggestions_stub.rs

@@ -0,0 +1,23 @@
+// src/editor/suggestions_stub.rs
+// Crate-private no-op methods so internal calls compile when feature is off.
+
+use crate::editor::FormEditor;
+use crate::DataProvider;
+
+impl<D: DataProvider> FormEditor<D> {
+    pub(crate) fn open_suggestions(&mut self, _field_index: usize) {
+        // no-op
+    }
+
+    pub(crate) fn close_suggestions(&mut self) {
+        // no-op
+    }
+
+    pub(crate) fn handle_escape_readonly(&mut self) {
+        // no-op
+    }
+
+    pub(crate) fn cancel_suggestions(&mut self) {
+        // no-op
+    }
+}

canvas/src/editor/validation_helpers.rs

@@ -0,0 +1,178 @@
+// src/editor/validation_helpers.rs
+
+use crate::editor::FormEditor;
+use crate::DataProvider;
+
+impl<D: DataProvider> FormEditor<D> {
+    #[cfg(feature = "validation")]
+    pub fn set_validation_enabled(&mut self, enabled: bool) {
+        self.ui_state.validation.set_enabled(enabled);
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn is_validation_enabled(&self) -> bool {
+        self.ui_state.validation.is_enabled()
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn set_field_validation(
+        &mut self,
+        field_index: usize,
+        config: crate::validation::ValidationConfig,
+    ) {
+        self.ui_state
+            .validation
+            .set_field_config(field_index, config);
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn remove_field_validation(&mut self, field_index: usize) {
+        self.ui_state.validation.remove_field_config(field_index);
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn validate_current_field(
+        &mut self,
+    ) -> crate::validation::ValidationResult {
+        let field_index = self.ui_state.current_field;
+        let current_text = self.current_text().to_string();
+        self.ui_state
+            .validation
+            .validate_field_content(field_index, &current_text)
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn validate_field(
+        &mut self,
+        field_index: usize,
+    ) -> Option<crate::validation::ValidationResult> {
+        if field_index < self.data_provider.field_count() {
+            let text =
+                self.data_provider.field_value(field_index).to_string();
+            Some(
+                self.ui_state
+                    .validation
+                    .validate_field_content(field_index, &text),
+            )
+        } else {
+            None
+        }
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn clear_validation_results(&mut self) {
+        self.ui_state.validation.clear_all_results();
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn validation_summary(
+        &self,
+    ) -> crate::validation::ValidationSummary {
+        self.ui_state.validation.summary()
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn can_switch_fields(&self) -> bool {
+        let current_text = self.current_text();
+        self.ui_state.validation.allows_field_switch(
+            self.ui_state.current_field,
+            current_text,
+        )
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn field_switch_block_reason(&self) -> Option<String> {
+        let current_text = self.current_text();
+        self.ui_state.validation.field_switch_block_reason(
+            self.ui_state.current_field,
+            current_text,
+        )
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn last_switch_block(&self) -> Option<&str> {
+        self.ui_state.validation.last_switch_block()
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn current_limits_status_text(&self) -> Option<String> {
+        let idx = self.ui_state.current_field;
+        if let Some(cfg) = self.ui_state.validation.get_field_config(idx) {
+            if let Some(limits) = &cfg.character_limits {
+                return limits.status_text(self.current_text());
+            }
+        }
+        None
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn current_formatter_warning(&self) -> Option<String> {
+        let idx = self.ui_state.current_field;
+        if let Some(cfg) = self.ui_state.validation.get_field_config(idx) {
+            if let Some((_fmt, _mapper, warn)) =
+                cfg.run_custom_formatter(self.current_text())
+            {
+                return warn;
+            }
+        }
+        None
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn external_validation_of(
+        &self,
+        field_index: usize,
+    ) -> crate::validation::ExternalValidationState {
+        self.ui_state
+            .validation
+            .get_external_validation(field_index)
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn clear_all_external_validation(&mut self) {
+        self.ui_state.validation.clear_all_external_validation();
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn clear_external_validation(&mut self, field_index: usize) {
+        self.ui_state
+            .validation
+            .clear_external_validation(field_index);
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn set_external_validation(
+        &mut self,
+        field_index: usize,
+        state: crate::validation::ExternalValidationState,
+    ) {
+        self.ui_state
+            .validation
+            .set_external_validation(field_index, state);
+    }
+
+    #[cfg(feature = "validation")]
+    pub fn set_external_validation_callback<F>(&mut self, callback: F)
+    where
+        F: FnMut(usize, &str) -> crate::validation::ExternalValidationState
+            + Send
+            + Sync
+            + 'static,
+    {
+        self.external_validation_callback = Some(Box::new(callback));
+    }
+
+    #[cfg(feature = "validation")]
+    pub(crate) fn initialize_validation(&mut self) {
+        let field_count = self.data_provider.field_count();
+        for field_index in 0..field_count {
+            if let Some(config) =
+                self.data_provider.validation_config(field_index)
+            {
+                self.ui_state
+                    .validation
+                    .set_field_config(field_index, config);
+            }
+        }
+    }
+}

canvas/src/keymap/mod.rs

@@ -0,0 +1,344 @@
+// src/keymap/mod.rs
+use std::collections::HashMap;
+use std::time::{Duration, Instant};
+
+use crossterm::event::{KeyCode, KeyModifiers};
+
+use crate::canvas::modes::AppMode;
+
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
+pub struct KeyStroke {
+    pub code: KeyCode,
+    pub modifiers: KeyModifiers,
+}
+
+#[derive(Clone, Debug)]
+struct Binding {
+    action: String,
+    sequence: Vec<KeyStroke>,
+}
+
+#[derive(Clone, Debug, Default)]
+pub struct CanvasKeyMap {
+    ro: Vec<Binding>,
+    edit: Vec<Binding>,
+    hl: Vec<Binding>,
+}
+
+// FIXED: Removed Copy because Option<String> is not Copy
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum KeyEventOutcome {
+    Consumed(Option<String>),
+    Pending,
+    NotMatched,
+}
+
+#[derive(Debug, Clone)]
+pub struct KeySequenceTracker {
+    sequence: Vec<KeyStroke>,
+    last_key_time: Instant,
+    timeout: Duration,
+}
+
+impl KeySequenceTracker {
+    pub fn new(timeout_ms: u64) -> Self {
+        Self {
+            sequence: Vec::new(),
+            last_key_time: Instant::now(),
+            timeout: Duration::from_millis(timeout_ms),
+        }
+    }
+
+    pub fn reset(&mut self) {
+        self.sequence.clear();
+        self.last_key_time = Instant::now();
+    }
+
+    pub fn add_key(&mut self, stroke: KeyStroke) {
+        let now = Instant::now();
+        if now.duration_since(self.last_key_time) > self.timeout {
+            self.reset();
+        }
+        self.sequence.push(normalize_stroke(stroke));
+        self.last_key_time = now;
+    }
+
+    pub fn sequence(&self) -> &[KeyStroke] {
+        &self.sequence
+    }
+}
+
+fn normalize_stroke(mut s: KeyStroke) -> KeyStroke {
+    // Normalize Shift+Tab to BackTab
+    let is_shift_tab =
+        s.code == KeyCode::Tab && s.modifiers.contains(KeyModifiers::SHIFT);
+    if is_shift_tab {
+        s.code = KeyCode::BackTab;
+        s.modifiers.remove(KeyModifiers::SHIFT);
+        return s;
+    }
+
+    // Normalize Shift+char to uppercase char without SHIFT when possible
+    if let KeyCode::Char(c) = s.code {
+        if s.modifiers.contains(KeyModifiers::SHIFT) {
+            let mut up = c;
+            // Only letters transform meaningfully
+            if c.is_ascii_alphabetic() {
+                up = c.to_ascii_uppercase();
+            }
+            s.code = KeyCode::Char(up);
+            s.modifiers.remove(KeyModifiers::SHIFT);
+            return s;
+        }
+    }
+    s
+}
+
+impl CanvasKeyMap {
+    pub fn from_mode_maps(
+        read_only: &HashMap<String, Vec<String>>,
+        edit: &HashMap<String, Vec<String>>,
+        highlight: &HashMap<String, Vec<String>>,
+    ) -> Self {
+        let mut km = Self::default();
+        km.ro = collect_bindings(read_only);
+        km.edit = collect_bindings(edit);
+        km.hl = collect_bindings(highlight);
+        km
+    }
+
+    pub fn lookup(
+        &self,
+        mode: AppMode,
+        seq: &[KeyStroke],
+    ) -> (Option<&str>, bool) {
+        let bindings = match mode {
+            AppMode::ReadOnly => &self.ro,
+            AppMode::Edit => &self.edit,
+            AppMode::Highlight => &self.hl,
+            _ => return (None, false),
+        };
+
+        if seq.is_empty() {
+            return (None, false);
+        }
+
+        // Exact match
+        for b in bindings {
+            if sequences_equal(&b.sequence, seq) {
+                return (Some(b.action.as_str()), false);
+            }
+        }
+
+        // Prefix match
+        for b in bindings {
+            if is_prefix(&b.sequence, seq) {
+                return (None, true);
+            }
+        }
+
+        (None, false)
+    }
+}
+
+fn sequences_equal(a: &[KeyStroke], b: &[KeyStroke]) -> bool {
+    if a.len() != b.len() {
+        return false;
+    }
+    a.iter().zip(b.iter()).all(|(x, y)| strokes_equal(x, y))
+}
+
+fn strokes_equal(a: &KeyStroke, b: &KeyStroke) -> bool {
+    // Both KeyStroke are already normalized
+    a.code == b.code && a.modifiers == b.modifiers
+}
+
+fn is_prefix(binding: &[KeyStroke], seq: &[KeyStroke]) -> bool {
+    if seq.len() >= binding.len() {
+        return false;
+    }
+    binding
+        .iter()
+        .zip(seq.iter())
+        .all(|(b, s)| strokes_equal(b, s))
+}
+
+fn collect_bindings(
+    mode_map: &HashMap<String, Vec<String>>,
+) -> Vec<Binding> {
+    let mut out = Vec::new();
+    for (action, list) in mode_map {
+        for binding_str in list {
+            if let Some(seq) = parse_binding_to_sequence(binding_str) {
+                out.push(Binding {
+                    action: action.to_string(),
+                    sequence: seq,
+                });
+            }
+        }
+    }
+    out
+}
+
+fn parse_binding_to_sequence(input: &str) -> Option<Vec<KeyStroke>> {
+    let s = input.trim();
+    if s.is_empty() {
+        return None;
+    }
+
+    let has_space = s.contains(' ');
+    let has_plus = s.contains('+');
+
+    if has_space {
+        let mut seq = Vec::new();
+        for part in s.split_whitespace() {
+            if let Some(mut strokes) = parse_part_to_sequence(part) {
+                seq.append(&mut strokes);
+            } else {
+                return None;
+            }
+        }
+        return Some(seq);
+    }
+
+    if has_plus {
+        if contains_modifier_token(s) {
+            if let Some(k) = parse_chord_with_modifiers(s) {
+                return Some(vec![k]);
+            }
+            return None;
+        } else {
+            let mut seq = Vec::new();
+            for t in s.split('+') {
+                if let Some(mut strokes) = parse_part_to_sequence(t) {
+                    seq.append(&mut strokes);
+                } else {
+                    return None;
+                }
+            }
+            return Some(seq);
+        }
+    }
+
+    if is_compound_key(s) {
+        if let Some(k) = parse_simple_key(s) {
+            return Some(vec![k]);
+        }
+        return None;
+    }
+
+    if s.len() > 1 {
+        let mut seq = Vec::new();
+        for ch in s.chars() {
+            seq.push(KeyStroke {
+                code: KeyCode::Char(ch),
+                modifiers: KeyModifiers::empty(),
+            });
+        }
+        return Some(seq);
+    }
+
+    if let Some(k) = parse_simple_key(s) {
+        return Some(vec![k]);
+    }
+    None
+}
+
+fn parse_part_to_sequence(part: &str) -> Option<Vec<KeyStroke>> {
+    let p = part.trim();
+    if p.is_empty() {
+        return None;
+    }
+
+    if p.contains('+') && contains_modifier_token(p) {
+        if let Some(k) = parse_chord_with_modifiers(p) {
+            return Some(vec![k]);
+        }
+        return None;
+    }
+
+    if is_compound_key(p) {
+        if let Some(k) = parse_simple_key(p) {
+            return Some(vec![k]);
+        }
+        return None;
+    }
+
+    if p.len() > 1 {
+        let mut seq = Vec::new();
+        for ch in p.chars() {
+            seq.push(KeyStroke {
+                code: KeyCode::Char(ch),
+                modifiers: KeyModifiers::empty(),
+            });
+        }
+        return Some(seq);
+    }
+
+    parse_simple_key(p).map(|k| vec![k])
+}
+
+fn contains_modifier_token(s: &str) -> bool {
+    let low = s.to_lowercase();
+    low.contains("ctrl") || low.contains("shift") || low.contains("alt") || 
+    low.contains("super") || low.contains("cmd") || low.contains("meta")
+}
+
+fn parse_chord_with_modifiers(s: &str) -> Option<KeyStroke> {
+    let mut mods = KeyModifiers::empty();
+    let mut key: Option<KeyCode> = None;
+
+    for comp in s.split('+') {
+        match comp.to_lowercase().as_str() {
+            "ctrl" => mods |= KeyModifiers::CONTROL,
+            "shift" => mods |= KeyModifiers::SHIFT,
+            "alt" => mods |= KeyModifiers::ALT,
+            "super" | "cmd" => mods |= KeyModifiers::SUPER,
+            "meta" => mods |= KeyModifiers::META,
+            other => {
+                key = string_to_keycode(other);
+            }
+        }
+    }
+
+    key.map(|k| normalize_stroke(KeyStroke { code: k, modifiers: mods }))
+}
+
+fn is_compound_key(s: &str) -> bool {
+    matches!(s.to_lowercase().as_str(),
+        "left" | "right" | "up" | "down" | "esc" | "enter" | "backspace" | 
+        "delete" | "tab" | "home" | "end" | "$" | "0"
+    )
+}
+
+fn parse_simple_key(s: &str) -> Option<KeyStroke> {
+    if let Some(kc) = string_to_keycode(&s.to_lowercase()) {
+        return Some(KeyStroke { code: kc, modifiers: KeyModifiers::empty() });
+    }
+
+    if s.chars().count() == 1 {
+        let ch = s.chars().next().unwrap();
+        return Some(KeyStroke { code: KeyCode::Char(ch), modifiers: KeyModifiers::empty() });
+    }
+
+    None
+}
+
+fn string_to_keycode(s: &str) -> Option<KeyCode> {
+    Some(match s {
+        "left" => KeyCode::Left,
+        "right" => KeyCode::Right, 
+        "up" => KeyCode::Up,
+        "down" => KeyCode::Down,
+        "esc" => KeyCode::Esc,
+        "enter" => KeyCode::Enter,
+        "backspace" => KeyCode::Backspace,
+        "delete" => KeyCode::Delete,
+        "tab" => KeyCode::Tab,
+        "home" => KeyCode::Home,
+        "end" => KeyCode::End,
+        "$" => KeyCode::Char('$'),
+        "0" => KeyCode::Char('0'),
+        _ => return None,
+    })
+}

canvas/src/lib.rs

@@ -0,0 +1,77 @@
+// src/lib.rs
+
+pub mod canvas;
+pub mod editor;
+pub mod data_provider;
+
+#[cfg(feature = "suggestions")]
+pub mod suggestions;
+
+#[cfg(feature = "validation")]
+pub mod validation;
+
+#[cfg(feature = "textarea")]
+pub mod textarea;
+
+#[cfg(feature = "computed")]
+pub mod computed;
+
+#[cfg(feature = "keymap")]
+pub mod keymap;
+
+#[cfg(feature = "cursor-style")]
+pub use canvas::CursorManager;
+
+// ===================================================================
+// NEW API: Library-owned state pattern
+// ===================================================================
+
+// Main API exports
+pub use editor::FormEditor;
+pub use data_provider::DataProvider;
+#[cfg(feature = "suggestions")]
+pub use data_provider::{SuggestionsProvider, SuggestionItem};
+
+// UI state (read-only access for users)
+pub use canvas::state::EditorState;
+pub use canvas::modes::AppMode;
+
+// Actions and results (for users who want to handle actions manually)
+pub use canvas::actions::{CanvasAction, ActionResult};
+
+// Validation exports (only when validation feature is enabled)
+#[cfg(feature = "validation")]
+pub use validation::{
+    ValidationConfig, ValidationResult, ValidationError,
+    CharacterLimits, ValidationConfigBuilder, ValidationState,
+    ValidationSummary, PatternFilters, PositionFilter, PositionRange, CharacterFilter, 
+    DisplayMask,  // Simple display mask instead of complex ReservedCharacters
+    // Feature 4: custom formatting exports
+    CustomFormatter, FormattingResult, PositionMapper, DefaultPositionMapper,
+};
+
+// Computed exports (only when computed feature is enabled)
+#[cfg(feature = "computed")]
+pub use computed::{ComputedProvider, ComputedContext, ComputedState};
+
+// Theming and GUI
+#[cfg(feature = "gui")]
+pub use canvas::theme::{CanvasTheme, DefaultCanvasTheme};
+
+#[cfg(feature = "gui")]
+pub use canvas::gui::{render_canvas, render_canvas_default};
+
+#[cfg(feature = "gui")]
+pub use canvas::gui::render_canvas_with_options;
+
+#[cfg(feature = "gui")]
+pub use canvas::gui::{CanvasDisplayOptions, OverflowMode};
+
+#[cfg(all(feature = "gui", feature = "suggestions"))]
+pub use suggestions::gui::render_suggestions_dropdown;
+
+#[cfg(feature = "keymap")]
+pub use keymap::{CanvasKeyMap, KeyEventOutcome};
+
+#[cfg(feature = "textarea")]
+pub use textarea::{TextArea, TextAreaProvider, TextAreaState, TextAreaEditor};

canvas/src/suggestions/gui.rs

@@ -0,0 +1,191 @@
+// src/suggestions/gui.rs
+//! Suggestions dropdown GUI (not inline autocomplete) updated to work with FormEditor
+
+#[cfg(feature = "gui")]
+use ratatui::{
+    layout::{Alignment, Rect},
+    style::{Modifier, Style},
+    widgets::{Block, List, ListItem, ListState, Paragraph},  // Removed Borders
+    Frame,
+};
+
+#[cfg(feature = "gui")]
+use crate::canvas::theme::CanvasTheme;
+use crate::data_provider::{DataProvider, SuggestionItem};
+use crate::editor::FormEditor;
+
+#[cfg(feature = "gui")]
+use unicode_width::UnicodeWidthStr;
+
+/// Render suggestions dropdown for FormEditor - call this AFTER rendering canvas
+#[cfg(feature = "gui")]
+pub fn render_suggestions_dropdown<T: CanvasTheme, D: DataProvider>(
+    f: &mut Frame,
+    frame_area: Rect,
+    input_rect: Rect,
+    theme: &T,
+    editor: &FormEditor<D>,
+) {
+    let ui_state = editor.ui_state();
+
+    if !ui_state.is_suggestions_active() {
+        return;
+    }
+
+    if ui_state.suggestions.is_loading {
+        render_loading_indicator(f, frame_area, input_rect, theme);
+    } else if !editor.suggestions().is_empty() {
+        render_suggestions_dropdown_list(f, frame_area, input_rect, theme, editor.suggestions(), ui_state.suggestions.selected_index);
+    }
+}
+
+/// Show loading spinner/text
+#[cfg(feature = "gui")]
+fn render_loading_indicator<T: CanvasTheme>(
+    f: &mut Frame,
+    frame_area: Rect,
+    input_rect: Rect,
+    theme: &T,
+) {
+    let loading_text = "Loading suggestions...";
+    let loading_width = loading_text.width() as u16 + 4; // +4 for borders and padding
+    let loading_height = 3;
+
+    let dropdown_area = calculate_dropdown_position(
+        input_rect,
+        frame_area,
+        loading_width,
+        loading_height,
+    );
+
+    let loading_block = Block::default()
+        .style(Style::default().bg(theme.bg()));
+
+    let loading_paragraph = Paragraph::new(loading_text)
+        .block(loading_block)
+        .style(Style::default().fg(theme.fg()))
+        .alignment(Alignment::Center);
+
+    f.render_widget(loading_paragraph, dropdown_area);
+}
+
+/// Show actual suggestions list
+#[cfg(feature = "gui")]
+fn render_suggestions_dropdown_list<T: CanvasTheme>(
+    f: &mut Frame,
+    frame_area: Rect,
+    input_rect: Rect,
+    theme: &T,
+    suggestions: &[SuggestionItem],  // Fixed: Removed <String> generic parameter
+    selected_index: Option<usize>,
+) {
+    let display_texts: Vec<&str> = suggestions
+        .iter()
+        .map(|item| item.display_text.as_str())
+        .collect();
+
+    let dropdown_dimensions = calculate_dropdown_dimensions(&display_texts);
+    let dropdown_area = calculate_dropdown_position(
+        input_rect,
+        frame_area,
+        dropdown_dimensions.width,
+        dropdown_dimensions.height,
+    );
+
+    // Background
+    let dropdown_block = Block::default()
+        .style(Style::default().bg(theme.bg()));
+
+    // List items
+    let items = create_suggestion_list_items(
+        &display_texts,
+        selected_index,
+        dropdown_dimensions.width,
+        theme,
+    );
+
+    let list = List::new(items).block(dropdown_block);
+    let mut list_state = ListState::default();
+    list_state.select(selected_index);
+
+    f.render_stateful_widget(list, dropdown_area, &mut list_state);
+}
+
+/// Calculate dropdown size based on suggestions
+#[cfg(feature = "gui")]
+fn calculate_dropdown_dimensions(display_texts: &[&str]) -> DropdownDimensions {
+    let max_width = display_texts
+        .iter()
+        .map(|text| text.width())
+        .max()
+        .unwrap_or(0) as u16;
+
+    let horizontal_padding = 2;
+    let width = (max_width + horizontal_padding).max(10);
+    let height = (display_texts.len() as u16).min(5);
+
+    DropdownDimensions { width, height }
+}
+
+/// Position dropdown to stay in bounds
+#[cfg(feature = "gui")]
+fn calculate_dropdown_position(
+    input_rect: Rect,
+    frame_area: Rect,
+    dropdown_width: u16,
+    dropdown_height: u16,
+) -> Rect {
+    let mut dropdown_area = Rect {
+        x: input_rect.x,
+        y: input_rect.y + 1, // below input field
+        width: dropdown_width,
+        height: dropdown_height,
+    };
+
+    // Keep in bounds
+    if dropdown_area.bottom() > frame_area.height {
+        dropdown_area.y = input_rect.y.saturating_sub(dropdown_height);
+    }
+    if dropdown_area.right() > frame_area.width {
+        dropdown_area.x = frame_area.width.saturating_sub(dropdown_width);
+    }
+    dropdown_area
+}
+
+/// Create styled list items
+#[cfg(feature = "gui")]
+fn create_suggestion_list_items<'a, T: CanvasTheme>(
+    display_texts: &'a [&'a str],
+    selected_index: Option<usize>,
+    dropdown_width: u16,
+    theme: &T,
+) -> Vec<ListItem<'a>> {
+    let available_width = dropdown_width;
+
+    display_texts
+        .iter()
+        .enumerate()
+        .map(|(i, text)| {
+            let is_selected = selected_index == Some(i);
+            let text_width = text.width() as u16;
+            let padding_needed = available_width.saturating_sub(text_width);
+            let padded_text = format!("{}{}", text, " ".repeat(padding_needed as usize));
+
+            ListItem::new(padded_text).style(if is_selected {
+                Style::default()
+                    .fg(theme.bg())
+                    .bg(theme.highlight())
+                    .add_modifier(Modifier::BOLD)
+            } else {
+                Style::default().fg(theme.fg()).bg(theme.bg())
+            })
+        })
+        .collect()
+}
+
+/// Helper struct for dropdown dimensions
+#[cfg(feature = "gui")]
+struct DropdownDimensions {
+    width: u16,
+    height: u16,
+}

canvas/src/suggestions/mod.rs

@@ -0,0 +1,16 @@
+// src/suggestions/mod.rs
+//! Suggestions subsystem - provider and optional GUI.
+//!
+//! Contains the suggestion provider types used by the editor and, when the GUI
+//! feature is enabled, the rendering helpers for the suggestions dropdown.
+
+pub mod state;
+#[cfg(feature = "gui")]
+pub mod gui;
+
+// Re-export the main suggestion types
+pub use state::{SuggestionsProvider, SuggestionItem};
+
+// Re-export GUI functions if available
+#[cfg(feature = "gui")]
+pub use gui::render_suggestions_dropdown;

canvas/src/suggestions/state.rs

@@ -0,0 +1,5 @@
+// src/suggestions/state.rs
+//! Suggestions provider types (for dropdown suggestions, not real inline autocomplete)
+
+// Re-export the main types from data_provider
+pub use crate::data_provider::{SuggestionsProvider, SuggestionItem};

canvas/src/textarea/highlight/chunks.rs

@@ -0,0 +1,183 @@
+// src/textarea/highlight/chunks.rs
+use ratatui::text::{Line, Span};
+use ratatui::style::Style;
+use unicode_width::UnicodeWidthChar;
+
+#[derive(Debug, Clone)]
+pub struct StyledChunk {
+    pub text: String,
+    pub style: Style,
+}
+
+pub fn display_width_chunks(chunks: &[StyledChunk]) -> u16 {
+    chunks
+        .iter()
+        .map(|c| {
+            c.text
+                .chars()
+                .map(|ch| UnicodeWidthChar::width(ch).unwrap_or(0) as u16)
+                .sum::<u16>()
+        })
+        .sum()
+}
+
+pub fn slice_chunks_by_display_cols(
+    chunks: &[StyledChunk],
+    start_cols: u16,
+    max_cols: u16,
+) -> Vec<StyledChunk> {
+    if max_cols == 0 {
+        return Vec::new();
+    }
+
+    let mut skipped: u16 = 0;
+    let mut taken: u16 = 0;
+    let mut out: Vec<StyledChunk> = Vec::new();
+
+    for ch in chunks {
+        if taken >= max_cols {
+            break;
+        }
+
+        let mut acc = String::new();
+
+        for c in ch.text.chars() {
+            let w = UnicodeWidthChar::width(c).unwrap_or(0) as u16;
+            if skipped + w <= start_cols {
+                skipped += w;
+                continue;
+            }
+            if taken + w > max_cols {
+                break;
+            }
+            acc.push(c);
+            taken = taken.saturating_add(w);
+            if taken >= max_cols {
+                break;
+            }
+        }
+
+        if !acc.is_empty() {
+            out.push(StyledChunk {
+                text: acc,
+                style: ch.style,
+            });
+        }
+    }
+
+    out
+}
+
+pub fn clip_chunks_window_with_indicator_padded(
+    chunks: &[StyledChunk],
+    view_width: u16,
+    indicator: char,
+    start_cols: u16,
+) -> Line<'static> {
+    if view_width == 0 {
+        return Line::from("");
+    }
+
+    let total = display_width_chunks(chunks);
+    let show_left = start_cols > 0;
+    let left_cols: u16 = if show_left { 1 } else { 0 };
+
+    let cap_with_right = view_width.saturating_sub(left_cols + 1);
+    let remaining = total.saturating_sub(start_cols);
+    let show_right = remaining > cap_with_right;
+
+    let max_visible = if show_right {
+        cap_with_right
+    } else {
+        view_width.saturating_sub(left_cols)
+    };
+
+    let visible = slice_chunks_by_display_cols(chunks, start_cols, max_visible);
+    let used_cols = left_cols + display_width_chunks(&visible);
+
+    let mut spans: Vec<Span> = Vec::new();
+    if show_left {
+        spans.push(Span::raw(indicator.to_string()));
+    }
+    for v in visible {
+        spans.push(Span::styled(v.text, v.style));
+    }
+    if show_right {
+        let right_pos = view_width.saturating_sub(1);
+        let filler = right_pos.saturating_sub(used_cols);
+        if filler > 0 {
+            spans.push(Span::raw(" ".repeat(filler as usize)));
+        }
+        spans.push(Span::raw(indicator.to_string()));
+    }
+
+    Line::from(spans)
+}
+
+pub fn wrap_chunks_indented(
+    chunks: &[StyledChunk],
+    width: u16,
+    indent: u16,
+) -> Vec<Line<'static>> {
+    if width == 0 {
+        return vec![Line::from("")];
+    }
+    let indent = indent.min(width.saturating_sub(1));
+    let cont_cap = width.saturating_sub(indent);
+    let indent_str = " ".repeat(indent as usize);
+
+    let mut lines: Vec<Line> = Vec::new();
+    let mut current_spans: Vec<Span> = Vec::new();
+    let mut used: u16 = 0;
+    let mut first_line = true;
+
+    // Fixed: Restructure to avoid borrow checker issues
+    for chunk in chunks {
+        let mut buf = String::new();
+        let mut buf_style = chunk.style;
+
+        for ch in chunk.text.chars() {
+            let w = UnicodeWidthChar::width(ch).unwrap_or(0) as u16;
+            let cap = if first_line { width } else { cont_cap };
+
+            if used > 0 && used.saturating_add(w) >= cap {
+                if !buf.is_empty() {
+                    current_spans.push(Span::styled(buf.clone(), buf_style));
+                    buf.clear();
+                }
+                lines.push(Line::from(current_spans));
+                current_spans = Vec::new();
+                first_line = false;
+                used = 0;
+                
+                // Add indent directly instead of using closure
+                if !first_line && indent > 0 {
+                    current_spans.push(Span::raw(indent_str.clone()));
+                    used = indent;
+                }
+            }
+
+            if !buf.is_empty() && buf_style != chunk.style {
+                current_spans.push(Span::styled(buf.clone(), buf_style));
+                buf.clear();
+            }
+            buf_style = chunk.style;
+            
+            // Add indent if needed
+            if used == 0 && !first_line && indent > 0 {
+                current_spans.push(Span::raw(indent_str.clone()));
+                used = indent;
+            }
+            
+            buf.push(ch);
+            used = used.saturating_add(w);
+        }
+
+        if !buf.is_empty() {
+            current_spans.push(Span::styled(buf, buf_style));
+        }
+    }
+
+    lines.push(Line::from(current_spans));
+    lines
+}

canvas/src/textarea/highlight/engine.rs

@@ -0,0 +1,294 @@
+// src/textarea/highlight/engine.rs
+#![allow(dead_code)]
+
+use std::collections::hash_map::DefaultHasher;
+use std::hash::{Hash, Hasher};
+
+use ratatui::style::{Modifier, Style};
+use syntect::{
+    highlighting::{
+        HighlightIterator, HighlightState, Highlighter, Style as SynStyle, Theme, ThemeSet,
+    },
+    parsing::{ParseState, ScopeStack, SyntaxReference, SyntaxSet},
+};
+
+use crate::data_provider::DataProvider;
+use super::chunks::StyledChunk;
+
+#[derive(Debug)]
+pub struct SyntectEngine {
+    ps: SyntaxSet,
+    ts: ThemeSet,
+    theme_name: String,
+    syntax_name: Option<String>,
+    // Cached parser state (after line i)
+    parse_after: Vec<ParseState>,
+    // Cached scope stack (after line i)
+    stack_after: Vec<ScopeStack>,
+    // Hash of line contents to detect edits
+    line_hashes: Vec<u64>,
+}
+
+impl Default for SyntectEngine {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl SyntectEngine {
+    pub fn new() -> Self {
+        let ps = SyntaxSet::load_defaults_newlines();
+        let ts = ThemeSet::load_defaults();
+        Self {
+            ps,
+            ts,
+            theme_name: "InspiredGitHub".to_string(),
+            syntax_name: None,
+            parse_after: Vec::new(),
+            stack_after: Vec::new(),
+            line_hashes: Vec::new(),
+        }
+    }
+
+    pub fn clear(&mut self) {
+        self.parse_after.clear();
+        self.stack_after.clear();
+        self.line_hashes.clear();
+    }
+
+    pub fn set_theme(&mut self, theme_name: &str) -> bool {
+        if self.ts.themes.contains_key(theme_name) {
+            self.theme_name = theme_name.to_string();
+            true
+        } else {
+            false
+        }
+    }
+
+    pub fn set_syntax_by_name(&mut self, name: &str) -> bool {
+        if self.ps.find_syntax_by_name(name).is_some() {
+            self.syntax_name = Some(name.to_string());
+            self.clear();
+            true
+        } else {
+            false
+        }
+    }
+
+    pub fn set_syntax_by_extension(&mut self, ext: &str) -> bool {
+        if let Some(s) = self.ps.find_syntax_by_extension(ext) {
+            self.syntax_name = Some(s.name.clone());
+            self.clear();
+            true
+        } else {
+            false
+        }
+    }
+
+    pub fn invalidate_from(&mut self, line_idx: usize) {
+        if line_idx < self.parse_after.len() {
+            self.parse_after.truncate(line_idx);
+        }
+        if line_idx < self.stack_after.len() {
+            self.stack_after.truncate(line_idx);
+        }
+        if line_idx < self.line_hashes.len() {
+            self.line_hashes.truncate(line_idx);
+        }
+    }
+
+    pub fn on_insert_line(&mut self, at: usize) {
+        self.invalidate_from(at);
+    }
+
+    pub fn on_delete_line(&mut self, at: usize) {
+        self.invalidate_from(at);
+    }
+
+    fn theme(&self) -> &Theme {
+        self.ts
+            .themes
+            .get(&self.theme_name)
+            .expect("theme exists")
+    }
+
+    fn syntax_ref(&self) -> &SyntaxReference {
+        if let Some(name) = &self.syntax_name {
+            if let Some(s) = self.ps.find_syntax_by_name(name) {
+                return s;
+            }
+        }
+        self.ps.find_syntax_plain_text()
+    }
+
+    fn map_syntect_style(s: SynStyle) -> Style {
+        let fg =
+            ratatui::style::Color::Rgb(s.foreground.r, s.foreground.g, s.foreground.b);
+        let mut st = Style::default().fg(fg);
+        use syntect::highlighting::FontStyle;
+        if s.font_style.contains(FontStyle::BOLD) {
+            st = st.add_modifier(Modifier::BOLD);
+        }
+        if s.font_style.contains(FontStyle::UNDERLINE) {
+            st = st.add_modifier(Modifier::UNDERLINED);
+        }
+        if s.font_style.contains(FontStyle::ITALIC) {
+            st = st.add_modifier(Modifier::ITALIC);
+        }
+        st
+    }
+
+    fn hash_line(s: &str) -> u64 {
+        let mut h = DefaultHasher::new();
+        s.hash(&mut h);
+        h.finish()
+    }
+
+    // Verify cached chain up to the nearest trusted predecessor of line_idx,
+    // using the provider to fetch the current lines.
+    fn verify_and_truncate_before(&mut self, line_idx: usize, provider: &dyn DataProvider) {
+        let mut k = std::cmp::min(line_idx, self.parse_after.len());
+        while k > 0 {
+            let j = k - 1;
+            let curr = Self::hash_line(provider.field_value(j));
+            if self.line_hashes.get(j) == Some(&curr) {
+                break;
+            }
+            self.invalidate_from(j);
+            k = j;
+        }
+    }
+
+    // Ensure we have parser + stack for lines [0..line_idx)
+    fn ensure_state_before(&mut self, line_idx: usize, provider: &dyn DataProvider) {
+        if line_idx == 0 || self.parse_after.len() >= line_idx {
+            return;
+        }
+
+        let syntax = self.syntax_ref();
+        let theme = self.theme().clone(); // Clone to avoid borrow conflicts
+        let highlighter = Highlighter::new(&theme);
+
+        let mut ps = if self.parse_after.is_empty() {
+            ParseState::new(syntax)
+        } else {
+            self.parse_after[self.parse_after.len() - 1].clone()
+        };
+        let mut stack = if self.stack_after.is_empty() {
+            ScopeStack::new()
+        } else {
+            self.stack_after[self.stack_after.len() - 1].clone()
+        };
+
+        let start = self.parse_after.len();
+        for i in start..line_idx {
+            let s = provider.field_value(i);
+            
+            // Fix: parse_line takes 2 arguments: line and &SyntaxSet
+            let ops = ps.parse_line(s, &self.ps).unwrap_or_default();
+            
+            // Fix: HighlightState::new requires &Highlighter and ScopeStack
+            let mut highlight_state = HighlightState::new(&highlighter, stack.clone());
+            
+            // Fix: HighlightIterator::new expects &mut HighlightState as first parameter
+            let it = HighlightIterator::new(&mut highlight_state, &ops[..], s, &highlighter);
+            for (_style, _text) in it {
+                // Iterate to apply ops; we don't need the tokens here.
+            }
+            
+            // Update the stack from the highlight state
+            stack = highlight_state.path.clone();
+
+            let h = Self::hash_line(s);
+
+            self.parse_after.push(ps.clone());
+            self.stack_after.push(stack.clone());
+            if i >= self.line_hashes.len() {
+                self.line_hashes.push(h);
+            } else {
+                self.line_hashes[i] = h;
+            }
+        }
+    }
+
+    // Highlight a single line using cached state; update caches for this line.
+    pub fn highlight_line_cached(
+        &mut self,
+        line_idx: usize,
+        line: &str,
+        provider: &dyn DataProvider,
+    ) -> Vec<StyledChunk> {
+        // Auto-detect prior changes and truncate cache if needed
+        self.verify_and_truncate_before(line_idx, provider);
+        // Precompute states up to line_idx
+        self.ensure_state_before(line_idx, provider);
+
+        let syntax = self.syntax_ref();
+        let theme = self.theme().clone(); // Clone to avoid borrow conflicts
+        let highlighter = Highlighter::new(&theme);
+
+        let mut ps = if line_idx == 0 {
+            ParseState::new(syntax)
+        } else if self.parse_after.len() >= line_idx {
+            self.parse_after[line_idx - 1].clone()
+        } else {
+            ParseState::new(syntax)
+        };
+
+        let stack = if line_idx == 0 {
+            ScopeStack::new()
+        } else if self.stack_after.len() >= line_idx {
+            self.stack_after[line_idx - 1].clone()
+        } else {
+            ScopeStack::new()
+        };
+
+        // Fix: parse_line takes 2 arguments: line and &SyntaxSet
+        let ops = ps.parse_line(line, &self.ps).unwrap_or_default();
+        
+        // Fix: HighlightState::new requires &Highlighter and ScopeStack
+        let mut highlight_state = HighlightState::new(&highlighter, stack);
+        
+        // Fix: HighlightIterator::new expects &mut HighlightState as first parameter
+        let iter = HighlightIterator::new(&mut highlight_state, &ops[..], line, &highlighter);
+
+        let mut out: Vec<StyledChunk> = Vec::new();
+        for (syn_style, slice) in iter {
+            if slice.is_empty() {
+                continue;
+            }
+            let text = slice.trim_end_matches('\n').to_string();
+            if text.is_empty() {
+                continue;
+            }
+            out.push(StyledChunk {
+                text,
+                style: Self::map_syntect_style(syn_style),
+            });
+        }
+
+        // Update caches for this line (state after this line)
+        let h = Self::hash_line(line);
+        if line_idx >= self.parse_after.len() {
+            self.parse_after.push(ps);
+        } else {
+            self.parse_after[line_idx] = ps;
+        }
+        
+        // Update stack from highlight state
+        let final_stack = highlight_state.path.clone();
+        if line_idx >= self.stack_after.len() {
+            self.stack_after.push(final_stack);
+        } else {
+            self.stack_after[line_idx] = final_stack;
+        }
+        
+        if line_idx >= self.line_hashes.len() {
+            self.line_hashes.push(h);
+        } else {
+            self.line_hashes[line_idx] = h;
+        }
+
+        out
+    }
+}

canvas/src/textarea/highlight/mod.rs

@@ -0,0 +1,18 @@
+// src/textarea/highlight/mod.rs
+#[cfg(all(feature = "syntect", feature = "gui"))]
+pub mod engine;
+#[cfg(all(feature = "syntect", feature = "gui"))]
+pub mod chunks;
+#[cfg(all(feature = "syntect", feature = "gui"))]
+pub mod state;
+#[cfg(all(feature = "syntect", feature = "gui"))]
+pub mod widget;
+
+#[cfg(all(feature = "syntect", feature = "gui"))]
+pub use engine::SyntectEngine;
+#[cfg(all(feature = "syntect", feature = "gui"))]
+pub use chunks::StyledChunk;
+#[cfg(all(feature = "syntect", feature = "gui"))]
+pub use state::TextAreaSyntaxState;
+#[cfg(all(feature = "syntect", feature = "gui"))]
+pub use widget::TextAreaSyntax;

canvas/src/textarea/highlight/state.rs

@@ -0,0 +1,45 @@
+// src/textarea/highlight/state.rs
+use std::ops::{Deref, DerefMut};
+
+use super::engine::SyntectEngine;
+use crate::textarea::state::TextAreaState;
+
+// Remove Debug derive since TextAreaState doesn't implement Debug
+#[derive(Default)]
+pub struct TextAreaSyntaxState {
+    pub textarea: TextAreaState,
+    pub engine: SyntectEngine,
+}
+
+impl TextAreaSyntaxState {
+    pub fn from_text<S: Into<String>>(text: S) -> Self {
+        let mut s = Self::default();
+        s.textarea.set_text(text);
+        s
+    }
+
+    // Optional: convenience setters
+    pub fn set_syntax_theme(&mut self, theme: &str) -> bool {
+        self.engine.set_theme(theme)
+    }
+    pub fn set_syntax_by_name(&mut self, name: &str) -> bool {
+        self.engine.set_syntax_by_name(name)
+    }
+    pub fn set_syntax_by_extension(&mut self, ext: &str) -> bool {
+        self.engine.set_syntax_by_extension(ext)
+    }
+}
+
+impl Deref for TextAreaSyntaxState {
+    type Target = TextAreaState;
+    fn deref(&self) -> &Self::Target {
+        &self.textarea
+    }
+}
+
+impl DerefMut for TextAreaSyntaxState {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.textarea
+    }
+}
+

canvas/src/textarea/highlight/widget.rs

@@ -0,0 +1,211 @@
+// src/textarea/highlight/widget.rs
+use ratatui::{
+    buffer::Buffer,
+    layout::{Alignment, Rect},
+    style::Style,
+    text::{Line, Span},
+    widgets::{Block, BorderType, Borders, Paragraph, StatefulWidget, Widget},
+};
+
+use unicode_width::UnicodeWidthChar;
+
+use super::chunks::{
+    clip_chunks_window_with_indicator_padded,
+    wrap_chunks_indented,
+};
+use super::state::TextAreaSyntaxState;
+
+use crate::data_provider::DataProvider;
+use crate::textarea::state::{
+    compute_h_scroll_with_padding, count_wrapped_rows_indented, TextOverflowMode,
+};
+
+#[derive(Debug, Clone)]
+pub struct TextAreaSyntax<'a> {
+    pub block: Option<Block<'a>>,
+    pub style: Style,
+    pub border_type: BorderType,
+}
+
+impl<'a> Default for TextAreaSyntax<'a> {
+    fn default() -> Self {
+        Self {
+            block: Some(
+                Block::default()
+                    .borders(Borders::ALL)
+                    .border_type(BorderType::Rounded),
+            ),
+            style: Style::default(),
+            border_type: BorderType::Rounded,
+        }
+    }
+}
+
+impl<'a> TextAreaSyntax<'a> {
+    pub fn block(mut self, block: Block<'a>) -> Self {
+        self.block = Some(block);
+        self
+    }
+    pub fn style(mut self, style: Style) -> Self {
+        self.style = style;
+        self
+    }
+    pub fn border_type(mut self, ty: BorderType) -> Self {
+        self.border_type = ty;
+        if let Some(b) = &mut self.block {
+            *b = b.clone().border_type(ty);
+        }
+        self
+    }
+}
+
+fn display_width(s: &str) -> u16 {
+    s.chars()
+        .map(|c| UnicodeWidthChar::width(c).unwrap_or(0) as u16)
+        .sum()
+}
+
+fn display_cols_up_to(s: &str, char_count: usize) -> u16 {
+    let mut cols: u16 = 0;
+    for (i, ch) in s.chars().enumerate() {
+        if i >= char_count {
+            break;
+        }
+        cols = cols.saturating_add(UnicodeWidthChar::width(ch).unwrap_or(0) as u16);
+    }
+    cols
+}
+
+fn resolve_start_line_and_intra_indented(
+    state: &TextAreaSyntaxState,
+    inner: Rect,
+) -> (usize, u16) {
+    let provider = state.textarea.editor.data_provider();
+    let total = provider.line_count();
+
+    if total == 0 {
+        return (0, 0);
+    }
+
+    let wrap = matches!(state.textarea.overflow_mode, TextOverflowMode::Wrap);
+    let width = inner.width;
+    let target_vis = state.textarea.scroll_y;
+
+    if !wrap {
+        let start = (target_vis as usize).min(total);
+        return (start, 0);
+    }
+
+    let indent = state.textarea.wrap_indent_cols;
+
+    let mut acc: u16 = 0;
+    for i in 0..total {
+        let s = provider.field_value(i);
+        let rows = count_wrapped_rows_indented(s, width, indent);
+        if acc.saturating_add(rows) > target_vis {
+            let intra = target_vis.saturating_sub(acc);
+            return (i, intra);
+        }
+        acc = acc.saturating_add(rows);
+    }
+
+    (total.saturating_sub(1), 0)
+}
+
+impl<'a> StatefulWidget for TextAreaSyntax<'a> {
+    type State = TextAreaSyntaxState;
+
+    fn render(self, area: Rect, buf: &mut Buffer, state: &mut Self::State) {
+        // Reuse existing scroll logic
+        state.textarea.ensure_visible(area, self.block.as_ref());
+
+        let inner = if let Some(b) = &self.block {
+            b.clone().render(area, buf);
+            b.inner(area)
+        } else {
+            area
+        };
+
+        let edited_now = state.textarea.take_edited_flag();
+
+        let wrap_mode = matches!(state.textarea.overflow_mode, TextOverflowMode::Wrap);
+        let provider = state.textarea.editor.data_provider();
+        let total = provider.line_count();
+
+        let (start, intra) = resolve_start_line_and_intra_indented(state, inner);
+
+        let mut display_lines: Vec<Line> = Vec::new();
+
+        if total == 0 || start >= total {
+            if let Some(ph) = &state.textarea.placeholder {
+                display_lines.push(Line::from(Span::raw(ph.clone())));
+            }
+        } else if wrap_mode {
+            let mut rows_left = inner.height;
+            let indent = state.textarea.wrap_indent_cols;
+
+            let mut i = start;
+            while i < total && rows_left > 0 {
+                let s = provider.field_value(i);
+
+                let chunks = state
+                    .engine
+                    .highlight_line_cached(i, s, provider);
+
+                let lines = wrap_chunks_indented(&chunks, inner.width, indent);
+                let skip = if i == start { intra as usize } else { 0 };
+                for l in lines.into_iter().skip(skip) {
+                    display_lines.push(l);
+                    rows_left = rows_left.saturating_sub(1);
+                    if rows_left == 0 {
+                        break;
+                    }
+                }
+                i += 1;
+            }
+        } else {
+            let end = (start.saturating_add(inner.height as usize)).min(total);
+
+            for i in start..end {
+                let s = provider.field_value(i);
+
+                let chunks = state.engine.highlight_line_cached(i, s, provider);
+
+                let fits = display_width(s) <= inner.width;
+                let start_cols = if i == state.textarea.current_field() {
+                    let col_idx = state.textarea.display_cursor_position();
+                    let cursor_cols = display_cols_up_to(s, col_idx);
+                    let (target_h, _left_cols) =
+                        compute_h_scroll_with_padding(cursor_cols, inner.width);
+
+                    if fits {
+                        if edited_now {
+                            target_h
+                        } else {
+                            0
+                        }
+                    } else {
+                        target_h.max(state.textarea.h_scroll)
+                    }
+                } else {
+                    0
+                };
+
+                if let TextOverflowMode::Indicator { ch } = state.textarea.overflow_mode {
+                    display_lines.push(clip_chunks_window_with_indicator_padded(
+                        &chunks,
+                        inner.width,
+                        ch,
+                        start_cols,
+                    ));
+                }
+            }
+        }
+
+        let p = Paragraph::new(display_lines)
+            .alignment(Alignment::Left)
+            .style(self.style);
+
+        p.render(inner, buf);
+    }
+}

canvas/src/textarea/mod.rs

@@ -0,0 +1,17 @@
+// src/textarea/mod.rs
+//! Text area convenience exports.
+
+pub mod provider;
+pub mod state;
+
+#[cfg(feature = "gui")]
+pub mod widget;
+
+#[cfg(all(feature = "syntect", feature = "gui"))]
+pub mod highlight;
+
+pub use provider::TextAreaProvider;
+pub use state::{TextAreaEditor, TextAreaState, TextOverflowMode};
+
+#[cfg(feature = "gui")]
+pub use widget::TextArea;

canvas/src/textarea/provider.rs

@@ -0,0 +1,250 @@
+// src/textarea/provider.rs
+use crate::DataProvider;
+use once_cell::unsync::OnceCell;
+use ropey::Rope;
+use std::io::{self, BufReader, Read};
+use std::path::Path;
+
+#[derive(Debug)] // Clone removed: OnceCell<String> is not Clone
+pub struct TextAreaProvider {
+    rope: Rope,
+    name: String,
+    // Lazy per-line cache; only lines that are actually used get materialized.
+    // This keeps memory low even for very large files.
+    line_cache: Vec<OnceCell<String>>,
+}
+
+impl Default for TextAreaProvider {
+    fn default() -> Self {
+        let rope = Rope::from_str("");
+        Self {
+            rope,
+            name: "Text".to_string(),
+            line_cache: vec![OnceCell::new()], // at least 1 logical line
+        }
+    }
+}
+
+impl TextAreaProvider {
+    pub fn from_text<S: Into<String>>(text: S) -> Self {
+        let s = text.into();
+        let rope = Rope::from_str(&s);
+        let lines = rope.len_lines().max(1);
+        Self {
+            rope,
+            name: "Text".to_string(),
+            line_cache: vec![(); lines].into_iter().map(|_| OnceCell::new()).collect(),
+        }
+    }
+
+    pub fn to_text(&self) -> String {
+        self.rope.to_string()
+    }
+
+    pub fn from_file<P: AsRef<Path>>(path: P) -> io::Result<Self> {
+        let f = std::fs::File::open(path)?;
+        let mut reader = BufReader::new(f);
+        Self::from_reader(&mut reader)
+    }
+
+    pub fn from_reader<R: Read>(reader: &mut R) -> io::Result<Self> {
+        let rope = Rope::from_reader(reader)?;
+        let lines = rope.len_lines().max(1);
+        Ok(Self {
+            rope,
+            name: "Text".to_string(),
+            line_cache: vec![(); lines].into_iter().map(|_| OnceCell::new()).collect(),
+        })
+    }
+
+    pub fn set_text<S: Into<String>>(&mut self, text: S) {
+        let s = text.into();
+        self.rope = Rope::from_str(&s);
+        self.resize_cache();
+        self.invalidate_cache_from(0);
+    }
+
+    pub fn line_count(&self) -> usize {
+        self.rope.len_lines().max(1)
+    }
+
+    fn resize_cache(&mut self) {
+        let want = self.line_count();
+        if self.line_cache.len() < want {
+            self.line_cache
+                .extend((0..(want - self.line_cache.len())).map(|_| OnceCell::new()));
+        } else if self.line_cache.len() > want {
+            self.line_cache.truncate(want);
+        }
+    }
+
+    fn invalidate_cache_from(&mut self, line_idx: usize) {
+        self.resize_cache();
+        if line_idx < self.line_cache.len() {
+            for cell in &mut self.line_cache[line_idx..] {
+                let _ = cell.take();
+            }
+        }
+    }
+
+    #[inline]
+    fn line_bounds_chars(&self, line_idx: usize) -> (usize, usize) {
+        // Returns [start, end) in char indices for content only (excluding newline).
+        let total_lines = self.line_count();
+        let start = self.rope.line_to_char(line_idx);
+        let end_exclusive = if line_idx + 1 < total_lines {
+            // Next line start is at the char index right after the newline.
+            // Exclude the newline itself by not including it in the range.
+            self.rope.line_to_char(line_idx + 1) - 1
+        } else {
+            self.rope.len_chars()
+        };
+        (start, end_exclusive)
+    }
+
+    fn line_content_len_chars(&self, line_idx: usize) -> usize {
+        let slice = self.rope.line(line_idx);
+        let mut len = slice.len_chars();
+        if line_idx + 1 < self.line_count() && len > 0 {
+            // Non-final lines include a trailing '\n' char in rope; exclude it.
+            len -= 1;
+        }
+        len
+    }
+
+    fn compute_line_string(&self, index: usize) -> String {
+        let mut s = self.rope.line(index).to_string();
+        // Trim trailing newline/CR if present (for non-final lines)
+        if s.ends_with('\n') {
+            s.pop();
+            if s.ends_with('\r') {
+                s.pop();
+            }
+        }
+        s
+    }
+
+    // --------------------------
+    // Editing helpers for TextAreaState (unchanged API)
+    // --------------------------
+
+    /// Split line at a character offset (within that line).
+    /// Returns the index of the newly created line (line_idx + 1).
+    pub fn split_line_at(&mut self, line_idx: usize, at_char: usize) -> usize {
+        let lines = self.line_count();
+        let clamped_line = line_idx.min(lines.saturating_sub(1));
+        let (start, end) = self.line_bounds_chars(clamped_line);
+        let line_len = end.saturating_sub(start);
+        let at = at_char.min(line_len);
+
+        let insert_at = start + at;
+        self.rope.insert(insert_at, "\n"); // rope insert at char index
+
+        self.resize_cache();
+        self.invalidate_cache_from(clamped_line);
+        clamped_line + 1
+    }
+
+    /// Join current line with the next by removing the newline.
+    /// Returns Some(new_cursor_col_on_merged_line) or None if no next line.
+    pub fn join_with_next(&mut self, line_idx: usize) -> Option<usize> {
+        if line_idx + 1 >= self.line_count() {
+            return None;
+        }
+        let newline_pos = self.rope.line_to_char(line_idx + 1) - 1; // index of '\n'
+        let left_len = self.line_content_len_chars(line_idx);
+        self.rope.remove(newline_pos..newline_pos + 1); // remove the newline
+
+        self.resize_cache();
+        self.invalidate_cache_from(line_idx);
+        Some(left_len)
+    }
+
+    /// Join current line with the previous by removing the previous newline.
+    /// Returns Some((new_prev_index, cursor_col)) or None if at line 0.
+    pub fn join_with_prev(&mut self, line_idx: usize) -> Option<(usize, usize)> {
+        if line_idx == 0 || line_idx >= self.line_count() {
+            return None;
+        }
+        let prev_idx = line_idx - 1;
+        let prev_len = self.line_content_len_chars(prev_idx);
+        let newline_pos = self.rope.line_to_char(line_idx) - 1; // index of '\n' before current line
+        self.rope.remove(newline_pos..newline_pos + 1);
+
+        self.resize_cache();
+        self.invalidate_cache_from(prev_idx);
+        Some((prev_idx, prev_len))
+    }
+
+    /// Insert an empty line after given index.
+    /// Returns the index of the inserted blank line (line_idx + 1).
+    pub fn insert_blank_line_after(&mut self, line_idx: usize) -> usize {
+        let lines = self.line_count();
+        let clamped = line_idx.min(lines.saturating_sub(1));
+        let pos = if clamped + 1 < lines {
+            self.rope.line_to_char(clamped + 1)
+        } else {
+            self.rope.len_chars()
+        };
+        self.rope.insert(pos, "\n");
+
+        self.resize_cache();
+        self.invalidate_cache_from(clamped);
+        clamped + 1
+    }
+
+    /// Insert an empty line before given index.
+    /// Returns the index of the inserted blank line (line_idx).
+    pub fn insert_blank_line_before(&mut self, line_idx: usize) -> usize {
+        let clamped = line_idx.min(self.line_count());
+        let pos = if clamped < self.line_count() {
+            self.rope.line_to_char(clamped)
+        } else {
+            self.rope.len_chars()
+        };
+        self.rope.insert(pos, "\n");
+
+        self.resize_cache();
+        self.invalidate_cache_from(clamped);
+        clamped
+    }
+}
+
+impl DataProvider for TextAreaProvider {
+    fn field_count(&self) -> usize {
+        self.line_count()
+    }
+
+    fn field_name(&self, _index: usize) -> &str {
+        &self.name
+    }
+
+    fn field_value(&self, index: usize) -> &str {
+        if index >= self.line_cache.len() {
+            return "";
+        }
+        let cell = &self.line_cache[index];
+        // Fill lazily on first read, from &self (no &mut needed).
+        let s_ref = cell.get_or_init(|| self.compute_line_string(index));
+        s_ref.as_str()
+    }
+
+    fn set_field_value(&mut self, index: usize, value: String) {
+        if index >= self.line_count() {
+            return;
+        }
+        // Enforce single-line invariant: strip embedded newlines
+        let clean = value.replace('\n', "");
+
+        let (start, end) = self.line_bounds_chars(index);
+        self.rope.remove(start..end);
+        self.rope.insert(start, &clean);
+
+        self.resize_cache();
+        if index < self.line_cache.len() {
+            // Replace this line’s cached string only; other lines unchanged
+            let _ = self.line_cache[index].take();
+            let _ = self.line_cache[index].set(clean);
+        }
+    }
+}

canvas/src/textarea/state.rs

@@ -0,0 +1,518 @@
+// src/textarea/state.rs
+use std::ops::{Deref, DerefMut};
+
+use crossterm::event::{KeyCode, KeyEvent, KeyEventKind, KeyModifiers};
+
+use crate::editor::FormEditor;
+use crate::textarea::provider::TextAreaProvider;
+use crate::data_provider::DataProvider;
+
+#[cfg(feature = "gui")]
+use ratatui::{layout::Rect, widgets::Block};
+
+#[cfg(feature = "gui")]
+use unicode_width::UnicodeWidthChar;
+
+#[cfg(feature = "gui")]
+pub(crate) const RIGHT_PAD: u16 = 3;
+
+#[cfg(feature = "gui")]
+pub(crate) fn compute_h_scroll_with_padding(
+    cursor_cols: u16,
+    width: u16,
+) -> (u16, u16) {
+    let mut h = 0u16;
+    for _ in 0..2 {
+        let left_cols = if h > 0 { 1 } else { 0 };
+        let max_x_visible = width.saturating_sub(1 + RIGHT_PAD + left_cols);
+        let needed = cursor_cols.saturating_sub(max_x_visible);
+        if needed <= h {
+            return (h, left_cols);
+        }
+        h = needed;
+    }
+    let left_cols = if h > 0 { 1 } else { 0 };
+    (h, left_cols)
+}
+
+#[cfg(feature = "gui")]
+fn normalize_indent(width: u16, indent: u16) -> u16 {
+    indent.min(width.saturating_sub(1))
+}
+
+#[cfg(feature = "gui")]
+pub(crate) fn count_wrapped_rows_indented(
+    s: &str,
+    width: u16,
+    indent: u16,
+) -> u16 {
+    if width == 0 {
+        return 1;
+    }
+    let indent = normalize_indent(width, indent);
+    let cont_cap = width.saturating_sub(indent);
+
+    let mut rows: u16 = 1;
+    let mut used: u16 = 0;
+    let mut first = true;
+
+    for ch in s.chars() {
+        let w = UnicodeWidthChar::width(ch).unwrap_or(0) as u16;
+        let cap = if first { width } else { cont_cap };
+
+        if used > 0 && used.saturating_add(w) >= cap {
+            rows = rows.saturating_add(1);
+            first = false;
+            used = indent;
+        }
+        used = used.saturating_add(w);
+    }
+
+    rows
+}
+
+#[cfg(feature = "gui")]
+fn wrapped_rows_to_cursor_indented(
+    s: &str,
+    width: u16,
+    indent: u16,
+    cursor_chars: usize,
+) -> (u16, u16) {
+    if width == 0 {
+        return (0, 0);
+    }
+    let indent = normalize_indent(width, indent);
+    let cont_cap = width.saturating_sub(indent);
+
+    let mut row: u16 = 0;
+    let mut used: u16 = 0;
+    let mut first = true;
+
+    for (i, ch) in s.chars().enumerate() {
+        if i >= cursor_chars {
+            break;
+        }
+        let w = UnicodeWidthChar::width(ch).unwrap_or(0) as u16;
+        let cap = if first { width } else { cont_cap };
+
+        if used > 0 && used.saturating_add(w) >= cap {
+            row = row.saturating_add(1);
+            first = false;
+            used = indent;
+        }
+        used = used.saturating_add(w);
+    }
+
+    (row, used.min(width.saturating_sub(1)))
+}
+
+pub type TextAreaEditor = FormEditor<TextAreaProvider>;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum TextOverflowMode {
+    Indicator { ch: char },
+    Wrap,
+}
+
+pub struct TextAreaState {
+    pub(crate) editor: TextAreaEditor,
+    pub(crate) scroll_y: u16,
+    pub(crate) placeholder: Option<String>,
+    pub(crate) overflow_mode: TextOverflowMode,
+    pub(crate) h_scroll: u16,
+    #[cfg(feature = "gui")]
+    pub(crate) wrap_indent_cols: u16,
+    #[cfg(feature = "gui")]
+    pub(crate) edited_this_frame: bool,
+}
+
+impl Default for TextAreaState {
+    fn default() -> Self {
+        Self {
+            editor: FormEditor::new(TextAreaProvider::default()),
+            scroll_y: 0,
+            placeholder: None,
+            overflow_mode: TextOverflowMode::Indicator { ch: '$' },
+            h_scroll: 0,
+            #[cfg(feature = "gui")]
+            wrap_indent_cols: 0,
+            #[cfg(feature = "gui")]
+            edited_this_frame: false,
+        }
+    }
+}
+
+impl Deref for TextAreaState {
+    type Target = TextAreaEditor;
+
+    fn deref(&self) -> &Self::Target {
+        &self.editor
+    }
+}
+
+impl DerefMut for TextAreaState {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.editor
+    }
+}
+
+impl TextAreaState {
+    pub fn from_text<S: Into<String>>(text: S) -> Self {
+        let provider = TextAreaProvider::from_text(text);
+        Self {
+            editor: FormEditor::new(provider),
+            scroll_y: 0,
+            placeholder: None,
+            overflow_mode: TextOverflowMode::Indicator { ch: '$' },
+            h_scroll: 0,
+            #[cfg(feature = "gui")]
+            wrap_indent_cols: 0,
+            #[cfg(feature = "gui")]
+            edited_this_frame: false,
+        }
+    }
+
+    pub fn text(&self) -> String {
+        self.editor.data_provider().to_text()
+    }
+
+    pub fn set_text<S: Into<String>>(&mut self, text: S) {
+        self.editor.data_provider_mut().set_text(text);
+        self.editor.ui_state.current_field = 0;
+        self.editor.ui_state.cursor_pos = 0;
+        self.editor.ui_state.ideal_cursor_column = 0;
+    }
+
+    pub fn set_placeholder<S: Into<String>>(&mut self, s: S) {
+        self.placeholder = Some(s.into());
+    }
+
+    pub fn use_overflow_indicator(&mut self, ch: char) {
+        self.overflow_mode = TextOverflowMode::Indicator { ch };
+    }
+
+    pub fn use_wrap(&mut self) {
+        self.overflow_mode = TextOverflowMode::Wrap;
+    }
+
+    pub fn set_wrap_indent_cols(&mut self, cols: u16) {
+        #[cfg(feature = "gui")]
+        {
+            self.wrap_indent_cols = cols;
+        }
+    }
+
+    pub fn insert_newline(&mut self) {
+        #[cfg(feature = "gui")]
+        {
+            self.edited_this_frame = true;
+        }
+        let line_idx = self.current_field();
+        let col = self.cursor_position();
+
+        let new_idx = self
+            .editor
+            .data_provider_mut()
+            .split_line_at(line_idx, col);
+
+        let _ = self.transition_to_field(new_idx);
+        self.move_line_start();
+        self.enter_edit_mode();
+    }
+
+    pub fn backspace(&mut self) {
+        let col = self.cursor_position();
+        if col > 0 {
+            #[cfg(feature = "gui")]
+            {
+                self.edited_this_frame = true;
+            }
+            let _ = self.delete_backward();
+            return;
+        }
+
+        let line_idx = self.current_field();
+        if line_idx == 0 {
+            return;
+        }
+
+        if let Some((prev_idx, new_col)) =
+            self.editor.data_provider_mut().join_with_prev(line_idx)
+        {
+            #[cfg(feature = "gui")]
+            {
+                self.edited_this_frame = true;
+            }
+            let _ = self.transition_to_field(prev_idx);
+            self.set_cursor_position(new_col);
+            self.enter_edit_mode();
+        }
+    }
+
+    pub fn delete_forward_or_join(&mut self) {
+        let line_idx = self.current_field();
+        let line_len = self.current_text().chars().count();
+        let col = self.cursor_position();
+
+        if col < line_len {
+            #[cfg(feature = "gui")]
+            {
+                self.edited_this_frame = true;
+            }
+            let _ = self.delete_forward();
+            return;
+        }
+
+        if let Some(new_col) =
+            self.editor.data_provider_mut().join_with_next(line_idx)
+        {
+            #[cfg(feature = "gui")]
+            {
+                self.edited_this_frame = true;
+            }
+            self.set_cursor_position(new_col);
+            self.enter_edit_mode();
+        }
+    }
+
+    pub fn input(&mut self, key: KeyEvent) {
+        if key.kind != KeyEventKind::Press {
+            return;
+        }
+
+        match (key.code, key.modifiers) {
+            (KeyCode::Enter, _) => self.insert_newline(),
+            (KeyCode::Backspace, _) => self.backspace(),
+            (KeyCode::Delete, _) => self.delete_forward_or_join(),
+
+            (KeyCode::Left, _) => {
+                let _ = self.move_left();
+            }
+            (KeyCode::Right, _) => {
+                let _ = self.move_right();
+            }
+            (KeyCode::Up, _) => {
+                let _ = self.move_up();
+            }
+            (KeyCode::Down, _) => {
+                let _ = self.move_down();
+            }
+
+            (KeyCode::Home, _)
+            | (KeyCode::Char('a'), KeyModifiers::CONTROL) => {
+                self.move_line_start();
+            }
+            (KeyCode::End, _)
+            | (KeyCode::Char('e'), KeyModifiers::CONTROL) => {
+                self.move_line_end();
+            }
+
+            (KeyCode::Char('b'), KeyModifiers::ALT) => self.move_word_prev(),
+            (KeyCode::Char('f'), KeyModifiers::ALT) => self.move_word_next(),
+            (KeyCode::Char('e'), KeyModifiers::ALT) => self.move_word_end(),
+
+            (KeyCode::Char(c), m) if m.is_empty() => {
+                self.enter_edit_mode();
+                #[cfg(feature = "gui")]
+                {
+                    self.edited_this_frame = true;
+                }
+                let _ = self.insert_char(c);
+            }
+
+            (KeyCode::Tab, _) => {
+                self.enter_edit_mode();
+                #[cfg(feature = "gui")]
+                {
+                    self.edited_this_frame = true;
+                }
+                for _ in 0..4 {
+                    let _ = self.insert_char(' ');
+                }
+            }
+
+            _ => {}
+        }
+    }
+
+    #[cfg(feature = "gui")]
+    fn visual_rows_before_line_and_intra_indented(
+        &self,
+        width: u16,
+        line_idx: usize,
+    ) -> u16 {
+        let provider = self.editor.data_provider();
+        let mut acc: u16 = 0;
+        let indent = self.wrap_indent_cols;
+
+        for i in 0..line_idx {
+            let s = provider.field_value(i);
+            acc = acc.saturating_add(count_wrapped_rows_indented(s, width, indent));
+        }
+        acc
+    }
+
+    #[cfg(feature = "gui")]
+    pub fn cursor(&self, area: Rect, block: Option<&Block<'_>>) -> (u16, u16) {
+        let inner = if let Some(b) = block { b.inner(area) } else { area };
+        let line_idx = self.current_field();
+
+        match self.overflow_mode {
+            TextOverflowMode::Wrap => {
+                let width = inner.width;
+                let y_top = inner.y;
+                let indent = self.wrap_indent_cols;
+
+                if width == 0 {
+                    let prefix = self.visual_rows_before_line_and_intra_indented(1, line_idx);
+                    let y = y_top.saturating_add(prefix.saturating_sub(self.scroll_y));
+                    return (inner.x, y);
+                }
+
+                let prefix_rows =
+                    self.visual_rows_before_line_and_intra_indented(width, line_idx);
+                let current_line = self.current_text();
+                let col_chars = self.display_cursor_position();
+
+                let (subrow, x_cols) = wrapped_rows_to_cursor_indented(
+                    current_line,
+                    width,
+                    indent,
+                    col_chars,
+                );
+
+                let caret_vis_row = prefix_rows.saturating_add(subrow);
+                let y = y_top.saturating_add(caret_vis_row.saturating_sub(self.scroll_y));
+                let x = inner.x.saturating_add(x_cols);
+                (x, y)
+            }
+            TextOverflowMode::Indicator { .. } => {
+                let y = inner.y + (line_idx as u16).saturating_sub(self.scroll_y);
+                let current_line = self.current_text();
+                let col = self.display_cursor_position();
+
+                let mut x_cols: u16 = 0;
+                let mut total_cols: u16 = 0;
+                for (i, ch) in current_line.chars().enumerate() {
+                    let w = UnicodeWidthChar::width(ch).unwrap_or(0) as u16;
+                    if i < col {
+                        x_cols = x_cols.saturating_add(w);
+                    }
+                    total_cols = total_cols.saturating_add(w);
+                }
+
+                let left_cols = if self.h_scroll > 0 { 1 } else { 0 };
+
+                let mut x_off_visible = x_cols
+                    .saturating_sub(self.h_scroll)
+                    .saturating_add(left_cols);
+
+                let limit = inner.width.saturating_sub(1 + RIGHT_PAD);
+
+                if x_off_visible > limit {
+                    x_off_visible = limit;
+                }
+
+                let x = inner.x.saturating_add(x_off_visible);
+                (x, y)
+            }
+        }
+    }
+
+    #[cfg(feature = "gui")]
+    pub(crate) fn ensure_visible(&mut self, area: Rect, block: Option<&Block<'_>>) {
+        let inner = if let Some(b) = block { b.inner(area) } else { area };
+        if inner.height == 0 {
+            return;
+        }
+
+        match self.overflow_mode {
+            TextOverflowMode::Indicator { .. } => {
+                let line_idx_u16 = self.current_field() as u16;
+                if line_idx_u16 < self.scroll_y {
+                    self.scroll_y = line_idx_u16;
+                } else if line_idx_u16 >= self.scroll_y + inner.height {
+                    self.scroll_y = line_idx_u16.saturating_sub(inner.height - 1);
+                }
+
+                let width = inner.width;
+                if width == 0 {
+                    return;
+                }
+
+                let current_line = self.current_text();
+                let mut total_cols: u16 = 0;
+                for ch in current_line.chars() {
+                    total_cols = total_cols
+                        .saturating_add(UnicodeWidthChar::width(ch).unwrap_or(0) as u16);
+                }
+                if total_cols <= width {
+                    self.h_scroll = 0;
+                    return;
+                }
+
+                let col = self.display_cursor_position();
+                let mut cursor_cols: u16 = 0;
+                for (i, ch) in current_line.chars().enumerate() {
+                    if i >= col {
+                        break;
+                    }
+                    cursor_cols = cursor_cols
+                        .saturating_add(UnicodeWidthChar::width(ch).unwrap_or(0) as u16);
+                }
+
+                let (target_h, _left_cols) =
+                    compute_h_scroll_with_padding(cursor_cols, width);
+
+                if target_h > self.h_scroll {
+                    self.h_scroll = target_h;
+                } else if cursor_cols < self.h_scroll {
+                    self.h_scroll = cursor_cols;
+                }
+            }
+            TextOverflowMode::Wrap => {
+                let width = inner.width;
+                if width == 0 {
+                    self.h_scroll = 0;
+                    return;
+                }
+
+                let indent = self.wrap_indent_cols;
+                let line_idx = self.current_field();
+
+                let prefix_rows =
+                    self.visual_rows_before_line_and_intra_indented(width, line_idx);
+
+                let current_line = self.current_text();
+                let col = self.display_cursor_position();
+
+                let (subrow, _x_cols) =
+                    wrapped_rows_to_cursor_indented(current_line, width, indent, col);
+
+                let caret_vis_row = prefix_rows.saturating_add(subrow);
+
+                let top = self.scroll_y;
+                let height = inner.height;
+
+                if caret_vis_row < top {
+                    self.scroll_y = caret_vis_row;
+                } else {
+                    let bottom = top.saturating_add(height.saturating_sub(1));
+                    if caret_vis_row > bottom {
+                        let shift = caret_vis_row.saturating_sub(bottom);
+                        self.scroll_y = top.saturating_add(shift);
+                    }
+                }
+
+                self.h_scroll = 0;
+            }
+        }
+    }
+    
+    #[cfg(feature = "gui")]
+    pub(crate) fn take_edited_flag(&mut self) -> bool {
+        let v = self.edited_this_frame;
+        self.edited_this_frame = false;
+        v
+    }
+}

canvas/src/textarea/widget.rs

@@ -0,0 +1,352 @@
+// src/textarea/widget.rs
+#[cfg(feature = "gui")]
+use ratatui::{
+    buffer::Buffer,
+    layout::{Alignment, Rect},
+    style::Style,
+    text::{Line, Span},
+    widgets::{
+        Block, BorderType, Borders, Paragraph, StatefulWidget, Widget,
+    },
+};
+
+#[cfg(feature = "gui")]
+use crate::data_provider::DataProvider;
+
+#[cfg(feature = "gui")]
+use crate::textarea::state::{
+    compute_h_scroll_with_padding,
+    count_wrapped_rows_indented,
+    TextAreaState,
+    TextOverflowMode,
+};
+
+#[cfg(feature = "gui")]
+use unicode_width::UnicodeWidthChar;
+
+#[cfg(feature = "gui")]
+#[derive(Debug, Clone)]
+pub struct TextArea<'a> {
+    pub(crate) block: Option<Block<'a>>,
+    pub(crate) style: Style,
+    pub(crate) border_type: BorderType,
+}
+
+#[cfg(feature = "gui")]
+impl<'a> Default for TextArea<'a> {
+    fn default() -> Self {
+        Self {
+            block: Some(
+                Block::default()
+                    .borders(Borders::ALL)
+                    .border_type(BorderType::Rounded),
+            ),
+            style: Style::default(),
+            border_type: BorderType::Rounded,
+        }
+    }
+}
+
+#[cfg(feature = "gui")]
+impl<'a> TextArea<'a> {
+    pub fn block(mut self, block: Block<'a>) -> Self {
+        self.block = Some(block);
+        self
+    }
+
+    pub fn style(mut self, style: Style) -> Self {
+        self.style = style;
+        self
+    }
+
+    pub fn border_type(mut self, ty: BorderType) -> Self {
+        self.border_type = ty;
+        if let Some(b) = &mut self.block {
+            *b = b.clone().border_type(ty);
+        }
+        self
+    }
+}
+
+#[cfg(feature = "gui")]
+fn display_width(s: &str) -> u16 {
+    s.chars()
+        .map(|c| UnicodeWidthChar::width(c).unwrap_or(0) as u16)
+        .sum()
+}
+
+#[cfg(feature = "gui")]
+fn display_cols_up_to(s: &str, char_count: usize) -> u16 {
+    let mut cols: u16 = 0;
+    for (i, ch) in s.chars().enumerate() {
+        if i >= char_count {
+            break;
+        }
+        cols = cols.saturating_add(UnicodeWidthChar::width(ch).unwrap_or(0) as u16);
+    }
+    cols
+}
+
+#[cfg(feature = "gui")]
+fn slice_by_display_cols(s: &str, start_cols: u16, max_cols: u16) -> String {
+    if max_cols == 0 {
+        return String::new();
+    }
+
+    let mut current_cols: u16 = 0;
+    let mut output = String::new();
+    let mut taken: u16 = 0;
+    let mut started = false;
+
+    for ch in s.chars() {
+        let w = UnicodeWidthChar::width(ch).unwrap_or(0) as u16;
+
+        if !started {
+            if current_cols.saturating_add(w) <= start_cols {
+                current_cols = current_cols.saturating_add(w);
+                continue;
+            } else {
+                started = true;
+            }
+        }
+
+        if taken.saturating_add(w) > max_cols {
+            break;
+        }
+
+        output.push(ch);
+        taken = taken.saturating_add(w);
+        current_cols = current_cols.saturating_add(w);
+    }
+
+    output
+}
+
+#[cfg(feature = "gui")]
+fn clip_window_with_indicator_padded(
+    text: &str,
+    view_width: u16,
+    indicator: char,
+    start_cols: u16,
+) -> Line<'static> {
+    if view_width == 0 {
+        return Line::from("");
+    }
+
+    let total = display_width(text);
+
+    // Left indicator if we scrolled
+    let show_left = start_cols > 0;
+    let left_cols: u16 = if show_left { 1 } else { 0 };
+
+    // Capacity for text if we also need a right indicator
+    let cap_with_right = view_width.saturating_sub(left_cols + 1);
+
+    // Do we still have content beyond this window?
+    let remaining = total.saturating_sub(start_cols);
+    let show_right = remaining > cap_with_right;
+
+    // Final capacity for visible text
+    let max_visible = if show_right {
+        cap_with_right
+    } else {
+        view_width.saturating_sub(left_cols)
+    };
+
+    let visible = slice_by_display_cols(text, start_cols, max_visible);
+
+    let mut spans: Vec<Span> = Vec::new();
+    if show_left {
+        spans.push(Span::raw(indicator.to_string()));
+    }
+
+    // Visible text
+    spans.push(Span::raw(visible.clone()));
+
+    // Place $ flush-right
+    if show_right {
+        let used_cols = left_cols + display_width(&visible);
+        let right_pos = view_width.saturating_sub(1);
+        let filler = right_pos.saturating_sub(used_cols);
+        if filler > 0 {
+            spans.push(Span::raw(" ".repeat(filler as usize)));
+        }
+        spans.push(Span::raw(indicator.to_string()));
+    }
+
+    Line::from(spans)
+}
+
+#[cfg(feature = "gui")]
+fn wrap_segments_with_indent(
+    s: &str,
+    width: u16,
+    indent: u16,
+) -> Vec<String> {
+    let mut segments: Vec<String> = Vec::new();
+    if width == 0 {
+        segments.push(String::new());
+        return segments;
+    }
+
+    let indent = indent.min(width.saturating_sub(1));
+    let cont_cap = width.saturating_sub(indent);
+    let indent_str = " ".repeat(indent as usize);
+
+    let mut buf = String::new();
+    let mut used: u16 = 0;
+    let mut first = true;
+
+    for ch in s.chars() {
+        let w = UnicodeWidthChar::width(ch).unwrap_or(0) as u16;
+        let cap = if first { width } else { cont_cap };
+
+        // Early-wrap: wrap before filling the last cell (and avoid empty segment)
+        if used > 0 && used.saturating_add(w) >= cap {
+            segments.push(buf);
+            buf = String::new();
+            used = 0;
+            first = false;
+            if indent > 0 {
+                buf.push_str(&indent_str);
+                used = indent;
+            }
+        }
+
+        buf.push(ch);
+        used = used.saturating_add(w);
+    }
+
+    segments.push(buf);
+    segments
+}
+
+// Map visual row offset to (logical line, intra segment)
+#[cfg(feature = "gui")]
+fn resolve_start_line_and_intra_indented(
+    state: &TextAreaState,
+    inner: Rect,
+) -> (usize, u16) {
+    let provider = state.editor.data_provider();
+    let total = provider.line_count();
+
+    if total == 0 {
+        return (0, 0);
+    }
+
+    let wrap = matches!(state.overflow_mode, TextOverflowMode::Wrap);
+    let width = inner.width;
+    let target_vis = state.scroll_y;
+
+    if !wrap {
+        let start = (target_vis as usize).min(total);
+        return (start, 0);
+    }
+
+    let indent = state.wrap_indent_cols;
+
+    let mut acc: u16 = 0;
+    for i in 0..total {
+        let s = provider.field_value(i);
+        let rows = count_wrapped_rows_indented(s, width, indent);
+        if acc.saturating_add(rows) > target_vis {
+            let intra = target_vis.saturating_sub(acc);
+            return (i, intra);
+        }
+        acc = acc.saturating_add(rows);
+    }
+
+    (total.saturating_sub(1), 0)
+}
+
+#[cfg(feature = "gui")]
+impl<'a> StatefulWidget for TextArea<'a> {
+    type State = TextAreaState;
+
+    fn render(self, area: Rect, buf: &mut Buffer, state: &mut Self::State) {
+        state.ensure_visible(area, self.block.as_ref());
+
+        let inner = if let Some(b) = &self.block {
+            b.clone().render(area, buf);
+            b.inner(area)
+        } else {
+            area
+        };
+
+        let edited_now = state.take_edited_flag();
+
+        let wrap_mode = matches!(state.overflow_mode, TextOverflowMode::Wrap);
+        let provider = state.editor.data_provider();
+        let total = provider.line_count();
+
+        let (start, intra) = resolve_start_line_and_intra_indented(state, inner);
+
+        let mut display_lines: Vec<Line> = Vec::new();
+
+        if total == 0 || start >= total {
+            if let Some(ph) = &state.placeholder {
+                display_lines.push(Line::from(Span::raw(ph.clone())));
+            }
+        } else if wrap_mode {
+            // manual pre-wrap path (unchanged)
+            let mut rows_left = inner.height;
+            let indent = state.wrap_indent_cols;
+            let mut i = start;
+            while i < total && rows_left > 0 {
+                let s = provider.field_value(i);
+                let segments = wrap_segments_with_indent(s, inner.width, indent);
+                let skip = if i == start { intra as usize } else { 0 };
+                for seg in segments.into_iter().skip(skip) {
+                    display_lines.push(Line::from(Span::raw(seg)));
+                    rows_left = rows_left.saturating_sub(1);
+                    if rows_left == 0 {
+                        break;
+                    }
+                }
+                i += 1;
+            }
+        } else {
+            // Indicator mode: full inner width; RIGHT_PAD only affects cursor clamp and h-scroll
+            let end = (start.saturating_add(inner.height as usize)).min(total);
+
+            for i in start..end {
+                let s = provider.field_value(i);
+                match state.overflow_mode {
+                    TextOverflowMode::Wrap => unreachable!(),
+                    TextOverflowMode::Indicator { ch } => {
+                        let fits = display_width(s) <= inner.width;
+
+                        let start_cols = if i == state.current_field() {
+                            let col_idx = state.display_cursor_position();
+                            let cursor_cols = display_cols_up_to(s, col_idx);
+                            let (target_h, _left_cols) =
+                                compute_h_scroll_with_padding(cursor_cols, inner.width);
+
+                            if fits {
+                                if edited_now { target_h } else { 0 }
+                            } else {
+                                target_h.max(state.h_scroll)
+                            }
+                        } else {
+                            0
+                        };
+
+                        display_lines.push(clip_window_with_indicator_padded(
+                            s,
+                            inner.width,
+                            ch,
+                            start_cols,
+                        ));
+                    }
+                }
+            }
+        }
+
+        let p = Paragraph::new(display_lines)
+            .alignment(Alignment::Left)
+            .style(self.style);
+
+        // No Paragraph::wrap/scroll in wrap mode — we pre-wrap.
+        p.render(inner, buf);
+    }
+}

canvas/src/validation/config.rs

@@ -0,0 +1,588 @@
+// src/validation/config.rs
+//! Validation configuration types and builders
+
+use crate::validation::{CharacterLimits, PatternFilters, DisplayMask};
+#[cfg(feature = "validation")]
+use crate::validation::{CustomFormatter, FormattingResult, PositionMapper};
+use std::sync::Arc;
+
+/// Whitelist of allowed exact values for a field.
+/// If configured, the field is valid when it is empty (by default) or when the
+/// content exactly matches one of the allowed values. This does not block field
+/// switching (unlike minimum length in CharacterLimits).
+#[derive(Clone, Debug)]
+pub struct AllowedValues {
+    allowed: Vec<String>,
+    allow_empty: bool,
+    case_insensitive: bool,
+}
+
+impl AllowedValues {
+    pub fn new(allowed: Vec<String>) -> Self {
+        Self {
+            allowed,
+            allow_empty: true,
+            case_insensitive: false,
+        }
+    }
+
+    /// Allow or disallow empty value to be considered valid (default: true).
+    pub fn allow_empty(mut self, allow: bool) -> Self {
+        self.allow_empty = allow;
+        self
+    }
+
+    /// Enable/disable ASCII case-insensitive matching (default: false).
+    pub fn case_insensitive(mut self, ci: bool) -> Self {
+        self.case_insensitive = ci;
+        self
+    }
+
+    fn matches(&self, text: &str) -> bool {
+        if self.case_insensitive {
+            self.allowed
+                .iter()
+                .any(|s| s.eq_ignore_ascii_case(text))
+        } else {
+            self.allowed.iter().any(|s| s == text)
+        }
+    }
+}
+
+/// Main validation configuration for a field
+#[derive(Clone, Default)]
+pub struct ValidationConfig {
+    /// Character limit configuration
+    pub character_limits: Option<CharacterLimits>,
+
+    /// Pattern filtering configuration
+    pub pattern_filters: Option<PatternFilters>,
+
+    /// User-defined display mask for visual formatting
+    pub display_mask: Option<DisplayMask>,
+
+    /// Optional: user-provided custom formatter (feature 4)
+    #[cfg(feature = "validation")]
+    pub custom_formatter: Option<Arc<dyn CustomFormatter + Send + Sync>>,
+
+    /// Optional: restrict the field to one of exact allowed values (or empty)
+    pub allowed_values: Option<AllowedValues>,
+
+    /// Enable external validation indicator UI (feature 5)
+    pub external_validation_enabled: bool,
+
+    /// Future: External validation
+    pub external_validation: Option<()>, // Placeholder for future implementation
+}
+
+/// Manual Debug to avoid requiring Debug on dyn CustomFormatter
+impl std::fmt::Debug for ValidationConfig {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let mut ds = f.debug_struct("ValidationConfig");
+        ds.field("character_limits", &self.character_limits)
+          .field("pattern_filters", &self.pattern_filters)
+          .field("display_mask", &self.display_mask)
+          // Do not print the formatter itself to avoid requiring Debug
+          .field(
+              "custom_formatter",
+              &{
+                  #[cfg(feature = "validation")]
+                  {
+                      if self.custom_formatter.is_some() { &"Some(<CustomFormatter>)" } else { &"None" }
+                  }
+                  #[cfg(not(feature = "validation"))]
+                  {
+                      &"N/A"
+                  }
+              },
+          )
+          .field("allowed_values", &self.allowed_values)
+          .field("external_validation_enabled", &self.external_validation_enabled)
+          .field("external_validation", &self.external_validation)
+          .finish()
+    }
+}
+
+// ✅ FIXED: Move function from struct definition to impl block
+impl ValidationConfig {
+    /// If a custom formatter is configured, run it and return the formatted text,
+    /// the position mapper and an optional warning message.
+    ///
+    /// Returns None when no custom formatter is configured.
+    #[cfg(feature = "validation")]
+    pub fn run_custom_formatter(
+        &self,
+        raw: &str,
+    ) -> Option<(String, Arc<dyn PositionMapper>, Option<String>)> {
+        let formatter = self.custom_formatter.as_ref()?;
+        match formatter.format(raw) {
+            FormattingResult::Success { formatted, mapper } => {
+                Some((formatted, mapper, None))
+            }
+            FormattingResult::Warning { formatted, message, mapper } => {
+                Some((formatted, mapper, Some(message)))
+            }
+            FormattingResult::Error { .. } => None, // Fall back to raw display
+        }
+    }
+
+    /// Create a new empty validation configuration
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Create a configuration with just character limits
+    pub fn with_max_length(max_length: usize) -> Self {
+        ValidationConfigBuilder::new()
+            .with_max_length(max_length)
+            .build()
+    }
+
+    /// Create a configuration with pattern filters
+    pub fn with_patterns(patterns: PatternFilters) -> Self {
+        ValidationConfigBuilder::new()
+            .with_pattern_filters(patterns)
+            .build()
+    }
+
+    /// Create a configuration with user-defined display mask
+    ///
+    /// # Examples
+    /// ```
+    /// use canvas::{ValidationConfig, DisplayMask};
+    ///
+    /// let phone_mask = DisplayMask::new("(###) ###-####", '#');
+    /// let config = ValidationConfig::with_mask(phone_mask);
+    /// ```
+    pub fn with_mask(mask: DisplayMask) -> Self {
+        ValidationConfigBuilder::new()
+            .with_display_mask(mask)
+            .build()
+    }
+
+    /// Validate a character insertion at a specific position (raw text space).
+    ///
+    /// Note: Display masks are visual-only and do not participate in validation.
+    /// Editor logic is responsible for skipping mask separator positions; here we
+    /// only validate the raw insertion against limits and patterns.
+    pub fn validate_char_insertion(
+        &self,
+        current_text: &str,
+        position: usize,
+        character: char,
+    ) -> ValidationResult {
+        // Character limits validation
+        if let Some(ref limits) = self.character_limits {
+            // ✅ FIXED: Explicit return type annotation
+            if let Some(result) = limits.validate_insertion(current_text, position, character) {
+                if !result.is_acceptable() {
+                    return result;
+                }
+            }
+        }
+
+        // Pattern filters validation
+        if let Some(ref patterns) = self.pattern_filters {
+            // ✅ FIXED: Explicit error handling
+            if let Err(message) = patterns.validate_char_at_position(position, character) {
+                return ValidationResult::error(message);
+            }
+        }
+
+        // Future: Add other validation types here
+
+        ValidationResult::Valid
+    }
+
+    /// Validate the current text content (raw text space)
+    pub fn validate_content(&self, text: &str) -> ValidationResult {
+        // Character limits validation
+        if let Some(ref limits) = self.character_limits {
+            // ✅ FIXED: Explicit return type annotation
+            if let Some(result) = limits.validate_content(text) {
+                if !result.is_acceptable() {
+                    return result;
+                }
+            }
+        }
+
+        // Pattern filters validation
+        if let Some(ref patterns) = self.pattern_filters {
+            // ✅ FIXED: Explicit error handling
+            if let Err(message) = patterns.validate_text(text) {
+                return ValidationResult::error(message);
+            }
+        }
+
+        // Allowed values (whitelist) validation
+        if let Some(ref allowed) = self.allowed_values {
+            // Empty value is allowed (default) or required (if allow_empty is false)
+            if text.is_empty() {
+                if !allowed.allow_empty {
+                    return ValidationResult::warning("Value required");
+                }
+            } else if !allowed.matches(text) {
+                return ValidationResult::error("Value must be one of the allowed options");
+            }
+        }
+
+        // Future: Add other validation types here
+
+        ValidationResult::Valid
+    }
+
+    /// Check if any validation rules are configured
+    pub fn has_validation(&self) -> bool {
+        self.character_limits.is_some()
+            || self.pattern_filters.is_some()
+            || self.display_mask.is_some()
+            || {
+                #[cfg(feature = "validation")]
+                { self.custom_formatter.is_some() }
+                #[cfg(not(feature = "validation"))]
+                { false }
+            }
+            || self.allowed_values.is_some()
+    }
+
+    /// Check if whitelist is configured
+    pub fn has_allowed_values(&self) -> bool {
+        self.allowed_values.is_some()
+    }
+
+    pub fn allows_field_switch(&self, text: &str) -> bool {
+        // Character limits validation
+        if let Some(ref limits) = self.character_limits {
+            // ✅ FIXED: Direct boolean return
+            if !limits.allows_field_switch(text) {
+                return false;
+            }
+        }
+
+        // Future: Add other validation types here
+
+        true
+    }
+
+    /// Get reason why field switching is blocked (if any)
+    pub fn field_switch_block_reason(&self, text: &str) -> Option<String> {
+        // Character limits validation
+        if let Some(ref limits) = self.character_limits {
+            // ✅ FIXED: Direct option return
+            if let Some(reason) = limits.field_switch_block_reason(text) {
+                return Some(reason);
+            }
+        }
+
+        // Future: Add other validation types here
+
+        None
+    }
+}
+
+/// Builder for creating validation configurations
+#[derive(Debug, Default)]
+pub struct ValidationConfigBuilder {
+    config: ValidationConfig,
+}
+
+impl ValidationConfigBuilder {
+    /// Create a new validation config builder
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Set character limits for the field
+    pub fn with_character_limits(mut self, limits: CharacterLimits) -> Self {
+        self.config.character_limits = Some(limits);
+        self
+    }
+
+    /// Set pattern filters for the field
+    pub fn with_pattern_filters(mut self, filters: PatternFilters) -> Self {
+        self.config.pattern_filters = Some(filters);
+        self
+    }
+
+    /// Set user-defined display mask for visual formatting
+    ///
+    /// # Examples
+    /// ```
+    /// use canvas::{ValidationConfigBuilder, DisplayMask};
+    ///
+    /// // Phone number with dynamic formatting
+    /// let phone_mask = DisplayMask::new("(###) ###-####", '#');
+    /// let config = ValidationConfigBuilder::new()
+    ///     .with_display_mask(phone_mask)
+    ///     .build();
+    ///
+    /// // Date with template formatting
+    /// let date_mask = DisplayMask::new("##/##/####", '#')
+    ///     .with_template('_');
+    /// let config = ValidationConfigBuilder::new()
+    ///     .with_display_mask(date_mask)
+    ///     .build();
+    ///
+    /// // Custom business format
+    /// let employee_id = DisplayMask::new("EMP-####-##", '#')
+    ///     .with_template('•');
+    /// let config = ValidationConfigBuilder::new()
+    ///     .with_display_mask(employee_id)
+    ///     .with_max_length(6)  // Only store the 6 digits
+    ///     .build();
+    /// ```
+    pub fn with_display_mask(mut self, mask: DisplayMask) -> Self {
+        self.config.display_mask = Some(mask);
+        self
+    }
+
+    /// Set optional custom formatter (feature 4)
+    #[cfg(feature = "validation")]
+    pub fn with_custom_formatter<F>(mut self, formatter: Arc<F>) -> Self
+    where
+        F: CustomFormatter + Send + Sync + 'static,
+    {
+        self.config.custom_formatter = Some(formatter);
+        // When custom formatter is present, it takes precedence over display mask.
+        self.config.display_mask = None;
+        self
+    }
+
+    /// Set maximum number of characters (convenience method)
+    pub fn with_max_length(mut self, max_length: usize) -> Self {
+        self.config.character_limits = Some(CharacterLimits::new(max_length));
+        self
+    }
+
+    /// Restrict content to one of the provided exact values (or empty).
+    /// - Empty is considered valid by default.
+    /// - Matching is case-sensitive by default.
+    pub fn with_allowed_values<S>(mut self, values: Vec<S>) -> Self
+    where
+        S: Into<String>,
+    {
+        let vals: Vec<String> = values.into_iter().map(Into::into).collect();
+        self.config.allowed_values = Some(AllowedValues::new(vals));
+        self
+    }
+
+    /// Same as with_allowed_values, but case-insensitive (ASCII).
+    pub fn with_allowed_values_ci<S>(mut self, values: Vec<S>) -> Self
+    where
+        S: Into<String>,
+    {
+        let vals: Vec<String> = values.into_iter().map(Into::into).collect();
+        self.config.allowed_values = Some(AllowedValues::new(vals).case_insensitive(true));
+        self
+    }
+
+    /// Configure whether empty value should be allowed when using AllowedValues.
+    pub fn with_allowed_values_allow_empty(mut self, allow_empty: bool) -> Self {
+        if let Some(av) = self.config.allowed_values.take() {
+            self.config.allowed_values = Some(AllowedValues {
+                allow_empty,
+                ..av
+            });
+        } else {
+            self.config.allowed_values = Some(AllowedValues::new(vec![]).allow_empty(allow_empty));
+        }
+        self
+    }
+
+    /// Enable or disable external validation indicator UI (feature 5)
+    pub fn with_external_validation_enabled(mut self, enabled: bool) -> Self {
+        self.config.external_validation_enabled = enabled;
+        self
+    }
+
+    /// Build the final validation configuration
+    pub fn build(self) -> ValidationConfig {
+        self.config
+    }
+}
+
+/// Result of a validation operation
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum ValidationResult {
+    /// Validation passed
+    Valid,
+
+    /// Validation failed with warning (input still accepted)
+    Warning { message: String },
+
+    /// Validation failed with error (input rejected)
+    Error { message: String },
+}
+
+impl ValidationResult {
+    /// Check if the validation result allows the input
+    pub fn is_acceptable(&self) -> bool {
+        matches!(self, ValidationResult::Valid | ValidationResult::Warning { .. })
+    }
+
+    /// Check if the validation result is an error
+    pub fn is_error(&self) -> bool {
+        matches!(self, ValidationResult::Error { .. })
+    }
+
+    /// Get the message if there is one
+    pub fn message(&self) -> Option<&str> {
+        match self {
+            ValidationResult::Valid => None,
+            ValidationResult::Warning { message } => Some(message),
+            ValidationResult::Error { message } => Some(message),
+        }
+    }
+
+    /// Create a warning result
+    pub fn warning(message: impl Into<String>) -> Self {
+        ValidationResult::Warning { message: message.into() }
+    }
+
+    /// Create an error result
+    pub fn error(message: impl Into<String>) -> Self {
+        ValidationResult::Error { message: message.into() }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_config_with_user_defined_mask() {
+        // User creates their own phone mask
+        let phone_mask = DisplayMask::new("(###) ###-####", '#');
+        let config = ValidationConfig::with_mask(phone_mask);
+
+        // has_validation should be true because mask is configured
+        assert!(config.has_validation());
+
+        // Display mask is visual only; validation still focuses on raw content
+        let result = config.validate_char_insertion("123", 3, '4');
+        assert!(result.is_acceptable());
+
+        // Content validation unaffected by mask
+        let result = config.validate_content("1234567890");
+        assert!(result.is_acceptable());
+    }
+
+    #[test]
+    fn test_validation_config_builder() {
+        let config = ValidationConfigBuilder::new()
+            .with_max_length(10)
+            .build();
+
+        assert!(config.character_limits.is_some());
+        assert_eq!(config.character_limits.unwrap().max_length(), Some(10));
+    }
+
+    #[test]
+    fn test_config_builder_with_user_mask() {
+        // User defines custom format
+        let custom_mask = DisplayMask::new("##-##-##", '#').with_template('_');
+        let config = ValidationConfigBuilder::new()
+            .with_display_mask(custom_mask)
+            .with_max_length(6)
+            .build();
+
+        assert!(config.has_validation());
+        assert!(config.character_limits.is_some());
+        assert!(config.display_mask.is_some());
+    }
+
+    #[test]
+    fn test_allowed_values() {
+        let config = ValidationConfigBuilder::new()
+            .with_allowed_values(vec!["alpha", "beta", "gamma", "delta", "epsilon"])
+            .build();
+
+        // Empty should be valid by default
+        let result = config.validate_content("");
+        assert!(result.is_acceptable());
+
+        // Exact allowed values are valid
+        assert!(config.validate_content("alpha").is_acceptable());
+        assert!(config.validate_content("beta").is_acceptable());
+
+        // Anything else is an error
+        let res = config.validate_content("alph");
+        assert!(res.is_error());
+        let res = config.validate_content("ALPHA");
+        assert!(res.is_error()); // case-sensitive by default
+    }
+
+    #[test]
+    fn test_allowed_values_case_insensitive_and_required() {
+        let config = ValidationConfigBuilder::new()
+            .with_allowed_values_ci(vec!["Yes", "No"])
+            .with_allowed_values_allow_empty(false)
+            .build();
+
+        // Empty is not allowed now (warning so it's still acceptable for typing)
+        let res = config.validate_content("");
+        assert!(res.is_acceptable());
+
+        // Case-insensitive matches
+        assert!(config.validate_content("yes").is_acceptable());
+        assert!(config.validate_content("NO").is_acceptable());
+
+        // Random text is an error
+        let res = config.validate_content("maybe");
+        assert!(res.is_error());
+    }
+
+    #[test]
+    fn test_validation_result() {
+        let valid = ValidationResult::Valid;
+        assert!(valid.is_acceptable());
+        assert!(!valid.is_error());
+        assert_eq!(valid.message(), None);
+
+        let warning = ValidationResult::warning("Too long");
+        assert!(warning.is_acceptable());
+        assert!(!warning.is_error());
+        assert_eq!(warning.message(), Some("Too long"));
+
+        let error = ValidationResult::error("Invalid");
+        assert!(!error.is_acceptable());
+        assert!(error.is_error());
+        assert_eq!(error.message(), Some("Invalid"));
+    }
+
+    #[test]
+    fn test_config_with_max_length() {
+        let config = ValidationConfig::with_max_length(5);
+        assert!(config.has_validation());
+
+        // Test valid insertion
+        let result = config.validate_char_insertion("test", 4, 'x');
+        assert!(result.is_acceptable());
+
+        // Test invalid insertion (would exceed limit)
+        let result = config.validate_char_insertion("tests", 5, 'x');
+        assert!(!result.is_acceptable());
+    }
+
+    #[test]
+    fn test_config_with_patterns() {
+        use crate::validation::{PatternFilters, PositionFilter, PositionRange, CharacterFilter};
+
+        let patterns = PatternFilters::new()
+            .add_filter(PositionFilter::new(
+                PositionRange::Range(0, 1),
+                CharacterFilter::Alphabetic,
+            ));
+
+        let config = ValidationConfig::with_patterns(patterns);
+        assert!(config.has_validation());
+
+        // Test valid pattern insertion
+        let result = config.validate_char_insertion("", 0, 'A');
+        assert!(result.is_acceptable());
+
+        // Test invalid pattern insertion
+        let result = config.validate_char_insertion("", 0, '1');
+        assert!(!result.is_acceptable());
+    }
+}

canvas/src/validation/formatting.rs

@@ -0,0 +1,222 @@
+// src/validation/formatting.rs
+//! Custom formatting and position mapping for validation/display.
+//!
+//! This module defines the CustomFormatter trait along with helpers to map
+//! cursor positions between the raw stored text and the formatted display
+//! representation. Implementors may provide a custom PositionMapper to handle
+//! advanced formatting scenarios.
+
+use std::sync::Arc;
+
+/// Bidirectional mapping between raw input positions and formatted display positions.
+///
+/// The library uses this to keep cursor/selection behavior intuitive when the UI
+/// shows a formatted transformation (e.g., "01001" -> "010 01") while the editor
+/// still stores raw text.
+pub trait PositionMapper: Send + Sync {
+    /// Map a raw cursor position to a formatted cursor position.
+    ///
+    /// raw_pos is an index into the raw text (0..=raw.len() in char positions).
+    /// Implementations should return a position within 0..=formatted.len() (in char positions).
+    fn raw_to_formatted(&self, raw: &str, formatted: &str, raw_pos: usize) -> usize;
+
+    /// Map a formatted cursor position to a raw cursor position.
+    ///
+    /// formatted_pos is an index into the formatted text (0..=formatted.len()).
+    /// Implementations should return a position within 0..=raw.len() (in char positions).
+    fn formatted_to_raw(&self, raw: &str, formatted: &str, formatted_pos: usize) -> usize;
+}
+
+/// A reasonable default mapper that works for "insert separators" style formatting,
+/// such as grouping digits or adding dashes/spaces.
+///
+/// Heuristic:
+/// - Treat letters and digits (is_alphanumeric) in the formatted string as user-entered characters
+///   corresponding to raw characters, in order.
+/// - Treat any non-alphanumeric characters as purely visual separators.
+/// - Raw positions are mapped by counting alphanumeric characters in the formatted string.
+/// - If the formatted contains fewer alphanumeric characters than the raw (shouldn't happen
+///   for plain grouping), we cap at the end of the formatted string.
+#[derive(Clone, Default)]
+pub struct DefaultPositionMapper;
+
+impl PositionMapper for DefaultPositionMapper {
+    fn raw_to_formatted(&self, raw: &str, formatted: &str, raw_pos: usize) -> usize {
+        // Convert to char indices for correctness in presence of UTF-8
+        let raw_len = raw.chars().count();
+        let clamped_raw_pos = raw_pos.min(raw_len);
+
+        // Count alphanumerics in formatted, find the index where we've seen `clamped_raw_pos` of them.
+        let mut seen_user_chars = 0usize;
+        for (idx, ch) in formatted.char_indices() {
+            if ch.is_alphanumeric() {
+                if seen_user_chars == clamped_raw_pos {
+                    // Cursor is positioned before this user character in the formatted view
+                    return idx;
+                }
+                seen_user_chars += 1;
+            }
+        }
+
+        // If we consumed all alphanumeric chars and still haven't reached clamped_raw_pos,
+        // place cursor at the end of the formatted string.
+        formatted.len()
+    }
+
+    fn formatted_to_raw(&self, raw: &str, formatted: &str, formatted_pos: usize) -> usize {
+        let clamped_fmt_pos = formatted_pos.min(formatted.len());
+
+        // Count alphanumerics in formatted up to formatted_pos.
+        let mut seen_user_chars = 0usize;
+        for (idx, ch) in formatted.char_indices() {
+            if idx >= clamped_fmt_pos {
+                break;
+            }
+            if ch.is_alphanumeric() {
+                seen_user_chars += 1;
+            }
+        }
+
+        // Map to raw position by clamping to raw char count
+        let raw_len = raw.chars().count();
+        seen_user_chars.min(raw_len)
+    }
+}
+
+/// Result of invoking a custom formatter on the raw input.
+///
+/// Success variants carry the formatted string and a position mapper to translate
+/// between raw and formatted cursor positions. If you don't provide a custom mapper,
+/// the library will fall back to DefaultPositionMapper.
+pub enum FormattingResult {
+    /// Successfully produced a formatted display value and a position mapper.
+    Success {
+        formatted: String,
+        /// Mapper to convert cursor positions between raw and formatted representations.
+        mapper: Arc<dyn PositionMapper>,
+    },
+    /// Successfully produced a formatted value, but with a non-fatal warning message
+    /// that can be shown in the UI (e.g., "incomplete value").
+    Warning {
+        formatted: String,
+        message: String,
+        mapper: Arc<dyn PositionMapper>,
+    },
+    /// Failed to produce a formatted display. The library will typically fall back to raw.
+    Error {
+        message: String,
+    },
+}
+
+impl FormattingResult {
+    /// Convenience to create a success result using the default mapper.
+    pub fn success(formatted: impl Into<String>) -> Self {
+        FormattingResult::Success {
+            formatted: formatted.into(),
+            mapper: Arc::new(DefaultPositionMapper),
+        }
+    }
+
+    /// Convenience to create a warning result using the default mapper.
+    pub fn warning(formatted: impl Into<String>, message: impl Into<String>) -> Self {
+        FormattingResult::Warning {
+            formatted: formatted.into(),
+            message: message.into(),
+            mapper: Arc::new(DefaultPositionMapper),
+        }
+    }
+
+    /// Convenience to create a success result with a custom mapper.
+    pub fn success_with_mapper(
+        formatted: impl Into<String>,
+        mapper: Arc<dyn PositionMapper>,
+    ) -> Self {
+        FormattingResult::Success {
+            formatted: formatted.into(),
+            mapper,
+        }
+    }
+
+    /// Convenience to create a warning result with a custom mapper.
+    pub fn warning_with_mapper(
+        formatted: impl Into<String>,
+        message: impl Into<String>,
+        mapper: Arc<dyn PositionMapper>,
+    ) -> Self {
+        FormattingResult::Warning {
+            formatted: formatted.into(),
+            message: message.into(),
+            mapper,
+        }
+    }
+
+    /// Convenience to create an error result.
+    pub fn error(message: impl Into<String>) -> Self {
+        FormattingResult::Error {
+            message: message.into(),
+        }
+    }
+}
+
+/// A user-implemented formatter that turns raw input into a formatted display string,
+/// optionally providing a custom cursor position mapper.
+///
+/// Notes:
+/// - The library will keep raw input authoritative for editing and validation.
+/// - The formatted value is only used for display.
+/// - If formatting fails, return Error; the library will show the raw value.
+/// - For common grouping (spaces/dashes), you can return Success/Warning and rely
+///   on DefaultPositionMapper, or provide your own mapper for advanced cases
+///   (reordering, compression, locale-specific rules, etc.).
+pub trait CustomFormatter: Send + Sync {
+    fn format(&self, raw: &str) -> FormattingResult;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    struct GroupEvery3;
+    impl CustomFormatter for GroupEvery3 {
+        fn format(&self, raw: &str) -> FormattingResult {
+            let mut out = String::new();
+            for (i, ch) in raw.chars().enumerate() {
+                if i > 0 && i % 3 == 0 {
+                    out.push(' ');
+                }
+                out.push(ch);
+            }
+            FormattingResult::success(out)
+        }
+    }
+
+    #[test]
+    fn default_mapper_roundtrip_basic() {
+        let mapper = DefaultPositionMapper;
+        let raw = "01001";
+        let formatted = "010 01";
+
+        // raw_to_formatted monotonicity and bounds
+        for rp in 0..=raw.chars().count() {
+            let fp = mapper.raw_to_formatted(raw, formatted, rp);
+            assert!(fp <= formatted.len());
+        }
+
+        // formatted_to_raw bounds
+        for fp in 0..=formatted.len() {
+            let rp = mapper.formatted_to_raw(raw, formatted, fp);
+            assert!(rp <= raw.chars().count());
+        }
+    }
+
+    #[test]
+    fn formatter_groups_every_3() {
+        let f = GroupEvery3;
+        match f.format("1234567") {
+            FormattingResult::Success { formatted, .. } => {
+                assert_eq!(formatted, "123 456 7");
+            }
+            _ => panic!("expected success"),
+        }
+    }
+}

canvas/src/validation/limits.rs

@@ -0,0 +1,423 @@
+// src/validation/limits.rs
+//! Character limits validation implementation
+
+use crate::validation::ValidationResult;
+use serde::{Deserialize, Serialize};
+use unicode_width::UnicodeWidthStr;
+
+/// Character limits configuration for a field
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct CharacterLimits {
+    /// Maximum number of characters allowed (None = unlimited)
+    max_length: Option<usize>,
+    
+    /// Minimum number of characters required (None = no minimum)
+    min_length: Option<usize>,
+    
+    /// Warning threshold (warn when approaching max limit)
+    warning_threshold: Option<usize>,
+    
+    /// Count mode: characters vs display width
+    count_mode: CountMode,
+}
+
+/// How to count characters for limit checking
+#[derive(Debug, Clone, Copy, Serialize, Deserialize)]
+#[derive(Default)]
+pub enum CountMode {
+    /// Count actual characters (default)
+    #[default]
+    Characters,
+    
+    /// Count display width (useful for CJK characters)
+    DisplayWidth,
+    
+    /// Count bytes (rarely used, but available)
+    Bytes,
+}
+
+
+/// Result of a character limit check
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum LimitCheckResult {
+    /// Within limits
+    Ok,
+    
+    /// Approaching limit (warning)
+    Warning { current: usize, max: usize },
+    
+    /// At or exceeding limit (error)
+    Exceeded { current: usize, max: usize },
+    
+    /// Below minimum length
+    TooShort { current: usize, min: usize },
+}
+
+impl CharacterLimits {
+    /// Create new character limits with just max length
+    pub fn new(max_length: usize) -> Self {
+        Self {
+            max_length: Some(max_length),
+            min_length: None,
+            warning_threshold: None,
+            count_mode: CountMode::default(),
+        }
+    }
+    
+    /// Create new character limits with min and max
+    pub fn new_range(min_length: usize, max_length: usize) -> Self {
+        Self {
+            max_length: Some(max_length),
+            min_length: Some(min_length),
+            warning_threshold: None,
+            count_mode: CountMode::default(),
+        }
+    }
+    
+    /// Set warning threshold (when to show warning before hitting limit)
+    pub fn with_warning_threshold(mut self, threshold: usize) -> Self {
+        self.warning_threshold = Some(threshold);
+        self
+    }
+    
+    /// Set count mode (characters vs display width vs bytes)
+    pub fn with_count_mode(mut self, mode: CountMode) -> Self {
+        self.count_mode = mode;
+        self
+    }
+    
+    /// Get maximum length
+    pub fn max_length(&self) -> Option<usize> {
+        self.max_length
+    }
+    
+    /// Get minimum length
+    pub fn min_length(&self) -> Option<usize> {
+        self.min_length
+    }
+    
+    /// Get warning threshold
+    pub fn warning_threshold(&self) -> Option<usize> {
+        self.warning_threshold
+    }
+    
+    /// Get count mode
+    pub fn count_mode(&self) -> CountMode {
+        self.count_mode
+    }
+    
+    /// Count characters/width/bytes according to the configured mode
+    fn count(&self, text: &str) -> usize {
+        match self.count_mode {
+            CountMode::Characters => text.chars().count(),
+            CountMode::DisplayWidth => text.width(),
+            CountMode::Bytes => text.len(),
+        }
+    }
+    
+    /// Check if inserting a character would exceed limits
+    pub fn validate_insertion(
+        &self,
+        current_text: &str,
+        position: usize,
+        character: char,
+    ) -> Option<ValidationResult> {
+        // FIX: Actually simulate the insertion at the specified position
+        // This makes the `position` parameter essential to the logic
+        
+        // 1. Create the new string by inserting the character at the correct position
+        let mut new_text = String::with_capacity(current_text.len() + character.len_utf8());
+        let mut chars = current_text.chars();
+
+        // Append characters from the original string that come before the insertion point
+        // We clamp the position to be safe
+        let clamped_pos = position.min(current_text.chars().count());
+        for _ in 0..clamped_pos {
+            if let Some(ch) = chars.next() {
+                new_text.push(ch);
+            }
+        }
+
+        // Insert the new character
+        new_text.push(character);
+
+        // Append the rest of the original string
+        for ch in chars {
+            new_text.push(ch);
+        }
+
+        // 2. Now perform all validation on the *actual* resulting text
+        let new_count = self.count(&new_text);
+        let current_count = self.count(current_text);
+
+        // Check max length
+        if let Some(max) = self.max_length {
+            if new_count > max {
+                return Some(ValidationResult::error(format!(
+                    "Character limit exceeded: {new_count}/{max}"
+                )));
+            }
+
+            // Check warning threshold
+            if let Some(warning_threshold) = self.warning_threshold {
+                if new_count >= warning_threshold && current_count < warning_threshold {
+                    return Some(ValidationResult::warning(format!(
+                        "Approaching character limit: {new_count}/{max}"
+                    )));
+                }
+            }
+        }
+
+        None // No validation issues
+    }
+    
+    /// Validate the current content
+    pub fn validate_content(&self, text: &str) -> Option<ValidationResult> {
+        let count = self.count(text);
+        
+        // Check minimum length
+        if let Some(min) = self.min_length {
+            if count < min {
+                return Some(ValidationResult::warning(format!(
+                    "Minimum length not met: {count}/{min}"
+                )));
+            }
+        }
+        
+        // Check maximum length
+        if let Some(max) = self.max_length {
+            if count > max {
+                return Some(ValidationResult::error(format!(
+                    "Character limit exceeded: {count}/{max}"
+                )));
+            }
+            
+            // Check warning threshold
+            if let Some(warning_threshold) = self.warning_threshold {
+                if count >= warning_threshold {
+                    return Some(ValidationResult::warning(format!(
+                        "Approaching character limit: {count}/{max}"
+                    )));
+                }
+            }
+        }
+        
+        None // No validation issues
+    }
+    
+    /// Get the current status of the text against limits
+    pub fn check_limits(&self, text: &str) -> LimitCheckResult {
+        let count = self.count(text);
+        
+        // Check max length first
+        if let Some(max) = self.max_length {
+            if count > max {
+                return LimitCheckResult::Exceeded { current: count, max };
+            }
+            
+            // Check warning threshold
+            if let Some(warning_threshold) = self.warning_threshold {
+                if count >= warning_threshold {
+                    return LimitCheckResult::Warning { current: count, max };
+                }
+            }
+        }
+        
+        // Check min length
+        if let Some(min) = self.min_length {
+            if count < min {
+                return LimitCheckResult::TooShort { current: count, min };
+            }
+        }
+        
+        LimitCheckResult::Ok
+    }
+    
+    /// Get a human-readable status string
+    pub fn status_text(&self, text: &str) -> Option<String> {
+        match self.check_limits(text) {
+            LimitCheckResult::Ok => {
+                // Show current/max if we have a max limit
+                self.max_length.map(|max| format!("{}/{}", self.count(text), max))
+            },
+            LimitCheckResult::Warning { current, max } => {
+                Some(format!("{current}/{max} (approaching limit)"))
+            },
+            LimitCheckResult::Exceeded { current, max } => {
+                Some(format!("{current}/{max} (exceeded)"))
+            },
+            LimitCheckResult::TooShort { current, min } => {
+                Some(format!("{current}/{min} minimum"))
+            },
+        }
+    }
+    pub fn allows_field_switch(&self, text: &str) -> bool {
+        if let Some(min) = self.min_length {
+            let count = self.count(text);
+            // Allow switching if field is empty OR meets minimum requirement
+            count == 0 || count >= min
+        } else {
+            true // No minimum requirement, always allow switching
+        }
+    }
+    
+    /// Get reason why field switching is not allowed (if any)
+    pub fn field_switch_block_reason(&self, text: &str) -> Option<String> {
+        if let Some(min) = self.min_length {
+            let count = self.count(text);
+            if count > 0 && count < min {
+                return Some(format!(
+                    "Field must be empty or have at least {min} characters (currently: {count})"
+                ));
+            }
+        }
+        None
+    }
+}
+
+impl Default for CharacterLimits {
+    fn default() -> Self {
+        Self {
+            max_length: Some(30), // Default 30 character limit as specified
+            min_length: None,
+            warning_threshold: None,
+            count_mode: CountMode::default(),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_character_limits_creation() {
+        let limits = CharacterLimits::new(10);
+        assert_eq!(limits.max_length(), Some(10));
+        assert_eq!(limits.min_length(), None);
+        
+        let range_limits = CharacterLimits::new_range(5, 15);
+        assert_eq!(range_limits.min_length(), Some(5));
+        assert_eq!(range_limits.max_length(), Some(15));
+    }
+    
+    #[test]
+    fn test_default_limits() {
+        let limits = CharacterLimits::default();
+        assert_eq!(limits.max_length(), Some(30));
+    }
+    
+    #[test]
+    fn test_character_counting() {
+        let limits = CharacterLimits::new(5);
+        
+        // Test character mode (default)
+        assert_eq!(limits.count("hello"), 5);
+        assert_eq!(limits.count("héllo"), 5); // Accented character counts as 1
+        
+        // Test display width mode
+        let limits = limits.with_count_mode(CountMode::DisplayWidth);
+        assert_eq!(limits.count("hello"), 5);
+        
+        // Test bytes mode
+        let limits = limits.with_count_mode(CountMode::Bytes);
+        assert_eq!(limits.count("hello"), 5);
+        assert_eq!(limits.count("héllo"), 6); // é takes 2 bytes in UTF-8
+    }
+    
+    #[test]
+    fn test_insertion_validation() {
+        let limits = CharacterLimits::new(5);
+        
+        // Valid insertion
+        let result = limits.validate_insertion("test", 4, 'x');
+        assert!(result.is_none()); // No validation issues
+        
+        // Invalid insertion (would exceed limit)
+        let result = limits.validate_insertion("tests", 5, 'x');
+        assert!(result.is_some());
+        assert!(!result.unwrap().is_acceptable());
+    }
+    
+    #[test]
+    fn test_content_validation() {
+        let limits = CharacterLimits::new_range(3, 10);
+        
+        // Too short
+        let result = limits.validate_content("hi");
+        assert!(result.is_some());
+        assert!(result.unwrap().is_acceptable()); // Warning, not error
+        
+        // Just right
+        let result = limits.validate_content("hello");
+        assert!(result.is_none());
+        
+        // Too long
+        let result = limits.validate_content("hello world!");
+        assert!(result.is_some());
+        assert!(!result.unwrap().is_acceptable()); // Error
+    }
+    
+    #[test]
+    fn test_warning_threshold() {
+        let limits = CharacterLimits::new(10).with_warning_threshold(8);
+        
+        // Below warning threshold
+        let result = limits.validate_insertion("1234567", 7, 'x');
+        assert!(result.is_none());
+        
+        // At warning threshold
+        let result = limits.validate_insertion("1234567", 7, 'x');
+        assert!(result.is_none()); // This brings us to 8 chars
+        
+        let result = limits.validate_insertion("12345678", 8, 'x');
+        assert!(result.is_some());
+        assert!(result.unwrap().is_acceptable()); // Warning, not error
+    }
+    
+    #[test]
+    fn test_status_text() {
+        let limits = CharacterLimits::new(10);
+        
+        assert_eq!(limits.status_text("hello"), Some("5/10".to_string()));
+        
+        let limits = limits.with_warning_threshold(8);
+        assert_eq!(limits.status_text("12345678"), Some("8/10 (approaching limit)".to_string()));
+        assert_eq!(limits.status_text("1234567890x"), Some("11/10 (exceeded)".to_string()));
+    }
+    
+    #[test]
+    fn test_field_switch_blocking() {
+        let limits = CharacterLimits::new_range(3, 10);
+        
+        // Empty field: should allow switching
+        assert!(limits.allows_field_switch(""));
+        assert!(limits.field_switch_block_reason("").is_none());
+        
+        // Field with content below minimum: should block switching
+        assert!(!limits.allows_field_switch("hi"));
+        assert!(limits.field_switch_block_reason("hi").is_some());
+        assert!(limits.field_switch_block_reason("hi").unwrap().contains("at least 3 characters"));
+        
+        // Field meeting minimum: should allow switching
+        assert!(limits.allows_field_switch("hello"));
+        assert!(limits.field_switch_block_reason("hello").is_none());
+        
+        // Field exceeding maximum: should still allow switching (validation shows error but doesn't block)
+        assert!(limits.allows_field_switch("this is way too long"));
+        assert!(limits.field_switch_block_reason("this is way too long").is_none());
+    }
+    
+    #[test]
+    fn test_field_switch_no_minimum() {
+        let limits = CharacterLimits::new(10); // Only max, no minimum
+        
+        // Should always allow switching when there's no minimum
+        assert!(limits.allows_field_switch(""));
+        assert!(limits.allows_field_switch("a"));
+        assert!(limits.allows_field_switch("hello"));
+        
+        assert!(limits.field_switch_block_reason("").is_none());
+        assert!(limits.field_switch_block_reason("a").is_none());
+    }
+}

canvas/src/validation/mask.rs

@@ -0,0 +1,330 @@
+// src/validation/mask.rs
+//! Pure display mask system - user-defined patterns only
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Default)]
+pub enum MaskDisplayMode {
+    /// Only show separators as user types
+    /// Example: "" → "", "123" → "123", "12345" → "(123) 45"
+    #[default]
+    Dynamic,
+    
+    /// Show full template with placeholders from start
+    /// Example: "" → "(___) ___-____", "123" → "(123) ___-____"
+    Template { 
+        /// Character to use as placeholder for empty input positions
+        placeholder: char 
+    },
+}
+
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct DisplayMask {
+    /// Mask pattern like "##-##-####" where # = input position, others are visual separators
+    pattern: String,
+    /// Character used to represent input positions (usually '#')
+    input_char: char,
+    /// How to display the mask (dynamic vs template)
+    display_mode: MaskDisplayMode,
+}
+
+impl DisplayMask {
+    /// Create a new display mask with dynamic mode (current behavior)
+    /// 
+    /// # Arguments
+    /// * `pattern` - The mask pattern (e.g., "##-##-####", "(###) ###-####")  
+    /// * `input_char` - Character representing input positions (usually '#')
+    /// 
+    /// # Examples
+    /// ```
+    /// // Phone number format
+    /// let phone_mask = DisplayMask::new("(###) ###-####", '#');
+    /// 
+    /// // Date format  
+    /// let date_mask = DisplayMask::new("##/##/####", '#');
+    /// 
+    /// // Custom business format
+    /// let employee_id = DisplayMask::new("EMP-####-##", '#');
+    /// ```
+    pub fn new(pattern: impl Into<String>, input_char: char) -> Self {
+        Self {
+            pattern: pattern.into(),
+            input_char,
+            display_mode: MaskDisplayMode::Dynamic,
+        }
+    }
+
+    /// Set the display mode for this mask
+    /// 
+    /// # Examples
+    /// ```
+    /// let dynamic_mask = DisplayMask::new("##-##", '#')
+    ///     .with_mode(MaskDisplayMode::Dynamic);
+    ///     
+    /// let template_mask = DisplayMask::new("##-##", '#')
+    ///     .with_mode(MaskDisplayMode::Template { placeholder: '_' });
+    /// ```
+    pub fn with_mode(mut self, mode: MaskDisplayMode) -> Self {
+        self.display_mode = mode;
+        self
+    }
+
+    /// Set template mode with custom placeholder
+    /// 
+    /// # Examples
+    /// ```
+    /// let phone_template = DisplayMask::new("(###) ###-####", '#')
+    ///     .with_template('_');  // Shows "(___) ___-____" when empty
+    ///     
+    /// let date_dots = DisplayMask::new("##/##/####", '#')
+    ///     .with_template('•');  // Shows "••/••/••••" when empty
+    /// ```
+    pub fn with_template(self, placeholder: char) -> Self {
+        self.with_mode(MaskDisplayMode::Template { placeholder })
+    }
+
+    /// Apply mask to raw input, showing visual separators and handling display mode
+    pub fn apply_to_display(&self, raw_input: &str) -> String {
+        match &self.display_mode {
+            MaskDisplayMode::Dynamic => self.apply_dynamic(raw_input),
+            MaskDisplayMode::Template { placeholder } => self.apply_template(raw_input, *placeholder),
+        }
+    }
+
+    /// Dynamic mode - only show separators as user types
+    fn apply_dynamic(&self, raw_input: &str) -> String {
+        let mut result = String::new();
+        let mut raw_chars = raw_input.chars();
+
+        for pattern_char in self.pattern.chars() {
+            if pattern_char == self.input_char {
+                // Input position - take from raw input
+                if let Some(input_char) = raw_chars.next() {
+                    result.push(input_char);
+                } else {
+                    // No more input - stop here in dynamic mode
+                    break;
+                }
+            } else {
+                // Visual separator - always show
+                result.push(pattern_char);
+            }
+        }
+
+        // Append any remaining raw characters that don't fit the pattern
+        for remaining_char in raw_chars {
+            result.push(remaining_char);
+        }
+
+        result
+    }
+
+    /// Template mode - show full pattern with placeholders
+    fn apply_template(&self, raw_input: &str, placeholder: char) -> String {
+        let mut result = String::new();
+        let mut raw_chars = raw_input.chars().peekable();
+
+        for pattern_char in self.pattern.chars() {
+            if pattern_char == self.input_char {
+                // Input position - take from raw input or use placeholder
+                if let Some(input_char) = raw_chars.next() {
+                    result.push(input_char);
+                } else {
+                    // No more input - use placeholder to show template
+                    result.push(placeholder);
+                }
+            } else {
+                // Visual separator - always show in template mode
+                result.push(pattern_char);
+            }
+        }
+
+        // In template mode, we don't append extra characters beyond the pattern
+        // This keeps the template consistent
+        result
+    }
+
+    /// Check if a display position should accept cursor/input
+    pub fn is_input_position(&self, display_position: usize) -> bool {
+        self.pattern.chars()
+            .nth(display_position)
+            .map(|c| c == self.input_char)
+            .unwrap_or(true) // Beyond pattern = accept input
+    }
+
+    /// Map display position to raw position
+    pub fn display_pos_to_raw_pos(&self, display_pos: usize) -> usize {
+        let mut raw_pos = 0;
+
+        for (i, pattern_char) in self.pattern.chars().enumerate() {
+            if i >= display_pos {
+                break;
+            }
+            if pattern_char == self.input_char {
+                raw_pos += 1;
+            }
+        }
+
+        raw_pos
+    }
+
+    /// Map raw position to display position
+    pub fn raw_pos_to_display_pos(&self, raw_pos: usize) -> usize {
+        let mut input_positions_seen = 0;
+
+        for (display_pos, pattern_char) in self.pattern.chars().enumerate() {
+            if pattern_char == self.input_char {
+                if input_positions_seen == raw_pos {
+                    return display_pos;
+                }
+                input_positions_seen += 1;
+            }
+        }
+
+        // Beyond pattern, return position after pattern
+        self.pattern.len() + (raw_pos - input_positions_seen)
+    }
+
+    /// Find next input position at or after the given display position
+    pub fn next_input_position(&self, display_pos: usize) -> usize {
+        for (i, pattern_char) in self.pattern.chars().enumerate().skip(display_pos) {
+            if pattern_char == self.input_char {
+                return i;
+            }
+        }
+        // Beyond pattern = all positions are input positions
+        display_pos.max(self.pattern.len())
+    }
+
+    /// Find previous input position at or before the given display position
+    pub fn prev_input_position(&self, display_pos: usize) -> Option<usize> {
+        // Collect pattern chars with indices first, then search backwards
+        let pattern_chars: Vec<(usize, char)> = self.pattern.chars().enumerate().collect();
+        
+        // Search backwards from display_pos
+        for &(i, pattern_char) in pattern_chars.iter().rev() {
+            if i <= display_pos && pattern_char == self.input_char {
+                return Some(i);
+            }
+        }
+        None
+    }
+
+    /// Get the display mode
+    pub fn display_mode(&self) -> &MaskDisplayMode {
+        &self.display_mode
+    }
+
+    /// Check if this mask uses template mode
+    pub fn is_template_mode(&self) -> bool {
+        matches!(self.display_mode, MaskDisplayMode::Template { .. })
+    }
+
+    /// Get the pattern string
+    pub fn pattern(&self) -> &str {
+        &self.pattern
+    }
+
+    /// Get the position of the first input character in the pattern
+    pub fn first_input_position(&self) -> usize {
+        for (pos, ch) in self.pattern.chars().enumerate() {
+            if ch == self.input_char {
+                return pos;
+            }
+        }
+        0
+    }
+}
+
+impl Default for DisplayMask {
+    fn default() -> Self {
+        Self::new("", '#')
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_user_defined_phone_mask() {
+        // User creates their own phone mask
+        let dynamic = DisplayMask::new("(###) ###-####", '#');
+        let template = DisplayMask::new("(###) ###-####", '#').with_template('_');
+        
+        // Dynamic mode
+        assert_eq!(dynamic.apply_to_display(""), "");
+        assert_eq!(dynamic.apply_to_display("1234567890"), "(123) 456-7890");
+        
+        // Template mode
+        assert_eq!(template.apply_to_display(""), "(___) ___-____");
+        assert_eq!(template.apply_to_display("123"), "(123) ___-____");
+    }
+
+    #[test]
+    fn test_user_defined_date_mask() {
+        // User creates their own date formats
+        let us_date = DisplayMask::new("##/##/####", '#');
+        let eu_date = DisplayMask::new("##.##.####", '#');
+        let iso_date = DisplayMask::new("####-##-##", '#');
+        
+        assert_eq!(us_date.apply_to_display("12252024"), "12/25/2024");
+        assert_eq!(eu_date.apply_to_display("25122024"), "25.12.2024");
+        assert_eq!(iso_date.apply_to_display("20241225"), "2024-12-25");
+    }
+
+    #[test]
+    fn test_user_defined_business_formats() {
+        // User creates custom business formats
+        let employee_id = DisplayMask::new("EMP-####-##", '#');
+        let product_code = DisplayMask::new("###-###-###", '#');
+        let invoice = DisplayMask::new("INV####/##", '#');
+        
+        assert_eq!(employee_id.apply_to_display("123456"), "EMP-1234-56");
+        assert_eq!(product_code.apply_to_display("123456789"), "123-456-789");
+        assert_eq!(invoice.apply_to_display("123456"), "INV1234/56");
+    }
+
+    #[test]
+    fn test_custom_input_characters() {
+        // User can define their own input character
+        let mask_with_x = DisplayMask::new("XXX-XX-XXXX", 'X');
+        let mask_with_hash = DisplayMask::new("###-##-####", '#');
+        let mask_with_n = DisplayMask::new("NNN-NN-NNNN", 'N');
+        
+        assert_eq!(mask_with_x.apply_to_display("123456789"), "123-45-6789");
+        assert_eq!(mask_with_hash.apply_to_display("123456789"), "123-45-6789");
+        assert_eq!(mask_with_n.apply_to_display("123456789"), "123-45-6789");
+    }
+
+    #[test]
+    fn test_custom_placeholders() {
+        // User can define custom placeholder characters
+        let underscores = DisplayMask::new("##-##", '#').with_template('_');
+        let dots = DisplayMask::new("##-##", '#').with_template('•');
+        let dashes = DisplayMask::new("##-##", '#').with_template('-');
+        
+        assert_eq!(underscores.apply_to_display(""), "__-__");
+        assert_eq!(dots.apply_to_display(""), "••-••");
+        assert_eq!(dashes.apply_to_display(""), "---");  // Note: dashes blend with separator
+    }
+
+    #[test]
+    fn test_position_mapping_user_patterns() {
+        let custom = DisplayMask::new("ABC-###-XYZ", '#');
+        
+        // Position mapping should work correctly with any pattern
+        assert_eq!(custom.raw_pos_to_display_pos(0), 4); // First # at position 4
+        assert_eq!(custom.raw_pos_to_display_pos(1), 5); // Second # at position 5
+        assert_eq!(custom.raw_pos_to_display_pos(2), 6); // Third # at position 6
+        
+        assert_eq!(custom.display_pos_to_raw_pos(4), 0); // Position 4 -> first input
+        assert_eq!(custom.display_pos_to_raw_pos(5), 1); // Position 5 -> second input
+        assert_eq!(custom.display_pos_to_raw_pos(6), 2); // Position 6 -> third input
+        
+        assert!(!custom.is_input_position(0)); // A
+        assert!(!custom.is_input_position(3)); // -
+        assert!(custom.is_input_position(4));  // #
+        assert!(!custom.is_input_position(8)); // Y
+    }
+}

canvas/src/validation/mod.rs

@@ -0,0 +1,45 @@
+// src/validation/mod.rs
+//! Validation subsystem re-exports and helpers.
+//!
+//! This module collects validation-related modules (limits, masks, patterns,
+//! formatting, and state) and re-exports the most commonly used types so that
+//! callers can import them from `crate::validation`.
+
+ // Core validation modules
+pub mod config;
+pub mod limits;
+pub mod state;
+pub mod patterns;
+pub mod mask;  // Simple display mask instead of complex reserved chars
+pub mod formatting; // Custom formatter and position mapping (feature 4)
+
+// Re-export main types
+pub use config::{ValidationConfig, ValidationResult, ValidationConfigBuilder};
+pub use limits::{CharacterLimits, LimitCheckResult};
+pub use state::{ValidationState, ValidationSummary};
+pub use patterns::{PatternFilters, PositionFilter, PositionRange, CharacterFilter};
+pub use mask::DisplayMask;  // Simple mask instead of ReservedCharacters
+pub use formatting::{CustomFormatter, FormattingResult, PositionMapper, DefaultPositionMapper};
+
+/// External validation UI state (Feature 5)
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum ExternalValidationState {
+    NotValidated,
+    Validating,
+    Valid(Option<String>),
+    Invalid { message: String, suggestion: Option<String> },
+    Warning { message: String },
+}
+
+/// Validation error types
+#[derive(Debug, Clone, thiserror::Error)]
+pub enum ValidationError {
+    #[error("Character limit exceeded: {message}")]
+    LimitExceeded { message: String },
+    
+    #[error("Pattern validation failed: {message}")]
+    PatternFailed { message: String },
+    
+    #[error("Custom validation failed: {message}")]
+    CustomFailed { message: String },
+}

canvas/src/validation/patterns.rs

@@ -0,0 +1,324 @@
+// src/validation/patterns.rs
+//! Position-based pattern filtering for validation
+
+use serde::{Deserialize, Serialize};
+use std::sync::Arc;
+
+/// A filter that applies to specific character positions in a field
+#[derive(Debug, Clone)]
+pub struct PositionFilter {
+    /// Which positions this filter applies to
+    pub positions: PositionRange,
+    /// What type of character filter to apply
+    pub filter: CharacterFilter,
+}
+
+/// Defines which character positions a filter applies to
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub enum PositionRange {
+    /// Single position (e.g., position 3 only)
+    Single(usize),
+    /// Range of positions (e.g., positions 0-2, inclusive)
+    Range(usize, usize),
+    /// From position onwards (e.g., position 4 and beyond)
+    From(usize),
+    /// Multiple specific positions (e.g., positions 0, 2, 5)
+    Multiple(Vec<usize>),
+}
+
+/// Types of character filters that can be applied
+pub enum CharacterFilter {
+    /// Allow only alphabetic characters (a-z, A-Z)
+    Alphabetic,
+    /// Allow only numeric characters (0-9)
+    Numeric,
+    /// Allow alphanumeric characters (a-z, A-Z, 0-9)
+    Alphanumeric,
+    /// Allow only exact character match
+    Exact(char),
+    /// Allow any character from the provided set
+    OneOf(Vec<char>),
+    /// Custom user-defined filter function
+    Custom(Arc<dyn Fn(char) -> bool + Send + Sync>),
+}
+
+// Manual implementations for Debug and Clone
+impl std::fmt::Debug for CharacterFilter {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            CharacterFilter::Alphabetic => write!(f, "Alphabetic"),
+            CharacterFilter::Numeric => write!(f, "Numeric"),
+            CharacterFilter::Alphanumeric => write!(f, "Alphanumeric"),
+            CharacterFilter::Exact(ch) => write!(f, "Exact('{ch}')"),
+            CharacterFilter::OneOf(chars) => write!(f, "OneOf({chars:?})"),
+            CharacterFilter::Custom(_) => write!(f, "Custom(<function>)"),
+        }
+    }
+}
+
+impl Clone for CharacterFilter {
+    fn clone(&self) -> Self {
+        match self {
+            CharacterFilter::Alphabetic => CharacterFilter::Alphabetic,
+            CharacterFilter::Numeric => CharacterFilter::Numeric,
+            CharacterFilter::Alphanumeric => CharacterFilter::Alphanumeric,
+            CharacterFilter::Exact(ch) => CharacterFilter::Exact(*ch),
+            CharacterFilter::OneOf(chars) => CharacterFilter::OneOf(chars.clone()),
+            CharacterFilter::Custom(func) => CharacterFilter::Custom(Arc::clone(func)),
+        }
+    }
+}
+
+impl PositionRange {
+    /// Check if a position is included in this range
+    pub fn contains(&self, position: usize) -> bool {
+        match self {
+            PositionRange::Single(pos) => position == *pos,
+            PositionRange::Range(start, end) => position >= *start && position <= *end,
+            PositionRange::From(start) => position >= *start,
+            PositionRange::Multiple(positions) => positions.contains(&position),
+        }
+    }
+
+    /// Get all positions up to a given length that this range covers
+    pub fn positions_up_to(&self, max_length: usize) -> Vec<usize> {
+        match self {
+            PositionRange::Single(pos) => {
+                if *pos < max_length { vec![*pos] } else { vec![] }
+            },
+            PositionRange::Range(start, end) => {
+                let actual_end = (*end).min(max_length.saturating_sub(1));
+                if *start <= actual_end {
+                    (*start..=actual_end).collect()
+                } else {
+                    vec![]
+                }
+            },
+            PositionRange::From(start) => {
+                if *start < max_length {
+                    (*start..max_length).collect()
+                } else {
+                    vec![]
+                }
+            },
+            PositionRange::Multiple(positions) => {
+                positions.iter()
+                    .filter(|&&pos| pos < max_length)
+                    .copied()
+                    .collect()
+            },
+        }
+    }
+}
+
+impl CharacterFilter {
+    /// Test if a character passes this filter
+    pub fn accepts(&self, ch: char) -> bool {
+        match self {
+            CharacterFilter::Alphabetic => ch.is_alphabetic(),
+            CharacterFilter::Numeric => ch.is_numeric(),
+            CharacterFilter::Alphanumeric => ch.is_alphanumeric(),
+            CharacterFilter::Exact(expected) => ch == *expected,
+            CharacterFilter::OneOf(chars) => chars.contains(&ch),
+            CharacterFilter::Custom(func) => func(ch),
+        }
+    }
+
+    /// Get a human-readable description of this filter
+    pub fn description(&self) -> String {
+        match self {
+            CharacterFilter::Alphabetic => "alphabetic characters (a-z, A-Z)".to_string(),
+            CharacterFilter::Numeric => "numeric characters (0-9)".to_string(),
+            CharacterFilter::Alphanumeric => "alphanumeric characters (a-z, A-Z, 0-9)".to_string(),
+            CharacterFilter::Exact(ch) => format!("exactly '{ch}'"),
+            CharacterFilter::OneOf(chars) => {
+                let char_list: String = chars.iter().collect();
+                format!("one of: {char_list}")
+            },
+            CharacterFilter::Custom(_) => "custom filter".to_string(),
+        }
+    }
+}
+
+impl PositionFilter {
+    /// Create a new position filter
+    pub fn new(positions: PositionRange, filter: CharacterFilter) -> Self {
+        Self { positions, filter }
+    }
+
+    /// Validate a character at a specific position
+    pub fn validate_position(&self, position: usize, character: char) -> bool {
+        if self.positions.contains(position) {
+            self.filter.accepts(character)
+        } else {
+            true // Position not covered by this filter, allow any character
+        }
+    }
+
+    /// Get error message for invalid character at position
+    pub fn error_message(&self, position: usize, character: char) -> Option<String> {
+        if self.positions.contains(position) && !self.filter.accepts(character) {
+            Some(format!(
+                "Position {} requires {} but got '{}'",
+                position,
+                self.filter.description(),
+                character
+            ))
+        } else {
+            None
+        }
+    }
+}
+
+/// A collection of position filters for a field
+#[derive(Debug, Clone, Default)]
+pub struct PatternFilters {
+    filters: Vec<PositionFilter>,
+}
+
+impl PatternFilters {
+    /// Create empty pattern filters
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Add a position filter
+    pub fn add_filter(mut self, filter: PositionFilter) -> Self {
+        self.filters.push(filter);
+        self
+    }
+
+    /// Add multiple filters
+    pub fn add_filters(mut self, filters: Vec<PositionFilter>) -> Self {
+        self.filters.extend(filters);
+        self
+    }
+
+    /// Validate a character at a specific position against all applicable filters
+    pub fn validate_char_at_position(&self, position: usize, character: char) -> Result<(), String> {
+        for filter in &self.filters {
+            if let Some(error) = filter.error_message(position, character) {
+                return Err(error);
+            }
+        }
+        Ok(())
+    }
+
+    /// Validate entire text against all filters
+    pub fn validate_text(&self, text: &str) -> Result<(), String> {
+        for (position, character) in text.char_indices() {
+            self.validate_char_at_position(position, character)?
+        }
+        Ok(())
+    }
+
+    /// Check if any filters are configured
+    pub fn has_filters(&self) -> bool {
+        !self.filters.is_empty()
+    }
+
+    /// Get all configured filters
+    pub fn filters(&self) -> &[PositionFilter] {
+        &self.filters
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_position_range_contains() {
+        assert!(PositionRange::Single(3).contains(3));
+        assert!(!PositionRange::Single(3).contains(2));
+
+        assert!(PositionRange::Range(1, 4).contains(3));
+        assert!(!PositionRange::Range(1, 4).contains(5));
+
+        assert!(PositionRange::From(2).contains(5));
+        assert!(!PositionRange::From(2).contains(1));
+
+        assert!(PositionRange::Multiple(vec![0, 2, 5]).contains(2));
+        assert!(!PositionRange::Multiple(vec![0, 2, 5]).contains(3));
+    }
+
+    #[test]
+    fn test_position_range_positions_up_to() {
+        assert_eq!(PositionRange::Single(3).positions_up_to(5), vec![3]);
+        assert_eq!(PositionRange::Single(5).positions_up_to(3), vec![]);
+
+        assert_eq!(PositionRange::Range(1, 3).positions_up_to(5), vec![1, 2, 3]);
+        assert_eq!(PositionRange::Range(1, 5).positions_up_to(3), vec![1, 2]);
+
+        assert_eq!(PositionRange::From(2).positions_up_to(5), vec![2, 3, 4]);
+
+        assert_eq!(PositionRange::Multiple(vec![0, 2, 5]).positions_up_to(4), vec![0, 2]);
+    }
+
+    #[test]
+    fn test_character_filter_accepts() {
+        assert!(CharacterFilter::Alphabetic.accepts('a'));
+        assert!(CharacterFilter::Alphabetic.accepts('Z'));
+        assert!(!CharacterFilter::Alphabetic.accepts('1'));
+
+        assert!(CharacterFilter::Numeric.accepts('5'));
+        assert!(!CharacterFilter::Numeric.accepts('a'));
+
+        assert!(CharacterFilter::Alphanumeric.accepts('a'));
+        assert!(CharacterFilter::Alphanumeric.accepts('5'));
+        assert!(!CharacterFilter::Alphanumeric.accepts('-'));
+
+        assert!(CharacterFilter::Exact('x').accepts('x'));
+        assert!(!CharacterFilter::Exact('x').accepts('y'));
+
+        assert!(CharacterFilter::OneOf(vec!['a', 'b', 'c']).accepts('b'));
+        assert!(!CharacterFilter::OneOf(vec!['a', 'b', 'c']).accepts('d'));
+    }
+
+    #[test]
+    fn test_position_filter_validation() {
+        let filter = PositionFilter::new(
+            PositionRange::Range(0, 1),
+            CharacterFilter::Alphabetic,
+        );
+
+        assert!(filter.validate_position(0, 'A'));
+        assert!(filter.validate_position(1, 'b'));
+        assert!(!filter.validate_position(0, '1'));
+        assert!(filter.validate_position(2, '1')); // Position 2 not covered, allow anything
+    }
+
+    #[test]
+    fn test_pattern_filters_validation() {
+        let patterns = PatternFilters::new()
+            .add_filter(PositionFilter::new(
+                PositionRange::Range(0, 1),
+                CharacterFilter::Alphabetic,
+            ))
+            .add_filter(PositionFilter::new(
+                PositionRange::Range(2, 4),
+                CharacterFilter::Numeric,
+            ));
+
+        // Valid pattern: AB123
+        assert!(patterns.validate_text("AB123").is_ok());
+
+        // Invalid: number in alphabetic position
+        assert!(patterns.validate_text("A1123").is_err());
+
+        // Invalid: letter in numeric position
+        assert!(patterns.validate_text("AB1A3").is_err());
+    }
+
+    #[test]
+    fn test_custom_filter() {
+        let pattern = PatternFilters::new()
+            .add_filter(PositionFilter::new(
+                PositionRange::From(0),
+                CharacterFilter::Custom(Arc::new(|c| c.is_lowercase())),
+            ));
+
+        assert!(pattern.validate_text("hello").is_ok());
+        assert!(pattern.validate_text("Hello").is_err()); // Uppercase not allowed
+    }
+}

canvas/src/validation/state.rs

@@ -0,0 +1,460 @@
+// src/validation/state.rs
+//! Validation state management
+
+use crate::validation::{ValidationConfig, ValidationResult, ExternalValidationState};
+use std::collections::HashMap;
+
+/// Validation state for all fields in a form
+#[derive(Debug, Clone, Default)]
+pub struct ValidationState {
+    /// Validation configurations per field index
+    field_configs: HashMap<usize, ValidationConfig>,
+    
+    /// Current validation results per field index
+    field_results: HashMap<usize, ValidationResult>,
+    
+    /// Track which fields have been validated
+    validated_fields: std::collections::HashSet<usize>,
+    
+    /// Global validation enabled/disabled
+    enabled: bool,
+
+    /// External validation results per field (Feature 5)
+    external_results: HashMap<usize, ExternalValidationState>,
+
+    last_switch_block: Option<String>,
+}
+
+impl ValidationState {
+    /// Create a new validation state
+    pub fn new() -> Self {
+        Self {
+            field_configs: HashMap::new(),
+            field_results: HashMap::new(),
+            validated_fields: std::collections::HashSet::new(),
+            enabled: true,
+            external_results: HashMap::new(),
+            last_switch_block: None,
+        }
+    }
+    
+    /// Enable or disable validation globally
+    pub fn set_enabled(&mut self, enabled: bool) {
+        self.enabled = enabled;
+        if !enabled {
+            // Clear all validation results when disabled
+            self.field_results.clear();
+            self.validated_fields.clear();
+            self.external_results.clear(); // Also clear external results
+        }
+    }
+    
+    /// Check if validation is enabled
+    pub fn is_enabled(&self) -> bool {
+        self.enabled
+    }
+    
+    /// Set validation configuration for a field
+    pub fn set_field_config(&mut self, field_index: usize, config: ValidationConfig) {
+        if config.has_validation() || config.external_validation_enabled {
+            self.field_configs.insert(field_index, config);
+        } else {
+            self.field_configs.remove(&field_index);
+            self.field_results.remove(&field_index);
+            self.validated_fields.remove(&field_index);
+            self.external_results.remove(&field_index);
+        }
+    }
+    
+    /// Get validation configuration for a field
+    pub fn get_field_config(&self, field_index: usize) -> Option<&ValidationConfig> {
+        self.field_configs.get(&field_index)
+    }
+    
+    /// Remove validation configuration for a field
+    pub fn remove_field_config(&mut self, field_index: usize) {
+        self.field_configs.remove(&field_index);
+        self.field_results.remove(&field_index);
+        self.validated_fields.remove(&field_index);
+        self.external_results.remove(&field_index);
+    }
+    
+    /// Set external validation state for a field (Feature 5)
+    pub fn set_external_validation(&mut self, field_index: usize, state: ExternalValidationState) {
+        self.external_results.insert(field_index, state);
+    }
+    
+    /// Get current external validation state for a field
+    pub fn get_external_validation(&self, field_index: usize) -> ExternalValidationState {
+        self.external_results
+            .get(&field_index)
+            .cloned()
+            .unwrap_or(ExternalValidationState::NotValidated)
+    }
+    
+    /// Clear external validation state for a field
+    pub fn clear_external_validation(&mut self, field_index: usize) {
+        self.external_results.remove(&field_index);
+    }
+    
+    /// Clear all external validation states
+    pub fn clear_all_external_validation(&mut self) {
+        self.external_results.clear();
+    }
+    
+    /// Validate character insertion for a field
+    pub fn validate_char_insertion(
+        &mut self,
+        field_index: usize,
+        current_text: &str,
+        position: usize,
+        character: char,
+    ) -> ValidationResult {
+        if !self.enabled {
+            return ValidationResult::Valid;
+        }
+        
+        if let Some(config) = self.field_configs.get(&field_index) {
+            let result = config.validate_char_insertion(current_text, position, character);
+            
+            // Store the validation result
+            self.field_results.insert(field_index, result.clone());
+            self.validated_fields.insert(field_index);
+            
+            result
+        } else {
+            ValidationResult::Valid
+        }
+    }
+    
+    /// Validate field content
+    pub fn validate_field_content(
+        &mut self,
+        field_index: usize,
+        text: &str,
+    ) -> ValidationResult {
+        if !self.enabled {
+            return ValidationResult::Valid;
+        }
+        
+        if let Some(config) = self.field_configs.get(&field_index) {
+            let result = config.validate_content(text);
+            
+            // Store the validation result
+            self.field_results.insert(field_index, result.clone());
+            self.validated_fields.insert(field_index);
+            
+            result
+        } else {
+            ValidationResult::Valid
+        }
+    }
+    
+    /// Get current validation result for a field
+    pub fn get_field_result(&self, field_index: usize) -> Option<&ValidationResult> {
+        self.field_results.get(&field_index)
+    }
+    
+    /// Get formatted display for a field if a custom formatter is configured.
+    /// Returns (formatted_text, position_mapper, optional_warning_message).
+    #[cfg(feature = "validation")]
+    pub fn formatted_for(
+        &self,
+        field_index: usize,
+        raw: &str,
+    ) -> Option<(String, std::sync::Arc<dyn crate::validation::PositionMapper>, Option<String>)> {
+        let config = self.field_configs.get(&field_index)?;
+        config.run_custom_formatter(raw)
+    }
+    
+    /// Check if a field has been validated
+    pub fn is_field_validated(&self, field_index: usize) -> bool {
+        self.validated_fields.contains(&field_index)
+    }
+    
+    /// Clear validation result for a field
+    pub fn clear_field_result(&mut self, field_index: usize) {
+        self.field_results.remove(&field_index);
+        self.validated_fields.remove(&field_index);
+    }
+    
+    /// Clear all validation results
+    pub fn clear_all_results(&mut self) {
+        self.field_results.clear();
+        self.validated_fields.clear();
+    }
+    
+    /// Get all field indices that have validation configured
+    pub fn validated_field_indices(&self) -> impl Iterator<Item = usize> + '_ {
+        self.field_configs.keys().copied()
+    }
+    
+    /// Get all field indices with validation errors
+    pub fn fields_with_errors(&self) -> impl Iterator<Item = usize> + '_ {
+        self.field_results
+            .iter()
+            .filter(|(_, result)| result.is_error())
+            .map(|(index, _)| *index)
+    }
+    
+    /// Get all field indices with validation warnings
+    pub fn fields_with_warnings(&self) -> impl Iterator<Item = usize> + '_ {
+        self.field_results
+            .iter()
+            .filter(|(_, result)| matches!(result, ValidationResult::Warning { .. }))
+            .map(|(index, _)| *index)
+    }
+    
+    /// Check if any field has validation errors
+    pub fn has_errors(&self) -> bool {
+        self.field_results.values().any(|result| result.is_error())
+    }
+    
+    /// Check if any field has validation warnings
+    pub fn has_warnings(&self) -> bool {
+        self.field_results.values().any(|result| matches!(result, ValidationResult::Warning { .. }))
+    }
+    
+    /// Get total count of fields with validation configured
+    pub fn validated_field_count(&self) -> usize {
+        self.field_configs.len()
+    }
+    
+    /// Check if field switching is allowed for a specific field
+    pub fn allows_field_switch(&self, field_index: usize, text: &str) -> bool {
+        if !self.enabled {
+            return true;
+        }
+        
+        if let Some(config) = self.field_configs.get(&field_index) {
+            config.allows_field_switch(text)
+        } else {
+            true // No validation configured, allow switching
+        }
+    }
+    
+    /// Get reason why field switching is blocked (if any)
+    pub fn field_switch_block_reason(&self, field_index: usize, text: &str) -> Option<String> {
+        if !self.enabled {
+            return None;
+        }
+        
+        if let Some(config) = self.field_configs.get(&field_index) {
+            config.field_switch_block_reason(text)
+        } else {
+            None // No validation configured
+        }
+    }
+    pub fn summary(&self) -> ValidationSummary {
+        let total_validated = self.validated_fields.len();
+        let errors = self.fields_with_errors().count();
+        let warnings = self.fields_with_warnings().count();
+        let valid = total_validated - errors - warnings;
+        
+        ValidationSummary {
+            total_fields: self.field_configs.len(),
+            validated_fields: total_validated,
+            valid_fields: valid,
+            warning_fields: warnings,
+            error_fields: errors,
+        }
+    }
+
+ 
+    /// Set the last switch block reason (for UI convenience)
+    pub fn set_last_switch_block<S: Into<String>>(&mut self, reason: S) {
+        self.last_switch_block = Some(reason.into());
+    }
+    
+    /// Clear the last switch block reason
+    pub fn clear_last_switch_block(&mut self) {
+        self.last_switch_block = None;
+    }
+    
+    /// Get the last switch block reason (if any)
+    pub fn last_switch_block(&self) -> Option<&str> {
+        self.last_switch_block.as_deref()
+    }
+}
+
+/// Summary of validation state across all fields
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct ValidationSummary {
+    /// Total number of fields with validation configured
+    pub total_fields: usize,
+    
+    /// Number of fields that have been validated
+    pub validated_fields: usize,
+    
+    /// Number of fields with valid validation results
+    pub valid_fields: usize,
+    
+    /// Number of fields with warnings
+    pub warning_fields: usize,
+    
+    /// Number of fields with errors
+    pub error_fields: usize,
+}
+
+impl ValidationSummary {
+    /// Check if all configured fields are valid
+    pub fn is_all_valid(&self) -> bool {
+        self.error_fields == 0 && self.validated_fields == self.total_fields
+    }
+    
+    /// Check if there are any errors
+    pub fn has_errors(&self) -> bool {
+        self.error_fields > 0
+    }
+    
+    /// Check if there are any warnings
+    pub fn has_warnings(&self) -> bool {
+        self.warning_fields > 0
+    }
+    
+    /// Get completion percentage (validated fields / total fields)
+    pub fn completion_percentage(&self) -> f32 {
+        if self.total_fields == 0 {
+            1.0
+        } else {
+            self.validated_fields as f32 / self.total_fields as f32
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::validation::{CharacterLimits, ValidationConfigBuilder};
+
+    #[test]
+    fn test_validation_state_creation() {
+        let state = ValidationState::new();
+        assert!(state.is_enabled());
+        assert_eq!(state.validated_field_count(), 0);
+    }
+    
+    #[test]
+    fn test_enable_disable() {
+        let mut state = ValidationState::new();
+        
+        // Add some validation config
+        let config = ValidationConfigBuilder::new()
+            .with_max_length(10)
+            .build();
+        state.set_field_config(0, config);
+        
+        // Validate something
+        let result = state.validate_field_content(0, "test");
+        assert!(result.is_acceptable());
+        assert!(state.is_field_validated(0));
+        
+        // Disable validation
+        state.set_enabled(false);
+        assert!(!state.is_enabled());
+        assert!(!state.is_field_validated(0)); // Should be cleared
+        
+        // Validation should now return valid regardless
+        let result = state.validate_field_content(0, "this is way too long for the limit");
+        assert!(result.is_acceptable());
+    }
+    
+    #[test]
+    fn test_field_config_management() {
+        let mut state = ValidationState::new();
+        
+        let config = ValidationConfigBuilder::new()
+            .with_max_length(5)
+            .build();
+        
+        // Set config
+        state.set_field_config(0, config);
+        assert_eq!(state.validated_field_count(), 1);
+        assert!(state.get_field_config(0).is_some());
+        
+        // Remove config
+        state.remove_field_config(0);
+        assert_eq!(state.validated_field_count(), 0);
+        assert!(state.get_field_config(0).is_none());
+    }
+    
+    #[test]
+    fn test_character_insertion_validation() {
+        let mut state = ValidationState::new();
+        
+        let config = ValidationConfigBuilder::new()
+            .with_max_length(5)
+            .build();
+        state.set_field_config(0, config);
+        
+        // Valid insertion
+        let result = state.validate_char_insertion(0, "test", 4, 'x');
+        assert!(result.is_acceptable());
+        
+        // Invalid insertion
+        let result = state.validate_char_insertion(0, "tests", 5, 'x');
+        assert!(!result.is_acceptable());
+        
+        // Check that result was stored
+        assert!(state.is_field_validated(0));
+        let stored_result = state.get_field_result(0);
+        assert!(stored_result.is_some());
+        assert!(!stored_result.unwrap().is_acceptable());
+    }
+    
+    #[test]
+    fn test_validation_summary() {
+        let mut state = ValidationState::new();
+        
+        // Configure two fields
+        let config1 = ValidationConfigBuilder::new().with_max_length(5).build();
+        let config2 = ValidationConfigBuilder::new().with_max_length(10).build();
+        state.set_field_config(0, config1);
+        state.set_field_config(1, config2);
+        
+        // Validate field 0 (valid)
+        state.validate_field_content(0, "test");
+        
+        // Validate field 1 (error)
+        state.validate_field_content(1, "this is too long");
+        
+        let summary = state.summary();
+        assert_eq!(summary.total_fields, 2);
+        assert_eq!(summary.validated_fields, 2);
+        assert_eq!(summary.valid_fields, 1);
+        assert_eq!(summary.error_fields, 1);
+        assert_eq!(summary.warning_fields, 0);
+        
+        assert!(!summary.is_all_valid());
+        assert!(summary.has_errors());
+        assert!(!summary.has_warnings());
+        assert_eq!(summary.completion_percentage(), 1.0);
+    }
+    
+    #[test]
+    fn test_error_and_warning_tracking() {
+        let mut state = ValidationState::new();
+        
+        let config = ValidationConfigBuilder::new()
+            .with_character_limits(
+                CharacterLimits::new_range(3, 10).with_warning_threshold(8)
+            )
+            .build();
+        state.set_field_config(0, config);
+        
+        // Too short (warning)
+        state.validate_field_content(0, "hi");
+        assert!(state.has_warnings());
+        assert!(!state.has_errors());
+        
+        // Just right
+        state.validate_field_content(0, "hello");
+        assert!(!state.has_warnings());
+        assert!(!state.has_errors());
+        
+        // Too long (error)
+        state.validate_field_content(0, "hello world!");
+        assert!(!state.has_warnings());
+        assert!(state.has_errors());
+    }
+}

canvas/view_docs.sh

@@ -0,0 +1,55 @@
+#!/bin/bash
+
+# Enhanced documentation viewer for your canvas library
+echo "=========================================="
+echo "CANVAS LIBRARY DOCUMENTATION"
+echo "=========================================="
+
+# Function to display module docs with colors
+show_module() {
+    local module=$1
+    local title=$2
+    
+    echo -e "\n\033[1;34m=== $title ===\033[0m"
+    echo -e "\033[33mFiles in $module:\033[0m"
+    find src/$module -name "*.rs" 2>/dev/null | sort
+    echo
+    
+    # Show doc comments for this module
+    find src/$module -name "*.rs" 2>/dev/null | while read file; do
+        if grep -q "///" "$file"; then
+            echo -e "\033[32m--- $file ---\033[0m"
+            grep -n "^\s*///" "$file" | sed 's/^\([0-9]*:\)\s*\/\/\/ /\1 /' | head -10
+            echo
+        fi
+    done
+}
+
+# Main modules
+show_module "canvas" "CANVAS SYSTEM"
+show_module "suggestions" "SUGGESTIONS SYSTEM" 
+show_module "config" "CONFIGURATION SYSTEM"
+
+# Show lib.rs and other root files
+echo -e "\n\033[1;34m=== ROOT DOCUMENTATION ===\033[0m"
+if [ -f "src/lib.rs" ]; then
+    echo -e "\033[32m--- src/lib.rs ---\033[0m"
+    grep -n "^\s*///" src/lib.rs | sed 's/^\([0-9]*:\)\s*\/\/\/ /\1 /' 2>/dev/null
+fi
+
+if [ -f "src/dispatcher.rs" ]; then
+    echo -e "\033[32m--- src/dispatcher.rs ---\033[0m"
+    grep -n "^\s*///" src/dispatcher.rs | sed 's/^\([0-9]*:\)\s*\/\/\/ /\1 /' 2>/dev/null
+fi
+
+echo -e "\n\033[1;36m=========================================="
+echo "To view specific module documentation:"
+echo "  ./view_canvas_docs.sh canvas"
+echo "  ./view_canvas_docs.sh suggestions" 
+echo "  ./view_canvas_docs.sh config"
+echo "==========================================\033[0m"
+
+# If specific module requested
+if [ $# -eq 1 ]; then
+    show_module "$1" "$(echo $1 | tr '[:lower:]' '[:upper:]') MODULE DETAILS"
+fi

client/.gitignore

@@ -0,0 +1 @@
+canvas_config.toml.txt

client/Cargo.toml

@@ -5,19 +5,36 @@ edition.workspace = true
 license.workspace = true
 
 [dependencies]
+anyhow = { workspace = true }
 async-trait = "0.1.88"
 common = { path = "../common" }
+canvas = { path = "../canvas", features = ["gui", "suggestions", "cursor-style", "keymap"] }
 
-crossterm = "0.28.1"
+ratatui = { workspace = true }
+crossterm = { workspace = true }
+prost-types = { workspace = true }
 dirs = "6.0.0"
 dotenvy = "0.15.7"
 lazy_static = "1.5.0"
 prost = "0.13.5"
-ratatui = "0.29.0"
-serde = { version = "1.0.218", features = ["derive"] }
-tokio = { version = "1.43.0", features = ["full", "macros"] }
-toml = "0.8.20"
-tonic = "0.12.3"
+serde = { version = "1.0.219", features = ["derive"] }
+serde_json = "1.0.140"
+time = "0.3.41"
+tokio = { version = "1.44.2", features = ["full", "macros"] }
+toml = { workspace = true }
+tonic = "0.13.0"
 tracing = "0.1.41"
+tracing-subscriber = "0.3.19"
+tui-textarea = { version = "0.7.0", features = ["crossterm", "ratatui", "search"] }
 unicode-segmentation = "1.12.0"
-unicode-width = "0.2.0"
+unicode-width.workspace = true
+
+[features]
+default = []
+ui-debug = []
+
+[dev-dependencies]
+rstest = "0.25.0"
+tokio-test = "0.4.4"
+uuid = { version = "1.17.0", features = ["v4"] }
+futures = "0.3.31"

client/config.toml

@@ -2,23 +2,24 @@
 [keybindings]
 
 enter_command_mode = [":", "ctrl+;"]
+next_buffer = ["space+b+n"]
+previous_buffer = ["space+b+p"] 
+close_buffer = ["space+b+d"]
 
 [keybindings.general]
-move_up = ["k", "Up"]
-move_down = ["j", "Down"]
-next_option = ["l", "Right"]
-previous_option = ["h", "Left"]
+up = ["k", "Up"]
+down = ["j", "Down"]
+left = ["h", "Left"]
+right = ["l", "Right"]
+next = ["Tab"]
+previous = ["Shift+Tab"]
 select = ["Enter"]
-toggle_sidebar = ["ctrl+t"]
-toggle_buffer_list = ["ctrl+b"]
-next_field = ["Tab"]
-prev_field = ["Shift+Tab"]
+esc = ["esc"]
+open_search = ["ctrl+f"]
 
 [keybindings.common]
 save = ["ctrl+s"]
 quit = ["ctrl+q"]
-# !!!change to space b r in the future and from edit mode 
-revert = ["ctrl+r"]
 
 force_quit = ["ctrl+shift+q"]
 save_and_quit = ["ctrl+shift+s"]
@@ -26,6 +27,7 @@ move_up = ["Up"]
 move_down = ["Down"]
 toggle_sidebar = ["ctrl+t"]
 toggle_buffer_list = ["ctrl+b"]
+revert = ["space+b+r"]
 
 # MODE SPECIFIC
 # READ ONLY MODE
@@ -35,31 +37,75 @@ enter_edit_mode_after = ["a"]
 previous_entry = ["left","q"]
 next_entry = ["right","1"]
 
-move_left = ["h"]
-move_right = ["l"]
-move_up = ["k"]
-move_down = ["j"]
+enter_highlight_mode = ["v"]
+enter_highlight_mode_linewise = ["shift+v"]
+
+### AUTOGENERATED CANVAS CONFIG
+# Required
+move_up = ["k", "Up"]
+move_left = ["h", "Left"]
+move_right = ["l", "Right"]
+move_down = ["j", "Down"]
+# Optional
+move_line_end = ["$"]
 move_word_next = ["w"]
-move_word_end = ["e"]
+next_field = ["Tab"]
 move_word_prev = ["b"]
+move_word_end = ["e"]
+move_last_line = ["shift+g"]
 move_word_end_prev = ["ge"]
 move_line_start = ["0"]
+move_first_line = ["g+g"]
+prev_field = ["Shift+Tab"]
+
+[keybindings.highlight]
+exit_highlight_mode = ["esc"]
+enter_highlight_mode_linewise = ["ctrl+v"]
+
+### AUTOGENERATED CANVAS CONFIG
+# Required
+move_left = ["h", "Left"]
+move_right = ["l", "Right"]
+move_up = ["k", "Up"]
+move_down = ["j", "Down"]
+# Optional
+move_word_next = ["w"]
+move_line_start = ["0"]
 move_line_end = ["$"]
-move_first_line = ["gg"]
-move_last_line = ["x"]
+move_word_prev = ["b"]
+move_word_end = ["e"]
+
 
 [keybindings.edit]
-exit_edit_mode = ["esc","ctrl+e"]
-delete_char_forward = ["delete"]
-delete_char_backward = ["backspace"]
-next_field = ["enter"]
-prev_field = ["shift+enter"]
-move_left = ["left"]
-move_right = ["right"]
+# BIG CHANGES NOW EXIT HANDLES EITHER IF THOSE
+# exit_edit_mode = ["esc","ctrl+e"]
+# exit_suggestion_mode = ["esc"]
+# select_suggestion = ["enter"]
+# next_field = ["enter"]
+enter_decider = ["enter"]
+exit = ["esc", "ctrl+e"]
 suggestion_down = ["ctrl+n", "tab"]
 suggestion_up = ["ctrl+p", "shift+tab"]
-select_suggestion = ["enter"]
-exit_suggestion_mode = ["esc"]
+
+### AUTOGENERATED CANVAS CONFIG
+# Required
+move_right = ["Right"]
+delete_char_backward = ["Backspace"]
+next_field = ["Tab", "Enter"]
+move_up = ["Up"]
+move_down = ["Down"]
+prev_field = ["Shift+Tab"]
+move_left = ["Left"]
+# Optional
+move_last_line = ["Ctrl+End"]
+delete_char_forward = ["Delete"]
+move_word_prev = ["Ctrl+Left"]
+# move_word_end = ["e"]
+# move_word_end_prev = ["ge"]
+move_first_line = ["Ctrl+Home"]
+move_word_next = ["Ctrl+Right"]
+move_line_start = ["Home"]
+move_line_end = ["End"]
 
 [keybindings.command]
 exit_command_mode = ["ctrl+g", "esc"]
@@ -70,7 +116,17 @@ quit = ["q"]
 force_quit = ["q!"]
 save_and_quit = ["wq"]
 revert = ["r"]
+find_file_palette_toggle = ["ff"]
+
+[editor]
+keybinding_mode = "vim"  # Options: "default", "vim", "emacs"
 
 [colors]
 theme = "dark" 
 # Options: "light", "dark", "high_contrast"
+
+
+
+
+
+

client/docs/canvas_add_functionality.md

@@ -0,0 +1,124 @@
+## How Canvas Library Custom Functionality Works
+
+### 1. **The Canvas Library Calls YOUR Custom Code First**
+
+When you call `ActionDispatcher::dispatch()`, here's what happens:
+
+```rust
+// Inside canvas library (canvas/src/actions/edit.rs):
+pub async fn execute_canvas_action<S: CanvasState>(
+    action: CanvasAction,
+    state: &mut S,
+    ideal_cursor_column: &mut usize,
+) -> Result<ActionResult> {
+    // 1. FIRST: Canvas library calls YOUR custom handler
+    if let Some(result) = state.handle_feature_action(&action, &context) {
+        return Ok(ActionResult::HandledByFeature(result)); // YOUR code handled it
+    }
+
+    // 2. ONLY IF your code returns None: Canvas handles generic actions
+    handle_generic_canvas_action(action, state, ideal_cursor_column).await
+}
+```
+
+### 2. **Your Extension Point: `handle_feature_action`**
+
+You add custom functionality by implementing `handle_feature_action` in your states:
+
+```rust
+// In src/state/pages/auth.rs
+impl CanvasState for LoginState {
+    // ... other methods ...
+
+    fn handle_feature_action(&mut self, action: &CanvasAction, context: &ActionContext) -> Option<String> {
+        match action {
+            // Custom login-specific actions
+            CanvasAction::Custom(action_str) if action_str == "submit_login" => {
+                if self.username.is_empty() || self.password.is_empty() {
+                    Some("Please fill in all required fields".to_string())
+                } else {
+                    // Trigger login process
+                    Some(format!("Logging in user: {}", self.username))
+                }
+            }
+            
+            CanvasAction::Custom(action_str) if action_str == "clear_form" => {
+                self.username.clear();
+                self.password.clear();
+                self.set_has_unsaved_changes(false);
+                Some("Login form cleared".to_string())
+            }
+
+            // Custom behavior for standard actions
+            CanvasAction::NextField => {
+                // Custom validation when moving between fields
+                if self.current_field == 0 && self.username.is_empty() {
+                    Some("Username cannot be empty".to_string())
+                } else {
+                    None // Let canvas library handle the normal field movement
+                }
+            }
+
+            // Let canvas library handle everything else
+            _ => None,
+        }
+    }
+}
+```
+
+### 3. **Multiple Ways to Add Custom Functionality**
+
+#### A) **Custom Actions via Config**
+```toml
+# In config.toml
+[keybindings.edit]
+submit_login = ["ctrl+enter"]
+clear_form = ["ctrl+r"]
+```
+
+#### B) **Override Standard Actions**
+```rust
+fn handle_feature_action(&mut self, action: &CanvasAction, context: &ActionContext) -> Option<String> {
+    match action {
+        CanvasAction::InsertChar('p') if self.current_field == 1 => {
+            // Custom behavior when typing 'p' in password field
+            Some("Password field - use secure input".to_string())
+        }
+        _ => None, // Let canvas handle normally
+    }
+}
+```
+
+#### C) **Context-Aware Logic**
+```rust
+fn handle_feature_action(&mut self, action: &CanvasAction, context: &ActionContext) -> Option<String> {
+    match action {
+        CanvasAction::MoveDown => {
+            // Custom logic based on current state
+            if context.current_field == 1 && context.current_input.len() < 8 {
+                Some("Password should be at least 8 characters".to_string())
+            } else {
+                None // Normal field movement
+            }
+        }
+        _ => None,
+    }
+}
+```
+
+## The Canvas Library Philosophy
+
+**Canvas Library = Generic behavior + Your extension points**
+
+- ✅ **Canvas handles**: Character insertion, cursor movement, field navigation, etc.
+- ✅ **You handle**: Validation, submission, clearing, app-specific logic
+- ✅ **You decide**: Return `Some(message)` to override, `None` to use canvas default
+
+## Summary
+
+You **don't communicate with the library elsewhere**. Instead:
+
+1. **Canvas library calls your code first** via `handle_feature_action`
+2. **Your code decides** whether to handle the action or let canvas handle it
+3. **Canvas library handles** generic form behavior when you return `None`
+

client/src/bottom_panel/command_line.rs

@@ -0,0 +1,69 @@
+// src/components/common/command_line.rs
+
+use ratatui::{
+    widgets::{Block, Paragraph},
+    style::Style,
+    layout::Rect,
+    Frame,
+};
+use crate::config::colors::themes::Theme;
+use unicode_width::UnicodeWidthStr; // Import for width calculation
+
+pub fn render_command_line(
+    f: &mut Frame,
+    area: Rect,
+    input: &str,    // This is event_handler.command_input
+    active: bool,   // This is event_handler.command_mode
+    theme: &Theme,
+    message: &str,  // This is event_handler.command_message
+) {
+    // Original logic for determining display_text
+    let display_text = if !active {
+        // If not in normal command mode, but there's a message (e.g. from Find File palette closing)
+        // Or if command mode is off and message is empty (render minimally)
+        if message.is_empty() {
+            "".to_string() // Render an empty string, background will cover
+        } else {
+            message.to_string()
+        }
+    } else { // active is true (normal command mode)
+        let prompt = ":";
+        if message.is_empty() || message == ":" {
+            format!("{}{}", prompt, input)
+        } else {
+            if input.is_empty() { // If command was just executed, input is cleared, show message
+                message.to_string()
+            } else { // Show input and message
+                format!("{}{} | {}", prompt, input, message)
+            }
+        }
+    };
+
+    let content_width = UnicodeWidthStr::width(display_text.as_str());
+    let available_width = area.width as usize;
+    let padding_needed = available_width.saturating_sub(content_width);
+
+    let display_text_padded = if padding_needed > 0 {
+        format!("{}{}", display_text, " ".repeat(padding_needed))
+    } else {
+        // If text is too long, ratatui's Paragraph will handle truncation.
+        // We could also truncate here if specific behavior is needed:
+        // display_text.chars().take(available_width).collect::<String>()
+        display_text
+    };
+
+    // Determine style based on active state, but apply to the whole paragraph
+    let text_style = if active {
+        Style::default().fg(theme.accent)
+    } else {
+        // If not active, but there's a message, use default foreground.
+        // If message is also empty, this style won't matter much for empty text.
+        Style::default().fg(theme.fg)
+    };
+
+    let paragraph = Paragraph::new(display_text_padded)
+        .block(Block::default().style(Style::default().bg(theme.bg))) // Block ensures bg for whole area
+        .style(text_style); // Style for the text itself
+
+    f.render_widget(paragraph, area);
+}

client/src/bottom_panel/find_file_palette.rs

@@ -0,0 +1,142 @@
+// src/bottom_panel/find_file_palette.rs
+
+use crate::config::colors::themes::Theme;
+use crate::modes::general::command_navigation::NavigationState; // Corrected path
+use ratatui::{
+    layout::{Constraint, Direction, Layout, Rect},
+    style::Style,
+    widgets::{Block, List, ListItem, Paragraph},
+    Frame,
+};
+use unicode_width::UnicodeWidthStr;
+
+const PALETTE_MAX_VISIBLE_OPTIONS: usize = 15;
+const PADDING_CHAR: &str = " ";
+
+pub fn render_find_file_palette(
+    f: &mut Frame,
+    area: Rect,
+    theme: &Theme,
+    navigation_state: &NavigationState,
+) {
+    let palette_display_input = navigation_state.get_display_input(); // Use the new method
+
+    let num_total_filtered = navigation_state.filtered_options.len();
+    let current_selected_list_idx = navigation_state.selected_index;
+
+    let mut display_start_offset = 0;
+    if num_total_filtered > PALETTE_MAX_VISIBLE_OPTIONS {
+        if let Some(sel_idx) = current_selected_list_idx {
+            if sel_idx >= display_start_offset + PALETTE_MAX_VISIBLE_OPTIONS {
+                display_start_offset = sel_idx - PALETTE_MAX_VISIBLE_OPTIONS + 1;
+            } else if sel_idx < display_start_offset {
+                display_start_offset = sel_idx;
+            }
+            display_start_offset = display_start_offset
+                .min(num_total_filtered.saturating_sub(PALETTE_MAX_VISIBLE_OPTIONS));
+        }
+    }
+    display_start_offset = display_start_offset.max(0);
+
+    let display_end_offset = (display_start_offset + PALETTE_MAX_VISIBLE_OPTIONS)
+        .min(num_total_filtered);
+
+    // navigation_state.filtered_options is Vec<(usize, String)>
+    // We only need the String part for display.
+    let visible_options_slice: Vec<&String> = if num_total_filtered > 0 {
+        navigation_state.filtered_options
+            [display_start_offset..display_end_offset]
+            .iter()
+            .map(|(_, opt_str)| opt_str)
+            .collect()
+    } else {
+        Vec::new()
+    };
+
+    let chunks = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([
+            Constraint::Length(1), // For palette input line
+            Constraint::Min(0), // For options list, take remaining space
+        ])
+        .split(area);
+    
+    // Ensure list_area height does not exceed PALETTE_MAX_VISIBLE_OPTIONS
+    let list_area_height = std::cmp::min(chunks[1].height, PALETTE_MAX_VISIBLE_OPTIONS as u16);
+    let final_list_area = Rect::new(chunks[1].x, chunks[1].y, chunks[1].width, list_area_height);
+
+
+    let input_area = chunks[0];
+    // let list_area = chunks[1]; // Use final_list_area
+
+    let prompt_prefix = match navigation_state.navigation_type {
+        crate::modes::general::command_navigation::NavigationType::FindFile => "Find File: ",
+        crate::modes::general::command_navigation::NavigationType::TableTree => "Table Path: ",
+    };
+    let base_prompt_text = format!("{}{}", prompt_prefix, palette_display_input);
+    let prompt_text_width = UnicodeWidthStr::width(base_prompt_text.as_str());
+    let input_area_width = input_area.width as usize;
+    let input_padding_needed =
+        input_area_width.saturating_sub(prompt_text_width);
+
+    let padded_prompt_text = if input_padding_needed > 0 {
+        format!(
+            "{}{}",
+            base_prompt_text,
+            PADDING_CHAR.repeat(input_padding_needed)
+        )
+    } else {
+        base_prompt_text
+    };
+
+    let input_paragraph = Paragraph::new(padded_prompt_text)
+        .style(Style::default().fg(theme.accent).bg(theme.bg));
+    f.render_widget(input_paragraph, input_area);
+
+    let mut display_list_items: Vec<ListItem> =
+        Vec::with_capacity(PALETTE_MAX_VISIBLE_OPTIONS);
+
+    for (idx_in_visible_slice, opt_str) in
+        visible_options_slice.iter().enumerate()
+    {
+        // The selected_index in navigation_state is relative to the full filtered_options list.
+        // We need to check if the current item (from the visible slice) corresponds to the selected_index.
+        let original_filtered_idx = display_start_offset + idx_in_visible_slice;
+        let is_selected =
+            current_selected_list_idx == Some(original_filtered_idx);
+
+        let style = if is_selected {
+            Style::default().fg(theme.bg).bg(theme.accent)
+        } else {
+            Style::default().fg(theme.fg).bg(theme.bg)
+        };
+
+        let opt_width = opt_str.width() as u16;
+        let list_item_width = final_list_area.width;
+        let padding_amount = list_item_width.saturating_sub(opt_width);
+        let padded_opt_str = format!(
+            "{}{}",
+            opt_str,
+            PADDING_CHAR.repeat(padding_amount as usize)
+        );
+        display_list_items.push(ListItem::new(padded_opt_str).style(style));
+    }
+
+    // Fill remaining lines in the list area to maintain fixed height appearance
+    let num_rendered_options = display_list_items.len();
+    if num_rendered_options < PALETTE_MAX_VISIBLE_OPTIONS && (final_list_area.height as usize) > num_rendered_options {
+        for _ in num_rendered_options..(final_list_area.height as usize) {
+            let empty_padded_str =
+                PADDING_CHAR.repeat(final_list_area.width as usize);
+            display_list_items.push(
+                ListItem::new(empty_padded_str)
+                    .style(Style::default().fg(theme.bg).bg(theme.bg)),
+            );
+        }
+    }
+
+
+    let options_list_widget = List::new(display_list_items)
+        .block(Block::default().style(Style::default().bg(theme.bg)));
+    f.render_widget(options_list_widget, final_list_area);
+}

client/src/bottom_panel/layout.rs

@@ -0,0 +1,98 @@
+// src/bottom_panel/layout.rs
+
+use ratatui::{layout::Constraint, layout::Rect, Frame};
+use crate::bottom_panel::{status_line::render_status_line, command_line::render_command_line};
+use crate::bottom_panel::find_file_palette;
+use crate::config::colors::themes::Theme;
+use crate::modes::general::command_navigation::NavigationState;
+use crate::state::app::state::AppState;
+use crate::pages::routing::Router;
+
+/// Calculate the layout constraints for the bottom panel (status line + command line/palette).
+pub fn bottom_panel_constraints(
+    app_state: &AppState,
+    navigation_state: &NavigationState,
+    event_handler_command_mode_active: bool,
+) -> Vec<Constraint> {
+    let mut status_line_height = 1;
+    #[cfg(feature = "ui-debug")]
+    {
+        if let Some(debug_state) = &app_state.debug_state {
+            if debug_state.is_error {
+                status_line_height = 4;
+            }
+        }
+    }
+
+    const PALETTE_OPTIONS_HEIGHT_FOR_LAYOUT: u16 = 15;
+    let command_palette_area_height = if navigation_state.active {
+        1 + PALETTE_OPTIONS_HEIGHT_FOR_LAYOUT
+    } else if event_handler_command_mode_active {
+        1
+    } else {
+        0
+    };
+
+    let mut constraints = vec![Constraint::Length(status_line_height)];
+    if command_palette_area_height > 0 {
+        constraints.push(Constraint::Length(command_palette_area_height));
+    }
+    constraints
+}
+
+/// Render the bottom panel (status line + command line/palette).
+pub fn render_bottom_panel(
+    f: &mut Frame,
+    root_chunks: &[Rect],
+    chunk_idx: &mut usize,
+    current_dir: &str,
+    theme: &Theme,
+    current_fps: f64,
+    app_state: &AppState,
+    router: &Router,
+    navigation_state: &NavigationState,
+    event_handler_command_input: &str,
+    event_handler_command_mode_active: bool,
+    event_handler_command_message: &str,
+) {
+    // --- Status line area ---
+    let status_line_area = root_chunks[*chunk_idx];
+    *chunk_idx += 1;
+
+    // --- Command line / palette area ---
+    let command_render_area = if root_chunks.len() > *chunk_idx {
+        Some(root_chunks[*chunk_idx])
+    } else {
+        None
+    };
+    if command_render_area.is_some() {
+        *chunk_idx += 1;
+    }
+
+    // --- Render status line ---
+    render_status_line(
+        f,
+        status_line_area,
+        current_dir,
+        theme,
+        current_fps,
+        app_state,
+        router,
+    );
+
+    // --- Render command line or palette ---
+    if let Some(area) = command_render_area {
+        if navigation_state.active {
+            find_file_palette::render_find_file_palette(f, area, theme, navigation_state);
+        } else if event_handler_command_mode_active {
+            render_command_line(
+                f,
+                area,
+                event_handler_command_input,
+                true,
+                theme,
+                event_handler_command_message,
+            );
+        }
+    }
+}

client/src/bottom_panel/mod.rs

@@ -0,0 +1,6 @@
+// src/bottom_panel/mod.rs
+
+pub mod status_line; 
+pub mod command_line;
+pub mod layout;
+pub mod find_file_palette;

client/src/bottom_panel/status_line.rs

@@ -0,0 +1,169 @@
+// client/src/components/common/status_line.rs
+use crate::config::colors::themes::Theme;
+use crate::state::app::state::AppState;
+use ratatui::{
+    layout::Rect,
+    style::Style,
+    text::{Line, Span, Text},
+    widgets::{Paragraph, Wrap},
+    Frame,
+};
+use crate::pages::routing::Page;
+use crate::pages::routing::Router;
+use std::path::Path;
+use unicode_width::UnicodeWidthStr;
+
+pub fn render_status_line(
+    f: &mut Frame,
+    area: Rect,
+    current_dir: &str,
+    theme: &Theme,
+    current_fps: f64,
+    app_state: &AppState,
+    router: &Router,
+) {
+    #[cfg(feature = "ui-debug")]
+    {
+        if let Some(debug_state) = &app_state.debug_state {
+            let paragraph = if debug_state.is_error {
+                // --- THIS IS THE CRITICAL LOGIC FOR ERRORS ---
+                // 1. Create a `Text` object, which can contain multiple lines.
+                let error_text = Text::from(debug_state.displayed_message.clone());
+
+                // 2. Create a Paragraph from the Text and TELL IT TO WRAP.
+                Paragraph::new(error_text)
+                    .wrap(Wrap { trim: true }) // This line makes the text break into new rows.
+                    .style(Style::default().bg(theme.highlight).fg(theme.bg))
+            } else {
+                // --- This is for normal, single-line info messages ---
+                Paragraph::new(debug_state.displayed_message.as_str())
+                    .style(Style::default().fg(theme.accent).bg(theme.bg))
+            };
+            f.render_widget(paragraph, area);
+        } else {
+            // Fallback for when debug state is None
+            let paragraph = Paragraph::new("").style(Style::default().bg(theme.bg));
+            f.render_widget(paragraph, area);
+        }
+        return; // Stop here and don't render the normal status line.
+    }
+
+    // --- The normal status line rendering logic (unchanged) ---
+    let program_info = format!("komp_ac v{}", env!("CARGO_PKG_VERSION"));
+    let mode_text = if let Page::Form(path) = &router.current {
+        if let Some(editor) = app_state.editor_for_path_ref(path) {
+            match editor.mode() {
+                canvas::AppMode::Edit => "[EDIT]",
+                canvas::AppMode::ReadOnly => "[READ-ONLY]",
+                canvas::AppMode::Highlight => "[VISUAL]",
+                _ => "",
+            }
+        } else {
+            ""
+        }
+    } else {
+        "" // No canvas active
+    };    
+
+    let home_dir = dirs::home_dir()
+        .map(|p| p.to_string_lossy().into_owned())
+        .unwrap_or_default();
+    let display_dir = if current_dir.starts_with(&home_dir) {
+        current_dir.replacen(&home_dir, "~", 1)
+    } else {
+        current_dir.to_string()
+    };
+
+    let available_width = area.width as usize;
+    let mode_width = UnicodeWidthStr::width(mode_text);
+    let program_info_width = UnicodeWidthStr::width(program_info.as_str());
+    let fps_text = format!("{:.0} FPS", current_fps);
+    let fps_width = UnicodeWidthStr::width(fps_text.as_str());
+    let separator = " | ";
+    let separator_width = UnicodeWidthStr::width(separator);
+
+    let fixed_width_with_fps = mode_width
+        + separator_width
+        + separator_width
+        + program_info_width
+        + separator_width
+        + fps_width;
+
+    let show_fps = fixed_width_with_fps <= available_width;
+
+    let remaining_width_for_dir = available_width.saturating_sub(
+        mode_width
+            + separator_width
+            + separator_width
+            + program_info_width
+            + (if show_fps {
+                separator_width + fps_width
+            } else {
+                0
+            }),
+    );
+
+    let dir_display_text_str = if UnicodeWidthStr::width(display_dir.as_str())
+        <= remaining_width_for_dir
+    {
+        display_dir
+    } else {
+        let dir_name = Path::new(current_dir)
+            .file_name()
+            .and_then(|n| n.to_str())
+            .unwrap_or(current_dir);
+        if UnicodeWidthStr::width(dir_name) <= remaining_width_for_dir {
+            dir_name.to_string()
+        } else {
+            dir_name
+                .chars()
+                .take(remaining_width_for_dir)
+                .collect::<String>()
+        }
+    };
+
+    let mut current_content_width = mode_width
+        + separator_width
+        + UnicodeWidthStr::width(dir_display_text_str.as_str())
+        + separator_width
+        + program_info_width;
+    if show_fps {
+        current_content_width += separator_width + fps_width;
+    }
+
+    let mut line_spans = vec![
+        Span::styled(mode_text, Style::default().fg(theme.accent)),
+        Span::styled(separator, Style::default().fg(theme.border)),
+        Span::styled(
+            dir_display_text_str.as_str(),
+            Style::default().fg(theme.fg),
+        ),
+        Span::styled(separator, Style::default().fg(theme.border)),
+        Span::styled(
+            program_info.as_str(),
+            Style::default().fg(theme.secondary),
+        ),
+    ];
+
+    if show_fps {
+        line_spans
+            .push(Span::styled(separator, Style::default().fg(theme.border)));
+        line_spans.push(Span::styled(
+            fps_text.as_str(),
+            Style::default().fg(theme.secondary),
+        ));
+    }
+
+    let padding_needed = available_width.saturating_sub(current_content_width);
+    if padding_needed > 0 {
+        line_spans.push(Span::styled(
+            " ".repeat(padding_needed),
+            Style::default().bg(theme.bg),
+        ));
+    }
+
+    let paragraph =
+        Paragraph::new(Line::from(line_spans)).style(Style::default().bg(theme.bg));
+
+    f.render_widget(paragraph, area);
+}

client/src/buffer/functions.rs

@@ -0,0 +1,35 @@
+// src/buffer/functions/buffer.rs
+
+use crate::buffer::state::BufferState;
+use crate::buffer::state::AppView;
+
+pub fn get_view_layer(view: &AppView) -> u8 {
+    match view {
+        AppView::Intro => 1,
+        AppView::Login | AppView::Register | AppView::Admin | AppView::AddTable | AppView::AddLogic => 2,
+        AppView::Form(_) | AppView::Scratch => 3,
+    }
+}
+
+/// Switches the active buffer index.
+pub fn switch_buffer(buffer_state: &mut BufferState, next: bool) -> bool {
+    if buffer_state.history.len() <= 1 {
+        return false;
+    }
+
+    let len = buffer_state.history.len();
+    let current_index = buffer_state.active_index;
+    let new_index = if next {
+        (current_index + 1) % len
+    } else {
+        (current_index + len - 1) % len
+    };
+
+    if new_index != current_index {
+        buffer_state.active_index = new_index;
+        true
+    } else {
+        false
+    }
+}
+

client/src/buffer/logic.rs

@@ -0,0 +1,20 @@
+// src/buffer/logic.rs
+use crossterm::event::{KeyCode, KeyModifiers};
+use crate::config::binds::config::Config;
+use crate::state::app::state::UiState;
+
+/// Toggle the buffer list visibility based on keybindings.
+pub fn toggle_buffer_list(
+    ui_state: &mut UiState,
+    config: &Config,
+    key: KeyCode,
+    modifiers: KeyModifiers,
+) -> bool {
+    if let Some(action) = config.get_common_action(key, modifiers) {
+        if action == "toggle_buffer_list" {
+            ui_state.show_buffer_list = !ui_state.show_buffer_list;
+            return true;
+        }
+    }
+    false
+}

client/src/buffer/mod.rs

@@ -0,0 +1,11 @@
+// src/buffer/mod.rs
+
+pub mod state;
+pub mod functions;
+pub mod ui;
+pub mod logic;
+
+pub use state::{AppView, BufferState};
+pub use functions::*;
+pub use ui::render_buffer_list;
+pub use logic::toggle_buffer_list;

client/src/buffer/state.rs

@@ -0,0 +1,123 @@
+// src/buffer/state/buffer.rs
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum AppView {
+    Intro,
+    Login,
+    Register,
+    Admin,
+    AddTable,
+    AddLogic,
+    Form(String),
+    Scratch,
+}
+
+impl AppView {
+    /// Returns the display name for the view.
+    /// For Form, pass the current table name to get dynamic naming.
+    pub fn display_name(&self) -> &str {
+        match self {
+            AppView::Intro => "Intro",
+            AppView::Login => "Login",
+            AppView::Register => "Register",
+            AppView::Admin => "Admin_Panel",
+            AppView::AddTable => "Add_Table",
+            AppView::AddLogic => "Add_Logic",
+            AppView::Form(_) => "Form",
+            AppView::Scratch => "*scratch*",
+        }
+    }
+
+    /// Returns the display name with dynamic context (for Form buffers)
+    pub fn display_name_with_context(&self, current_table_name: Option<&str>) -> String {
+        match self {
+            AppView::Form(path) => {
+                // Derive table name from "profile/table" path
+                let table = path.split('/').nth(1).unwrap_or("");
+                if !table.is_empty() {
+                    table.to_string()
+                } else {
+                    current_table_name.unwrap_or("Data Form").to_string()
+                }
+            }
+            _ => self.display_name().to_string(),
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct BufferState {
+    pub history: Vec<AppView>,
+    pub active_index: usize,
+}
+
+impl Default for BufferState {
+    fn default() -> Self {
+        Self {
+            history: vec![AppView::Intro],
+            active_index: 0,
+        }
+    }
+}
+
+impl BufferState {
+    pub fn update_history(&mut self, view: AppView) {
+        let existing_pos = self.history.iter().position(|v| v == &view);
+        match existing_pos {
+            Some(pos) => self.active_index = pos,
+            None => {
+                self.history.push(view.clone());
+                self.active_index = self.history.len() - 1;
+            }
+        }
+    }
+
+    pub fn get_active_view(&self) -> Option<&AppView> {
+        self.history.get(self.active_index)
+    }
+
+    pub fn close_active_buffer(&mut self) -> bool {
+        if self.history.is_empty() {
+            self.history.push(AppView::Intro);
+            self.active_index = 0;
+            return false;
+        }
+
+        let current_index = self.active_index;
+        self.history.remove(current_index);
+
+        if self.history.is_empty() {
+            self.history.push(AppView::Intro);
+            self.active_index = 0;
+        } else if self.active_index >= self.history.len() {
+            self.active_index = self.history.len() - 1;
+        }
+        true
+    }
+
+    pub fn close_buffer_with_intro_fallback(&mut self, current_table_name: Option<&str>) -> String {
+        let current_view_cloned = self.get_active_view().cloned();
+
+        if let Some(AppView::Intro) = current_view_cloned {
+            if self.history.len() == 1 {
+                self.close_active_buffer();
+                return "Intro buffer reset".to_string();
+            }
+        }
+
+        let closed_name = current_view_cloned
+            .as_ref()
+            .map(|v| v.display_name_with_context(current_table_name))
+            .unwrap_or_else(|| "Unknown".to_string());
+
+        if self.close_active_buffer() {
+            if self.history.len() == 1 && matches!(self.history.get(0), Some(AppView::Intro)) {
+                format!("Closed '{}' - returned to Intro", closed_name)
+            } else {
+                format!("Closed '{}'", closed_name)
+            }
+        } else {
+            format!("Buffer '{}' could not be closed", closed_name)
+        }
+    }
+}

client/src/buffer/ui.rs

@@ -1,20 +1,23 @@
-// src/components/handlers/buffer_list.rs
+// src/buffer/ui.rs
 
 use crate::config::colors::themes::Theme;
-use crate::state::app::state::AppState;
+use crate::buffer::state::BufferState;
+use crate::state::app::state::AppState;  // Add this import
 use ratatui::{
     layout::{Alignment, Rect},
-    style::{Style, Stylize},
+    style::Style,
     text::{Line, Span},
     widgets::Paragraph,
     Frame,
 };
 use unicode_width::UnicodeWidthStr;
+use crate::buffer::functions::get_view_layer;
 
 pub fn render_buffer_list(
     f: &mut Frame,
     area: Rect,
     theme: &Theme,
+    buffer_state: &BufferState,
     app_state: &AppState,
 ) {
     // --- Style Definitions ---
@@ -26,14 +29,26 @@ pub fn render_buffer_list(
         .fg(theme.fg)
         .bg(theme.bg);
 
+    // --- Determine Active Layer ---
+    let active_layer = match buffer_state.history.get(buffer_state.active_index) {
+        Some(view) => get_view_layer(view),
+        None => 1,
+    };
+
     // --- Create Spans ---
     let mut spans = Vec::new();
-    let history = &app_state.ui.buffer_history;
     let mut current_width = 0;
 
-    for (i, view) in history.iter().enumerate() {
-        let is_active = i == app_state.ui.active_buffer_index;
-        let buffer_name = view.display_name();
+    let current_table_name = app_state.current_view_table_name.as_deref();
+
+    for (original_index, view) in buffer_state.history.iter().enumerate() {
+        // Filter: Only process views matching the active layer
+        if get_view_layer(view) != active_layer {
+            continue;
+        }
+
+        let is_active = original_index == buffer_state.active_index;
+        let buffer_name = view.display_name_with_context(current_table_name);
         let buffer_text = format!(" {} ", buffer_name);
         let text_width = UnicodeWidthStr::width(buffer_text.as_str());
 
@@ -51,10 +66,12 @@ pub fn render_buffer_list(
 
     // --- Filler Span ---
     let remaining_width = area.width.saturating_sub(current_width as u16);
-    spans.push(Span::styled(
-        " ".repeat(remaining_width as usize),
-        inactive_style,
-    ));
+    if !spans.is_empty() || remaining_width > 0 {
+        spans.push(Span::styled(
+                " ".repeat(remaining_width as usize),
+                inactive_style,
+        ));
+    }
 
     // --- Render ---
     let buffer_line = Line::from(spans);

client/src/components/admin.rs

@@ -1,4 +0,0 @@
-// src/components/admin.rs
-pub mod admin_panel;
-
-pub use admin_panel::*;

client/src/components/auth.rs

@@ -1,6 +0,0 @@
-// src/components/form.rs
-pub mod login;
-pub mod register;
-
-pub use login::*;
-pub use register::*;

client/src/components/common.rs

@@ -1,12 +1,9 @@
 // src/components/common.rs
-pub mod command_line;
-pub mod status_line;
+
+pub mod text_editor;
 pub mod background;
-pub mod dialog;
 pub mod autocomplete;
 
-pub use command_line::*;
-pub use status_line::*;
+pub use text_editor::*;
 pub use background::*;
-pub use dialog::*;
 pub use autocomplete::*;

client/src/components/common/autocomplete.rs

@@ -1,6 +1,8 @@
 // src/components/common/autocomplete.rs
 
 use crate::config::colors::themes::Theme;
+use common::proto::komp_ac::search::search_response::Hit;
+use crate::pages::forms::FormState;
 use ratatui::{
     layout::Rect,
     style::{Color, Modifier, Style},
@@ -9,7 +11,8 @@ use ratatui::{
 };
 use unicode_width::UnicodeWidthStr;
 
-/// Renders an opaque dropdown list for autocomplete suggestions.
+/// Renders an opaque dropdown list for simple string-based suggestions.
+/// THIS IS THE RESTORED FUNCTION.
 pub fn render_autocomplete_dropdown(
     f: &mut Frame,
     input_rect: Rect,
@@ -21,39 +24,32 @@ pub fn render_autocomplete_dropdown(
     if suggestions.is_empty() {
         return;
     }
-    // --- Calculate Dropdown Size & Position ---
-    let max_suggestion_width = suggestions.iter().map(|s| s.width()).max().unwrap_or(0) as u16;
+    let max_suggestion_width =
+        suggestions.iter().map(|s| s.width()).max().unwrap_or(0) as u16;
     let horizontal_padding: u16 = 2;
     let dropdown_width = (max_suggestion_width + horizontal_padding).max(10);
     let dropdown_height = (suggestions.len() as u16).min(5);
 
     let mut dropdown_area = Rect {
-        x: input_rect.x, // Align horizontally with input
-        y: input_rect.y + 1, // Position directly below input
+        x: input_rect.x,
+        y: input_rect.y + 1,
         width: dropdown_width,
         height: dropdown_height,
     };
 
-    // --- Clamping Logic (prevent rendering off-screen) ---
-    // Clamp vertically (if it goes below the frame)
     if dropdown_area.bottom() > frame_area.height {
-        dropdown_area.y = input_rect.y.saturating_sub(dropdown_height); // Try rendering above
+        dropdown_area.y = input_rect.y.saturating_sub(dropdown_height);
     }
-    // Clamp horizontally (if it goes past the right edge)
     if dropdown_area.right() > frame_area.width {
         dropdown_area.x = frame_area.width.saturating_sub(dropdown_width);
     }
-    // Ensure x is not negative (if clamping pushes it left)
     dropdown_area.x = dropdown_area.x.max(0);
-    // Ensure y is not negative (if clamping pushes it up)
     dropdown_area.y = dropdown_area.y.max(0);
-    // --- End Clamping ---
 
-    // Render a solid background block first to ensure opacity
-    let background_block = Block::default().style(Style::default().bg(Color::DarkGray));
+    let background_block =
+        Block::default().style(Style::default().bg(Color::DarkGray));
     f.render_widget(background_block, dropdown_area);
 
-    // Create list items, ensuring each has a defined background
     let items: Vec<ListItem> = suggestions
         .iter()
         .enumerate()
@@ -61,30 +57,97 @@ pub fn render_autocomplete_dropdown(
             let is_selected = selected_index == Some(i);
             let s_width = s.width() as u16;
             let padding_needed = dropdown_width.saturating_sub(s_width);
-            let padded_s = format!("{}{}", s, " ".repeat(padding_needed as usize));
+            let padded_s =
+                format!("{}{}", s, " ".repeat(padding_needed as usize));
 
             ListItem::new(padded_s).style(if is_selected {
                 Style::default()
-                    .fg(theme.bg) // Text color on highlight
-                    .bg(theme.highlight) // Highlight background
+                    .fg(theme.bg)
+                    .bg(theme.highlight)
                     .add_modifier(Modifier::BOLD)
             } else {
-                // Style for non-selected items (matching background block)
-                Style::default()
-                    .fg(theme.fg) // Text color on gray
-                    .bg(Color::DarkGray) // Explicit gray background
+                Style::default().fg(theme.fg).bg(Color::DarkGray)
             })
         })
         .collect();
 
-    // Create the list widget (without its own block)
     let list = List::new(items);
-
-    // State for managing selection highlight (still needed for logic)
     let mut list_state = ListState::default();
     list_state.select(selected_index);
 
-    // Render the list statefully *over* the background block
     f.render_stateful_widget(list, dropdown_area, &mut list_state);
 }
 
+/// Renders an opaque dropdown list for rich `Hit`-based suggestions.
+/// RENAMED from render_rich_autocomplete_dropdown
+pub fn render_hit_autocomplete_dropdown(
+    f: &mut Frame,
+    input_rect: Rect,
+    frame_area: Rect,
+    theme: &Theme,
+    suggestions: &[Hit],
+    selected_index: Option<usize>,
+    form_state: &FormState,
+) {
+    if suggestions.is_empty() {
+        return;
+    }
+
+    let display_names: Vec<String> = suggestions
+        .iter()
+        .map(|hit| form_state.get_display_name_for_hit(hit))
+        .collect();
+
+    let max_suggestion_width =
+        display_names.iter().map(|s| s.width()).max().unwrap_or(0) as u16;
+    let horizontal_padding: u16 = 2;
+    let dropdown_width = (max_suggestion_width + horizontal_padding).max(10);
+    let dropdown_height = (suggestions.len() as u16).min(5);
+
+    let mut dropdown_area = Rect {
+        x: input_rect.x,
+        y: input_rect.y + 1,
+        width: dropdown_width,
+        height: dropdown_height,
+    };
+
+    if dropdown_area.bottom() > frame_area.height {
+        dropdown_area.y = input_rect.y.saturating_sub(dropdown_height);
+    }
+    if dropdown_area.right() > frame_area.width {
+        dropdown_area.x = frame_area.width.saturating_sub(dropdown_width);
+    }
+    dropdown_area.x = dropdown_area.x.max(0);
+    dropdown_area.y = dropdown_area.y.max(0);
+
+    let background_block =
+        Block::default().style(Style::default().bg(Color::DarkGray));
+    f.render_widget(background_block, dropdown_area);
+
+    let items: Vec<ListItem> = display_names
+        .iter()
+        .enumerate()
+        .map(|(i, s)| {
+            let is_selected = selected_index == Some(i);
+            let s_width = s.width() as u16;
+            let padding_needed = dropdown_width.saturating_sub(s_width);
+            let padded_s =
+                format!("{}{}", s, " ".repeat(padding_needed as usize));
+
+            ListItem::new(padded_s).style(if is_selected {
+                Style::default()
+                    .fg(theme.bg)
+                    .bg(theme.highlight)
+                    .add_modifier(Modifier::BOLD)
+            } else {
+                Style::default().fg(theme.fg).bg(Color::DarkGray)
+            })
+        })
+        .collect();
+
+    let list = List::new(items);
+    let mut list_state = ListState::default();
+    list_state.select(selected_index);
+
+    f.render_stateful_widget(list, dropdown_area, &mut list_state);
+}

client/src/components/common/command_line.rs

@@ -1,35 +0,0 @@
-// src/client/components/command_line.rs
-use ratatui::{
-    widgets::{Block, Paragraph},
-    style::Style,
-    layout::Rect,
-    Frame,
-};
-use crate::config::colors::themes::Theme;
-
-pub fn render_command_line(f: &mut Frame, area: Rect, input: &str, active: bool, theme: &Theme, message: &str) {
-    let prompt = if active {
-        ":"
-    } else {
-        ""
-    };
-
-    // Combine the prompt, input, and message
-    let display_text = if message.is_empty() {
-        format!("{}{}", prompt, input)
-    } else {
-        format!("{}{} | {}", prompt, input, message)
-    };
-
-    let style = if active {
-        Style::default().fg(theme.accent)
-    } else {
-        Style::default().fg(theme.fg)
-    };
-
-    let paragraph = Paragraph::new(display_text)
-        .block(Block::default().style(Style::default().bg(theme.bg)))
-        .style(style);
-
-    f.render_widget(paragraph, area);
-}

client/src/components/common/dialog.rs

@@ -1,171 +0,0 @@
-use crate::config::colors::themes::Theme;
-use ratatui::{
-    layout::{Constraint, Direction, Layout, Margin, Rect},
-    prelude::Alignment,
-    style::{Modifier, Style},
-    text::{Line, Span, Text},
-    widgets::{Block, BorderType, Borders, Paragraph, Clear},
-    Frame,
-};
-use unicode_segmentation::UnicodeSegmentation; // For grapheme clusters
-use unicode_width::UnicodeWidthStr; // For accurate width calculation
-
-pub fn render_dialog(
-    f: &mut Frame,
-    area: Rect,
-    theme: &Theme,
-    dialog_title: &str,
-    dialog_message: &str,
-    dialog_buttons: &[String],
-    dialog_active_button_index: usize,
-) {
-    // Calculate required height based on the actual number of lines in the message
-    let message_lines: Vec<_> = dialog_message.lines().collect();
-    let message_height = message_lines.len() as u16;
-    let button_row_height = if dialog_buttons.is_empty() { 0 } else { 3 };
-    let vertical_padding = 2; // Block borders (top/bottom)
-    let inner_vertical_margin = 2; // Margin inside block (top/bottom)
-
-    // Calculate required height based on actual message lines
-    let required_inner_height =
-        message_height + button_row_height + inner_vertical_margin;
-    let required_total_height = required_inner_height + vertical_padding;
-
-    // Use a fixed percentage width, clamped to min/max
-    let width_percentage: u16 = 60;
-    let dialog_width = (area.width * width_percentage / 100)
-        .max(20) // Minimum width
-        .min(area.width); // Maximum width
-
-    // Ensure height doesn't exceed available area
-    let dialog_height = required_total_height.min(area.height);
-
-    // Calculate centered area manually
-    let dialog_x = area.x + (area.width.saturating_sub(dialog_width)) / 2;
-    let dialog_y = area.y + (area.height.saturating_sub(dialog_height)) / 2;
-    let dialog_area = Rect::new(dialog_x, dialog_y, dialog_width, dialog_height);
-
-    // Clear the area first before drawing the dialog
-    f.render_widget(Clear, dialog_area);
-
-    let block = Block::default()
-        .borders(Borders::ALL)
-        .border_type(BorderType::Rounded)
-        .border_style(Style::default().fg(theme.accent))
-        .title(format!(" {} ", dialog_title)) // Add padding to title
-        .style(Style::default().bg(theme.bg));
-
-    f.render_widget(block, dialog_area);
-
-    // Calculate inner area *after* defining the block
-    let inner_area = dialog_area.inner(Margin {
-        horizontal: 2, // Left/Right padding inside border
-        vertical: 1,   // Top/Bottom padding inside border
-    });
-
-    // Layout for Message and Buttons based on actual message height
-    let mut constraints = vec![
-        // Allocate space for message, ensuring at least 1 line height
-        Constraint::Length(message_height.max(1)), // Use actual calculated height
-    ];
-    if button_row_height > 0 {
-        constraints.push(Constraint::Length(button_row_height));
-    }
-
-    let chunks = Layout::default()
-        .direction(Direction::Vertical)
-        .constraints(constraints)
-        .split(inner_area);
-
-    // Render Message
-    let available_width = inner_area.width as usize;
-    let ellipsis = "...";
-    let ellipsis_width = UnicodeWidthStr::width(ellipsis);
-
-    let processed_lines: Vec<Line> =
-        message_lines
-            .into_iter()
-            .map(|line| {
-                let line_width = UnicodeWidthStr::width(line);
-                if line_width > available_width {
-                    // Truncate with ellipsis
-                    let mut truncated_len = 0;
-                    let mut current_width = 0;
-                    // Iterate over graphemes to handle multi-byte characters correctly
-                    for (idx, grapheme) in line.grapheme_indices(true) {
-                        let grapheme_width = UnicodeWidthStr::width(grapheme);
-                        if current_width + grapheme_width > available_width.saturating_sub(ellipsis_width) {
-                            break; // Stop before exceeding width needed for text + ellipsis
-                        }
-                        current_width += grapheme_width;
-                        truncated_len = idx + grapheme.len(); // Store the byte index of the end of the last fitting grapheme
-                    }
-                    let truncated_line = format!("{}{}", &line[..truncated_len], ellipsis);
-                    Line::from(Span::styled(truncated_line, Style::default().fg(theme.fg)))
-                } else {
-                    // Line fits, use it as is
-                    Line::from(Span::styled(line, Style::default().fg(theme.fg)))
-                }
-            })
-            .collect();
-
-    let message_paragraph =
-        Paragraph::new(Text::from(processed_lines)).alignment(Alignment::Center);
-    // Render message in the first chunk
-    f.render_widget(message_paragraph, chunks[0]);
-
-    // Render Buttons if they exist and there's a chunk for them
-    if !dialog_buttons.is_empty() && chunks.len() > 1 {
-        let button_area = chunks[1];
-        let button_count = dialog_buttons.len();
-
-        // Use Ratio for potentially more even distribution with few buttons
-        let button_constraints = std::iter::repeat(Constraint::Ratio(
-            1,
-            button_count as u32,
-        ))
-        .take(button_count)
-        .collect::<Vec<_>>();
-
-        let button_chunks = Layout::default()
-            .direction(Direction::Horizontal)
-            .constraints(button_constraints)
-            .horizontal_margin(1) // Add space between buttons
-            .split(button_area);
-
-        for (i, button_label) in dialog_buttons.iter().enumerate() {
-            // Ensure we don't try to render into a non-existent chunk
-            if i >= button_chunks.len() {
-                break;
-            }
-
-            let is_active = i == dialog_active_button_index;
-            let (button_style, border_style) = if is_active {
-                (
-                    Style::default()
-                        .fg(theme.highlight)
-                        .add_modifier(Modifier::BOLD),
-                    Style::default().fg(theme.accent), // Highlight border
-                )
-            } else {
-                (
-                    Style::default().fg(theme.fg),
-                    Style::default().fg(theme.border), // Normal border
-                )
-            };
-
-            let button_block = Block::default()
-                .borders(Borders::ALL)
-                .border_type(BorderType::Plain)
-                .border_style(border_style);
-
-            f.render_widget(
-                Paragraph::new(button_label.as_str())
-                    .block(button_block)
-                    .style(button_style)
-                    .alignment(Alignment::Center),
-                button_chunks[i],
-            );
-        }
-    }
-}

client/src/components/common/status_line.rs

@@ -1,80 +0,0 @@
-// src/client/components/handlers/status_line.rs
-use ratatui::{
-    widgets::Paragraph,
-    style::Style,
-    layout::Rect,
-    Frame,
-    text::{Line, Span},
-};
-use crate::config::colors::themes::Theme;
-use std::path::Path;
-
-pub fn render_status_line(
-    f: &mut Frame,
-    area: Rect,
-    current_dir: &str,
-    theme: &Theme,
-    is_edit_mode: bool,
-) {
-    // Program name and version
-    let program_info = format!("multieko2 v{}", env!("CARGO_PKG_VERSION"));
-
-    let mode_text = if is_edit_mode {
-        "[EDIT]"
-    } else {
-        "[READ-ONLY]"
-    };
-
-    // Shorten the current directory path
-    let home_dir = dirs::home_dir().map(|p| p.to_string_lossy().into_owned()).unwrap_or_default();
-    let display_dir = if current_dir.starts_with(&home_dir) {
-        current_dir.replacen(&home_dir, "~", 1)
-    } else {
-        current_dir.to_string()
-    };
-
-    // Create the full status line text
-    let full_text = format!("{} | {} | {}", mode_text, display_dir, program_info);
-
-    // Check if the full text fits in the available width
-    let available_width = area.width as usize;
-    let mut display_text = if full_text.len() <= available_width {
-        // If it fits, use the full text
-        full_text
-    } else {
-        // If it doesn't fit, prioritize mode and program info, and show only the directory name
-        let dir_name = Path::new(current_dir)
-            .file_name()
-            .and_then(|n| n.to_str())
-            .unwrap_or(current_dir);
-        format!("{} | {} | {}", mode_text, dir_name, program_info)
-    };
-
-    // If even the shortened version overflows, truncate it
-    if display_text.len() > available_width {
-        display_text = display_text.chars().take(available_width).collect();
-    }
-
-    // Create the status line text using Line and Span
-    let status_line = Line::from(vec![
-        Span::styled(mode_text, Style::default().fg(theme.accent)),
-        Span::styled(" | ", Style::default().fg(theme.border)),
-        Span::styled(
-            display_text.split(" | ").nth(1).unwrap_or(""), // Directory part
-            Style::default().fg(theme.fg),
-        ),
-        Span::styled(" | ", Style::default().fg(theme.border)),
-        Span::styled(
-            program_info,
-            Style::default()
-                .fg(theme.secondary)
-                .add_modifier(ratatui::style::Modifier::BOLD),
-        ),
-    ]);
-
-    // Render the status line
-    let paragraph = Paragraph::new(status_line)
-        .style(Style::default().bg(theme.bg));
-
-    f.render_widget(paragraph, area);
-}

client/src/components/common/text_editor.rs

@@ -0,0 +1,331 @@
+// src/components/common/text_editor.rs
+use crate::config::binds::config::{EditorConfig, EditorKeybindingMode};
+use crossterm::event::{KeyEvent, KeyCode, KeyModifiers};
+use ratatui::style::{Color, Style, Modifier};
+use tui_textarea::{Input, Key, TextArea, CursorMove};
+use std::fmt;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum VimMode {
+    Normal,
+    Insert,
+    Visual,
+    Operator(char),
+}
+
+impl VimMode {
+    pub fn cursor_style(&self) -> Style {
+        let color = match self {
+            Self::Normal => Color::Reset,
+            Self::Insert => Color::LightBlue,
+            Self::Visual => Color::LightYellow,
+            Self::Operator(_) => Color::LightGreen,
+        };
+        Style::default().fg(color).add_modifier(Modifier::REVERSED)
+    }
+}
+
+impl fmt::Display for VimMode {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
+        match self {
+            Self::Normal => write!(f, "NORMAL"),
+            Self::Insert => write!(f, "INSERT"),
+            Self::Visual => write!(f, "VISUAL"),
+            Self::Operator(c) => write!(f, "OPERATOR({})", c),
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq)]
+enum Transition {
+    Nop,
+    Mode(VimMode),
+    Pending(Input),
+}
+
+#[derive(Debug, Clone)]
+pub struct VimState {
+    pub mode: VimMode,
+    pub pending: Input,
+}
+
+impl Default for VimState {
+    fn default() -> Self {
+        Self {
+            mode: VimMode::Normal,
+            pending: Input::default(),
+        }
+    }
+}
+
+impl VimState {
+    pub fn new(mode: VimMode) -> Self {
+        Self {
+            mode,
+            pending: Input::default(),
+        }
+    }
+
+    fn with_pending(self, pending: Input) -> Self {
+        Self {
+            mode: self.mode,
+            pending,
+        }
+    }
+
+    fn transition(&self, input: Input, textarea: &mut TextArea<'_>) -> Transition {
+        if input.key == Key::Null {
+            return Transition::Nop;
+        }
+
+        match self.mode {
+            VimMode::Normal | VimMode::Visual | VimMode::Operator(_) => {
+                match input {
+                    Input { key: Key::Char('h'), .. } => textarea.move_cursor(CursorMove::Back),
+                    Input { key: Key::Char('j'), .. } => textarea.move_cursor(CursorMove::Down),
+                    Input { key: Key::Char('k'), .. } => textarea.move_cursor(CursorMove::Up),
+                    Input { key: Key::Char('l'), .. } => textarea.move_cursor(CursorMove::Forward),
+                    Input { key: Key::Char('w'), .. } => textarea.move_cursor(CursorMove::WordForward),
+                    Input { key: Key::Char('e'), ctrl: false, .. } => {
+                        textarea.move_cursor(CursorMove::WordEnd);
+                        if matches!(self.mode, VimMode::Operator(_)) {
+                            textarea.move_cursor(CursorMove::Forward);
+                        }
+                    }
+                    Input { key: Key::Char('b'), ctrl: false, .. } => textarea.move_cursor(CursorMove::WordBack),
+                    Input { key: Key::Char('^'), .. } => textarea.move_cursor(CursorMove::Head),
+                    Input { key: Key::Char('$'), .. } => textarea.move_cursor(CursorMove::End),
+                    Input { key: Key::Char('0'), .. } => textarea.move_cursor(CursorMove::Head),
+                    Input { key: Key::Char('D'), .. } => {
+                        textarea.delete_line_by_end();
+                        return Transition::Mode(VimMode::Normal);
+                    }
+                    Input { key: Key::Char('C'), .. } => {
+                        textarea.delete_line_by_end();
+                        textarea.cancel_selection();
+                        return Transition::Mode(VimMode::Insert);
+                    }
+                    Input { key: Key::Char('p'), .. } => {
+                        textarea.paste();
+                        return Transition::Mode(VimMode::Normal);
+                    }
+                    Input { key: Key::Char('u'), ctrl: false, .. } => {
+                        textarea.undo();
+                        return Transition::Mode(VimMode::Normal);
+                    }
+                    Input { key: Key::Char('r'), ctrl: true, .. } => {
+                        textarea.redo();
+                        return Transition::Mode(VimMode::Normal);
+                    }
+                    Input { key: Key::Char('x'), .. } => {
+                        textarea.delete_next_char();
+                        return Transition::Mode(VimMode::Normal);
+                    }
+                    Input { key: Key::Char('i'), .. } => {
+                        textarea.cancel_selection();
+                        return Transition::Mode(VimMode::Insert);
+                    }
+                    Input { key: Key::Char('a'), .. } => {
+                        textarea.cancel_selection();
+                        textarea.move_cursor(CursorMove::Forward);
+                        return Transition::Mode(VimMode::Insert);
+                    }
+                    Input { key: Key::Char('A'), .. } => {
+                        textarea.cancel_selection();
+                        textarea.move_cursor(CursorMove::End);
+                        return Transition::Mode(VimMode::Insert);
+                    }
+                    Input { key: Key::Char('o'), .. } => {
+                        textarea.move_cursor(CursorMove::End);
+                        textarea.insert_newline();
+                        return Transition::Mode(VimMode::Insert);
+                    }
+                    Input { key: Key::Char('O'), .. } => {
+                        textarea.move_cursor(CursorMove::Head);
+                        textarea.insert_newline();
+                        textarea.move_cursor(CursorMove::Up);
+                        return Transition::Mode(VimMode::Insert);
+                    }
+                    Input { key: Key::Char('I'), .. } => {
+                        textarea.cancel_selection();
+                        textarea.move_cursor(CursorMove::Head);
+                        return Transition::Mode(VimMode::Insert);
+                    }
+                    Input { key: Key::Char('v'), ctrl: false, .. } if self.mode == VimMode::Normal => {
+                        textarea.start_selection();
+                        return Transition::Mode(VimMode::Visual);
+                    }
+                    Input { key: Key::Char('V'), ctrl: false, .. } if self.mode == VimMode::Normal => {
+                        textarea.move_cursor(CursorMove::Head);
+                        textarea.start_selection();
+                        textarea.move_cursor(CursorMove::End);
+                        return Transition::Mode(VimMode::Visual);
+                    }
+                    Input { key: Key::Esc, .. } | Input { key: Key::Char('v'), ctrl: false, .. } if self.mode == VimMode::Visual => {
+                        textarea.cancel_selection();
+                        return Transition::Mode(VimMode::Normal);
+                    }
+                    Input { key: Key::Char('g'), ctrl: false, .. } if matches!(
+                        self.pending,
+                        Input { key: Key::Char('g'), ctrl: false, .. }
+                    ) => {
+                        textarea.move_cursor(CursorMove::Top)
+                    }
+                    Input { key: Key::Char('G'), ctrl: false, .. } => textarea.move_cursor(CursorMove::Bottom),
+                    Input { key: Key::Char(c), ctrl: false, .. } if self.mode == VimMode::Operator(c) => {
+                        textarea.move_cursor(CursorMove::Head);
+                        textarea.start_selection();
+                        let cursor = textarea.cursor();
+                        textarea.move_cursor(CursorMove::Down);
+                        if cursor == textarea.cursor() {
+                            textarea.move_cursor(CursorMove::End);
+                        }
+                    }
+                    Input { key: Key::Char(op @ ('y' | 'd' | 'c')), ctrl: false, .. } if self.mode == VimMode::Normal => {
+                        textarea.start_selection();
+                        return Transition::Mode(VimMode::Operator(op));
+                    }
+                    Input { key: Key::Char('y'), ctrl: false, .. } if self.mode == VimMode::Visual => {
+                        textarea.move_cursor(CursorMove::Forward);
+                        textarea.copy();
+                        return Transition::Mode(VimMode::Normal);
+                    }
+                    Input { key: Key::Char('d'), ctrl: false, .. } if self.mode == VimMode::Visual => {
+                        textarea.move_cursor(CursorMove::Forward);
+                        textarea.cut();
+                        return Transition::Mode(VimMode::Normal);
+                    }
+                    Input { key: Key::Char('c'), ctrl: false, .. } if self.mode == VimMode::Visual => {
+                        textarea.move_cursor(CursorMove::Forward);
+                        textarea.cut();
+                        return Transition::Mode(VimMode::Insert);
+                    }
+                    // Arrow keys work in normal mode
+                    Input { key: Key::Up, .. } => textarea.move_cursor(CursorMove::Up),
+                    Input { key: Key::Down, .. } => textarea.move_cursor(CursorMove::Down),
+                    Input { key: Key::Left, .. } => textarea.move_cursor(CursorMove::Back),
+                    Input { key: Key::Right, .. } => textarea.move_cursor(CursorMove::Forward),
+                    input => return Transition::Pending(input),
+                }
+
+                // Handle the pending operator
+                match self.mode {
+                    VimMode::Operator('y') => {
+                        textarea.copy();
+                        Transition::Mode(VimMode::Normal)
+                    }
+                    VimMode::Operator('d') => {
+                        textarea.cut();
+                        Transition::Mode(VimMode::Normal)
+                    }
+                    VimMode::Operator('c') => {
+                        textarea.cut();
+                        Transition::Mode(VimMode::Insert)
+                    }
+                    _ => Transition::Nop,
+                }
+            }
+            VimMode::Insert => match input {
+                Input { key: Key::Esc, .. } | Input { key: Key::Char('c'), ctrl: true, .. } => {
+                    Transition::Mode(VimMode::Normal)
+                }
+                input => {
+                    textarea.input(input);
+                    Transition::Mode(VimMode::Insert)
+                }
+            },
+        }
+    }
+}
+
+pub struct TextEditor;
+
+impl TextEditor {
+    pub fn new_textarea(editor_config: &EditorConfig) -> TextArea<'static> {
+        let mut textarea = TextArea::default();
+
+        if editor_config.show_line_numbers {
+            textarea.set_line_number_style(Style::default().fg(Color::DarkGray));
+        }
+
+        textarea.set_tab_length(editor_config.tab_width);
+
+        textarea
+    }
+
+    pub fn handle_input(
+        textarea: &mut TextArea<'static>,
+        key_event: KeyEvent,
+        keybinding_mode: &EditorKeybindingMode,
+        vim_state: &mut VimState,
+    ) -> bool {
+        match keybinding_mode {
+            EditorKeybindingMode::Vim => {
+                Self::handle_vim_input(textarea, key_event, vim_state)
+            }
+            _ => {
+                let tui_input: Input = key_event.into();
+                textarea.input(tui_input)
+            }
+        }
+    }
+
+    fn handle_vim_input(
+        textarea: &mut TextArea<'static>,
+        key_event: KeyEvent,
+        vim_state: &mut VimState,
+    ) -> bool {
+        let input = Self::convert_key_event_to_input(key_event);
+        
+        *vim_state = match vim_state.transition(input, textarea) {
+            Transition::Mode(mode) if vim_state.mode != mode => {
+                // Update cursor style based on mode
+                textarea.set_cursor_style(mode.cursor_style());
+                VimState::new(mode)
+            }
+            Transition::Nop | Transition::Mode(_) => vim_state.clone(),
+            Transition::Pending(input) => vim_state.clone().with_pending(input),
+        };
+
+        true // Always consider input as handled in vim mode
+    }
+
+    fn convert_key_event_to_input(key_event: KeyEvent) -> Input {
+        let key = match key_event.code {
+            KeyCode::Char(c) => Key::Char(c),
+            KeyCode::Enter => Key::Enter,
+            KeyCode::Left => Key::Left,
+            KeyCode::Right => Key::Right,
+            KeyCode::Up => Key::Up,
+            KeyCode::Down => Key::Down,
+            KeyCode::Backspace => Key::Backspace,
+            KeyCode::Delete => Key::Delete,
+            KeyCode::Home => Key::Home,
+            KeyCode::End => Key::End,
+            KeyCode::PageUp => Key::PageUp,
+            KeyCode::PageDown => Key::PageDown,
+            KeyCode::Tab => Key::Tab,
+            KeyCode::Esc => Key::Esc,
+            _ => Key::Null,
+        };
+
+        Input {
+            key,
+            ctrl: key_event.modifiers.contains(KeyModifiers::CONTROL),
+            alt: key_event.modifiers.contains(KeyModifiers::ALT),
+            shift: key_event.modifiers.contains(KeyModifiers::SHIFT),
+        }
+    }
+
+    pub fn get_vim_mode_status(vim_state: &VimState) -> String {
+        vim_state.mode.to_string()
+    }
+
+    pub fn is_vim_insert_mode(vim_state: &VimState) -> bool {
+        matches!(vim_state.mode, VimMode::Insert)
+    }
+
+    pub fn is_vim_normal_mode(vim_state: &VimState) -> bool {
+        matches!(vim_state.mode, VimMode::Normal)
+    }
+}

client/src/components/form.rs

@@ -1,4 +0,0 @@
-// src/components/form.rs
-pub mod form;
-
-pub use form::*;

client/src/components/form/form.rs

@@ -1,66 +0,0 @@
-// src/components/form/form.rs
-use ratatui::{
-    widgets::{Paragraph, Block, Borders},
-    layout::{Layout, Constraint, Direction, Rect, Margin, Alignment},
-    style::Style,
-    Frame,
-};
-use crate::config::colors::themes::Theme;
-use crate::state::pages::canvas_state::CanvasState;
-use crate::components::handlers::canvas::render_canvas;
-
-pub fn render_form(
-    f: &mut Frame,
-    area: Rect,
-    form_state: &impl CanvasState,
-    fields: &[&str],
-    current_field: &usize,
-    inputs: &[&String],
-    theme: &Theme,
-    is_edit_mode: bool,
-    total_count: u64,
-    current_position: u64,
-) {
-    // Create Adresar card
-    let adresar_card = Block::default()
-        .borders(Borders::ALL)
-        .border_style(Style::default().fg(theme.border))
-        .title(" Adresar ")
-        .style(Style::default().bg(theme.bg).fg(theme.fg));
-
-    f.render_widget(adresar_card, area);
-
-    // Define inner area
-    let inner_area = area.inner(Margin {
-        horizontal: 1,
-        vertical: 1,
-    });
-
-    // Create main layout
-    let main_layout = Layout::default()
-        .direction(Direction::Vertical)
-        .constraints([
-            Constraint::Length(1),
-            Constraint::Min(1),
-        ])
-        .split(inner_area);
-
-    // Render count/position
-    let count_position_text = format!("Total: {} | Position: {}", total_count, current_position);
-    let count_para = Paragraph::new(count_position_text)
-        .style(Style::default().fg(theme.fg))
-        .alignment(Alignment::Left);
-    f.render_widget(count_para, main_layout[0]);
-
-    // Delegate input handling to canvas
-    render_canvas(
-        f,
-        main_layout[1],
-        form_state,
-        fields,
-        current_field,
-        inputs,
-        theme,
-        is_edit_mode,
-    );
-}