renamed capital lettered functions and fixed examples

.gitignore

@@ -5,3 +5,4 @@ server/tantivy_indexes
 steel_decimal/tests/property_tests.proptest-regressions
 .direnv/
 canvas/*.toml
+.aider*

canvas/CANVAS_MIGRATION.md

@@ -2,7 +2,7 @@
 
 ## 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 autocomplete features, providing better type safety and maintainability.
+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
 
@@ -10,7 +10,7 @@ This guide covers the migration from the legacy canvas library structure to the
 ```
 # Old Structure (LEGACY)
 src/
-├── state.rs              # Mixed canvas + autocomplete
+├── state.rs              # Mixed canvas + suggestions
 ├── actions/edit.rs       # Mixed concerns
 ├── gui/render.rs         # Everything together
 └── suggestions.rs        # Legacy file
@@ -21,9 +21,9 @@ src/
 │   ├── state.rs         # CanvasState trait only
 │   ├── actions/edit.rs  # Canvas actions only
 │   └── gui.rs           # Canvas rendering
-├── autocomplete/         # Rich autocomplete features
-│   ├── state.rs         # AutocompleteCanvasState trait
-│   ├── types.rs         # SuggestionItem, AutocompleteState
+├── 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
@@ -31,7 +31,7 @@ src/
 
 ### 2. **Trait Separation**
 - **CanvasState**: Core form functionality (navigation, input, validation)
-- **AutocompleteCanvasState**: Optional rich autocomplete features
+- Suggestions module: Optional dropdown suggestions support
 
 ### 3. **Rich Suggestions**
 Replaced simple string suggestions with typed, rich suggestion objects.
@@ -93,34 +93,29 @@ impl CanvasState for YourFormState {
 
 ### Step 3: Implement Rich Autocomplete (Optional)
 
-**If you want rich autocomplete features:**
+**If you want suggestions dropdown features:**
 
 ```rust
-use canvas::autocomplete::{AutocompleteCanvasState, SuggestionItem, AutocompleteState};
+use canvas::{SuggestionItem};
 
-impl AutocompleteCanvasState for YourFormState {
-    type SuggestionData = YourDataType; // e.g., Hit, CustomRecord, etc.
-
-    fn supports_autocomplete(&self, field_index: usize) -> bool {
-        // Define which fields support autocomplete
+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
     }
 
-    fn autocomplete_state(&self) -> Option<&AutocompleteState<Self::SuggestionData>> {
-        Some(&self.autocomplete)
-    }
+    // Manage your own suggestion state or rely on FormEditor APIs
 
-    fn autocomplete_state_mut(&mut self) -> Option<&mut AutocompleteState<Self::SuggestionData>> {
-        Some(&mut self.autocomplete)
-    }
+    // Manage your own suggestion state or rely on FormEditor APIs
 }
 ```
 
-**Add autocomplete field to your state:**
+**Add suggestions storage to your state (optional, if you need to persist outside the editor):**
 ```rust
 pub struct YourFormState {
     // ... existing fields
-    pub autocomplete: AutocompleteState<YourDataType>,
+    // Optional: your own suggestions cache if needed
+    // pub suggestion_cache: Vec<SuggestionItem>,
 }
 ```
 
@@ -149,9 +144,9 @@ form_state.set_autocomplete_suggestions(suggestions);
 
 **Old rendering:**
 ```rust
-// Manual autocomplete rendering
-if form_state.autocomplete_active {
-    render_autocomplete_dropdown(/* ... */);
+// Manual suggestions rendering
+if editor.is_suggestions_active() {
+    suggestions::gui::render_suggestions_dropdown(/* ... */);
 }
 ```
 
@@ -162,13 +157,12 @@ use canvas::canvas::render_canvas;
 
 let active_field_rect = render_canvas(f, area, form_state, theme, edit_mode, highlight_state);
 
-// Optional: Rich autocomplete (if implementing AutocompleteCanvasState)
-if form_state.is_autocomplete_active() {
-    if let Some(autocomplete_state) = form_state.autocomplete_state() {
-        canvas::autocomplete::render_autocomplete_dropdown(
-            f, f.area(), active_field_rect.unwrap(), theme, autocomplete_state
-        );
-    }
+// Suggestions dropdown (if active)
+if editor.is_suggestions_active() {
+    canvas::suggestions::render_suggestions_dropdown(
+        f, f.area(), active_field_rect.unwrap(), theme, &editor
+    );
+}
 }
 ```
 
@@ -181,16 +175,16 @@ form_state.deactivate_suggestions();
 
 # NEW - Option A: Add your own method
 impl YourFormState {
-    pub fn deactivate_autocomplete(&mut self) {
+    pub fn deactivate_suggestions(&mut self) {
         self.autocomplete_active = false;
         self.autocomplete_suggestions.clear();
         self.selected_suggestion_index = None;
     }
 }
-form_state.deactivate_autocomplete();
+editor.ui_state_mut().deactivate_suggestions();
 
-# NEW - Option B: Use rich autocomplete trait
-form_state.deactivate_autocomplete(); // If implementing AutocompleteCanvasState
+# NEW - Option B: Suggestions via editor APIs
+editor.ui_state_mut().deactivate_suggestions();
 ```
 
 ## Benefits of New Architecture
@@ -217,8 +211,8 @@ let suggestions: Vec<SuggestionItem<UserRecord>> = vec![
 - **Display Overrides**: Show friendly text while storing normalized data
 
 ### 4. **Future-Proof**
-- Easy to add new autocomplete features
-- Canvas features don't interfere with autocomplete
+- Easy to add new suggestion features
+- Canvas features don't interfere with suggestions
 - Modular: Use only what you need
 
 ## Advanced Features
@@ -262,7 +256,7 @@ 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 rich autocomplete or custom methods
+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
 
@@ -283,11 +277,11 @@ SuggestionItem::new(user, "John Doe (Manager)".to_string(), "123".to_string());
 
 - [ ] Updated all import paths
 - [ ] Removed legacy methods from CanvasState implementation
-- [ ] Added custom autocomplete methods if needed
-- [ ] Updated suggestion usage to SuggestionItem
+- [ ] Added custom suggestion methods if needed
+- [ ] Updated usage to SuggestionItem
 - [ ] Updated rendering calls
 - [ ] Tested form functionality
-- [ ] Tested autocomplete functionality (if using)
+- [ ] Tested suggestions functionality (if using)
 
 ## Example: Complete Migration
 
@@ -305,29 +299,25 @@ impl CanvasState for FormState {
 **After:**
 ```rust
 use canvas::canvas::{CanvasState, CanvasAction};
-use canvas::autocomplete::{AutocompleteCanvasState, SuggestionItem};
+use canvas::SuggestionItem;
 
 impl CanvasState for FormState {
-    // Only core canvas methods, no suggestion methods
+    // Only core canvas methods
     fn current_field(&self) -> usize { /* ... */ }
     fn get_current_input(&self) -> &str { /* ... */ }
     // ... other core methods only
 }
 
-impl AutocompleteCanvasState for FormState {
+// Use FormEditor + SuggestionsProvider for suggestions dropdown
     type SuggestionData = Hit;
     
-    fn supports_autocomplete(&self, field_index: usize) -> bool {
+    fn supports_suggestions(&self, field_index: usize) -> bool {
         self.fields[field_index].is_link
     }
     
-    fn autocomplete_state(&self) -> Option<&AutocompleteState<Self::SuggestionData>> {
-        Some(&self.autocomplete)
-    }
+    // Maintain suggestion state through FormEditor and DataProvider
     
-    fn autocomplete_state_mut(&mut self) -> Option<&mut AutocompleteState<Self::SuggestionData>> {
-        Some(&mut self.autocomplete)
-    }
+    // Maintain suggestion state through FormEditor and DataProvider
 }
 ```
 

canvas/Cargo.toml

@@ -30,21 +30,47 @@ tokio-test = "0.4.4"
 
 [features]
 default = []
-gui = ["ratatui"]
-autocomplete = ["tokio"]
+gui = ["ratatui", "crossterm"]
+suggestions = ["tokio"]
 cursor-style = ["crossterm"]
 validation = ["regex"]
+computed = []
 
 [[example]]
-name = "autocomplete"
-required-features = ["autocomplete", "gui"]
-path = "examples/autocomplete.rs"
+name = "suggestions"
+required-features = ["suggestions", "gui", "cursor-style"]
+path = "examples/suggestions.rs"
 
 [[example]]
-name = "canvas_gui_demo"
-required-features = ["gui"]
-path = "examples/canvas_gui_demo.rs"
+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"]
+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"]

canvas/README.md

@@ -7,7 +7,7 @@ A reusable, type-safe canvas system for building form-based TUI applications wit
 - **Type-Safe Actions**: No more string-based action names - everything is compile-time checked
 - **Generic Design**: Implement `CanvasState` once, get navigation, editing, and suggestions for free
 - **Vim-Like Experience**: Modal editing with familiar keybindings
-- **Suggestion System**: Built-in autocomplete and suggestions support
+- **Suggestion System**: Built-in suggestions dropdown support
 - **Framework Agnostic**: Works with any TUI framework or raw terminal handling
 - **Async Ready**: Full async/await support for modern Rust applications
 - **Batch Operations**: Execute multiple actions atomically
@@ -144,7 +144,7 @@ pub enum CanvasAction {
 
 ## 🔧 Advanced Features
 
-### Suggestions and Autocomplete
+### Suggestions Dropdown (not inline autocomplete)
 
 ```rust
 impl CanvasState for MyForm {
@@ -170,7 +170,7 @@ impl CanvasState for MyForm {
             CanvasAction::SelectSuggestion => {
                 if let Some(suggestion) = self.suggestions.get_selected() {
                     *self.get_current_input_mut() = suggestion.clone();
-                    self.deactivate_autocomplete();
+                    self.deactivate_suggestions();
                     Some("Applied suggestion".to_string())
                 }
                 None

canvas/examples/autocomplete.rs

@@ -1,392 +0,0 @@
-// examples/autocomplete.rs
-// Run with: cargo run --example autocomplete --features "autocomplete,gui"
-
-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,
-    text::{Line, Span},
-    widgets::{Block, Borders, Paragraph},
-    Frame, Terminal,
-};
-
-use canvas::{
-    canvas::{
-        gui::render_canvas,
-        modes::AppMode,
-        theme::CanvasTheme,
-    },
-    autocomplete::gui::render_autocomplete_dropdown,
-    FormEditor, DataProvider, AutocompleteProvider, SuggestionItem,
-};
-
-use async_trait::async_trait;
-use anyhow::Result;
-
-// Simple theme implementation
-#[derive(Clone)]
-struct DemoTheme;
-
-impl CanvasTheme for DemoTheme {
-    fn bg(&self) -> Color { Color::Reset }
-    fn fg(&self) -> Color { Color::White }
-    fn accent(&self) -> Color { Color::Cyan }
-    fn secondary(&self) -> Color { Color::Gray }
-    fn highlight(&self) -> Color { Color::Yellow }
-    fn highlight_bg(&self) -> Color { Color::DarkGray }
-    fn warning(&self) -> Color { Color::Red }
-    fn border(&self) -> Color { Color::Gray }
-}
-
-// Custom suggestion data type
-#[derive(Clone, Debug)]
-struct EmailSuggestion {
-    email: String,
-    provider: String,
-}
-
-// ===================================================================
-// SIMPLE DATA PROVIDER - Only business data, no UI concerns!
-// ===================================================================
-
-struct ContactForm {
-    // Only business data - no UI state!
-    name: String,
-    email: String,
-    phone: String,
-    city: String,
-}
-
-impl ContactForm {
-    fn new() -> Self {
-        Self {
-            name: "John Doe".to_string(),
-            email: "john@".to_string(), // Partial email for demo
-            phone: "+1 234 567 8900".to_string(),
-            city: "San Francisco".to_string(),
-        }
-    }
-}
-
-// Simple trait implementation - only 4 methods!
-impl DataProvider for ContactForm {
-    fn field_count(&self) -> usize { 4 }
-    
-    fn field_name(&self, index: usize) -> &str {
-        match index {
-            0 => "Name",
-            1 => "Email", 
-            2 => "Phone",
-            3 => "City",
-            _ => "",
-        }
-    }
-    
-    fn field_value(&self, index: usize) -> &str {
-        match index {
-            0 => &self.name,
-            1 => &self.email,
-            2 => &self.phone,
-            3 => &self.city,
-            _ => "",
-        }
-    }
-    
-    fn set_field_value(&mut self, index: usize, value: String) {
-        match index {
-            0 => self.name = value,
-            1 => self.email = value,
-            2 => self.phone = value,
-            3 => self.city = value,
-            _ => {}
-        }
-    }
-    
-    fn supports_autocomplete(&self, field_index: usize) -> bool {
-        field_index == 1 // Only email field
-    }
-}
-
-// ===================================================================
-// SIMPLE AUTOCOMPLETE PROVIDER - Only data fetching!
-// ===================================================================
-
-struct EmailAutocomplete;
-
-#[async_trait]
-impl AutocompleteProvider for EmailAutocomplete {
-    type SuggestionData = EmailSuggestion;
-    
-    async fn fetch_suggestions(&mut self, _field_index: usize, query: &str) 
-        -> Result<Vec<SuggestionItem<Self::SuggestionData>>> 
-    {
-        // Extract domain part from email
-        let (email_prefix, domain_part) = if let Some(at_pos) = query.find('@') {
-            (query[..at_pos].to_string(), query[at_pos + 1..].to_string())
-        } else {
-            return Ok(Vec::new()); // No @ symbol
-        };
-
-        // Simulate async API call
-        let suggestions = tokio::task::spawn_blocking(move || {
-            // Simulate network delay
-            std::thread::sleep(std::time::Duration::from_millis(200));
-
-            // Mock email suggestions
-            let popular_domains = vec![
-                ("gmail.com", "Gmail"),
-                ("yahoo.com", "Yahoo Mail"),
-                ("outlook.com", "Outlook"),
-                ("hotmail.com", "Hotmail"),
-                ("company.com", "Company Email"),
-                ("university.edu", "University"),
-            ];
-
-            let mut results = Vec::new();
-            for (domain, provider) in popular_domains {
-                if domain.starts_with(&domain_part) || domain_part.is_empty() {
-                    let full_email = format!("{}@{}", email_prefix, domain);
-                    results.push(SuggestionItem {
-                        data: EmailSuggestion {
-                            email: full_email.clone(),
-                            provider: provider.to_string(),
-                        },
-                        display_text: format!("{} ({})", full_email, provider),
-                        value_to_store: full_email,
-                    });
-                }
-            }
-            results
-        }).await.unwrap_or_default();
-
-        Ok(suggestions)
-    }
-}
-
-// ===================================================================
-// APPLICATION STATE - Much simpler!
-// ===================================================================
-
-struct AppState {
-    editor: FormEditor<ContactForm>,
-    autocomplete: EmailAutocomplete,
-    debug_message: String,
-}
-
-impl AppState {
-    fn new() -> Self {
-        let contact_form = ContactForm::new();
-        let mut editor = FormEditor::new(contact_form);
-        
-        // Start on email field (index 1) at end of existing text
-        editor.set_mode(AppMode::Edit);
-        // TODO: Add method to set initial field/cursor position
-        
-        Self {
-            editor,
-            autocomplete: EmailAutocomplete,
-            debug_message: "Type in email field, Tab to trigger autocomplete, Enter to select, Esc to cancel".to_string(),
-        }
-    }
-}
-
-// ===================================================================
-// INPUT HANDLING - Much cleaner!
-// ===================================================================
-
-async fn handle_key_press(key: KeyCode, modifiers: KeyModifiers, state: &mut AppState) -> bool {
-    if key == KeyCode::F(10) || (key == KeyCode::Char('c') && modifiers.contains(KeyModifiers::CONTROL)) {
-        return false; // Quit
-    }
-
-    // Handle input based on key
-    let result = match key {
-        // === AUTOCOMPLETE KEYS ===
-        KeyCode::Tab => {
-            if state.editor.is_autocomplete_active() {
-                state.editor.autocomplete_next();
-                Ok("Navigated to next suggestion".to_string())
-            } else if state.editor.data_provider().supports_autocomplete(state.editor.current_field()) {
-                state.editor.trigger_autocomplete(&mut state.autocomplete).await
-                    .map(|_| "Triggered autocomplete".to_string())
-            } else {
-                state.editor.move_to_next_field();
-                Ok("Moved to next field".to_string())
-            }
-        }
-
-        KeyCode::Enter => {
-            if state.editor.is_autocomplete_active() {
-                if let Some(applied) = state.editor.apply_autocomplete() {
-                    Ok(format!("Applied: {}", applied))
-                } else {
-                    Ok("No suggestion to apply".to_string())
-                }
-            } else {
-                state.editor.move_to_next_field();
-                Ok("Moved to next field".to_string())
-            }
-        }
-
-        KeyCode::Esc => {
-            if state.editor.is_autocomplete_active() {
-                // Autocomplete will be cleared automatically by mode change
-                Ok("Cancelled autocomplete".to_string())
-            } else {
-                // Toggle between edit and readonly mode
-                let new_mode = match state.editor.mode() {
-                    AppMode::Edit => AppMode::ReadOnly,
-                    _ => AppMode::Edit,
-                };
-                state.editor.set_mode(new_mode);
-                Ok(format!("Switched to {:?} mode", new_mode))
-            }
-        }
-
-        // === MOVEMENT KEYS ===
-        KeyCode::Left => {
-            state.editor.move_left();
-            Ok("Moved left".to_string())
-        }
-        KeyCode::Right => {
-            state.editor.move_right();
-            Ok("Moved right".to_string())
-        }
-        KeyCode::Up => {
-            state.editor.move_to_next_field(); // TODO: Add move_up method
-            Ok("Moved up".to_string())
-        }
-        KeyCode::Down => {
-            state.editor.move_to_next_field(); // TODO: Add move_down method  
-            Ok("Moved down".to_string())
-        }
-
-        // === TEXT INPUT ===
-        KeyCode::Char(c) if !modifiers.contains(KeyModifiers::CONTROL) => {
-            state.editor.insert_char(c)
-                .map(|_| format!("Inserted '{}'", c))
-        }
-
-        KeyCode::Backspace => {
-            // TODO: Add delete_backward method to FormEditor
-            Ok("Backspace (not implemented yet)".to_string())
-        }
-
-        _ => Ok(format!("Unhandled key: {:?}", key)),
-    };
-
-    // Update debug message
-    match result {
-        Ok(msg) => state.debug_message = msg,
-        Err(e) => state.debug_message = format!("Error: {}", e),
-    }
-
-    true
-}
-
-async fn run_app<B: Backend>(terminal: &mut Terminal<B>, mut state: AppState) -> io::Result<()> {
-    let theme = DemoTheme;
-
-    loop {
-        terminal.draw(|f| ui(f, &state, &theme))?;
-
-        if let Event::Key(key) = event::read()? {
-            let should_continue = handle_key_press(key.code, key.modifiers, &mut state).await;
-            if !should_continue {
-                break;
-            }
-        }
-    }
-
-    Ok(())
-}
-
-fn ui(f: &mut Frame, state: &AppState, theme: &DemoTheme) {
-    let chunks = Layout::default()
-        .direction(Direction::Vertical)
-        .constraints([
-            Constraint::Min(8),
-            Constraint::Length(5),
-        ])
-        .split(f.area());
-
-    // Render the canvas form - much simpler!
-    let active_field_rect = render_canvas(
-        f,
-        chunks[0],
-        &state.editor,
-        theme,
-    );
-
-    // Render autocomplete dropdown if active
-    if let Some(input_rect) = active_field_rect {
-        render_autocomplete_dropdown(
-            f,
-            chunks[0],
-            input_rect,
-            theme,
-            &state.editor,
-        );
-    }
-
-    // Status info
-    let autocomplete_status = if state.editor.is_autocomplete_active() {
-        if state.editor.ui_state().is_autocomplete_loading() {
-            "Loading suggestions..."
-        } else if !state.editor.suggestions().is_empty() {
-            "Use Tab to navigate, Enter to select, Esc to cancel"
-        } else {
-            "No suggestions found"
-        }
-    } else {
-        "Tab to trigger autocomplete"
-    };
-
-    let status_lines = vec![
-        Line::from(Span::raw(format!("Mode: {:?} | Field: {}/{} | Cursor: {}",
-            state.editor.mode(), 
-            state.editor.current_field() + 1, 
-            state.editor.data_provider().field_count(), 
-            state.editor.cursor_position()))),
-        Line::from(Span::raw(format!("Autocomplete: {}", autocomplete_status))),
-        Line::from(Span::raw(state.debug_message.clone())),
-        Line::from(Span::raw("F10: Quit | Tab: Trigger/Navigate autocomplete | Enter: Select | Esc: Cancel/Toggle mode")),
-    ];
-
-    let status = Paragraph::new(status_lines)
-        .block(Block::default().borders(Borders::ALL).title("Status & Help"));
-
-    f.render_widget(status, chunks[1]);
-}
-
-#[tokio::main]
-async fn main() -> Result<(), Box<dyn std::error::Error>> {
-    enable_raw_mode()?;
-    let mut stdout = io::stdout();
-    execute!(stdout, EnterAlternateScreen, EnableMouseCapture)?;
-    let backend = CrosstermBackend::new(stdout);
-    let mut terminal = Terminal::new(backend)?;
-
-    let state = AppState::new();
-    let res = run_app(&mut terminal, state).await;
-
-    disable_raw_mode()?;
-    execute!(
-        terminal.backend_mut(),
-        LeaveAlternateScreen,
-        DisableMouseCapture
-    )?;
-    terminal.show_cursor()?;
-
-    if let Err(err) = res {
-        println!("{:?}", err);
-    }
-
-    Ok(())
-}

canvas/examples/canvas_cursor_auto.rs

@@ -275,7 +275,8 @@ impl<D: DataProvider> AutoCursorFormEditor<D> {
     }
 
     fn current_text(&self) -> &str {
-        self.editor.current_text()
+        let field_index = self.editor.current_field();
+        self.editor.data_provider().field_value(field_index)
     }
 
     fn data_provider(&self) -> &D {
@@ -306,6 +307,42 @@ impl<D: DataProvider> AutoCursorFormEditor<D> {
     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
@@ -346,7 +383,7 @@ impl DataProvider for CursorDemoData {
         self.fields[index].1 = value;
     }
 
-    fn supports_autocomplete(&self, _field_index: usize) -> bool {
+    fn supports_suggestions(&self, _field_index: usize) -> bool {
         false
     }
 
@@ -389,10 +426,17 @@ fn handle_key_press(
             editor.set_debug_message("✏️  INSERT (end of line) - Cursor: Steady Bar |".to_string());
             editor.clear_command_buffer();
         }
+
         (AppMode::ReadOnly, KeyCode::Char('o'), _) => {
-            editor.move_line_end();
-            editor.enter_edit_mode(); // 🎯 Automatic: cursor becomes bar |
-            editor.set_debug_message("✏️  INSERT (open line) - Cursor: Steady Bar |".to_string());
+            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();
         }
 
@@ -507,10 +551,40 @@ fn handle_key_press(
             editor.clear_command_buffer();
         }
         (AppMode::ReadOnly | AppMode::Highlight, KeyCode::Char('e'), _) => {
-            editor.move_word_end();
-            editor.set_debug_message("e: word end".to_string());
+            // 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'), _)
@@ -721,9 +795,9 @@ fn render_status_and_help(
                 }
             } else {
                 "🎯 CURSOR-STYLE DEMO: Normal █ | Insert | | Visual blinking█\n\
-                 Normal: hjkl/arrows=move, w/b/e=words, 0/$=line, gg/G=first/last\n\
-                 i/a/A=insert, v/b=visual, x/X=delete, ?=info\n\
-                 F1=demo manual cursor, F2=restore automatic"
+                Normal: hjkl/arrows=move, w/b/e=words, W/B/E=WORDS, 0/$=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 => {

canvas/examples/computed_fields.rs

@@ -0,0 +1,623 @@
+// 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!("{:.2}", subtotal)
+                }
+            }
+            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!("{:.2}", tax_amount)
+                }
+            }
+            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!("{:.2}", total)
+                }
+            }
+            _ => "".to_string(),
+        }
+    }
+    
+    fn handles_field(&self, field_index: usize) -> bool {
+        matches!(field_index, 4 | 5 | 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 | 2 | 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 | 2 | 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 | 2 | 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", field_name, field_type);
+        }
+    }
+
+    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", field_name, field_type);
+        }
+    }
+
+    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!(
+                "🚫 {} is computed (read-only) - Press Tab to move to editable fields",
+                field_name
+            );
+            return;
+        }
+        
+        self.editor.enter_edit_mode();
+        let field_name = self.editor.data_provider().field_name(current);
+        self.debug_message = format!("✏️ Editing {} - Type to see calculations update", field_name);
+    }
+
+    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!(
+                "🚫 {} is computed (read-only) - Press Tab to move to editable fields",
+                field_name
+            );
+            return;
+        }
+        
+        self.editor.enter_append_mode();
+        let field_name = self.editor.data_provider().field_name(current);
+        self.debug_message = format!("✏️ Appending to {} - Type to see calculations", field_name);
+    }
+
+    fn exit_edit_mode(&mut self) {
+        let current_field = self.editor.current_field();
+        self.editor.exit_edit_mode();
+
+        if matches!(current_field, 1 | 2 | 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/full_canvas_demo.rs

@@ -345,7 +345,7 @@ impl DataProvider for FullDemoData {
         self.fields[index].1 = value;
     }
 
-    fn supports_autocomplete(&self, _field_index: usize) -> bool {
+    fn supports_suggestions(&self, _field_index: usize) -> bool {
         false
     }
 

canvas/examples/validation_1.rs

@@ -1,7 +1,7 @@
 // examples/validation_1.rs
 //! Demonstrates field validation with the canvas library
 //!
-//! This example REQUIRES the `validation` feature to compile.
+//! This example REQUIRES the `validation` and `cursor-style` features to compile.
 //!
 //! Run with:
 //! cargo run --example validation_1 --features "gui,validation"
@@ -10,10 +10,10 @@
 //! cargo run --example validation_1 --features "gui"
 
 // REQUIRE validation feature - example won't compile without it
-#[cfg(not(feature = "validation"))]
+#[cfg(not(all(feature = "validation", feature = "cursor-style")))]
 compile_error!(
-    "This example requires the 'validation' feature. \
-     Run with: cargo run --example validation_1 --features \"gui,validation\""
+    "This example requires the 'validation' and 'cursor-style' features. \
+     Run with: cargo run --example validation_1 --features \"gui,validation,cursor-style\""
 );
 
 use std::io;
@@ -34,11 +34,11 @@ use ratatui::{
     widgets::{Block, Borders, Paragraph, Wrap},
     Frame, Terminal,
 };
-
 use canvas::{
     canvas::{
         gui::render_canvas_default,
         modes::AppMode,
+        CursorManager,
     },
     DataProvider, FormEditor,
     ValidationConfig, ValidationConfigBuilder, CharacterLimits, ValidationResult,
@@ -61,10 +61,8 @@ struct ValidationFormEditor<D: DataProvider> {
 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,
@@ -97,7 +95,6 @@ impl<D: DataProvider> ValidationFormEditor<D> {
     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 {
@@ -109,14 +106,12 @@ impl<D: DataProvider> ValidationFormEditor<D> {
         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)
     }
 
@@ -124,11 +119,9 @@ impl<D: DataProvider> ValidationFormEditor<D> {
         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)
@@ -161,7 +154,6 @@ impl<D: DataProvider> ValidationFormEditor<D> {
         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",
@@ -249,38 +241,37 @@ impl<D: DataProvider> ValidationFormEditor<D> {
         if !self.validation_enabled {
             return;
         }
-
-        if let Some(result) = self.editor.current_field_validation() {
-            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);
-                }
+        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);
             }
-        } else {
-            self.debug_message = format!("Field {}: 🔍 Not validated yet", self.editor.current_field() + 1);
         }
     }
 
     // === 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 - Type to test validation".to_string();
+        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) - Validation active".to_string();
+        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 - Press 'v' to validate current field".to_string();
+        self.debug_message = "🔒 NORMAL MODE - Cursor: Steady Block █ - Press 'v' to validate current field".to_string();
         self.update_field_validation_status();
     }
 
@@ -289,22 +280,24 @@ impl<D: DataProvider> ValidationFormEditor<D> {
         if result.is_ok() {
             self.has_unsaved_changes = true;
             // Show real-time validation feedback
-            if let Some(validation_result) = self.editor.current_field_validation() {
-                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() {
-                            if let Some(status) = limits.status_text(self.editor.current_text()) {
-                                self.debug_message = format!("✏️  {}", status);
-                            }
+            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);
-                    }
+                }
+                ValidationResult::Warning { message } => {
+                    self.debug_message = format!("⚠️  {}", message);
+                }
+                ValidationResult::Error { message } => {
+                    self.debug_message = format!("❌ {}", message);
                 }
             }
         }
@@ -350,7 +343,8 @@ impl<D: DataProvider> ValidationFormEditor<D> {
     }
 
     fn current_text(&self) -> &str {
-        self.editor.current_text()
+        let field_index = self.editor.current_field();
+        self.editor.data_provider().field_value(field_index)
     }
 
     fn data_provider(&self) -> &D {
@@ -362,6 +356,7 @@ impl<D: DataProvider> ValidationFormEditor<D> {
     }
 
     fn set_mode(&mut self, mode: AppMode) {
+        // Library automatically updates cursor for the mode
         self.editor.set_mode(mode);
     }
 
@@ -447,7 +442,7 @@ impl DataProvider for ValidationDemoData {
         self.fields[index].1 = value;
     }
 
-    fn supports_autocomplete(&self, _field_index: usize) -> bool {
+    fn supports_suggestions(&self, _field_index: usize) -> bool {
         false
     }
 
@@ -531,7 +526,6 @@ fn handle_key_press(
             editor.enter_edit_mode();
             editor.clear_command_buffer();
         }
-
         // Escape: Exit edit mode
         (_, KeyCode::Esc, _) => {
             if mode == AppMode::Edit {
@@ -624,7 +618,6 @@ fn handle_key_press(
                 summary.validated_fields
             ));
         }
-
         _ => {
             if editor.has_pending_command() {
                 editor.clear_command_buffer();
@@ -656,7 +649,6 @@ fn run_app<B: Backend>(
             }
         }
     }
-
     Ok(())
 }
 
@@ -694,33 +686,33 @@ fn render_validation_status(
 
     // Status bar with validation information
     let mode_text = match editor.mode() {
-        AppMode::Edit => "INSERT",
-        AppMode::ReadOnly => "NORMAL",
-        _ => "OTHER",
+        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: {}", 
+        format!("-- {} -- {} [{}] | Validation: {}",
                 mode_text, editor.debug_message(), editor.get_command_buffer(), validation_status)
     } else if editor.has_unsaved_changes() {
-        format!("-- {} -- [Modified] {} | Validation: {}", 
+        format!("-- {} -- [Modified] {} | Validation: {}",
                 mode_text, editor.debug_message(), validation_status)
     } else {
-        format!("-- {} -- {} | Validation: {}", 
+        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: {}", 
+            format!("\n🚫 Field switching blocked: {}",
                    editor.block_reason.as_deref().unwrap_or("Unknown reason"))
         } else {
             let (can_switch, reason) = editor.check_field_switch_allowed();
@@ -759,34 +751,32 @@ fn render_validation_status(
         .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 => {
-            "🔍 VALIDATION DEMO: Different fields have different limits!\n\
-             Fields with MINIMUM requirements will block field switching if too short!\n\
+            "🎯 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 - Type to test validation limits!\n\
-             Some fields have MINIMUM character requirements!\n\
+            "🎯 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!"
         }
-        _ => "🔍 Validation Demo Active!"
+        _ => "🎯 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]);
 }
 
@@ -810,10 +800,20 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let mut terminal = Terminal::new(backend)?;
 
     let data = ValidationDemoData::new();
-    let editor = ValidationFormEditor::new(data);
+    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(),

canvas/examples/validation_2.rs

@@ -4,13 +4,13 @@
 //! 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"
+//! Run with: cargo run --example validation_advanced_patterns --features "validation,gui,cursor-style"
 
-// REQUIRE validation and gui features
-#[cfg(not(all(feature = "validation", feature = "gui")))]
+// REQUIRE validation, gui and cursor-style features
+#[cfg(not(all(feature = "validation", feature = "gui", feature = "cursor-style")))]
 compile_error!(
-    "This example requires the 'validation' and 'gui' features. \
-     Run with: cargo run --example validation_advanced_patterns --features \"validation,gui\""
+    "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;
@@ -38,6 +38,7 @@ use canvas::{
     canvas::{
         gui::render_canvas_default,
         modes::AppMode,
+        CursorManager,
     },
     DataProvider, FormEditor,
     ValidationConfig, ValidationConfigBuilder, PatternFilters, PositionFilter, PositionRange, CharacterFilter,
@@ -70,12 +71,12 @@ impl<D: DataProvider> AdvancedPatternFormEditor<D> {
 
     // ... (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);
@@ -88,14 +89,14 @@ impl<D: DataProvider> AdvancedPatternFormEditor<D> {
 
     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; }
@@ -105,32 +106,34 @@ impl<D: DataProvider> AdvancedPatternFormEditor<D> {
 
     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 - Testing advanced pattern validation".to_string();
+        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) - Advanced patterns active".to_string();
+        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".to_string();
+        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() {
-            if let Some(validation_result) = self.editor.current_field_validation() {
-                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); }
-                }
+            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); }
             }
         }
         Ok(result?)
@@ -152,7 +155,10 @@ impl<D: DataProvider> AdvancedPatternFormEditor<D> {
     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 { self.editor.current_text() }
+    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); }
@@ -176,12 +182,11 @@ impl<D: DataProvider> AdvancedPatternFormEditor<D> {
 
     fn update_field_validation_status(&mut self) {
         if !self.validation_enabled { return; }
-        if let Some(result) = self.editor.current_field_validation() {
-            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); }
-            }
+        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); }
         }
     }
 
@@ -380,7 +385,7 @@ impl DataProvider for AdvancedPatternData {
                             // 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()
@@ -522,9 +527,9 @@ fn render_advanced_validation_status(
 
     // Status bar
     let mode_text = match editor.mode() {
-        AppMode::Edit => "INSERT",
-        AppMode::ReadOnly => "NORMAL",
-        _ => "OTHER",
+        AppMode::Edit => "INSERT | (bar cursor)",
+        AppMode::ReadOnly => "NORMAL █ (block cursor)",
+        _ => "NORMAL █ (block cursor)",
     };
 
     let validation_status = editor.get_validation_status();
@@ -613,6 +618,7 @@ 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!");
@@ -625,10 +631,20 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let mut terminal = Terminal::new(backend)?;
 
     let data = AdvancedPatternData::new();
-    let editor = AdvancedPatternFormEditor::new(data);
+    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(),

canvas/examples/validation_3.rs

@@ -18,13 +18,13 @@
 //! 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"
+//! Run with: cargo run --example validation_3 --features "gui,validation,cursor-style"
 
-// REQUIRE validation and gui features for mask functionality
-#[cfg(not(all(feature = "validation", feature = "gui")))]
+// 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' and 'gui' features. \
-     Run with: cargo run --example validation_3 --features \"gui,validation\""
+    "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;
@@ -50,6 +50,7 @@ use canvas::{
     canvas::{
         gui::render_canvas_default,
         modes::AppMode,
+        CursorManager,
     },
     DataProvider, FormEditor,
     ValidationConfig, ValidationConfigBuilder, DisplayMask,
@@ -107,7 +108,7 @@ impl<D: DataProvider> MaskDemoFormEditor<D> {
 
     fn get_current_field_info(&self) -> (String, String, String) {
         let field_index = self.editor.current_field();
-        let raw_data = self.editor.current_text();
+        let raw_data = self.editor.data_provider().field_value(field_index);
         let display_data = if self.validation_enabled {
             self.editor.current_display_text()
         } else {
@@ -116,8 +117,8 @@ impl<D: DataProvider> MaskDemoFormEditor<D> {
 
         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(), 
+                format!("Pattern: '{}', Mode: {:?}",
+                       mask.pattern(),
                        mask.display_mode())
             } else {
                 "No mask configured".to_string()
@@ -130,13 +131,13 @@ impl<D: DataProvider> MaskDemoFormEditor<D> {
     }
 
     // === ENHANCED MOVEMENT WITH MASK AWARENESS ===
-    fn move_left(&mut self) { 
-        self.editor.move_left(); 
+    fn move_left(&mut self) {
+        self.editor.move_left();
         self.update_cursor_info();
     }
 
-    fn move_right(&mut self) { 
-        self.editor.move_right(); 
+    fn move_right(&mut self) {
+        self.editor.move_right();
         self.update_cursor_info();
     }
 
@@ -154,13 +155,13 @@ impl<D: DataProvider> MaskDemoFormEditor<D> {
         }
     }
 
-    fn move_line_start(&mut self) { 
-        self.editor.move_line_start(); 
+    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(); 
+    fn move_line_end(&mut self) {
+        self.editor.move_line_end();
         self.update_cursor_info();
     }
 
@@ -183,18 +184,21 @@ impl<D: DataProvider> MaskDemoFormEditor<D> {
 
     // === 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 - Type to see mask formatting in real-time".to_string();
+        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) - Mask formatting active".to_string();
+        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 - Press 'r' to see raw data, 'm' for mask info".to_string();
+        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<()> {
@@ -233,10 +237,16 @@ impl<D: DataProvider> MaskDemoFormEditor<D> {
     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 { self.editor.current_text() }
+    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 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() {
@@ -258,7 +268,7 @@ impl<D: DataProvider> MaskDemoFormEditor<D> {
 
     fn show_mask_details(&mut self) {
         let (raw, display, mask_info) = self.get_current_field_info();
-        self.debug_message = format!("🔍 Field {}: {} | Raw: '{}' Display: '{}'", 
+        self.debug_message = format!("🔍 Field {}: {} | Raw: '{}' Display: '{}'",
                                    self.current_field() + 1, mask_info, raw, display);
     }
 
@@ -324,11 +334,11 @@ impl DataProvider for MaskDemoData {
                     .build())
             }
             1 => {
-                // 📞 Phone (Template) - FIXED: Perfect mask/limit coordination  
+                // 📞 Phone (Template) - FIXED: Perfect mask/limit coordination
                 let phone_template = DisplayMask::new("(###) ###-####", '#')
                     .with_template('_');
                 Some(ValidationConfigBuilder::new()
-                    .with_display_mask(phone_template)  
+                    .with_display_mask(phone_template)
                     .with_max_length(10)  // ✅ CRITICAL: Exactly matches 10 input positions
                     .build())
             }
@@ -354,7 +364,7 @@ impl DataProvider for MaskDemoData {
                 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  
+                    .with_max_length(9)  // ✅ CRITICAL: Exactly matches 9 input positions
                     .build())
             }
             6 => {
@@ -582,15 +592,15 @@ fn render_mask_status(
 
     // Status bar with mask information
     let mode_text = match editor.mode() {
-        AppMode::Edit => "INSERT",
-        AppMode::ReadOnly => "NORMAL",
-        _ => "OTHER",
+        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(), 
+    let status_text = format!("-- {} -- {} | Masks: {} | View: {}",
+                             mode_text,
+                             editor.debug_message(),
                              mask_status,
                              if editor.show_raw_data { "RAW" } else { "FORMATTED" });
 
@@ -602,7 +612,7 @@ fn render_mask_status(
     // 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\
@@ -634,17 +644,19 @@ fn render_mask_status(
     // Enhanced help text
     let help_text = match editor.mode() {
         AppMode::ReadOnly => {
-            "🎭 MASK DEMO: See how visual formatting keeps business logic clean!\n\
+            "🎯 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=$=line start/end, Tab=next field, F1=toggle masks\n\
+             Movement: hjkl/arrows=move, 0/$=line start/end, Tab=next field, F1=toggle masks\n\
              ?=detailed info, Ctrl+C=quit"
         }
         AppMode::Edit => {
-            "✏️ INSERT MODE - Type to see real-time mask formatting!\n\
+            "🎯 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\
@@ -670,6 +682,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     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");
@@ -690,7 +703,13 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let mut terminal = Terminal::new(backend)?;
 
     let data = MaskDemoData::new();
-    let editor = MaskDemoFormEditor::new(data);
+    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);
 
@@ -702,6 +721,10 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     )?;
     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);
     }

canvas/integration_patterns.rs

@@ -114,7 +114,7 @@ async fn state_machine_example() {
             }
         }
 
-        fn handle_feature_action(&mut self, action: &CanvasAction, _context: &ActionContext) -> Option<String> {
+        fn handle_feature_action(&mut self, action: &CanvasAction, context: &ActionContext) -> Option<String> {
             match action {
                 CanvasAction::Custom(cmd) => match cmd.as_str() {
                     "submit" => {
@@ -147,7 +147,7 @@ async fn state_machine_example() {
     println!("  Initial state: {:?}", form.state);
 
     // Type some text to trigger state change
-    let _result = ActionDispatcher::dispatch(
+    let result = ActionDispatcher::dispatch(
         CanvasAction::InsertChar('u'),
         &mut form,
         &mut ideal_cursor,
@@ -231,7 +231,7 @@ async fn event_driven_example() {
             self.has_changes = changed;
         }
 
-        fn handle_feature_action(&mut self, action: &CanvasAction, _context: &ActionContext) -> Option<String> {
+        fn handle_feature_action(&mut self, action: &CanvasAction, context: &ActionContext) -> Option<String> {
             match action {
                 CanvasAction::Custom(cmd) => match cmd.as_str() {
                     "validate" => {
@@ -384,7 +384,7 @@ async fn validation_pipeline_example() {
         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> {
+        fn handle_feature_action(&mut self, action: &CanvasAction, context: &ActionContext) -> Option<String> {
             match action {
                 CanvasAction::Custom(cmd) => match cmd.as_str() {
                     "validate" => {

canvas/src/autocomplete/mod.rs

@@ -1,12 +0,0 @@
-// src/autocomplete/mod.rs
-
-pub mod state;
-#[cfg(feature = "gui")]
-pub mod gui;
-
-// Re-export the main autocomplete types
-pub use state::{AutocompleteProvider, SuggestionItem};
-
-// Re-export GUI functions if available
-#[cfg(feature = "gui")]
-pub use gui::render_autocomplete_dropdown;

canvas/src/autocomplete/state.rs

@@ -1,5 +0,0 @@
-// src/autocomplete/state.rs
-//! Autocomplete provider types
-
-// Re-export the main types from data_provider
-pub use crate::data_provider::{AutocompleteProvider, SuggestionItem};

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

@@ -5,6 +5,12 @@ 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};
+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

@@ -1,6 +1,7 @@
 // src/canvas/actions/movement/word.rs
+// Replace the entire file with this corrected version:
 
-#[derive(PartialEq)]
+#[derive(PartialEq, Copy, Clone)]
 enum CharType {
     Whitespace,
     Alphanumeric,
@@ -55,7 +56,7 @@ pub fn find_word_end(text: &str, current_pos: usize) -> usize {
 
     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 {
@@ -107,40 +108,296 @@ pub fn find_prev_word_start(text: &str, current_pos: usize) -> usize {
     }
 }
 
-/// Find the end of the previous word
+/// 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 && get_char_type(chars[pos]) == CharType::Whitespace {
+    while pos > 0 && chars[pos].is_whitespace() {
         pos -= 1;
     }
 
-    if pos == 0 && get_char_type(chars[0]) == CharType::Whitespace {
-        return 0;
-    }
-    if pos == 0 && get_char_type(chars[0]) != CharType::Whitespace {
-        return 0;
-    }
-
-    let word_type = get_char_type(chars[pos]);
-    while pos > 0 && get_char_type(chars[pos - 1]) == word_type {
+    // Find start of current big_word by going back while non-whitespace
+    while pos > 0 && !chars[pos - 1].is_whitespace() {
         pos -= 1;
     }
 
-    // Skip whitespace before this word
-    while pos > 0 && get_char_type(chars[pos - 1]) == CharType::Whitespace {
-        pos -= 1;
-    }
-
-    if pos > 0 {
-        pos - 1
-    } else {
-        0
-    }
+    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

@@ -30,12 +30,12 @@ pub enum CanvasAction {
     DeleteBackward,
     DeleteForward,
 
-    // Autocomplete actions
-    TriggerAutocomplete,
-    SuggestionUp,
-    SuggestionDown,
-    SelectSuggestion,
-    ExitSuggestions,
+    // Suggestions actions
+        TriggerSuggestions,
+        SuggestionUp,
+        SuggestionDown,
+        SelectSuggestion,
+        ExitSuggestions,
 
     // Custom actions
     Custom(String),
@@ -101,7 +101,7 @@ impl CanvasAction {
             Self::InsertChar(_c) => "insert character",
             Self::DeleteBackward => "delete backward",
             Self::DeleteForward => "delete forward",
-            Self::TriggerAutocomplete => "trigger autocomplete",
+            Self::TriggerSuggestions => "trigger suggestions",
             Self::SuggestionUp => "suggestion up",
             Self::SuggestionDown => "suggestion down",
             Self::SelectSuggestion => "select suggestion",
@@ -139,10 +139,10 @@ impl CanvasAction {
         ]
     }
 
-    /// Get all autocomplete-related actions
-    pub fn autocomplete_actions() -> Vec<CanvasAction> {
+    /// Get all suggestions-related actions
+    pub fn suggestions_actions() -> Vec<CanvasAction> {
         vec![
-            Self::TriggerAutocomplete,
+            Self::TriggerSuggestions,
             Self::SuggestionUp,
             Self::SuggestionDown,
             Self::SelectSuggestion,

canvas/src/canvas/gui.rs

@@ -15,11 +15,12 @@ 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};
 
-/// Render ONLY the canvas form fields - no autocomplete
+/// Render ONLY the canvas form fields - no suggestions rendering here
 /// Updated to work with FormEditor instead of CanvasState trait
 #[cfg(feature = "gui")]
 pub fn render_canvas<T: CanvasTheme, D: DataProvider>(
@@ -67,6 +68,19 @@ pub fn render_canvas_with_highlight<T: CanvasTheme, D: DataProvider>(
     let current_field_idx = ui_state.current_field();
     let is_edit_mode = matches!(ui_state.mode(), crate::canvas::modes::AppMode::Edit);
 
+    // Precompute completion for active field
+    #[cfg(feature = "suggestions")]
+    let active_completion = if ui_state.is_suggestions_active()
+        && ui_state.suggestions.active_field == Some(current_field_idx)
+    {
+        ui_state.suggestions.completion_text.clone()
+    } else {
+        None
+    };
+
+    #[cfg(not(feature = "suggestions"))]
+    let active_completion: Option<String> = None;
+
     render_canvas_fields(
         f,
         area,
@@ -78,37 +92,30 @@ pub fn render_canvas_with_highlight<T: CanvasTheme, D: DataProvider>(
         highlight_state,
         editor.display_cursor_position(), // Use display cursor position for masks
         false, // TODO: track unsaved changes in editor
-        |i| {
-            // Get display value for field i using editor logic (Feature 4 + masks)
-            #[cfg(feature = "validation")]
-            {
-                editor.display_text_for_field(i)
-            }
-            #[cfg(not(feature = "validation"))]
-            {
-                data_provider.field_value(i).to_string()
-            }
+        // Closures for getting display values and overrides
+        #[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(),
+        // Closure for checking display overrides
+        #[cfg(feature = "validation")]
+        |field_idx| {
+            editor.ui_state().validation_state().get_field_config(field_idx)
+                .map(|cfg| {
+                    let has_formatter = cfg.custom_formatter.is_some();
+                    let has_mask = cfg.display_mask.is_some();
+                    has_formatter || has_mask
+                })
+                .unwrap_or(false)
         },
-        |i| {
-            // Check if field has display override (custom formatter or mask)
-            #[cfg(feature = "validation")]
-            {
-                editor.ui_state().validation_state().get_field_config(i)
-                    .map(|cfg| {
-                        // Formatter takes precedence; if present, it's a display override
-                        #[allow(unused_mut)]
-                        let mut has_override = false;
-                        #[cfg(feature = "validation")]
-                        {
-                            has_override = cfg.custom_formatter.is_some();
-                        }
-                        has_override || cfg.display_mask.is_some()
-                    })
-                    .unwrap_or(false)
-            }
-            #[cfg(not(feature = "validation"))]
-            {
-                false
+        #[cfg(not(feature = "validation"))]
+        |_field_idx| false,
+        // Closure for providing completion
+        |field_idx| {
+            if field_idx == current_field_idx {
+                active_completion.clone()
+            } else {
+                None
             }
         },
     )
@@ -128,7 +135,7 @@ fn convert_selection_to_highlight(selection: &crate::canvas::state::SelectionSta
 
 /// Core canvas field rendering
 #[cfg(feature = "gui")]
-fn render_canvas_fields<T: CanvasTheme, F1, F2>(
+fn render_canvas_fields<T: CanvasTheme, F1, F2, F3>(
     f: &mut Frame,
     area: Rect,
     fields: &[&str],
@@ -141,10 +148,12 @@ fn render_canvas_fields<T: CanvasTheme, F1, F2>(
     has_unsaved_changes: bool,
     get_display_value: F1,
     has_display_override: F2,
+    get_completion: F3,
 ) -> Option<Rect>
 where
     F1: Fn(usize) -> String,
     F2: Fn(usize) -> bool,
+    F3: Fn(usize) -> Option<String>,
 {
     // Create layout
     let columns = Layout::default()
@@ -198,6 +207,7 @@ where
         current_cursor_pos,
         get_display_value,
         has_display_override,
+        get_completion,
     )
 }
 
@@ -229,7 +239,7 @@ fn render_field_labels<T: CanvasTheme>(
 
 /// Render field values with highlighting
 #[cfg(feature = "gui")]
-fn render_field_values<T: CanvasTheme, F1, F2>(
+fn render_field_values<T: CanvasTheme, F1, F2, F3>(
     f: &mut Frame,
     input_rows: Vec<Rect>,
     inputs: &[String],
@@ -239,35 +249,55 @@ fn render_field_values<T: CanvasTheme, F1, F2>(
     current_cursor_pos: usize,
     get_display_value: F1,
     has_display_override: F2,
+    get_completion: F3,
 ) -> Option<Rect>
 where
     F1: Fn(usize) -> String,
     F2: Fn(usize) -> bool,
+    F3: Fn(usize) -> Option<String>,
 {
     let mut active_field_input_rect = None;
 
-    for (i, _input) in inputs.iter().enumerate() {
+    // FIX: Iterate over indices only since we never use the input values directly
+    for i in 0..inputs.len() {
         let is_active = i == *current_field_idx;
-        let text = get_display_value(i);
+        let typed_text = get_display_value(i);
 
-        // Apply highlighting
-        let line = apply_highlighting(
-            &text,
-            i,
-            current_field_idx,
-            current_cursor_pos,
-            highlight_state,
-            theme,
-            is_active,
-        );
+        let line = if is_active {
+            // Compose typed + gray completion for the active field
+            let normal_style = Style::default().fg(theme.fg());
+            let gray_style = Style::default().fg(theme.suggestion_gray());
+
+            let mut spans: Vec<Span> = Vec::new();
+            spans.push(Span::styled(typed_text.clone(), normal_style));
+
+            if let Some(completion) = get_completion(i) {
+                if !completion.is_empty() {
+                    spans.push(Span::styled(completion, gray_style));
+                }
+            }
+
+            Line::from(spans)
+        } else {
+            // Non-active fields: keep existing highlighting logic
+            apply_highlighting(
+                &typed_text,
+                i,
+                current_field_idx,
+                current_cursor_pos,
+                highlight_state,
+                theme,
+                is_active,
+            )
+        };
 
         let input_display = Paragraph::new(line).alignment(Alignment::Left);
         f.render_widget(input_display, input_rows[i]);
 
-        // Set cursor for active field
+        // Set cursor for active field at end of typed text (not after completion)
         if is_active {
             active_field_input_rect = Some(input_rows[i]);
-            set_cursor_position(f, input_rows[i], &text, current_cursor_pos, has_display_override(i));
+            set_cursor_position(f, input_rows[i], &typed_text, current_cursor_pos, has_display_override(i));
         }
     }
 
@@ -283,7 +313,7 @@ fn apply_highlighting<'a, T: CanvasTheme>(
     current_cursor_pos: usize,
     highlight_state: &HighlightState,
     theme: &T,
-    _is_active: bool,
+    is_active: bool,
 ) -> Line<'a> {
     let text_len = text.chars().count();
 
@@ -295,10 +325,10 @@ fn apply_highlighting<'a, T: CanvasTheme>(
             ))
         }
         HighlightState::Characterwise { anchor } => {
-            apply_characterwise_highlighting(text, text_len, field_index, current_field_idx, current_cursor_pos, anchor, theme, _is_active)
+            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_linewise_highlighting(text, field_index, current_field_idx, anchor_line, theme, is_active)
         }
     }
 }
@@ -447,16 +477,24 @@ fn set_cursor_position(
     field_rect: Rect,
     text: &str,
     current_cursor_pos: usize,
-    has_display_override: bool,
+    _has_display_override: bool,
 ) {
-    // BUG FIX: Use the correct display cursor position, not end of text
-    let cursor_x = field_rect.x + current_cursor_pos as u16;
+    // Sum display widths of the first current_cursor_pos characters
+    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 cursor_x = field_rect.x.saturating_add(cols);
     let cursor_y = field_rect.y;
-    
-    // SAFETY: Ensure cursor doesn't go beyond field bounds
+
+    // Clamp to field bounds
     let max_cursor_x = field_rect.x + field_rect.width.saturating_sub(1);
     let safe_cursor_x = cursor_x.min(max_cursor_x);
-    
+
     f.set_cursor_position((safe_cursor_x, cursor_y));
 }
 

canvas/src/canvas/state.rs

@@ -14,23 +14,31 @@ pub struct EditorState {
     // Mode state
     pub(crate) current_mode: AppMode,
 
-    // Autocomplete state
-    pub(crate) autocomplete: AutocompleteUIState,
+    // 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)]
-pub struct AutocompleteUIState {
+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)]
@@ -47,15 +55,20 @@ impl EditorState {
             cursor_pos: 0,
             ideal_cursor_column: 0,
             current_mode: AppMode::Edit,
-            autocomplete: AutocompleteUIState {
+            #[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,
         }
     }
 
@@ -68,6 +81,15 @@ impl EditorState {
         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
@@ -83,21 +105,23 @@ impl EditorState {
         self.current_mode
     }
 
-    /// Check if autocomplete is active (for user's business logic)
-    pub fn is_autocomplete_active(&self) -> bool {
-        self.autocomplete.is_active
+    /// 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 autocomplete is loading (for user's business logic)
-    pub fn is_autocomplete_loading(&self) -> bool {
-        self.autocomplete.is_loading
+    /// 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")]
@@ -117,7 +141,12 @@ impl EditorState {
         }
     }
 
-    pub(crate) fn set_cursor(&mut self, position: usize, max_position: usize, for_edit_mode: bool) {
+    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);
@@ -128,18 +157,26 @@ impl EditorState {
         self.ideal_cursor_column = self.cursor_pos;
     }
 
-    pub(crate) fn activate_autocomplete(&mut self, field_index: usize) {
-        self.autocomplete.is_active = true;
-        self.autocomplete.is_loading = true;
-        self.autocomplete.active_field = Some(field_index);
-        self.autocomplete.selected_index = None;
+    /// 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;
     }
 
-    pub(crate) fn deactivate_autocomplete(&mut self) {
-        self.autocomplete.is_active = false;
-        self.autocomplete.is_loading = false;
-        self.autocomplete.active_field = None;
-        self.autocomplete.selected_index = 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;
     }
 }
 

canvas/src/canvas/theme.rs

@@ -14,6 +14,7 @@ pub trait CanvasTheme {
     fn highlight(&self) -> Color;
     fn highlight_bg(&self) -> Color;
     fn warning(&self) -> Color;
+    fn suggestion_gray(&self) -> Color;
 }
 
 
@@ -47,4 +48,7 @@ impl CanvasTheme for DefaultCanvasTheme {
     fn warning(&self) -> Color {
         Color::Red
     }
+    fn suggestion_gray(&self) -> Color {
+        Color::DarkGray
+    }
 }

canvas/src/computed/mod.rs

@@ -0,0 +1,5 @@
+pub mod provider;
+pub mod state;
+
+pub use provider::{ComputedContext, ComputedProvider};
+pub use state::ComputedState;

canvas/src/computed/provider.rs

@@ -0,0 +1,31 @@
+// ================================================================================================
+// COMPUTED FIELDS - Provider and Context
+// ================================================================================================
+
+/// 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 +1,88 @@
+/* file: canvas/src/computed/state.rs */
+/*
+Add computed state module file implementing caching and dependencies
+*/
+
+// ================================================================================================
+// COMPUTED FIELDS - State: caching and dependencies
+// ================================================================================================
+
+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

@@ -1,7 +1,9 @@
 // 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
@@ -18,8 +20,8 @@ pub trait DataProvider {
     /// Set field value (library calls this when text changes)
     fn set_field_value(&mut self, index: usize, value: String);
 
-    /// Check if field supports autocomplete (optional)
-    fn supports_autocomplete(&self, _field_index: usize) -> bool {
+    /// Check if field supports suggestions (optional)
+    fn supports_suggestions(&self, _field_index: usize) -> bool {
         false
     }
 
@@ -27,23 +29,39 @@ pub trait DataProvider {
     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 autocomplete data
+/// Optional: User implements this for suggestions data
+#[cfg(feature = "suggestions")]
 #[async_trait]
-pub trait AutocompleteProvider {
-    /// Fetch autocomplete suggestions (user's business logic)
+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,

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 +1,122 @@
+// 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;
+
+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,
+        >,
+    >,
+}
+
+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,
+        };
+
+        #[cfg(feature = "validation")]
+        {
+            let mut editor = editor;
+            editor.initialize_validation();
+            editor
+        }
+        #[cfg(not(feature = "validation"))]
+        {
+            editor
+        }
+    }
+
+    // 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/mod.rs

@@ -0,0 +1,21 @@
+// src/editor/mod.rs
+// Only module declarations and re-exports.
+
+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;
+
+// Re-export the main type
+pub use core::FormEditor;

canvas/src/editor/mode.rs

@@ -0,0 +1,222 @@
+// 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 (for vim compatibility)
+    pub fn set_mode(&mut self, mode: AppMode) {
+        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 (vim Escape)
+    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);
+                        }
+                    }
+                }
+            }
+        }
+
+        self.set_mode(AppMode::ReadOnly);
+        #[cfg(feature = "suggestions")]
+        {
+            self.close_suggestions();
+        }
+        Ok(())
+    }
+
+    /// Enter edit mode from read-only mode (vim i/a/o)
+    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;
+                }
+            }
+        }
+        self.set_mode(AppMode::Edit);
+    }
+
+    // -------------------- Highlight/Visual mode -------------------------
+
+    pub fn enter_highlight_mode(&mut self) {
+        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) {
+        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) {
+        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 {
+        self.ui_state.current_mode == AppMode::Highlight
+    }
+
+    pub fn selection_state(&self) -> &SelectionState {
+        &self.ui_state.selection
+    }
+
+    // Visual-mode movements reuse existing movement methods
+    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 +1,690 @@
+// 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 {
+            if 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().map_or(false, |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().map_or(false, |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().map_or(false, |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().map_or(false, |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() {
+                if 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() {
+                if 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 +1,166 @@
+// 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 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/lib.rs

@@ -4,14 +4,18 @@ pub mod canvas;
 pub mod editor;
 pub mod data_provider;
 
-// Only include autocomplete module if feature is enabled
-#[cfg(feature = "autocomplete")]
-pub mod autocomplete;
+// Only include suggestions module if feature is enabled
+#[cfg(feature = "suggestions")]
+pub mod suggestions;
 
 // Only include validation module if feature is enabled
 #[cfg(feature = "validation")]
 pub mod validation;
 
+// Only include computed module if feature is enabled
+#[cfg(feature = "computed")]
+pub mod computed;
+
 #[cfg(feature = "cursor-style")]
 pub use canvas::CursorManager;
 
@@ -21,7 +25,9 @@ pub use canvas::CursorManager;
 
 // Main API exports
 pub use editor::FormEditor;
-pub use data_provider::{DataProvider, AutocompleteProvider, SuggestionItem};
+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;
@@ -41,6 +47,10 @@ pub use validation::{
     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};
@@ -51,5 +61,5 @@ pub use canvas::gui::render_canvas;
 #[cfg(feature = "gui")]
 pub use canvas::gui::render_canvas_default;
 
-#[cfg(all(feature = "gui", feature = "autocomplete"))]
-pub use autocomplete::gui::render_autocomplete_dropdown;
+#[cfg(all(feature = "gui", feature = "suggestions"))]
+pub use suggestions::gui::render_suggestions_dropdown;

canvas/src/suggestions/gui.rs

@@ -1,5 +1,5 @@
-// src/autocomplete/gui.rs
-//! Autocomplete GUI updated to work with FormEditor
+// src/suggestions/gui.rs
+//! Suggestions dropdown GUI (not inline autocomplete) updated to work with FormEditor
 
 #[cfg(feature = "gui")]
 use ratatui::{
@@ -17,9 +17,9 @@ use crate::editor::FormEditor;
 #[cfg(feature = "gui")]
 use unicode_width::UnicodeWidthStr;
 
-/// Render autocomplete dropdown for FormEditor - call this AFTER rendering canvas
+/// Render suggestions dropdown for FormEditor - call this AFTER rendering canvas
 #[cfg(feature = "gui")]
-pub fn render_autocomplete_dropdown<T: CanvasTheme, D: DataProvider>(
+pub fn render_suggestions_dropdown<T: CanvasTheme, D: DataProvider>(
     f: &mut Frame,
     frame_area: Rect,
     input_rect: Rect,
@@ -28,14 +28,14 @@ pub fn render_autocomplete_dropdown<T: CanvasTheme, D: DataProvider>(
 ) {
     let ui_state = editor.ui_state();
 
-    if !ui_state.is_autocomplete_active() {
+    if !ui_state.is_suggestions_active() {
         return;
     }
 
-    if ui_state.autocomplete.is_loading {
+    if ui_state.suggestions.is_loading {
         render_loading_indicator(f, frame_area, input_rect, theme);
     } else if !editor.suggestions().is_empty() {
-        render_suggestions_dropdown(f, frame_area, input_rect, theme, editor.suggestions(), ui_state.autocomplete.selected_index);
+        render_suggestions_dropdown_list(f, frame_area, input_rect, theme, editor.suggestions(), ui_state.suggestions.selected_index);
     }
 }
 
@@ -71,7 +71,7 @@ fn render_loading_indicator<T: CanvasTheme>(
 
 /// Show actual suggestions list
 #[cfg(feature = "gui")]
-fn render_suggestions_dropdown<T: CanvasTheme>(
+fn render_suggestions_dropdown_list<T: CanvasTheme>(
     f: &mut Frame,
     frame_area: Rect,
     input_rect: Rect,

canvas/src/suggestions/mod.rs

@@ -0,0 +1,12 @@
+// src/suggestions/mod.rs
+
+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/validation/config.rs

@@ -22,6 +22,9 @@ pub struct ValidationConfig {
     #[cfg(feature = "validation")]
     pub custom_formatter: Option<Arc<dyn CustomFormatter + Send + Sync>>,
 
+    /// Enable external validation indicator UI (feature 5)
+    pub external_validation_enabled: bool,
+
     /// Future: External validation
     pub external_validation: Option<()>, // Placeholder for future implementation
 }
@@ -47,6 +50,7 @@ impl std::fmt::Debug for ValidationConfig {
                   }
               },
           )
+          .field("external_validation_enabled", &self.external_validation_enabled)
           .field("external_validation", &self.external_validation)
           .finish()
     }
@@ -285,6 +289,12 @@ impl ValidationConfigBuilder {
         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

canvas/src/validation/limits.rs

@@ -122,42 +122,59 @@ impl CharacterLimits {
     pub fn validate_insertion(
         &self,
         current_text: &str,
-        _position: usize,
+        position: usize,
         character: char,
     ) -> Option<ValidationResult> {
-        let current_count = self.count(current_text);
-        let char_count = match self.count_mode {
-            CountMode::Characters => 1,
-            CountMode::DisplayWidth => {
-                let char_str = character.to_string();
-                char_str.width()
-            },
-            CountMode::Bytes => character.len_utf8(),
-        };
-        let new_count = current_count + char_count;
+        // 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, 
+                    "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, 
+                        "Approaching character limit: {}/{}",
+                        new_count,
                         max
                     )));
                 }
             }
         }
-        
+
         None // No validation issues
     }
     

canvas/src/validation/mod.rs

@@ -16,6 +16,16 @@ pub use patterns::{PatternFilters, PositionFilter, PositionRange, CharacterFilte
 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 {

canvas/src/validation/state.rs

@@ -1,9 +1,7 @@
 // src/validation/state.rs
 //! Validation state management
 
-use crate::validation::{ValidationConfig, ValidationResult};
-#[cfg(feature = "validation")]
-use crate::validation::{PositionMapper};
+use crate::validation::{ValidationConfig, ValidationResult, ExternalValidationState};
 use std::collections::HashMap;
 
 /// Validation state for all fields in a form
@@ -20,6 +18,11 @@ pub struct ValidationState {
     
     /// 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 {
@@ -30,6 +33,8 @@ impl ValidationState {
             field_results: HashMap::new(),
             validated_fields: std::collections::HashSet::new(),
             enabled: true,
+            external_results: HashMap::new(),
+            last_switch_block: None,
         }
     }
     
@@ -40,6 +45,7 @@ impl ValidationState {
             // Clear all validation results when disabled
             self.field_results.clear();
             self.validated_fields.clear();
+            self.external_results.clear(); // Also clear external results
         }
     }
     
@@ -50,12 +56,13 @@ impl ValidationState {
     
     /// Set validation configuration for a field
     pub fn set_field_config(&mut self, field_index: usize, config: ValidationConfig) {
-        if config.has_validation() {
+        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);
         }
     }
     
@@ -69,6 +76,30 @@ impl ValidationState {
         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
@@ -123,7 +154,7 @@ impl ValidationState {
     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")]
@@ -131,7 +162,7 @@ impl ValidationState {
         &self,
         field_index: usize,
         raw: &str,
-    ) -> Option<(String, std::sync::Arc<dyn PositionMapper>, Option<String>)> {
+    ) -> Option<(String, std::sync::Arc<dyn crate::validation::PositionMapper>, Option<String>)> {
         let config = self.field_configs.get(&field_index)?;
         config.run_custom_formatter(raw)
     }
@@ -228,6 +259,22 @@ impl ValidationState {
             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

canvas/view_docs.sh

@@ -27,7 +27,7 @@ show_module() {
 
 # Main modules
 show_module "canvas" "CANVAS SYSTEM"
-show_module "autocomplete" "AUTOCOMPLETE SYSTEM" 
+show_module "suggestions" "SUGGESTIONS SYSTEM" 
 show_module "config" "CONFIGURATION SYSTEM"
 
 # Show lib.rs and other root files
@@ -45,7 +45,7 @@ fi
 echo -e "\n\033[1;36m=========================================="
 echo "To view specific module documentation:"
 echo "  ./view_canvas_docs.sh canvas"
-echo "  ./view_canvas_docs.sh autocomplete" 
+echo "  ./view_canvas_docs.sh suggestions" 
 echo "  ./view_canvas_docs.sh config"
 echo "==========================================\033[0m"