automatic cursor style handled by the library

canvas/src/canvas/cursor.rs

@@ -0,0 +1,45 @@
+// src/canvas/cursor.rs
+//! Cursor style management for different canvas modes
+
+#[cfg(feature = "cursor-style")]
+use crossterm::{cursor::SetCursorStyle, execute};
+#[cfg(feature = "cursor-style")]
+use std::io;
+
+use crate::canvas::modes::AppMode;
+
+/// Manages cursor styles based on canvas modes
+pub struct CursorManager;
+
+impl CursorManager {
+    /// Update cursor style based on current mode
+    #[cfg(feature = "cursor-style")]
+    pub fn update_for_mode(mode: AppMode) -> io::Result<()> {
+        let style = match mode {
+            AppMode::Edit => SetCursorStyle::SteadyBar,           // Thin line for insert
+            AppMode::ReadOnly => SetCursorStyle::SteadyBlock,     // Block for normal
+            AppMode::Highlight => SetCursorStyle::BlinkingBlock,  // Blinking for visual
+            AppMode::General => SetCursorStyle::SteadyBlock,      // Block for general
+            AppMode::Command => SetCursorStyle::SteadyUnderScore, // Underscore for command
+        };
+        
+        execute!(io::stdout(), style)
+    }
+
+    /// No-op when cursor-style feature is disabled
+    #[cfg(not(feature = "cursor-style"))]
+    pub fn update_for_mode(_mode: AppMode) -> io::Result<()> {
+        Ok(())
+    }
+
+    /// Reset cursor to default on cleanup
+    #[cfg(feature = "cursor-style")]
+    pub fn reset() -> io::Result<()> {
+        execute!(io::stdout(), SetCursorStyle::DefaultUserShape)
+    }
+
+    #[cfg(not(feature = "cursor-style"))]
+    pub fn reset() -> io::Result<()> {
+        Ok(())
+    }
+}

canvas/src/canvas/mod.rs

@@ -6,9 +6,14 @@ pub mod modes;
 
 #[cfg(feature = "gui")]
 pub mod gui;
-
 #[cfg(feature = "gui")]
 pub mod theme;
 
+#[cfg(feature = "cursor-style")]
+pub mod cursor;
+
 // Keep these exports for current functionality
 pub use modes::{AppMode, ModeManager, HighlightState};
+
+#[cfg(feature = "cursor-style")]
+pub use cursor::CursorManager;

canvas/src/canvas/modes/manager.rs

@@ -1,6 +1,8 @@
 // src/modes/handlers/mode_manager.rs
 // canvas/src/modes/manager.rs
 
+#[cfg(feature = "cursor-style")]
+use crate::canvas::CursorManager;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum AppMode {
@@ -30,4 +32,39 @@ impl ModeManager {
     pub fn can_enter_highlight_mode(current_mode: AppMode) -> bool {
         matches!(current_mode, AppMode::ReadOnly)
     }
+
+
+    /// Transition to new mode with automatic cursor update (when cursor-style feature enabled)
+    pub fn transition_to_mode(current_mode: AppMode, new_mode: AppMode) -> std::io::Result<AppMode> {
+        if current_mode != new_mode {
+            #[cfg(feature = "cursor-style")]
+            {
+                let _ = CursorManager::update_for_mode(new_mode);
+            }
+        }
+        Ok(new_mode)
+    }
+
+    /// Enter highlight mode with cursor styling
+    pub fn enter_highlight_mode_with_cursor(current_mode: AppMode) -> std::io::Result<bool> {
+        if Self::can_enter_highlight_mode(current_mode) {
+            #[cfg(feature = "cursor-style")]
+            {
+                let _ = CursorManager::update_for_mode(AppMode::Highlight);
+            }
+            Ok(true)
+        } else {
+            Ok(false)
+        }
+    }
+
+    /// Exit highlight mode with cursor styling
+    pub fn exit_highlight_mode_with_cursor() -> std::io::Result<AppMode> {
+        let new_mode = AppMode::ReadOnly;
+        #[cfg(feature = "cursor-style")]
+        {
+            let _ = CursorManager::update_for_mode(new_mode);
+        }
+        Ok(new_mode)
+    }
 }

canvas/src/editor.rs

@@ -1,6 +1,9 @@
 // src/editor.rs
 //! Main API for the canvas library - FormEditor with library-owned state
 
+#[cfg(feature = "cursor-style")]
+use crate::canvas::CursorManager;
+
 use anyhow::Result;
 use crate::canvas::state::EditorState;
 use crate::data_provider::{DataProvider, AutocompleteProvider, SuggestionItem};
@@ -145,12 +148,21 @@ impl<D: DataProvider> FormEditor<D> {
 
     /// Change mode (for vim compatibility)
     pub fn set_mode(&mut self, mode: AppMode) {
+        #[cfg(feature = "cursor-style")]
+        let old_mode = self.ui_state.current_mode;
+
         self.ui_state.current_mode = mode;
 
         // Clear autocomplete when changing modes
         if mode != AppMode::Edit {
             self.ui_state.deactivate_autocomplete();
         }
+
+        // Update cursor style if mode changed and cursor-style feature is enabled
+        #[cfg(feature = "cursor-style")]
+        if old_mode != mode {
+            let _ = crate::canvas::CursorManager::update_for_mode(mode);
+        }
     }
 
     // ===================================================================
@@ -457,4 +469,75 @@ impl<D: DataProvider> FormEditor<D> {
         
         self.ui_state.cursor_pos = safe_pos;
     }
+
+  
+    /// Set the value of the current field
+    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);
+        // Reset cursor to start of field
+        self.ui_state.cursor_pos = 0;
+        self.ui_state.ideal_cursor_column = 0;
+    }
+    
+    /// Set the value of a specific field by index
+    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);
+            // If we're modifying the current field, reset cursor
+            if field_index == self.ui_state.current_field {
+                self.ui_state.cursor_pos = 0;
+                self.ui_state.ideal_cursor_column = 0;
+            }
+        }
+    }
+    
+    /// Clear the current field (set to empty string)
+    pub fn clear_current_field(&mut self) {
+        self.set_current_field_value(String::new());
+    }
+    
+    /// Get mutable access to data provider (for advanced operations)
+    pub fn data_provider_mut(&mut self) -> &mut D {
+        &mut self.data_provider
+    }
+
+    /// Set cursor to exact position (for vim-style movements like f, F, t, T)
+    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;
+        
+        // Clamp to valid bounds for current mode
+        let max_pos = if is_edit_mode {
+            current_text.len() // Edit mode: can go past end
+        } else {
+            current_text.len().saturating_sub(1).max(0) // Read-only: stay within text
+        };
+        
+        let clamped_pos = position.min(max_pos);
+        
+        // Update cursor position directly
+        self.ui_state.cursor_pos = clamped_pos;
+        self.ui_state.ideal_cursor_column = clamped_pos;
+    }
+
+    /// Cleanup cursor style (call this when shutting down)
+    pub fn cleanup_cursor(&self) -> std::io::Result<()> {
+        #[cfg(feature = "cursor-style")]
+        {
+            crate::canvas::CursorManager::reset()
+        }
+        #[cfg(not(feature = "cursor-style"))]
+        {
+            Ok(())
+        }
+    }
+}
+
+// Add Drop implementation for automatic cleanup
+impl<D: DataProvider> Drop for FormEditor<D> {
+    fn drop(&mut self) {
+        // Reset cursor to default when FormEditor is dropped
+        let _ = self.cleanup_cursor();
+    }
 }

canvas/src/lib.rs

@@ -8,6 +8,9 @@ pub mod data_provider;
 #[cfg(feature = "autocomplete")]
 pub mod autocomplete;
 
+#[cfg(feature = "cursor-style")]
+pub use canvas::CursorManager;
+
 // ===================================================================
 // NEW API: Library-owned state pattern
 // ===================================================================