gui of canvas is from the canvas crate now

canvas/src/gui/mod.rs

@@ -0,0 +1,7 @@
+// canvas/src/gui/mod.rs
+
+pub mod theme;
+pub mod render;
+
+pub use theme::CanvasTheme;
+pub use render::render_canvas;

canvas/src/gui/render.rs

@@ -0,0 +1,244 @@
+// canvas/src/gui/render.rs
+
+#[cfg(feature = "gui")]
+use ratatui::{
+    layout::{Alignment, Constraint, Direction, Layout, Rect},
+    style::{Modifier, Style},
+    text::{Line, Span},
+    widgets::{Block, Borders, Paragraph},
+    Frame,
+};
+use crate::state::CanvasState;
+use crate::modes::HighlightState;
+#[cfg(feature = "gui")]
+use super::theme::CanvasTheme;
+#[cfg(feature = "gui")]
+use std::cmp::{max, min};
+
+/// Render canvas using the CanvasState trait and CanvasTheme
+#[cfg(feature = "gui")]
+pub fn render_canvas<T: CanvasTheme>(
+    f: &mut Frame,
+    area: Rect,
+    form_state: &impl CanvasState,
+    theme: &T,
+    is_edit_mode: bool,
+    highlight_state: &HighlightState,
+) -> Option<Rect> {
+    let fields: Vec<&str> = form_state.fields();
+    let current_field_idx = form_state.current_field();
+    let inputs: Vec<&String> = form_state.inputs();
+    
+    render_canvas_impl(
+        f,
+        area,
+        &fields,
+        &current_field_idx,
+        &inputs,
+        theme,
+        is_edit_mode,
+        highlight_state,
+        form_state.current_cursor_pos(),
+        form_state.has_unsaved_changes(),
+        |i| form_state.get_display_value_for_field(i).to_string(),
+        |i| form_state.has_display_override(i),
+    )
+}
+
+/// Internal implementation of canvas rendering
+#[cfg(feature = "gui")]
+fn render_canvas_impl<T: CanvasTheme, F1, F2>(
+    f: &mut Frame,
+    area: Rect,
+    fields: &[&str],
+    current_field_idx: &usize,
+    inputs: &[&String],
+    theme: &T,
+    is_edit_mode: bool,
+    highlight_state: &HighlightState,
+    current_cursor_pos: usize,
+    has_unsaved_changes: bool,
+    get_display_value: F1,
+    has_display_override: F2,
+) -> Option<Rect>
+where
+    F1: Fn(usize) -> String,
+    F2: Fn(usize) -> bool,
+{
+    let columns = Layout::default()
+        .direction(Direction::Horizontal)
+        .constraints([Constraint::Percentage(30), Constraint::Percentage(70)])
+        .split(area);
+
+    let border_style = if has_unsaved_changes {
+        Style::default().fg(theme.warning())
+    } else if is_edit_mode {
+        Style::default().fg(theme.accent())
+    } else {
+        Style::default().fg(theme.secondary())
+    };
+    
+    let input_container = Block::default()
+        .borders(Borders::ALL)
+        .border_style(border_style)
+        .style(Style::default().bg(theme.bg()));
+
+    let input_block = Rect {
+        x: columns[1].x,
+        y: columns[1].y,
+        width: columns[1].width,
+        height: fields.len() as u16 + 2,
+    };
+
+    f.render_widget(&input_container, input_block);
+
+    let input_area = input_container.inner(input_block);
+    let input_rows = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints(vec![Constraint::Length(1); fields.len()])
+        .split(input_area);
+
+    let mut active_field_input_rect = None;
+
+    // Render field labels
+    for (i, field) in fields.iter().enumerate() {
+        let label = Paragraph::new(Line::from(Span::styled(
+            format!("{}:", field),
+            Style::default().fg(theme.fg()),
+        )));
+        f.render_widget(
+            label,
+            Rect {
+                x: columns[0].x,
+                y: input_block.y + 1 + i as u16,
+                width: columns[0].width,
+                height: 1,
+            },
+        );
+    }
+
+    // Render field values
+    for (i, _input) in inputs.iter().enumerate() {
+        let is_active = i == *current_field_idx;
+
+        // Use the provided closure to get display value
+        let text = get_display_value(i);
+        let text_len = text.chars().count();
+        let line: Line;
+
+        match highlight_state {
+            HighlightState::Off => {
+                line = Line::from(Span::styled(
+                    &text,
+                    if is_active {
+                        Style::default().fg(theme.highlight())
+                    } else {
+                        Style::default().fg(theme.fg())
+                    },
+                ));
+            }
+            HighlightState::Characterwise { anchor } => {
+                let (anchor_field, anchor_char) = *anchor;
+                let start_field = min(anchor_field, *current_field_idx);
+                let end_field = max(anchor_field, *current_field_idx);
+
+                let (start_char, end_char) = if anchor_field == *current_field_idx {
+                    (min(anchor_char, current_cursor_pos), max(anchor_char, current_cursor_pos))
+                } else if anchor_field < *current_field_idx {
+                    (anchor_char, current_cursor_pos)
+                } else {
+                    (current_cursor_pos, anchor_char)
+                };
+
+                let highlight_style = Style::default()
+                    .fg(theme.highlight())
+                    .bg(theme.highlight_bg())
+                    .add_modifier(Modifier::BOLD);
+                let normal_style_in_highlight = Style::default().fg(theme.highlight());
+                let normal_style_outside = Style::default().fg(theme.fg());
+
+                if i >= start_field && i <= end_field {
+                    if start_field == end_field {
+                        let clamped_start = start_char.min(text_len);
+                        let clamped_end = end_char.min(text_len);
+
+                        let before: String = text.chars().take(clamped_start).collect();
+                        let highlighted: String = text.chars()
+                            .skip(clamped_start)
+                            .take(clamped_end.saturating_sub(clamped_start) + 1)
+                            .collect();
+                        let after: String = text.chars().skip(clamped_end + 1).collect();
+
+                        line = Line::from(vec![
+                            Span::styled(before, normal_style_in_highlight),
+                            Span::styled(highlighted, highlight_style),
+                            Span::styled(after, normal_style_in_highlight),
+                        ]);
+                    } else if i == start_field {
+                        let safe_start = start_char.min(text_len);
+                        let before: String = text.chars().take(safe_start).collect();
+                        let highlighted: String = text.chars().skip(safe_start).collect();
+                        line = Line::from(vec![
+                            Span::styled(before, normal_style_in_highlight),
+                            Span::styled(highlighted, highlight_style),
+                        ]);
+                    } else if i == end_field {
+                        let safe_end_inclusive = if text_len > 0 { end_char.min(text_len - 1) } else { 0 };
+                        let highlighted: String = text.chars().take(safe_end_inclusive + 1).collect();
+                        let after: String = text.chars().skip(safe_end_inclusive + 1).collect();
+                        line = Line::from(vec![
+                            Span::styled(highlighted, highlight_style),
+                            Span::styled(after, normal_style_in_highlight),
+                        ]);
+                    } else {
+                        line = Line::from(Span::styled(&text, highlight_style));
+                    }
+                } else {
+                    line = Line::from(Span::styled(
+                        &text,
+                        if is_active { normal_style_in_highlight } else { normal_style_outside }
+                    ));
+                }
+            }
+            HighlightState::Linewise { anchor_line } => {
+                let start_field = min(*anchor_line, *current_field_idx);
+                let end_field = max(*anchor_line, *current_field_idx);
+                let highlight_style = Style::default()
+                    .fg(theme.highlight())
+                    .bg(theme.highlight_bg())
+                    .add_modifier(Modifier::BOLD);
+                let normal_style_in_highlight = Style::default().fg(theme.highlight());
+                let normal_style_outside = Style::default().fg(theme.fg());
+
+                if i >= start_field && i <= end_field {
+                    line = Line::from(Span::styled(&text, highlight_style));
+                } else {
+                    line = Line::from(Span::styled(
+                        &text,
+                        if is_active { normal_style_in_highlight } else { normal_style_outside }
+                    ));
+                }
+            }
+        }
+
+        let input_display = Paragraph::new(line).alignment(Alignment::Left);
+        f.render_widget(input_display, input_rows[i]);
+
+        if is_active {
+            active_field_input_rect = Some(input_rows[i]);
+
+            // Use the provided closure to check for display override
+            let cursor_x = if has_display_override(i) {
+                // If an override exists, place the cursor at the end.
+                input_rows[i].x + text.chars().count() as u16
+            } else {
+                // Otherwise, use the real cursor position.
+                input_rows[i].x + current_cursor_pos as u16
+            };
+            let cursor_y = input_rows[i].y;
+            f.set_cursor_position((cursor_x, cursor_y));
+        }
+    }
+
+    active_field_input_rect
+}

canvas/src/gui/theme.rs

@@ -0,0 +1,17 @@
+// canvas/src/gui/theme.rs
+
+#[cfg(feature = "gui")]
+use ratatui::style::Color;
+
+/// Theme trait that must be implemented by applications using the canvas GUI
+#[cfg(feature = "gui")]
+pub trait CanvasTheme {
+    fn bg(&self) -> Color;
+    fn fg(&self) -> Color;
+    fn border(&self) -> Color;
+    fn accent(&self) -> Color;
+    fn secondary(&self) -> Color;
+    fn highlight(&self) -> Color;
+    fn highlight_bg(&self) -> Color;
+    fn warning(&self) -> Color;
+}

canvas/src/lib.rs

@@ -11,6 +11,10 @@ pub mod config;
 pub mod suggestions;
 pub mod dispatcher;
 
+// GUI module (optional, enabled with "gui" feature)
+#[cfg(feature = "gui")]
+pub mod gui;
+
 // Re-export the main types for easy use
 pub use state::{CanvasState, ActionContext};
 pub use actions::{CanvasAction, ActionResult, execute_edit_action, execute_canvas_action};
@@ -18,6 +22,10 @@ pub use modes::{AppMode, ModeManager, HighlightState};
 pub use suggestions::SuggestionState;
 pub use dispatcher::ActionDispatcher;
 
+// Re-export GUI types when available
+#[cfg(feature = "gui")]
+pub use gui::{CanvasTheme, render_canvas};
+
 // High-level convenience API
 pub mod prelude {
     pub use crate::{
@@ -33,4 +41,7 @@ pub mod prelude {
         HighlightState,
         SuggestionState,
     };
+    
+    #[cfg(feature = "gui")]
+    pub use crate::{CanvasTheme, render_canvas};
 }