syntec, but not compiling

canvas/src/textarea/highlight/chunks.rs

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

canvas/src/textarea/highlight/engine.rs

@@ -0,0 +1,269 @@
+// src/textarea/highlight/engine.rs
+#![allow(dead_code)]
+
+use std::collections::hash_map::DefaultHasher;
+use std::hash::{Hash, Hasher};
+
+use ratatui::style::{Modifier, Style};
+use syntect::{
+    highlighting::{
+        HighlightIterator, Highlighter, Style as SynStyle, Theme, ThemeSet,
+    },
+    parsing::{ParseState, ScopeStack, SyntaxReference, SyntaxSet},
+};
+
+use crate::data_provider::DataProvider;
+use super::chunks::StyledChunk;
+
+#[derive(Debug)]
+pub struct SyntectEngine {
+    ps: SyntaxSet,
+    ts: ThemeSet,
+    theme_name: String,
+    syntax_name: Option<String>,
+    // Cached parser state (after line i)
+    parse_after: Vec<ParseState>,
+    // Cached scope stack (after line i)
+    stack_after: Vec<ScopeStack>,
+    // Hash of line contents to detect edits
+    line_hashes: Vec<u64>,
+}
+
+impl SyntectEngine {
+    pub fn new() -> Self {
+        let ps = SyntaxSet::load_defaults_newlines();
+        let ts = ThemeSet::load_defaults();
+        Self {
+            ps,
+            ts,
+            theme_name: "InspiredGitHub".to_string(),
+            syntax_name: None,
+            parse_after: Vec::new(),
+            stack_after: Vec::new(),
+            line_hashes: Vec::new(),
+        }
+    }
+
+    pub fn clear(&mut self) {
+        self.parse_after.clear();
+        self.stack_after.clear();
+        self.line_hashes.clear();
+    }
+
+    pub fn set_theme(&mut self, theme_name: &str) -> bool {
+        if self.ts.themes.contains_key(theme_name) {
+            self.theme_name = theme_name.to_string();
+            true
+        } else {
+            false
+        }
+    }
+
+    pub fn set_syntax_by_name(&mut self, name: &str) -> bool {
+        if self.ps.find_syntax_by_name(name).is_some() {
+            self.syntax_name = Some(name.to_string());
+            self.clear();
+            true
+        } else {
+            false
+        }
+    }
+
+    pub fn set_syntax_by_extension(&mut self, ext: &str) -> bool {
+        if let Some(s) = self.ps.find_syntax_by_extension(ext) {
+            self.syntax_name = Some(s.name.clone());
+            self.clear();
+            true
+        } else {
+            false
+        }
+    }
+
+    pub fn invalidate_from(&mut self, line_idx: usize) {
+        if line_idx < self.parse_after.len() {
+            self.parse_after.truncate(line_idx);
+        }
+        if line_idx < self.stack_after.len() {
+            self.stack_after.truncate(line_idx);
+        }
+        if line_idx < self.line_hashes.len() {
+            self.line_hashes.truncate(line_idx);
+        }
+    }
+
+    pub fn on_insert_line(&mut self, at: usize) {
+        self.invalidate_from(at);
+    }
+
+    pub fn on_delete_line(&mut self, at: usize) {
+        self.invalidate_from(at);
+    }
+
+    fn theme(&self) -> &Theme {
+        self.ts
+            .themes
+            .get(&self.theme_name)
+            .expect("theme exists")
+    }
+
+    fn syntax_ref(&self) -> &SyntaxReference {
+        if let Some(name) = &self.syntax_name {
+            if let Some(s) = self.ps.find_syntax_by_name(name) {
+                return s;
+            }
+        }
+        self.ps.find_syntax_plain_text()
+    }
+
+    fn map_syntect_style(s: SynStyle) -> Style {
+        let fg =
+            ratatui::style::Color::Rgb(s.foreground.r, s.foreground.g, s.foreground.b);
+        let mut st = Style::default().fg(fg);
+        use syntect::highlighting::FontStyle;
+        if s.font_style.contains(FontStyle::BOLD) {
+            st = st.add_modifier(Modifier::BOLD);
+        }
+        if s.font_style.contains(FontStyle::UNDERLINE) {
+            st = st.add_modifier(Modifier::UNDERLINED);
+        }
+        if s.font_style.contains(FontStyle::ITALIC) {
+            st = st.add_modifier(Modifier::ITALIC);
+        }
+        st
+    }
+
+    fn hash_line(s: &str) -> u64 {
+        let mut h = DefaultHasher::new();
+        s.hash(&mut h);
+        h.finish()
+    }
+
+    // Verify cached chain up to the nearest trusted predecessor of line_idx,
+    // using the provider to fetch the current lines.
+    fn verify_and_truncate_before(&mut self, line_idx: usize, provider: &dyn DataProvider) {
+        let mut k = std::cmp::min(line_idx, self.parse_after.len());
+        while k > 0 {
+            let j = k - 1;
+            let curr = Self::hash_line(provider.field_value(j));
+            if self.line_hashes.get(j) == Some(&curr) {
+                break;
+            }
+            self.invalidate_from(j);
+            k = j;
+        }
+    }
+
+    // Ensure we have parser + stack for lines [0..line_idx)
+    fn ensure_state_before(&mut self, line_idx: usize, provider: &dyn DataProvider) {
+        if line_idx == 0 || self.parse_after.len() >= line_idx {
+            return;
+        }
+
+        let syntax = self.syntax_ref();
+        let theme = self.theme();
+        let highlighter = Highlighter::new(theme);
+
+        let mut ps = if self.parse_after.is_empty() {
+            ParseState::new(syntax)
+        } else {
+            self.parse_after[self.parse_after.len() - 1].clone()
+        };
+        let mut stack = if self.stack_after.is_empty() {
+            ScopeStack::new()
+        } else {
+            self.stack_after[self.stack_after.len() - 1].clone()
+        };
+
+        let start = self.parse_after.len();
+        for i in start..line_idx {
+            let s = provider.field_value(i);
+            let ops = ps.parse_line(s);
+            // Advance stack by applying ops using HighlightIterator
+            let mut it = HighlightIterator::new(&highlighter, &ops[..], s, &mut stack);
+            while let Some((_style, _text)) = it.next() {
+                // Iterate to apply ops; we don't need the tokens here.
+            }
+
+            let h = Self::hash_line(s);
+
+            self.parse_after.push(ps.clone());
+            self.stack_after.push(stack.clone());
+            if i >= self.line_hashes.len() {
+                self.line_hashes.push(h);
+            } else {
+                self.line_hashes[i] = h;
+            }
+        }
+    }
+
+    // Highlight a single line using cached state; update caches for this line.
+    pub fn highlight_line_cached(
+        &mut self,
+        line_idx: usize,
+        line: &str,
+        provider: &dyn DataProvider,
+    ) -> Vec<StyledChunk> {
+        // Auto-detect prior changes and truncate cache if needed
+        self.verify_and_truncate_before(line_idx, provider);
+        // Precompute states up to line_idx
+        self.ensure_state_before(line_idx, provider);
+
+        let syntax = self.syntax_ref();
+        let theme = self.theme();
+        let highlighter = Highlighter::new(theme);
+
+        let mut ps = if line_idx == 0 {
+            ParseState::new(syntax)
+        } else if self.parse_after.len() >= line_idx {
+            self.parse_after[line_idx - 1].clone()
+        } else {
+            ParseState::new(syntax)
+        };
+
+        let mut stack = if line_idx == 0 {
+            ScopeStack::new()
+        } else if self.stack_after.len() >= line_idx {
+            self.stack_after[line_idx - 1].clone()
+        } else {
+            ScopeStack::new()
+        };
+
+        let ops = ps.parse_line(line);
+        let mut iter = HighlightIterator::new(&highlighter, &ops[..], line, &mut stack);
+
+        let mut out: Vec<StyledChunk> = Vec::new();
+        while let Some((syn_style, slice)) = iter.next() {
+            if slice.is_empty() {
+                continue;
+            }
+            let text = slice.trim_end_matches('\n').to_string();
+            if text.is_empty() {
+                continue;
+            }
+            out.push(StyledChunk {
+                text,
+                style: Self::map_syntect_style(syn_style),
+            });
+        }
+
+        // Update caches for this line (state after this line)
+        let h = Self::hash_line(line);
+        if line_idx >= self.parse_after.len() {
+            self.parse_after.push(ps);
+        } else {
+            self.parse_after[line_idx] = ps;
+        }
+        if line_idx >= self.stack_after.len() {
+            self.stack_after.push(stack);
+        } else {
+            self.stack_after[line_idx] = stack;
+        }
+        if line_idx >= self.line_hashes.len() {
+            self.line_hashes.push(h);
+        } else {
+            self.line_hashes[line_idx] = h;
+        }
+
+        out
+    }
+}

canvas/src/textarea/highlight/mod.rs

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

canvas/src/textarea/highlight/state.rs

@@ -0,0 +1,53 @@
+// src/textarea/highlight/state.rs
+use std::ops::{Deref, DerefMut};
+
+use super::engine::SyntectEngine;
+use crate::textarea::state::TextAreaState;
+
+// Remove Debug derive since TextAreaState doesn't implement Debug
+pub struct TextAreaSyntaxState {
+    pub textarea: TextAreaState,
+    pub engine: SyntectEngine,
+}
+
+impl Default for TextAreaSyntaxState {
+    fn default() -> Self {
+        Self {
+            textarea: TextAreaState::default(),
+            engine: SyntectEngine::new(),
+        }
+    }
+}
+
+impl TextAreaSyntaxState {
+    pub fn from_text<S: Into<String>>(text: S) -> Self {
+        let mut s = Self::default();
+        s.textarea.set_text(text);
+        s
+    }
+
+    // Optional: convenience setters
+    pub fn set_syntax_theme(&mut self, theme: &str) -> bool {
+        self.engine.set_theme(theme)
+    }
+    pub fn set_syntax_by_name(&mut self, name: &str) -> bool {
+        self.engine.set_syntax_by_name(name)
+    }
+    pub fn set_syntax_by_extension(&mut self, ext: &str) -> bool {
+        self.engine.set_syntax_by_extension(ext)
+    }
+}
+
+impl Deref for TextAreaSyntaxState {
+    type Target = TextAreaState;
+    fn deref(&self) -> &Self::Target {
+        &self.textarea
+    }
+}
+
+impl DerefMut for TextAreaSyntaxState {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.textarea
+    }
+}
+

canvas/src/textarea/highlight/widget.rs

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

canvas/src/textarea/mod.rs

@@ -1,8 +1,5 @@
 // src/textarea/mod.rs
 //! Text area convenience exports.
-//!
-//! Re-export the core textarea types and provider so consumers can use
-//! `canvas::textarea::TextArea` / `TextAreaState` / `TextAreaProvider`.
 
 pub mod provider;
 pub mod state;
@@ -10,6 +7,9 @@ pub mod state;
 #[cfg(feature = "gui")]
 pub mod widget;
 
+#[cfg(all(feature = "syntect", feature = "gui"))]
+pub mod highlight;
+
 pub use provider::TextAreaProvider;
 pub use state::{TextAreaEditor, TextAreaState, TextOverflowMode};