feat: add literal buffer search and match navigation

src/tui.rs

@@ -228,6 +228,20 @@ fn draw(frame: &mut Frame, editor: &Editor, top: &mut usize, left: &mut usize) {
         Paragraph::new(lines),
         Rect::new(area.x, area.y, area.width, area.height - 2),
     );
+    if let Some(found) = editor.search_match()
+        && found.start.row >= *top
+        && found.start.row < top.saturating_add(height)
+    {
+        let line = &editor.lines()[found.start.row];
+        let start = display_column(line, found.start.column).max(*left);
+        let end = display_column(line, found.end_column).min(left.saturating_add(width));
+        let y = area.y + (found.start.row - *top) as u16;
+        let style = Style::default().fg(Color::Black).bg(Color::Yellow);
+        let buffer = frame.buffer_mut();
+        for column in start..end {
+            buffer[(area.x + (column - *left) as u16, y)].set_style(style);
+        }
+    }
     let path = editor
         .path()
         .map(|p| p.to_string_lossy().into_owned())
@@ -249,9 +263,14 @@ fn draw(frame: &mut Frame, editor: &Editor, top: &mut usize, left: &mut usize) {
         Rect::new(area.x, area.y + area.height - 2, area.width, 1),
     );
     let bottom = area.y + area.height - 1;
-    if editor.mode() == Mode::Command {
-        let command = format!(":{}", editor.command_line());
-        let command_width = UnicodeWidthStr::width(command.as_str());
+    if matches!(editor.mode(), Mode::Command | Mode::Search) {
+        let prefix = if editor.mode() == Mode::Search {
+            '/'
+        } else {
+            ':'
+        };
+        let command = format!("{prefix}{}", editor.command_line());
+        let command_width = display_column(&command, usize::MAX);
         let offset = command_width.saturating_sub(width - 1);
         frame.render_widget(
             Paragraph::new(visible_line(&command, offset, width)),
@@ -282,6 +301,57 @@ mod tests {
         assert_eq!(visible_line(text, 5, 2), " e\u{301}");
     }
 
+    #[test]
+    fn active_search_highlight_uses_display_cells_and_clips_with_horizontal_scroll() {
+        let mut editor = Editor::open(None, vec![]).unwrap();
+        editor
+            .apply(vec![crate::editor::Effect::Replace(
+                "a\t界e\u{301}zz".into(),
+            )])
+            .unwrap();
+        editor.handle(Input::Char('/'));
+        for ch in "\t界e\u{301}".chars() {
+            editor.handle(Input::Char(ch));
+        }
+        editor.handle(Input::Enter);
+        editor.handle(Input::End);
+        let mut terminal = Terminal::new(ratatui::backend::TestBackend::new(5, 5)).unwrap();
+        let (mut top, mut left) = (0, 0);
+        terminal
+            .draw(|frame| draw(frame, &editor, &mut top, &mut left))
+            .unwrap();
+        let buffer = terminal.backend().buffer();
+        assert_eq!(left, 4);
+        assert_eq!(buffer[(0, 0)].symbol(), "界");
+        assert_eq!(buffer[(2, 0)].symbol(), "e\u{301}");
+        for x in [0, 2] {
+            assert_eq!(buffer[(x, 0)].bg, Color::Yellow);
+        }
+        for x in 3..5 {
+            assert_ne!(buffer[(x, 0)].bg, Color::Yellow);
+        }
+        editor.handle(Input::Char('/'));
+        for ch in "界界".chars() {
+            editor.handle(Input::Char(ch));
+        }
+        terminal
+            .draw(|frame| draw(frame, &editor, &mut top, &mut left))
+            .unwrap();
+        let buffer = terminal.backend().buffer();
+        assert_eq!(buffer[(0, 4)].symbol(), "界");
+        assert_eq!(buffer[(2, 4)].symbol(), "界");
+        editor.handle(Input::Backspace);
+        editor.handle(Input::Backspace);
+        editor.handle(Input::Char('\t'));
+        terminal
+            .draw(|frame| draw(frame, &editor, &mut top, &mut left))
+            .unwrap();
+        assert_eq!(
+            terminal.get_cursor_position().unwrap(),
+            ratatui::layout::Position::new(4, 4)
+        );
+    }
+
     #[cfg(unix)]
     #[test]
     fn terminal_session_scopes_the_callers_panic_hook() {