feat: add pane copy mode

refs #231

3 files changed, 60 insertions, 0 deletions

diff --git a/src/ui/keybind_help.rs b/src/ui/keybind_help.rs
index c3664dec..4fb559c6 100644
--- a/src/ui/keybind_help.rs
+++ b/src/ui/keybind_help.rs
@@ -126,6 +126,7 @@ pub(super) fn keybind_help_groups(
         (keybind_label(&kb.close_pane), "close pane"),
         (keybind_label(&kb.rename_pane), "rename pane"),
         (keybind_label(&kb.edit_scrollback), "edit scrollback"),
+        (keybind_label(&kb.copy_mode), "copy mode"),
         (keybind_label(&kb.zoom), "zoom pane"),
         (keybind_label(&kb.resize_mode), "resize mode"),
         (keybind_label(&kb.toggle_sidebar), "toggle sidebar"),
diff --git a/src/ui/menus.rs b/src/ui/menus.rs
index b711358e..e974d524 100644
--- a/src/ui/menus.rs
+++ b/src/ui/menus.rs
@@ -60,6 +60,39 @@ pub(super) fn render_prefix_overlay(app: &AppState, frame: &mut Frame, area: Rec
     render_bottom_bar(frame, overlay_area, line, app.palette.panel_bg);
 }
 
+pub(super) fn render_copy_mode_overlay(app: &AppState, frame: &mut Frame, area: Rect) {
+    let key = Style::default()
+        .fg(app.palette.accent)
+        .add_modifier(Modifier::BOLD);
+    let dim = Style::default().fg(app.palette.overlay0);
+    let mode_style = Style::default()
+        .fg(panel_contrast_fg(&app.palette))
+        .bg(app.palette.accent)
+        .add_modifier(Modifier::BOLD);
+
+    let select = if app.copy_mode.is_some_and(|copy_mode| copy_mode.selecting) {
+        "selecting"
+    } else {
+        "select"
+    };
+    let line = Line::from(vec![
+        Span::styled(" COPY ", mode_style),
+        Span::raw(" "),
+        Span::styled("h/j/k/l w/b/e { }", key),
+        Span::styled(" move  ", dim),
+        Span::styled("v/space", key),
+        Span::styled(format!(" {select}  "), dim),
+        Span::styled("y/enter", key),
+        Span::styled(" copy  ", dim),
+        Span::styled("q/esc", key),
+        Span::styled(" exit", dim),
+    ]);
+
+    let overlay_y = area.y + area.height.saturating_sub(1);
+    let overlay_area = Rect::new(area.x, overlay_y, area.width, 1);
+    render_bottom_bar(frame, overlay_area, line, app.palette.panel_bg);
+}
+
 pub(super) fn render_navigate_overlay(app: &AppState, frame: &mut Frame, area: Rect) {
     let key = Style::default()
         .fg(app.palette.accent)
diff --git a/src/ui/panes.rs b/src/ui/panes.rs
index c211ec9d..8c7d1f02 100644
--- a/src/ui/panes.rs
+++ b/src/ui/panes.rs
@@ -313,10 +313,36 @@ pub(super) fn render_panes(
                 rt.scroll_metrics(),
                 &app.palette,
             );
+            render_copy_mode_cursor(app, frame, info);
         }
     }
 }
 
+fn render_copy_mode_cursor(app: &AppState, frame: &mut Frame, info: &PaneInfo) {
+    if app.mode != Mode::Copy {
+        return;
+    }
+    let Some(copy_mode) = app.copy_mode else {
+        return;
+    };
+    if copy_mode.pane_id != info.id
+        || copy_mode.cursor_row >= info.inner_rect.height
+        || copy_mode.cursor_col >= info.inner_rect.width
+    {
+        return;
+    }
+
+    let x = info.inner_rect.x + copy_mode.cursor_col;
+    let y = info.inner_rect.y + copy_mode.cursor_row;
+    let cell = &mut frame.buffer_mut()[(x, y)];
+    cell.set_style(
+        Style::default()
+            .fg(panel_contrast_fg(&app.palette))
+            .bg(app.palette.accent)
+            .add_modifier(Modifier::BOLD),
+    );
+}
+
 fn render_selection_highlight(
     selection: &Option<crate::selection::Selection>,
     frame: &mut Frame,