style: refine tab bar appearance

docs/editing.md

@@ -218,7 +218,7 @@ Use `:tab.new` to open the current buffer in a new, focused tab with one pane. E
 | `:tab.close` | `config.core.tab.close` | Close the current tab and all its panes, protecting unsaved changes |
 | `:tab.force_close` | `config.core.tab.force_close` | Explicitly discard exclusively displayed edits and close the tab |
 
-Multiple tabs show a top row with numbered filenames, dirty markers, and an active-tab highlight. Narrow terminals keep the active tab visible. New/close actions have no default keybinding; for example, `config.bind "leader t", config.core.tab.new`.
+Multiple tabs show a single top row with padded numbered filenames, subtle separators, and dirty markers. The active tab uses bold, underlined accent text; the row keeps the terminal's background instead of painting a full-width band. Narrow terminals keep the active tab visible. New/close actions have no default keybinding; for example, `config.bind "leader t", config.core.tab.new`.
 
 Closing a tab refuses dirty buffers whose final displayed owner would disappear, including a comparison's working and return buffers. Buffers displayed in another tab remain open with their edits, even on force-close. Other hidden buffers remain loaded. Closing the last tab quits only if every open buffer is clean; force-close quits without saving.
 

src/tui.rs

@@ -1040,21 +1040,28 @@ fn draw_tab_bar(frame: &mut Frame, editor: &Editor, area: Rect) -> Rect {
         .collect();
     let active = editor.tab_index();
     let mut first = active;
-    let mut width = labels[active].width();
-    while first > 0 && width + labels[first - 1].width() <= usize::from(bar.width) {
+    let padding = u16::from(bar.width > 1);
+    let mut width = labels[active].width() + usize::from(padding);
+    while first > 0 && width + 2 + labels[first - 1].width() <= usize::from(bar.width) {
         first -= 1;
-        width += labels[first].width();
+        width += 2 + labels[first].width();
     }
-    let inactive = Style::default().fg(Color::Gray).bg(Color::DarkGray);
-    frame.render_widget(Paragraph::new("").style(inactive), bar);
-    let mut x = bar.x;
+    let inactive = Style::default().fg(Color::Gray);
+    let mut x = bar.x + padding;
     for (index, label) in labels.iter().enumerate().skip(first) {
+        if index != first {
+            let width = 2.min(bar.right() - x);
+            frame.render_widget(
+                Paragraph::new("│ ").style(Style::default().fg(Color::DarkGray)),
+                Rect::new(x, bar.y, width, 1),
+            );
+            x += width;
+        }
         let width = label.width().min(usize::from(bar.right() - x)) as u16;
         let style = if index == active {
             Style::default()
-                .fg(Color::Black)
-                .bg(Color::Cyan)
-                .add_modifier(Modifier::BOLD)
+                .fg(Color::Cyan)
+                .add_modifier(Modifier::BOLD | Modifier::UNDERLINED)
         } else {
             inactive
         };
@@ -5189,12 +5196,6 @@ mod tests {
         let titles = pane_screen(&terminal, Rect::new(0, 0, 80, 1));
         assert!(titles.contains("1 a�name.txt [+]"), "{titles}");
         assert!(titles.contains("2 a�name.txt [+]"), "{titles}");
-        let active_x = display_column(&titles[..titles.find("2 a�name.txt").unwrap()], usize::MAX);
-        assert_eq!(terminal.backend().buffer()[(0, 0)].bg, Color::DarkGray);
-        assert_eq!(
-            terminal.backend().buffer()[(active_x as u16, 0)].bg,
-            Color::Cyan
-        );
         assert_eq!(views.document.geometry.unwrap().1.y, 1);
         assert!(terminal.get_cursor_position().unwrap().y >= 1);
         assert!(pane_screen(&terminal, views.rects[0].1).contains("changed DOCUMENT"));
@@ -5231,9 +5232,7 @@ mod tests {
                 .unwrap();
             if width > 0 && height > 0 {
                 let title = pane_screen(&terminal, Rect::new(0, 0, width, 1));
-                let expected: String = "3 active.txt".chars().take(usize::from(width)).collect();
-                assert_eq!(title, expected);
-                assert_eq!(terminal.backend().buffer()[(0, 0)].bg, Color::Cyan);
+                assert!(title.trim_start().starts_with('3'), "{title}");
             }
         }