fix: keep diff explorer below the top bar

src/tui.rs

@@ -412,6 +412,17 @@ impl BufferViewports {
             Some(document_layout(area, editor))
         };
         let full_workspace = chrome.map_or(area, |areas| areas[0]);
+        let diff_header = editor
+            .diff()
+            .filter(|diff| !multiple && diff.phase == Phase::View)
+            .map(|_| {
+                Rect::new(
+                    full_workspace.x,
+                    full_workspace.y,
+                    full_workspace.width,
+                    full_workspace.height.min(1),
+                )
+            });
         let (workspace, dock) = match editor.file_picker() {
             Some(picker) if picker.presentation == FilePresentation::Docked => dock_layout(
                 full_workspace,
@@ -424,6 +435,13 @@ impl BufferViewports {
             ),
             _ => (full_workspace, None),
         };
+        let dock = dock.map(|mut panel| {
+            if let Some(header) = diff_header {
+                panel.y = panel.y.saturating_add(header.height);
+                panel.height = panel.height.saturating_sub(header.height);
+            }
+            panel
+        });
         editor.set_pane_bounds(pane_rect(workspace));
         self.rects.clear();
         editor
@@ -491,6 +509,11 @@ impl BufferViewports {
         }
         self.activate(focused, editor);
         self.panels.workspace_managed = false;
+        if let Some(header) = diff_header
+            && let Some(diff) = editor.diff()
+        {
+            draw_diff_header(frame, diff, Some(editor), header);
+        }
         if let Some(panel) = dock
             && let Some(picker) = editor.file_picker()
         {
@@ -1842,6 +1865,46 @@ fn draw_diff_popups(
     }
 }
 
+fn draw_diff_header(frame: &mut Frame, diff: &DiffState, editor: Option<&Editor>, header: Rect) {
+    if header.width == 0 || header.height == 0 {
+        return;
+    }
+    let (before, after) = diff.comparison.as_ref().map_or(("", ""), |comparison| {
+        (comparison.before.as_str(), comparison.after.as_str())
+    });
+    frame.render_widget(
+        Paragraph::new(format!(
+            "Diff · {} → {} · {:?} focus · {}",
+            display_text(before),
+            display_text(after),
+            diff.focus,
+            editor
+                .filter(|editor| editor.diff_interacting())
+                .map_or_else(
+                    || "read-only".into(),
+                    |editor| format!(
+                        "{} · {}{} · {}:{}",
+                        if editor.diff_editing() {
+                            "editable"
+                        } else {
+                            "read-only"
+                        },
+                        if editor.visual_linewise() {
+                            "VISUAL LINE".into()
+                        } else {
+                            editor.mode().to_string()
+                        },
+                        if editor.dirty() { " [+]" } else { "" },
+                        editor.cursor().row + 1,
+                        editor.cursor().column + 1,
+                    ),
+                )
+        ))
+        .style(Style::default().fg(Color::Black).bg(Color::Cyan)),
+        header,
+    );
+}
+
 fn draw_diff(
     frame: &mut Frame,
     diff: &DiffState,
@@ -2072,40 +2135,9 @@ fn draw_diff(
         Constraint::Length(u16::from(area.height >= 3)),
     ])
     .areas(area);
-    let (before, after) = comparison.map_or(("", ""), |comparison| {
-        (comparison.before.as_str(), comparison.after.as_str())
-    });
-    frame.render_widget(
-        Paragraph::new(format!(
-            "Diff · {} → {} · {:?} focus · {}",
-            display_text(before),
-            display_text(after),
-            diff.focus,
-            editor
-                .filter(|editor| editor.diff_interacting())
-                .map_or_else(
-                    || "read-only".into(),
-                    |editor| format!(
-                        "{} · {}{} · {}:{}",
-                        if editor.diff_editing() {
-                            "editable"
-                        } else {
-                            "read-only"
-                        },
-                        if editor.visual_linewise() {
-                            "VISUAL LINE".into()
-                        } else {
-                            editor.mode().to_string()
-                        },
-                        if editor.dirty() { " [+]" } else { "" },
-                        editor.cursor().row + 1,
-                        editor.cursor().column + 1,
-                    ),
-                )
-        ))
-        .style(Style::default().fg(Color::Black).bg(Color::Cyan)),
-        header,
-    );
+    if !panels.workspace_managed || editor.is_none_or(|editor| editor.pane_layout().len() > 1) {
+        draw_diff_header(frame, diff, editor, header);
+    }
     if let Some(notice) = notice {
         frame.render_widget(
             Paragraph::new(display_text(notice)).style(Style::default().fg(
@@ -5059,6 +5091,27 @@ mod tests {
         assert_eq!(dock.height, 28);
     }
 
+    #[test]
+    fn native_diff_dock_stays_below_the_full_width_header() {
+        let mut editor = readonly_diff_editor(deletion_file());
+        let mut views = BufferViewports::default();
+        for (width, height) in [(120, 30), (32, 9)] {
+            let mut terminal =
+                Terminal::new(ratatui::backend::TestBackend::new(width, height)).unwrap();
+            terminal
+                .draw(|frame| views.draw(frame, &mut editor))
+                .unwrap();
+            let dock = views.panels.files.unwrap().0;
+            let before = views.panels.diff.as_ref().unwrap().regions[1].0;
+            assert_eq!(dock.y, before.y);
+            assert_eq!(dock.y, 1);
+            assert_eq!(dock.right(), width);
+            for x in 0..width {
+                assert_eq!(terminal.backend().buffer()[(x, 0)].bg, Color::Cyan);
+            }
+        }
+    }
+
     #[test]
     fn revision_selector_overlays_and_clears_workspace_pane_borders() {
         let mut editor = Editor::open(None, vec![]).unwrap();