Add editor::BlameHover action for triggering the blame popover via keyboard (#32096)

Make the git blame popover available via the keymap by making it an
action. The blame popover stays open after being shown via the action,
similar to the `editor::Hover` action.

I added a default vim-mode key binding for `g b`, which goes in hand
with `g h` for hover. I'm not sure what the keybind would be for regular
layouts, if any would be set by default.

I'm opening this as a draft because I coludn't figure out a way to
position the popover correctly above/under the cursor head. I saw some
uses of `content_origin` in other places for calculating absolute pixel
positions, but I'm not sure how to make use of it here without doing a
big refactor of the blame popover code 🤔. I would appreciate some
help/tips with positioning, because it seems like the last thing to
implement here.

Opening as a draft for now because I think without the correct
positioning this feature is not complete.

Closes https://github.com/zed-industries/zed/discussions/26447

Release Notes:

- Added `editor::BlameHover` action for showing the git blame popover
under the cursor. By default bound to `ctrl-k ctrl-b` and to `g h` in
vim mode.

assets/keymaps/default-linux.json

@@ -483,6 +483,7 @@
       "ctrl-k ctrl-d": ["editor::SelectNext", { "replace_newest": true }], // editor.action.moveSelectionToNextFindMatch  / find_under_expand_skip
       "ctrl-k ctrl-shift-d": ["editor::SelectPrevious", { "replace_newest": true }], // editor.action.moveSelectionToPreviousFindMatch
       "ctrl-k ctrl-i": "editor::Hover",
+      "ctrl-k ctrl-b": "editor::BlameHover",
       "ctrl-/": ["editor::ToggleComments", { "advance_downwards": false }],
       "f8": ["editor::GoToDiagnostic", { "severity": { "min": "hint", "max": "error" } }],
       "shift-f8": ["editor::GoToPreviousDiagnostic", { "severity": { "min": "hint", "max": "error" } }],

assets/keymaps/default-macos.json

@@ -537,6 +537,7 @@
       "ctrl-cmd-d": ["editor::SelectPrevious", { "replace_newest": false }], // editor.action.addSelectionToPreviousFindMatch
       "cmd-k ctrl-cmd-d": ["editor::SelectPrevious", { "replace_newest": true }], // editor.action.moveSelectionToPreviousFindMatch
       "cmd-k cmd-i": "editor::Hover",
+      "cmd-k cmd-b": "editor::BlameHover",
       "cmd-/": ["editor::ToggleComments", { "advance_downwards": false }],
       "f8": ["editor::GoToDiagnostic", { "severity": { "min": "hint", "max": "error" } }],
       "shift-f8": ["editor::GoToPreviousDiagnostic", { "severity": { "min": "hint", "max": "error" } }],

assets/keymaps/vim.json

@@ -124,6 +124,7 @@
       "g r a": "editor::ToggleCodeActions",
       "g g": "vim::StartOfDocument",
       "g h": "editor::Hover",
+      "g B": "editor::BlameHover",
       "g t": "pane::ActivateNextItem",
       "g shift-t": "pane::ActivatePreviousItem",
       "g d": "editor::GoToDefinition",

crates/editor/src/actions.rs

@@ -322,6 +322,8 @@ actions!(
         ApplyDiffHunk,
         /// Deletes the character before the cursor.
         Backspace,
+        /// Shows git blame information for the current line.
+        BlameHover,
         /// Cancels the current operation.
         Cancel,
         /// Cancels the running flycheck operation.

crates/editor/src/editor.rs

@@ -950,6 +950,7 @@ struct InlineBlamePopover {
     hide_task: Option<Task<()>>,
     popover_bounds: Option<Bounds<Pixels>>,
     popover_state: InlineBlamePopoverState,
+    keyboard_grace: bool,
 }
 
 enum SelectionDragState {
@@ -6517,21 +6518,55 @@ impl Editor {
         }
     }
 
+    pub fn blame_hover(&mut self, _: &BlameHover, window: &mut Window, cx: &mut Context<Self>) {
+        let snapshot = self.snapshot(window, cx);
+        let cursor = self.selections.newest::<Point>(cx).head();
+        let Some((buffer, point, _)) = snapshot.buffer_snapshot.point_to_buffer_point(cursor)
+        else {
+            return;
+        };
+
+        let Some(blame) = self.blame.as_ref() else {
+            return;
+        };
+
+        let row_info = RowInfo {
+            buffer_id: Some(buffer.remote_id()),
+            buffer_row: Some(point.row),
+            ..Default::default()
+        };
+        let Some(blame_entry) = blame
+            .update(cx, |blame, cx| blame.blame_for_rows(&[row_info], cx).next())
+            .flatten()
+        else {
+            return;
+        };
+
+        let anchor = self.selections.newest_anchor().head();
+        let position = self.to_pixel_point(anchor, &snapshot, window);
+        if let (Some(position), Some(last_bounds)) = (position, self.last_bounds) {
+            self.show_blame_popover(&blame_entry, position + last_bounds.origin, true, cx);
+        };
+    }
+
     fn show_blame_popover(
         &mut self,
         blame_entry: &BlameEntry,
         position: gpui::Point<Pixels>,
+        ignore_timeout: bool,
         cx: &mut Context<Self>,
     ) {
         if let Some(state) = &mut self.inline_blame_popover {
             state.hide_task.take();
         } else {
-            let delay = EditorSettings::get_global(cx).hover_popover_delay;
+            let blame_popover_delay = EditorSettings::get_global(cx).hover_popover_delay;
             let blame_entry = blame_entry.clone();
             let show_task = cx.spawn(async move |editor, cx| {
-                cx.background_executor()
+                if !ignore_timeout {
-                    .timer(std::time::Duration::from_millis(delay))
+                    cx.background_executor()
-                    .await;
+                        .timer(std::time::Duration::from_millis(blame_popover_delay))
+                        .await;
+                }
                 editor
                     .update(cx, |editor, cx| {
                         editor.inline_blame_popover_show_task.take();
@@ -6560,6 +6595,7 @@ impl Editor {
                                 commit_message: details,
                                 markdown,
                             },
+                            keyboard_grace: ignore_timeout,
                         });
                         cx.notify();
                     })

crates/editor/src/element.rs

@@ -216,6 +216,7 @@ impl EditorElement {
         register_action(editor, window, Editor::newline_above);
         register_action(editor, window, Editor::newline_below);
         register_action(editor, window, Editor::backspace);
+        register_action(editor, window, Editor::blame_hover);
         register_action(editor, window, Editor::delete);
         register_action(editor, window, Editor::tab);
         register_action(editor, window, Editor::backtab);
@@ -1143,10 +1144,14 @@ impl EditorElement {
                 .as_ref()
                 .and_then(|state| state.popover_bounds)
                 .map_or(false, |bounds| bounds.contains(&event.position));
+            let keyboard_grace = editor
+                .inline_blame_popover
+                .as_ref()
+                .map_or(false, |state| state.keyboard_grace);
 
             if mouse_over_inline_blame || mouse_over_popover {
-                editor.show_blame_popover(&blame_entry, event.position, cx);
+                editor.show_blame_popover(&blame_entry, event.position, false, cx);
-            } else {
+            } else if !keyboard_grace {
                 editor.hide_blame_popover(cx);
             }
         } else {