multi_workspace: Move up action handler and modal rendering from workspace to multi workspace (#49995)

Anthony Eid and cameron created 

Now that MultiWorkspace is the root view, actions bound to the
`Workspace` key context wouldn't be dispatched when `Workspace` is not
in the key context stack (e.g. when the sidebar is focused). To fix
this, the `Workspace` key context and action handlers are moved up to
the MultiWorkspace rendering layer. This avoids introducing a new key
context and the keymap migration that would require.

This PR also moves modal rendering up a layer so modals are centered
within the window (MultiWorkspace element) instead of the Workspace
element.

### Before
<img width="3248" height="2122" alt="image"
src="https://github.com/user-attachments/assets/233a0b75-47a1-423a-8394-c6a1b50fb991"
/>
### After
<img width="3248" height="2122" alt="image"
src="https://github.com/user-attachments/assets/9c51c839-e524-4ef8-afc9-9429b028def0"
/>


Before you mark this PR as ready for review, make sure that you have:
- [x] Added a solid test coverage and/or screenshots from doing manual
testing
- [x] Done a self-review taking into account security and performance
aspects
- [x] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)

Release Notes:

- N/A

---------

Co-authored-by: cameron <cameron.studdstreet@gmail.com>

Change summary

crates/workspace/src/multi_workspace.rs |  11 +
crates/workspace/src/workspace.rs       | 109 ++++++++++++++------------
2 files changed, 68 insertions(+), 52 deletions(-)

Detailed changes

crates/workspace/src/multi_workspace.rs 🔗 

@@ -460,6 +460,7 @@ impl MultiWorkspace {
             .update(cx, |workspace, cx| workspace.focus_panel::<T>(window, cx))
     }
 
+    // used in a test
     pub fn toggle_modal<V: ModalView, B>(
         &mut self,
         window: &mut Window,
@@ -722,9 +723,12 @@ impl Render for MultiWorkspace {
             None
         };
 
+        let workspace = self.workspace().clone();
+        let workspace_key_context = workspace.update(cx, |workspace, cx| workspace.key_context(cx));
+        let root = workspace.update(cx, |workspace, cx| workspace.actions(h_flex(), window, cx));
+
         client_side_decorations(
-            h_flex()
-                .key_context("Workspace")
+            root.key_context(workspace_key_context)
                 .relative()
                 .size_full()
                 .on_action(cx.listener(Self::close_window))
@@ -777,7 +781,8 @@ impl Render for MultiWorkspace {
                         .overflow_hidden()
                         .when(is_zoomed, |this| this.absolute().inset_0())
                         .child(self.workspace().clone()),
-                ),
+                )
+                .child(self.workspace().read(cx).modal_layer.clone()),
             window,
             cx,
             Tiling {

crates/workspace/src/workspace.rs 🔗 

@@ -1251,7 +1251,7 @@ pub struct Workspace {
     last_active_center_pane: Option<WeakEntity<Pane>>,
     last_active_view_id: Option<proto::ViewId>,
     status_bar: Entity<StatusBar>,
-    modal_layer: Entity<ModalLayer>,
+    pub(crate) modal_layer: Entity<ModalLayer>,
     toast_layer: Entity<ToastLayer>,
     titlebar_item: Option<AnyView>,
     notifications: Notifications,
@@ -6333,7 +6333,47 @@ impl Workspace {
         })
     }
 
-    fn actions(&self, div: Div, window: &mut Window, cx: &mut Context<Self>) -> Div {
+    pub fn key_context(&self, cx: &App) -> KeyContext {
+        let mut context = KeyContext::new_with_defaults();
+        context.add("Workspace");
+        context.set("keyboard_layout", cx.keyboard_layout().name().to_string());
+        if let Some(status) = self
+            .debugger_provider
+            .as_ref()
+            .and_then(|provider| provider.active_thread_state(cx))
+        {
+            match status {
+                ThreadStatus::Running | ThreadStatus::Stepping => {
+                    context.add("debugger_running");
+                }
+                ThreadStatus::Stopped => context.add("debugger_stopped"),
+                ThreadStatus::Exited | ThreadStatus::Ended => {}
+            }
+        }
+
+        if self.left_dock.read(cx).is_open() {
+            if let Some(active_panel) = self.left_dock.read(cx).active_panel() {
+                context.set("left_dock", active_panel.panel_key());
+            }
+        }
+
+        if self.right_dock.read(cx).is_open() {
+            if let Some(active_panel) = self.right_dock.read(cx).active_panel() {
+                context.set("right_dock", active_panel.panel_key());
+            }
+        }
+
+        if self.bottom_dock.read(cx).is_open() {
+            if let Some(active_panel) = self.bottom_dock.read(cx).active_panel() {
+                context.set("bottom_dock", active_panel.panel_key());
+            }
+        }
+
+        context
+    }
+
+    /// Multiworkspace uses this to add workspace action handling to itself
+    pub fn actions(&self, div: Div, window: &mut Window, cx: &mut Context<Self>) -> Div {
         self.add_workspace_actions_listeners(div, window, cx)
             .on_action(cx.listener(
                 |_workspace, action_sequence: &settings::ActionSequence, window, cx| {
@@ -7390,40 +7430,6 @@ impl Render for Workspace {
         if FIRST_PAINT.swap(false, std::sync::atomic::Ordering::Relaxed) {
             log::info!("Rendered first frame");
         }
-        let mut context = KeyContext::new_with_defaults();
-        context.add("Workspace");
-        context.set("keyboard_layout", cx.keyboard_layout().name().to_string());
-        if let Some(status) = self
-            .debugger_provider
-            .as_ref()
-            .and_then(|provider| provider.active_thread_state(cx))
-        {
-            match status {
-                ThreadStatus::Running | ThreadStatus::Stepping => {
-                    context.add("debugger_running");
-                }
-                ThreadStatus::Stopped => context.add("debugger_stopped"),
-                ThreadStatus::Exited | ThreadStatus::Ended => {}
-            }
-        }
-
-        if self.left_dock.read(cx).is_open() {
-            if let Some(active_panel) = self.left_dock.read(cx).active_panel() {
-                context.set("left_dock", active_panel.panel_key());
-            }
-        }
-
-        if self.right_dock.read(cx).is_open() {
-            if let Some(active_panel) = self.right_dock.read(cx).active_panel() {
-                context.set("right_dock", active_panel.panel_key());
-            }
-        }
-
-        if self.bottom_dock.read(cx).is_open() {
-            if let Some(active_panel) = self.bottom_dock.read(cx).active_panel() {
-                context.set("bottom_dock", active_panel.panel_key());
-            }
-        }
 
         let centered_layout = self.centered_layout
             && self.center.panes().len() == 1
@@ -7461,8 +7467,7 @@ impl Render for Workspace {
             .collect::<Vec<_>>();
         let bottom_dock_layout = WorkspaceSettings::get_global(cx).bottom_dock_layout;
 
-        self.actions(div(), window, cx)
-            .key_context(context)
+        div()
             .relative()
             .size_full()
             .flex()
@@ -7862,7 +7867,6 @@ impl Render for Workspace {
                         .when(self.status_bar_visible(cx), |parent| {
                             parent.child(self.status_bar.clone())
                         })
-                        .child(self.modal_layer.clone())
                         .child(self.toast_layer.clone()),
                 )
     }
@@ -10057,6 +10061,7 @@ mod tests {
         let project_b = Project::test(fs, ["root".as_ref()], cx).await;
         let multi_workspace_handle =
             cx.add_window(|window, cx| MultiWorkspace::test_new(project_a.clone(), window, cx));
+        cx.run_until_parked();
 
         let workspace_a = multi_workspace_handle
             .read_with(cx, |mw, _| mw.workspace().clone())
@@ -10636,8 +10641,9 @@ mod tests {
         init_test(cx);
         let fs = FakeFs::new(cx.executor());
         let project = Project::test(fs, [], cx).await;
-        let (workspace, cx) =
-            cx.add_window_view(|window, cx| Workspace::test_new(project, window, cx));
+        let (multi_workspace, cx) =
+            cx.add_window_view(|window, cx| MultiWorkspace::test_new(project, window, cx));
+        let workspace = multi_workspace.read_with(cx, |mw, _| mw.workspace().clone());
 
         workspace.update_in(cx, |workspace, window, cx| {
             let first_item = cx.new(|cx| {
@@ -11131,8 +11137,9 @@ mod tests {
         init_test(cx);
         let fs = FakeFs::new(cx.executor());
         let project = Project::test(fs, [], cx).await;
-        let (workspace, cx) =
-            cx.add_window_view(|window, cx| Workspace::test_new(project, window, cx));
+        let (multi_workspace, cx) =
+            cx.add_window_view(|window, cx| MultiWorkspace::test_new(project, window, cx));
+        let workspace = multi_workspace.read_with(cx, |mw, _| mw.workspace().clone());
 
         // Open two docks (left and right) with one panel each
         let (left_panel, right_panel) = workspace.update_in(cx, |workspace, window, cx| {
@@ -11563,8 +11570,9 @@ mod tests {
         let fs = FakeFs::new(cx.executor());
 
         let project = Project::test(fs, [], cx).await;
-        let (workspace, cx) =
-            cx.add_window_view(|window, cx| Workspace::test_new(project, window, cx));
+        let (multi_workspace, cx) =
+            cx.add_window_view(|window, cx| MultiWorkspace::test_new(project, window, cx));
+        let workspace = multi_workspace.read_with(cx, |mw, _| mw.workspace().clone());
 
         let (panel_1, panel_2) = workspace.update_in(cx, |workspace, window, cx| {
             let panel_1 = cx.new(|cx| TestPanel::new(DockPosition::Left, 100, cx));
@@ -12471,8 +12479,9 @@ mod tests {
         init_test(cx);
         let fs = FakeFs::new(cx.executor());
         let project = Project::test(fs, [], cx).await;
-        let (workspace, cx) =
-            cx.add_window_view(|window, cx| Workspace::test_new(project, window, cx));
+        let (multi_workspace, cx) =
+            cx.add_window_view(|window, cx| MultiWorkspace::test_new(project, window, cx));
+        let workspace = multi_workspace.read_with(cx, |mw, _| mw.workspace().clone());
 
         // Add a new panel to the right dock, opening the dock and setting the
         // focus to the new panel.
@@ -13161,8 +13170,9 @@ mod tests {
 
         let fs = FakeFs::new(cx.executor());
         let project = Project::test(fs, [], cx).await;
-        let (workspace, cx) =
-            cx.add_window_view(|window, cx| Workspace::test_new(project, window, cx));
+        let (multi_workspace, cx) =
+            cx.add_window_view(|window, cx| MultiWorkspace::test_new(project, window, cx));
+        let workspace = multi_workspace.read_with(cx, |mw, _| mw.workspace().clone());
         let panel = workspace.update_in(cx, |workspace, window, cx| {
             let panel = cx.new(|cx| TestPanel::new(DockPosition::Right, 100, cx));
             workspace.add_panel(panel.clone(), window, cx);
@@ -13226,6 +13236,7 @@ mod tests {
 
         let multi_workspace_handle =
             cx.add_window(|window, cx| MultiWorkspace::test_new(project_a.clone(), window, cx));
+        cx.run_until_parked();
 
         let workspace_a = multi_workspace_handle
             .read_with(cx, |mw, _| mw.workspace().clone())