tab_switcher: Subscribe to workspace events instead of pane events (#44101)

Closes #43171

Previously the tab switcher only subscribed to events from a single pane
so closing tabs in other panes wouldn't cause the tab switcher to
update. This PR changes that so the tab switcher subscribes to the whole
workspace and thus updates when tabs in other panes are closed.

It also modifies the work in #44006 to sync selected index across the
whole workspace instead of just the original pane in the case of the
all-panes tab switcher.

Release Notes:

- Fixed all-panes tab switcher not updating in response to changes in
other panes

Author: HactarCE

crates/tab_switcher/src/tab_switcher.rs

@@ -23,9 +23,9 @@ use ui::{
 };
 use util::ResultExt;
 use workspace::{
-    ModalView, Pane, SaveIntent, Workspace,
+    Event as WorkspaceEvent, ModalView, Pane, SaveIntent, Workspace,
     item::{ItemHandle, ItemSettings, ShowDiagnostics, TabContentParams},
-    pane::{Event as PaneEvent, render_item_indicator, tab_details},
+    pane::{render_item_indicator, tab_details},
 };
 
 const PANEL_WIDTH_REMS: f32 = 28.;
@@ -322,7 +322,7 @@ impl TabSwitcherDelegate {
         cx: &mut Context<TabSwitcher>,
         original_items: Vec<(Entity<Pane>, usize)>,
     ) -> Self {
-        Self::subscribe_to_updates(&pane, window, cx);
+        Self::subscribe_to_updates(&workspace, window, cx);
         Self {
             select_last,
             tab_switcher,
@@ -338,34 +338,36 @@ impl TabSwitcherDelegate {
     }
 
     fn subscribe_to_updates(
-        pane: &WeakEntity<Pane>,
+        workspace: &WeakEntity<Workspace>,
         window: &mut Window,
         cx: &mut Context<TabSwitcher>,
     ) {
-        let Some(pane) = pane.upgrade() else {
+        let Some(workspace) = workspace.upgrade() else {
             return;
         };
-        cx.subscribe_in(&pane, window, |tab_switcher, _, event, window, cx| {
+        cx.subscribe_in(&workspace, window, |tab_switcher, _, event, window, cx| {
             match event {
-                PaneEvent::AddItem { .. } | PaneEvent::Remove { .. } => {
+                WorkspaceEvent::ItemAdded { .. } | WorkspaceEvent::PaneRemoved => {
                     tab_switcher.picker.update(cx, |picker, cx| {
                         let query = picker.query(cx);
                         picker.delegate.update_matches(query, window, cx);
                         cx.notify();
                     })
                 }
-                PaneEvent::RemovedItem { .. } => tab_switcher.picker.update(cx, |picker, cx| {
-                    let query = picker.query(cx);
-                    picker.delegate.update_matches(query, window, cx);
-
-                    // When the Tab Switcher is being used and an item is
-                    // removed, there's a chance that the new selected index
-                    // will not match the actual tab that is now being displayed
-                    // by the pane, as such, the selected index needs to be
-                    // updated to match the pane's state.
-                    picker.delegate.sync_selected_index(cx);
-                    cx.notify();
-                }),
+                WorkspaceEvent::ItemRemoved { .. } => {
+                    tab_switcher.picker.update(cx, |picker, cx| {
+                        let query = picker.query(cx);
+                        picker.delegate.update_matches(query, window, cx);
+
+                        // When the Tab Switcher is being used and an item is
+                        // removed, there's a chance that the new selected index
+                        // will not match the actual tab that is now being displayed
+                        // by the pane, as such, the selected index needs to be
+                        // updated to match the pane's state.
+                        picker.delegate.sync_selected_index(cx);
+                        cx.notify();
+                    })
+                }
                 _ => {}
             };
         })
@@ -563,7 +565,14 @@ impl TabSwitcherDelegate {
     /// as the pane's active item can be indirectly updated and this method
     /// ensures that the picker can react to those changes.
     fn sync_selected_index(&mut self, cx: &mut Context<Picker<TabSwitcherDelegate>>) {
-        let Ok(Some(item)) = self.pane.read_with(cx, |pane, _cx| pane.active_item()) else {
+        let item = if self.is_all_panes {
+            self.workspace
+                .read_with(cx, |workspace, cx| workspace.active_item(cx))
+        } else {
+            self.pane.read_with(cx, |pane, _cx| pane.active_item())
+        };
+
+        let Ok(Some(item)) = item else {
             return;
         };