agent_ui: Show notifications also when the panel is hidden (#40942)

Currently Zed only displays agent notifications (e.g. when the agent
completes a task) if the user has switched apps and Zed is not in the
foreground. This adds PR supports the scenario where the agent finishes
a long-running task and the user is busy coding within Zed on something
else.

Releases Note:

- If agent notifications are turned on, they will now also be displayed
when the agent panel is hidden, in complement to them showing when the
Zed window is in the background.

---------

Co-authored-by: Danilo Leal <daniloleal09@gmail.com>

crates/agent_ui/src/acp/thread_view.rs

@@ -4571,14 +4571,29 @@ impl AcpThreadView {
         window: &mut Window,
         cx: &mut Context<Self>,
     ) {
-        if window.is_window_active() || !self.notifications.is_empty() {
+        if !self.notifications.is_empty() {
+            return;
+        }
+
+        let settings = AgentSettings::get_global(cx);
+
+        let window_is_inactive = !window.is_window_active();
+        let panel_is_hidden = self
+            .workspace
+            .upgrade()
+            .map(|workspace| AgentPanel::is_hidden(&workspace, cx))
+            .unwrap_or(true);
+
+        let should_notify = window_is_inactive || panel_is_hidden;
+
+        if !should_notify {
             return;
         }
 
         // TODO: Change this once we have title summarization for external agents.
         let title = self.agent.name();
 
-        match AgentSettings::get_global(cx).notify_when_agent_waiting {
+        match settings.notify_when_agent_waiting {
             NotifyWhenAgentWaiting::PrimaryScreen => {
                 if let Some(primary) = cx.primary_display() {
                     self.pop_up(icon, caption.into(), title, window, primary, cx);
@@ -5892,6 +5907,107 @@ pub(crate) mod tests {
         );
     }
 
+    #[gpui::test]
+    async fn test_notification_when_panel_hidden(cx: &mut TestAppContext) {
+        init_test(cx);
+
+        let (thread_view, cx) = setup_thread_view(StubAgentServer::default_response(), cx).await;
+
+        add_to_workspace(thread_view.clone(), cx);
+
+        let message_editor = cx.read(|cx| thread_view.read(cx).message_editor.clone());
+
+        message_editor.update_in(cx, |editor, window, cx| {
+            editor.set_text("Hello", window, cx);
+        });
+
+        // Window is active (don't deactivate), but panel will be hidden
+        // Note: In the test environment, the panel is not actually added to the dock,
+        // so is_agent_panel_hidden will return true
+
+        thread_view.update_in(cx, |thread_view, window, cx| {
+            thread_view.send(window, cx);
+        });
+
+        cx.run_until_parked();
+
+        // Should show notification because window is active but panel is hidden
+        assert!(
+            cx.windows()
+                .iter()
+                .any(|window| window.downcast::<AgentNotification>().is_some()),
+            "Expected notification when panel is hidden"
+        );
+    }
+
+    #[gpui::test]
+    async fn test_notification_still_works_when_window_inactive(cx: &mut TestAppContext) {
+        init_test(cx);
+
+        let (thread_view, cx) = setup_thread_view(StubAgentServer::default_response(), cx).await;
+
+        let message_editor = cx.read(|cx| thread_view.read(cx).message_editor.clone());
+        message_editor.update_in(cx, |editor, window, cx| {
+            editor.set_text("Hello", window, cx);
+        });
+
+        // Deactivate window - should show notification regardless of setting
+        cx.deactivate_window();
+
+        thread_view.update_in(cx, |thread_view, window, cx| {
+            thread_view.send(window, cx);
+        });
+
+        cx.run_until_parked();
+
+        // Should still show notification when window is inactive (existing behavior)
+        assert!(
+            cx.windows()
+                .iter()
+                .any(|window| window.downcast::<AgentNotification>().is_some()),
+            "Expected notification when window is inactive"
+        );
+    }
+
+    #[gpui::test]
+    async fn test_notification_respects_never_setting(cx: &mut TestAppContext) {
+        init_test(cx);
+
+        // Set notify_when_agent_waiting to Never
+        cx.update(|cx| {
+            AgentSettings::override_global(
+                AgentSettings {
+                    notify_when_agent_waiting: NotifyWhenAgentWaiting::Never,
+                    ..AgentSettings::get_global(cx).clone()
+                },
+                cx,
+            );
+        });
+
+        let (thread_view, cx) = setup_thread_view(StubAgentServer::default_response(), cx).await;
+
+        let message_editor = cx.read(|cx| thread_view.read(cx).message_editor.clone());
+        message_editor.update_in(cx, |editor, window, cx| {
+            editor.set_text("Hello", window, cx);
+        });
+
+        // Window is active
+
+        thread_view.update_in(cx, |thread_view, window, cx| {
+            thread_view.send(window, cx);
+        });
+
+        cx.run_until_parked();
+
+        // Should NOT show notification because notify_when_agent_waiting is Never
+        assert!(
+            !cx.windows()
+                .iter()
+                .any(|window| window.downcast::<AgentNotification>().is_some()),
+            "Expected no notification when notify_when_agent_waiting is Never"
+        );
+    }
+
     async fn setup_thread_view(
         agent: impl AgentServer + 'static,
         cx: &mut TestAppContext,

crates/agent_ui/src/agent_panel.rs

@@ -729,6 +729,25 @@ impl AgentPanel {
         &self.context_server_registry
     }
 
+    pub fn is_hidden(workspace: &Entity<Workspace>, cx: &App) -> bool {
+        let workspace_read = workspace.read(cx);
+
+        workspace_read
+            .panel::<AgentPanel>(cx)
+            .map(|panel| {
+                let panel_id = Entity::entity_id(&panel);
+
+                let is_visible = workspace_read.all_docks().iter().any(|dock| {
+                    dock.read(cx)
+                        .visible_panel()
+                        .is_some_and(|visible_panel| visible_panel.panel_id() == panel_id)
+                });
+
+                !is_visible
+            })
+            .unwrap_or(true)
+    }
+
     fn active_thread_view(&self) -> Option<&Entity<AcpThreadView>> {
         match &self.active_view {
             ActiveView::ExternalAgentThread { thread_view, .. } => Some(thread_view),