dock: Fix panel zoom when it split and added to other StackPanel. (#245)

crates/ui/src/dock/mod.rs

@@ -202,36 +202,6 @@ impl DockArea {
     /// Subscribe event on the panels
     #[allow(clippy::only_used_in_recursion)]
     fn subscribe_item(&self, item: &DockItem, cx: &mut ViewContext<Self>) {
-        /// Subscribe zoom event on the panel
-        fn subscribe_zoom<P: Panel>(view: &View<P>, cx: &mut ViewContext<DockArea>) {
-            cx.subscribe(view, move |_, panel, event, cx| match event {
-                PanelEvent::ZoomIn => {
-                    let dock_area = cx.view().clone();
-                    let panel = panel.clone();
-                    cx.spawn(|_, mut cx| async move {
-                        let _ = cx.update(|cx| {
-                            let _ = dock_area.update(cx, |dock, cx| {
-                                dock.set_zoomed_in(panel, cx);
-                                cx.notify();
-                            });
-                        });
-                    })
-                    .detach();
-                }
-                PanelEvent::ZoomOut => {
-                    let dock_area = cx.view().clone();
-                    cx.spawn(|_, mut cx| async move {
-                        let _ = cx.update(|cx| {
-                            let _ = dock_area.update(cx, |view, cx| view.set_zoomed_out(cx));
-                        });
-                    })
-                    .detach()
-                }
-                PanelEvent::LayoutChanged => cx.emit(DockEvent::LayoutChanged),
-            })
-            .detach();
-        }
-
         match item {
             DockItem::Split { items, view, .. } => {
                 for item in items {
@@ -244,14 +214,42 @@ impl DockArea {
                 })
                 .detach();
             }
-            DockItem::Tabs { view, .. } => {
+            DockItem::Tabs { .. } => {
-                // We need, only subscribe to the zoom events on the TabPanel
+                // We subscribe the tab panel event is in StackPanel insert_panel
-                // Because we always wrap the DockItem::Panel in a DockItem::Tabs
-                subscribe_zoom(view, cx);
             }
         }
     }
 
+    /// Subscribe zoom event on the panel
+    pub(crate) fn subscribe_panel<P: Panel>(view: &View<P>, cx: &mut ViewContext<DockArea>) {
+        cx.subscribe(view, move |_, panel, event, cx| match event {
+            PanelEvent::ZoomIn => {
+                let dock_area = cx.view().clone();
+                let panel = panel.clone();
+                cx.spawn(|_, mut cx| async move {
+                    let _ = cx.update(|cx| {
+                        let _ = dock_area.update(cx, |dock, cx| {
+                            dock.set_zoomed_in(panel, cx);
+                            cx.notify();
+                        });
+                    });
+                })
+                .detach();
+            }
+            PanelEvent::ZoomOut => {
+                let dock_area = cx.view().clone();
+                cx.spawn(|_, mut cx| async move {
+                    let _ = cx.update(|cx| {
+                        let _ = dock_area.update(cx, |view, cx| view.set_zoomed_out(cx));
+                    });
+                })
+                .detach()
+            }
+            PanelEvent::LayoutChanged => cx.emit(DockEvent::LayoutChanged),
+        })
+        .detach();
+    }
+
     /// Returns the ID of the dock area.
     pub fn id(&self) -> SharedString {
         self.id.clone()

crates/ui/src/dock/stack_panel.rs

@@ -163,7 +163,7 @@ impl StackPanel {
         panel: Arc<dyn PanelView>,
         ix: usize,
         size: Option<Pixels>,
-        _dock_area: WeakView<DockArea>,
+        dock_area: WeakView<DockArea>,
         cx: &mut ViewContext<Self>,
     ) {
         // If the panel is already in the stack, return.
@@ -185,6 +185,13 @@ impl StackPanel {
             }
         });
 
+        // Subscribe to the panel's layout change event.
+        _ = dock_area.update(cx, |_, cx| {
+            if let Ok(tab_panel) = panel.view().downcast::<TabPanel>() {
+                DockArea::subscribe_panel(&tab_panel, cx);
+            }
+        });
+
         let ix = if ix > self.panels.len() {
             self.panels.len()
         } else {

crates/ui/src/dock/tab_panel.rs

@@ -581,12 +581,12 @@ impl TabPanel {
     }
 
     fn on_action_toggle_zoom(&mut self, _: &ToggleZoom, cx: &mut ViewContext<Self>) {
-        self.is_zoomed = !self.is_zoomed;
+        if !self.is_zoomed {
-        if self.is_zoomed {
             cx.emit(PanelEvent::ZoomIn)
         } else {
             cx.emit(PanelEvent::ZoomOut)
         }
+        self.is_zoomed = !self.is_zoomed;
     }
 
     fn on_action_close_panel(&mut self, _: &ClosePanel, cx: &mut ViewContext<Self>) {