dock: Fix zoom support for side dock panel. (#327)

- Fix emit `PanelEvent::LayoutChanged` when panel resized.

crates/ui/src/dock/dock.rs

@@ -6,7 +6,7 @@ use gpui::{
     div, prelude::FluentBuilder as _, px, Axis, Element, InteractiveElement as _, IntoElement,
     MouseMoveEvent, MouseUpEvent, ParentElement as _, Pixels, Point, Render,
     StatefulInteractiveElement, Style, Styled as _, View, ViewContext, VisualContext as _,
-    WeakView,
+    WeakView, WindowContext,
 };
 use serde::{Deserialize, Serialize};
 
@@ -74,10 +74,11 @@ impl Dock {
         let panel = cx.new_view(|cx| {
             let mut tab = TabPanel::new(None, dock_area.clone(), cx);
             tab.closeable = false;
-            tab.zoomable = false;
             tab
         });
 
+        Self::subscribe_panel_events(dock_area.clone(), panel.clone(), cx);
+
         Self {
             placement,
             dock_area,
@@ -106,7 +107,10 @@ impl Dock {
         size: Pixels,
         panel: View<TabPanel>,
         open: bool,
+        cx: &mut WindowContext,
     ) -> Self {
+        Self::subscribe_panel_events(dock_area.clone(), panel.clone(), cx);
+
         Self {
             placement,
             dock_area,
@@ -117,6 +121,21 @@ impl Dock {
         }
     }
 
+    fn subscribe_panel_events(
+        dock_area: WeakView<DockArea>,
+        panel: View<TabPanel>,
+        cx: &mut WindowContext,
+    ) {
+        // Subscribe the panel to the dock area.
+        cx.defer({
+            move |cx| {
+                _ = dock_area.update(cx, |this, cx| {
+                    this.subscribe_panel(&panel, cx);
+                });
+            }
+        });
+    }
+
     pub fn set_panels(&mut self, panels: Vec<Arc<dyn PanelView>>, cx: &mut ViewContext<Self>) {
         self.panel.update(cx, |tab_panel, _| {
             tab_panel.panels = panels;

crates/ui/src/dock/mod.rs

@@ -10,7 +10,7 @@ pub use dock::*;
 use gpui::{
     actions, canvas, div, prelude::FluentBuilder, AnyElement, AnyView, AppContext, Axis, Bounds,
     EventEmitter, InteractiveElement as _, IntoElement, ParentElement as _, Pixels, Render,
-    SharedString, Styled, View, ViewContext, VisualContext, WeakView, WindowContext,
+    SharedString, Styled, Subscription, View, ViewContext, VisualContext, WeakView, WindowContext,
 };
 pub use panel::*;
 pub use stack_panel::*;
@@ -50,6 +50,8 @@ pub struct DockArea {
     right_dock: Option<View<Dock>>,
     /// The top zoom view of the dockarea, if any.
     zoom_view: Option<AnyView>,
+
+    _subscriptions: Vec<Subscription>,
 }
 
 /// DockItem is a tree structure that represents the layout of the dock.
@@ -108,6 +110,17 @@ impl DockItem {
 
             stack_panel
         });
+
+        cx.defer({
+            let stack_panel = stack_panel.clone();
+            let dock_area = dock_area.clone();
+            move |cx| {
+                _ = dock_area.update(cx, |this, cx| {
+                    this.subscribe_panel(&stack_panel, cx);
+                });
+            }
+        });
+
         Self::Split {
             axis,
             items,
@@ -189,6 +202,7 @@ impl DockArea {
         cx: &mut ViewContext<Self>,
     ) -> Self {
         let stack_panel = cx.new_view(|cx| StackPanel::new(Axis::Horizontal, cx));
+
         let dock_item = DockItem::Split {
             axis: Axis::Horizontal,
             items: vec![],
@@ -196,7 +210,7 @@ impl DockArea {
             view: stack_panel.clone(),
         };
 
-        Self {
+        let mut this = Self {
             id: id.into(),
             version,
             bounds: Bounds::default(),
@@ -205,7 +219,12 @@ impl DockArea {
             left_dock: None,
             right_dock: None,
             bottom_dock: None,
-        }
+            _subscriptions: vec![],
+        };
+
+        this.subscribe_panel(&stack_panel, cx);
+
+        this
     }
 
     /// Set version of the dock area.
@@ -372,18 +391,18 @@ impl DockArea {
 
     /// Subscribe event on the panels
     #[allow(clippy::only_used_in_recursion)]
-    fn subscribe_item(&self, item: &DockItem, cx: &mut ViewContext<Self>) {
+    fn subscribe_item(&mut self, item: &DockItem, cx: &mut ViewContext<Self>) {
         match item {
             DockItem::Split { items, view, .. } => {
                 for item in items {
                     self.subscribe_item(item, cx);
                 }
 
-                cx.subscribe(view, move |_, _, event, cx| match event {
+                self._subscriptions
-                    PanelEvent::LayoutChanged => cx.emit(DockEvent::LayoutChanged),
+                    .push(cx.subscribe(view, move |_, _, event, cx| match event {
-                    _ => {}
+                        PanelEvent::LayoutChanged => cx.emit(DockEvent::LayoutChanged),
-                })
+                        _ => {}
-                .detach();
+                    }));
             }
             DockItem::Tabs { .. } => {
                 // We subscribe the tab panel event is in StackPanel insert_panel
@@ -392,8 +411,12 @@ impl DockArea {
     }
 
     /// Subscribe zoom event on the panel
-    pub(crate) fn subscribe_panel<P: Panel>(view: &View<P>, cx: &mut ViewContext<DockArea>) {
+    pub(crate) fn subscribe_panel<P: Panel>(
-        cx.subscribe(view, move |_, panel, event, cx| match event {
+        &mut self,
+        view: &View<P>,
+        cx: &mut ViewContext<DockArea>,
+    ) {
+        let subscription = cx.subscribe(view, move |_, panel, event, cx| match event {
             PanelEvent::ZoomIn => {
                 let dock_area = cx.view().clone();
                 let panel = panel.clone();
@@ -417,8 +440,9 @@ impl DockArea {
                 .detach()
             }
             PanelEvent::LayoutChanged => cx.emit(DockEvent::LayoutChanged),
-        })
+        });
-        .detach();
+
+        self._subscriptions.push(subscription);
     }
 
     /// Returns the ID of the dock area.

crates/ui/src/dock/stack_panel.rs

@@ -14,8 +14,8 @@ use crate::{
 use super::{DockArea, DockItemState, Panel, PanelEvent, PanelView, TabPanel};
 use gpui::{
     prelude::FluentBuilder as _, AppContext, Axis, DismissEvent, Entity, EventEmitter, FocusHandle,
-    FocusableView, IntoElement, ParentElement, Pixels, Render, Styled, View, ViewContext,
+    FocusableView, IntoElement, ParentElement, Pixels, Render, Styled, Subscription, View,
-    VisualContext, WeakView,
+    ViewContext, VisualContext, WeakView,
 };
 use smallvec::SmallVec;
 
@@ -25,6 +25,7 @@ pub struct StackPanel {
     focus_handle: FocusHandle,
     pub(crate) panels: SmallVec<[Arc<dyn PanelView>; 2]>,
     panel_group: View<ResizablePanelGroup>,
+    _subscriptions: Vec<Subscription>,
 }
 
 impl Panel for StackPanel {
@@ -59,10 +60,10 @@ impl StackPanel {
         });
 
         // Bubble up the resize event.
-        cx.subscribe(&panel_group, |_, _, _: &ResizablePanelEvent, cx| {
+        let _subscriptions = vec![cx
-            cx.emit(PanelEvent::LayoutChanged)
+            .subscribe(&panel_group, |_, _, _: &ResizablePanelEvent, cx| {
-        })
+                cx.emit(PanelEvent::LayoutChanged)
-        .detach();
+            })];
 
         Self {
             axis,
@@ -70,6 +71,7 @@ impl StackPanel {
             focus_handle: cx.focus_handle(),
             panels: SmallVec::new(),
             panel_group,
+            _subscriptions,
         }
     }
 
@@ -184,9 +186,11 @@ impl StackPanel {
                 }
 
                 // Subscribe to the panel's layout change event.
-                _ = dock_area.update(cx, |_, cx| {
+                _ = dock_area.update(cx, |this, cx| {
                     if let Ok(tab_panel) = panel.view().downcast::<TabPanel>() {
-                        DockArea::subscribe_panel(&tab_panel, cx);
+                        this.subscribe_panel(&tab_panel, cx);
+                    } else if let Ok(stack_panel) = panel.view().downcast::<Self>() {
+                        this.subscribe_panel(&stack_panel, cx);
                     }
                 });
             }

crates/ui/src/dock/state.rs

@@ -51,13 +51,14 @@ impl DockState {
     ) -> Result<View<Dock>> {
         let view = self.panel.to_item(dock_area.clone(), cx).view();
         if let Ok(tab_panel) = view.view().downcast::<TabPanel>() {
-            let dock = cx.new_view(|_| {
+            let dock = cx.new_view(|cx| {
                 Dock::from_state(
                     dock_area.clone(),
                     self.placement,
                     self.size,
                     tab_panel,
                     self.open,
+                    cx,
                 )
             });
 

crates/ui/src/dock/tab_panel.rs

@@ -68,9 +68,6 @@ pub struct TabPanel {
     /// If this is true, the Panel closeable will follow the active panel's closeable,
     /// otherwise this TabPanel will not able to close
     pub(crate) closeable: bool,
-    /// If this is true, the Panel zoomable will follow the active panel's zoomable,
-    /// otherwise this TabPanel will not able to zoom
-    pub(crate) zoomable: bool,
 
     /// When drag move, will get the placement of the panel to be split
     will_split_placement: Option<Placement>,
@@ -98,10 +95,6 @@ impl Panel for TabPanel {
     }
 
     fn zoomable(&self, cx: &WindowContext) -> bool {
-        if !self.zoomable {
-            return false;
-        }
-
         self.active_panel()
             .map(|panel| panel.zoomable(cx))
             .unwrap_or(false)
@@ -147,7 +140,6 @@ impl TabPanel {
             will_split_placement: None,
             is_zoomed: false,
             closeable: true,
-            zoomable: true,
         }
     }