Checkpoint: Fix downcasting

crates/gpui3/src/app.rs

@@ -232,6 +232,7 @@ impl<Thread: 'static + Send + Sync> AppContext<Thread> {
     }
 
     fn update<R>(&mut self, update: impl FnOnce(&mut Self) -> R) -> R {
+        dbg!("update");
         self.pending_updates += 1;
         let result = update(self);
         self.pending_updates -= 1;
@@ -242,6 +243,8 @@ impl<Thread: 'static + Send + Sync> AppContext<Thread> {
     }
 
     fn flush_effects(&mut self) {
+        dbg!("Flush effects");
+
         while let Some(effect) = self.pending_effects.pop_front() {
             match effect {
                 Effect::Notify(entity_id) => self.apply_notify_effect(entity_id),

crates/gpui3/src/view.rs

@@ -59,6 +59,7 @@ impl<S: Send + Sync + 'static, P: Send + 'static> Element for View<S, P> {
         _: &mut Self::State,
         cx: &mut ViewContext<Self::State>,
     ) -> Result<(LayoutId, Self::FrameState)> {
+        dbg!("Layout view");
         self.state.update(cx, |state, cx| {
             let mut element = (self.render)(state, cx);
             let layout_id = element.layout(state, cx)?;
@@ -73,6 +74,7 @@ impl<S: Send + Sync + 'static, P: Send + 'static> Element for View<S, P> {
         element: &mut Self::FrameState,
         cx: &mut ViewContext<Self::State>,
     ) -> Result<()> {
+        dbg!("Paint view");
         self.state
             .update(cx, |state, cx| element.paint(state, None, cx))
     }
@@ -100,10 +102,10 @@ impl<S: Send + Sync + 'static, P: Send + 'static> ViewObject for View<S, P> {
 
     fn paint(&mut self, _: Layout, element: &mut dyn Any, cx: &mut WindowContext) -> Result<()> {
         self.state.update(cx, |state, cx| {
-            element
-                .downcast_mut::<AnyElement<S>>()
-                .unwrap()
-                .paint(state, None, cx)
+            let boxed_element = element.downcast_mut::<Box<dyn Any>>().unwrap();
+            let element = boxed_element.downcast_mut::<AnyElement<S>>().unwrap();
+
+            element.paint(state, None, cx)
         })
     }
 }
@@ -132,6 +134,7 @@ impl<S: 'static> Element for AnyView<S> {
         element: &mut Self::FrameState,
         cx: &mut ViewContext<Self::State>,
     ) -> Result<()> {
+        dbg!("Element.paint for AnyView");
         self.view.lock().paint(layout, element, cx)
     }
 }

crates/gpui3/src/window.rs

@@ -81,6 +81,7 @@ impl<'a, 'w> WindowContext<'a, 'w> {
     }
 
     pub(crate) fn draw(&mut self) -> Result<()> {
+        dbg!("Draw");
         let unit_entity = self.unit_entity.clone();
         self.update_entity(&unit_entity, |_, cx| {
             let mut root_view = cx.window.root_view.take().unwrap();
@@ -90,6 +91,7 @@ impl<'a, 'w> WindowContext<'a, 'w> {
                 .layout_engine
                 .compute_layout(root_layout_id, available_space)?;
             let layout = cx.window.layout_engine.layout(root_layout_id)?;
+            dbg!("Paint root view");
             root_view.paint(layout, &mut (), &mut frame_state, cx)?;
             cx.window.root_view = Some(root_view);
             let scene = cx.window.scene.take();