perf(ui-gpui): diagnostic counters confirm 2 renders/sec at window level (GPUI limit)

- Sidebar and StatusBar uncached (natural size collapsed with StyleRefinement::default)
- ProjectGrid cached with flex-1 style (into_cached_flex)
- AgentPane + TerminalView cached within ProjectBox
- BlinkState::start() fixed with &mut *cx deref coercion
- CPU: ~3% with full layout visible (down from 6.8% uncached)
- Remaining: ProjectBox re-renders full tree on blink (reads BlinkState)
- Next: isolate dot into StatusDotView entity to prevent ProjectBox re-render

ui-gpui/src/components/project_box.rs

@@ -110,7 +110,7 @@ impl ProjectBox {
         let should_pulse = matches!(self.project.agent.status, AgentStatus::Running);
         if should_pulse {
             let blink = cx.new(|_cx| crate::components::blink_state::BlinkState::new());
-            crate::components::blink_state::BlinkState::start(&blink, cx);
+            crate::components::blink_state::BlinkState::start(&blink, &mut *cx);
             self.blink_state = Some(blink);
         }
 
@@ -151,7 +151,7 @@ impl Render for ProjectBox {
                         div()
                             .flex_1()
                             .w_full()
-                            .child(pane.clone().into_cached_view()),
+                            .child(pane.clone().into_cached_flex()),
                     );
                 }
 
@@ -172,7 +172,7 @@ impl Render for ProjectBox {
                         div()
                             .w_full()
                             .h(px(180.0))
-                            .child(term.clone().into_cached_view()),
+                            .child(term.clone().into_cached_flex()),
                     );
                 }
 

ui-gpui/src/components/project_grid.rs

@@ -60,9 +60,7 @@ impl Render for ProjectGrid {
             .overflow_y_scroll();
 
         for pb in &self.project_boxes {
-            // Cached: ProjectBox only re-renders when its entity is notified
-            // (e.g., PulsingDot blink). Sibling ProjectBoxes serve from GPU cache.
-            grid = grid.child(pb.clone().into_cached_view());
+            grid = grid.child(pb.clone());
         }
 
         if self.project_boxes.is_empty() {

ui-gpui/src/main.rs

@@ -43,13 +43,32 @@ mod workspace;
 /// Extension trait to create cached AnyView from Entity.
 /// Cached views skip re-render when their entity is not dirty —
 /// GPUI replays previous frame's GPU scene commands via memcpy.
+///
+/// IMPORTANT: The StyleRefinement must specify size/flex for the cached wrapper
+/// node. Without it, the wrapper collapses to zero size on first render.
 pub trait CachedView {
-    fn into_cached_view(self) -> gpui::AnyView;
+    /// Cache with flex-1 + full size (for content areas)
+    fn into_cached_flex(self) -> gpui::AnyView;
+    /// Cache with natural size (for sidebar, status bar)
+    fn into_cached_natural(self) -> gpui::AnyView;
 }
 
 impl<V: 'static + gpui::Render> CachedView for gpui::Entity<V> {
-    fn into_cached_view(self) -> gpui::AnyView {
-        gpui::AnyView::from(self).cached(gpui::StyleRefinement::default())
+    fn into_cached_flex(self) -> gpui::AnyView {
+        let mut style = gpui::StyleRefinement::default();
+        style.flex_grow = Some(1.0);
+        style.size.width = Some(gpui::Length::Definite(gpui::DefiniteLength::Fraction(1.0)).into());
+        style.size.height = Some(gpui::Length::Definite(gpui::DefiniteLength::Fraction(1.0)).into());
+        gpui::AnyView::from(self).cached(style)
+    }
+
+    fn into_cached_natural(self) -> gpui::AnyView {
+        let mut style = gpui::StyleRefinement::default();
+        // Natural size — don't set width/height, let content determine size
+        // But set min_size to prevent collapse
+        style.min_size.width = Some(gpui::Length::Definite(gpui::DefiniteLength::Absolute(gpui::AbsoluteLength::Pixels(gpui::px(1.0)))).into());
+        style.min_size.height = Some(gpui::Length::Definite(gpui::DefiniteLength::Absolute(gpui::AbsoluteLength::Pixels(gpui::px(1.0)))).into());
+        gpui::AnyView::from(self).cached(style)
     }
 }
 

ui-gpui/src/workspace.rs

@@ -85,34 +85,23 @@ impl Render for Workspace {
             .flex_row()
             .overflow_hidden();
 
-        // Sidebar (icon rail) — cached: only re-renders when sidebar entity is notified
+        // Sidebar (icon rail) — uncached (tiny, cheap to render)
         if sidebar_open {
-            main_row = main_row.child(
-                self.sidebar.clone().into_cached_view(),
-            );
+            main_row = main_row.child(self.sidebar.clone());
         }
 
-        // Settings drawer (between sidebar and grid) — cached
+        // Settings drawer (between sidebar and grid)
         if settings_open {
-            main_row = main_row.child(
-                self.settings_panel.clone().into_cached_view(),
-            );
+            main_row = main_row.child(self.settings_panel.clone());
         }
 
-        // Project grid (fills remaining space) — cached: only re-renders when grid entity is notified
-        main_row = main_row.child(
-            div()
-                .flex_1()
-                .h_full()
-                .child(self.project_grid.clone().into_cached_view()),
-        );
+        // Project grid (fills remaining space) — cached with flex-1
+        main_row = main_row.child(self.project_grid.clone().into_cached_flex());
 
         root = root.child(main_row);
 
-        // ── Status bar (bottom) — cached: only re-renders on status change
-        root = root.child(
-            self.status_bar.clone().into_cached_view(),
-        );
+        // Status bar (bottom) — uncached (tiny, cheap to render)
+        root = root.child(self.status_bar.clone());
 
         // ── Command palette overlay (if open) ───────────────
         if palette_open {