fix: prevent traffic light buttons flashing on deminiaturize (#50209)

trop[bot] · codebytere · web-flow · commit 6d2986302c6e · 2026-03-11T17:00:10.000-04:00
* fix: prevent traffic light buttons flashing on deminiaturize

When a window with a custom `trafficLightPosition` is minimized and
restored, macOS re-layouts the title bar container during the
deminiaturize animation, causing the traffic light buttons to briefly
appear at their default position before being repositioned.

Fix this by hiding the buttons container in `windowWillMiniaturize` and
restoring them (with a redraw to the correct position) in
`windowDidDeminiaturize`.

Co-authored-by: Shelley Vohr &lt;shelley.vohr@gmail.com&gt;

* chore: address feedback from review

Co-authored-by: Shelley Vohr &lt;shelley.vohr@gmail.com&gt;

---------

Co-authored-by: trop[bot] &lt;37223003+trop[bot]@users.noreply.github.com&gt;
Co-authored-by: Shelley Vohr &lt;shelley.vohr@gmail.com&gt;
diff --git a/shell/browser/native_window_mac.h b/shell/browser/native_window_mac.h
@@ -170,6 +170,12 @@ class NativeWindowMac : public NativeWindow,
   void NotifyWindowDidFailToEnterFullScreen();
   void NotifyWindowWillLeaveFullScreen();
 
+  // Hide/show traffic light buttons around miniaturize/deminiaturize to
+  // prevent them from flashing at the default position during the restore
+  // animation when a custom trafficLightPosition is configured.
+  void HideTrafficLights();
+  void RestoreTrafficLights();
+
   // Cleanup observers when window is getting closed. Note that the destructor
   // can be called much later after window gets closed, so we should not do
   // cleanup in destructor.
diff --git a/shell/browser/native_window_mac.mm b/shell/browser/native_window_mac.mm
@@ -1533,6 +1533,18 @@ static bool FromV8(v8::Isolate* isolate,
     [buttons_proxy_ redraw];
 }
 
+void NativeWindowMac::HideTrafficLights() {
+  if (buttons_proxy_)
+    [buttons_proxy_ setVisible:NO];
+}
+
+void NativeWindowMac::RestoreTrafficLights() {
+  if (buttons_proxy_ && window_button_visibility_.value_or(true)) {
+    [buttons_proxy_ redraw];
+    [buttons_proxy_ setVisible:YES];
+  }
+}
+
 // In simpleFullScreen mode, update the frame for new bounds.
 void NativeWindowMac::UpdateFrame() {
   NSWindow* window = GetNativeWindow().GetNativeNSWindow();
diff --git a/shell/browser/ui/cocoa/electron_ns_window_delegate.mm b/shell/browser/ui/cocoa/electron_ns_window_delegate.mm
@@ -256,6 +256,10 @@ - (void)windowWillMiniaturize:(NSNotification*)notification {
   shell_->SetWindowLevel(NSNormalWindowLevel);
   shell_->UpdateWindowOriginalFrame();
   shell_->DetachChildren();
+  // Hide the traffic light buttons container before miniaturize so that
+  // when the window is restored, macOS does not render the buttons at
+  // their default position during the deminiaturize animation.
+  shell_->HideTrafficLights();
 }
 
 - (void)windowDidMiniaturize:(NSNotification*)notification {
@@ -273,6 +277,10 @@ - (void)windowDidDeminiaturize:(NSNotification*)notification {
   shell_->set_wants_to_be_visible(true);
   shell_->AttachChildren();
   shell_->SetWindowLevel(level_);
+  // Reposition traffic light buttons and make them visible again.
+  // They were hidden in windowWillMiniaturize to prevent a flash at
+  // the default (0,0) position during the restore animation.
+  shell_->RestoreTrafficLights();
   shell_->NotifyWindowRestore();
 }
 
