fix: reposition traffic lights on theme change (electron#22534)

MarshallOfSound · web-flow · commit 3c19aee73cfd · 2020-03-05T12:19:05.000-08:00
diff --git a/shell/browser/native_window_mac.h b/shell/browser/native_window_mac.h
@@ -14,6 +14,7 @@
 
 #include "base/mac/scoped_nsobject.h"
 #include "shell/browser/native_window.h"
+#include "ui/native_theme/native_theme_observer.h"
 #include "ui/views/controls/native/native_view_host.h"
 
 @class ElectronNSWindow;
@@ -26,7 +27,7 @@ namespace electron {
 
 class RootViewMac;
 
-class NativeWindowMac : public NativeWindow {
+class NativeWindowMac : public NativeWindow, public ui::NativeThemeObserver {
  public:
   NativeWindowMac(const gin_helper::Dictionary& options, NativeWindow* parent);
   ~NativeWindowMac() override;
@@ -152,6 +153,7 @@ class NativeWindowMac : public NativeWindow {
   // Custom traffic light positioning
   void RepositionTrafficLights();
   void SetExitingFullScreen(bool flag);
+  void OnNativeThemeUpdated(ui::NativeTheme* observed_theme) override;
 
   enum class TitleBarStyle {
     NORMAL,
diff --git a/shell/browser/native_window_mac.mm b/shell/browser/native_window_mac.mm
@@ -16,8 +16,11 @@
 #include "base/mac/scoped_cftyperef.h"
 #include "base/numerics/ranges.h"
 #include "base/strings/sys_string_conversions.h"
+#include "base/task/post_task.h"
 #include "components/remote_cocoa/app_shim/native_widget_ns_window_bridge.h"
 #include "content/public/browser/browser_accessibility_state.h"
+#include "content/public/browser/browser_task_traits.h"
+#include "content/public/browser/browser_thread.h"
 #include "content/public/browser/desktop_media_id.h"
 #include "shell/browser/native_browser_view_mac.h"
 #include "shell/browser/ui/cocoa/electron_native_widget_mac.h"
@@ -324,6 +327,8 @@ void ViewDidMoveToSuperview(NSView* self, SEL _cmd) {
 NativeWindowMac::NativeWindowMac(const gin_helper::Dictionary& options,
                                  NativeWindow* parent)
     : NativeWindow(options, parent), root_view_(new RootViewMac(this)) {
+  ui::NativeTheme::GetInstanceForNativeUi()->AddObserver(this);
+
   int width = 800, height = 600;
   options.Get(options::kWidth, &width);
   options.Get(options::kHeight, &height);
@@ -509,6 +514,7 @@ void ViewDidMoveToSuperview(NSView* self, SEL _cmd) {
 }
 
 NativeWindowMac::~NativeWindowMac() {
+  ui::NativeTheme::GetInstanceForNativeUi()->RemoveObserver(this);
   if (wheel_event_monitor_)
     [NSEvent removeMonitor:wheel_event_monitor_];
 }
@@ -700,6 +706,12 @@ void ViewDidMoveToSuperview(NSView* self, SEL _cmd) {
   exiting_fullscreen_ = flag;
 }
 
+void NativeWindowMac::OnNativeThemeUpdated(ui::NativeTheme* observed_theme) {
+  base::PostTask(FROM_HERE, {content::BrowserThread::UI},
+                 base::BindOnce(&NativeWindowMac::RepositionTrafficLights,
+                                base::Unretained(this)));
+}
+
 bool NativeWindowMac::IsEnabled() {
   return [window_ attachedSheet] == nil;
 }
