feat: programmatically modify traffic light positioning (#22533)

* setter

* getter

* specs and docs

* fixup

Co-authored-by: Samuel Attard <samuel.r.attard@gmail.com>

shell/browser/api/electron_api_top_level_window.cc

@@ -814,6 +814,16 @@ void TopLevelWindow::SetVibrancy(v8::Isolate* isolate,
   window_->SetVibrancy(type);
 }
 
+#if defined(OS_MACOSX)
+void TopLevelWindow::SetTrafficLightPosition(const gfx::Point& position) {
+  window_->SetTrafficLightPosition(position);
+}
+
+gfx::Point TopLevelWindow::GetTrafficLightPosition() const {
+  return window_->GetTrafficLightPosition();
+}
+#endif
+
 void TopLevelWindow::SetTouchBar(
     std::vector<gin_helper::PersistentDictionary> items) {
   window_->SetTouchBar(std::move(items));
@@ -1184,6 +1194,12 @@ void TopLevelWindow::BuildPrototype(v8::Isolate* isolate,
       .SetMethod("setAutoHideCursor", &TopLevelWindow::SetAutoHideCursor)
 #endif
       .SetMethod("setVibrancy", &TopLevelWindow::SetVibrancy)
+#if defined(OS_MACOSX)
+      .SetMethod("setTrafficLightPosition",
+                 &TopLevelWindow::SetTrafficLightPosition)
+      .SetMethod("getTrafficLightPosition",
+                 &TopLevelWindow::GetTrafficLightPosition)
+#endif
       .SetMethod("_setTouchBarItems", &TopLevelWindow::SetTouchBar)
       .SetMethod("_refreshTouchBarItem", &TopLevelWindow::RefreshTouchBarItem)
       .SetMethod("_setEscapeTouchBarItem",

shell/browser/api/electron_api_top_level_window.h

@@ -185,6 +185,12 @@ class TopLevelWindow : public gin_helper::TrackableObject<TopLevelWindow>,
   bool IsVisibleOnAllWorkspaces();
   void SetAutoHideCursor(bool auto_hide);
   virtual void SetVibrancy(v8::Isolate* isolate, v8::Local<v8::Value> value);
+
+#if defined(OS_MACOSX)
+  void SetTrafficLightPosition(const gfx::Point& position);
+  gfx::Point GetTrafficLightPosition() const;
+#endif
+
   void SetTouchBar(std::vector<gin_helper::PersistentDictionary> items);
   void RefreshTouchBarItem(const std::string& item_id);
   void SetEscapeTouchBarItem(gin_helper::PersistentDictionary item);

shell/browser/native_window.h

@@ -194,6 +194,12 @@ class NativeWindow : public base::SupportsUserData,
   // Vibrancy API
   virtual void SetVibrancy(const std::string& type);
 
+  // Traffic Light API
+#if defined(OS_MACOSX)
+  virtual void SetTrafficLightPosition(const gfx::Point& position) = 0;
+  virtual gfx::Point GetTrafficLightPosition() const = 0;
+#endif
+
   // Touchbar API
   virtual void SetTouchBar(std::vector<gin_helper::PersistentDictionary> items);
   virtual void RefreshTouchBarItem(const std::string& item_id);

shell/browser/native_window_mac.h

@@ -153,6 +153,8 @@ class NativeWindowMac : public NativeWindow, public ui::NativeThemeObserver {
   // Custom traffic light positioning
   void RepositionTrafficLights();
   void SetExitingFullScreen(bool flag);
+  void SetTrafficLightPosition(const gfx::Point& position) override;
+  gfx::Point GetTrafficLightPosition() const override;
   void OnNativeThemeUpdated(ui::NativeTheme* observed_theme) override;
 
   enum class TitleBarStyle {

shell/browser/native_window_mac.mm

@@ -1552,6 +1552,15 @@ void NativeWindowMac::SetVibrancy(const std::string& type) {
     [effect_view setMaterial:vibrancyType];
 }
 
+void NativeWindowMac::SetTrafficLightPosition(const gfx::Point& position) {
+  traffic_light_position_ = position;
+  RepositionTrafficLights();
+}
+
+gfx::Point NativeWindowMac::GetTrafficLightPosition() const {
+  return traffic_light_position_;
+}
+
 void NativeWindowMac::SetTouchBar(
     std::vector<gin_helper::PersistentDictionary> items) {
   if (@available(macOS 10.12.2, *)) {