refactor: Consolidate display notification methods into a single NotifyListeners function for improved code clarity and maintainability

Author: lijy91

src/display_manager.cpp

@@ -11,15 +11,10 @@ void DisplayManager::RemoveListener(DisplayListener* listener) {
                    listeners_.end());
 }
 
-void DisplayManager::NotifyDisplayAdded(const Display& display) {
+void DisplayManager::NotifyListeners(
+    std::function<void(DisplayListener*)> callback) {
   for (const auto& listener : listeners_) {
-    listener->OnDisplayAdded(display);
-  }
-}
-
-void DisplayManager::NotifyDisplayRemoved(const Display& display) {
-  for (const auto& listener : listeners_) {
-    listener->OnDisplayRemoved(display);
+    callback(listener);
   }
 }
 

src/display_manager.h

@@ -42,8 +42,7 @@ class DisplayManager {
  private:
   std::vector<Display> displays_;
   std::vector<DisplayListener*> listeners_;
-  void NotifyDisplayAdded(const Display& display);
-  void NotifyDisplayRemoved(const Display& display);
+  void NotifyListeners(std::function<void(DisplayListener*)> callback);
 };
 
 // DisplayEventHandler is an implementation of DisplayListener that uses

src/display_manager_macos.mm

@@ -67,7 +67,8 @@ static Display CreateDisplayFromNSScreen(NSScreen* screen, bool isPrimary) {
                   old_ids.insert(d.id);
                 for (const auto& d : new_displays) {
                   if (old_ids.find(d.id) == old_ids.end()) {
-                    NotifyDisplayAdded(d);
+                    NotifyListeners(
+                        [d](DisplayListener* listener) { listener->OnDisplayAdded(d); });
                   }
                 }
 
@@ -77,7 +78,8 @@ static Display CreateDisplayFromNSScreen(NSScreen* screen, bool isPrimary) {
                   new_ids.insert(d.id);
                 for (const auto& d : old_displays) {
                   if (new_ids.find(d.id) == new_ids.end()) {
-                    NotifyDisplayRemoved(d);
+                    NotifyListeners(
+                        [d](DisplayListener* listener) { listener->OnDisplayRemoved(d); });
                   }
                 }