wip: Rename ScreenRetriever to DisplayManager

Author: lijy91

.github/workflows/build.yml

@@ -50,4 +50,4 @@ jobs:
       uses: actions/upload-artifact@v4
       with:
         name: examples-${{ matrix.platform }}
-        path: build/examples/screen_info/ 
+        path: build/examples/display_example/ 

CMakeLists.txt

@@ -6,5 +6,5 @@ project(libnativeapi_library VERSION 0.0.1 LANGUAGES CXX)
 add_subdirectory(src)
 
 # Add example programs subdirectory
-add_subdirectory(examples/screen_info)
+add_subdirectory(examples/display_example)
 add_subdirectory(examples/window_example)

examples/screen_info/CMakeLists.txt renamed to examples/display_example/CMakeLists.txt

@@ -1,22 +1,22 @@
 cmake_minimum_required(VERSION 3.10)
 
-project(screen_info_example VERSION 0.0.1 LANGUAGES CXX)
+project(display_example VERSION 0.0.1 LANGUAGES CXX)
 
 # Set C++ standard
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
 # Add example program
-add_executable(screen_info_example
+add_executable(display_example
   "main.cpp"
 )
 
 # Link main library
-target_link_libraries(screen_info_example PRIVATE libnativeapi)
+target_link_libraries(display_example PRIVATE libnativeapi)
 
 # Set example program properties
-set_target_properties(screen_info_example PROPERTIES
-  OUTPUT_NAME "screen_info_example"
+set_target_properties(display_example PROPERTIES
+  OUTPUT_NAME "display_example"
 )
 
 # Set example program compile options (macOS only)

examples/screen_info/main.cpp renamed to examples/display_example/main.cpp

@@ -3,14 +3,13 @@
 
 using nativeapi::Display;
 using nativeapi::Point;
-using nativeapi::ScreenEventType;
-using nativeapi::ScreenRetriever;
+using nativeapi::DisplayManager;
 
 int main() {
-  ScreenRetriever screenRetriever = ScreenRetriever();
+  DisplayManager displayManager = DisplayManager();
 
   // Get primary display information
-  Display primaryDisplay = screenRetriever.GetPrimaryDisplay();
+  Display primaryDisplay = displayManager.GetPrimary();
   std::cout << "Primary Display Information:" << std::endl;
   std::cout << "ID: " << primaryDisplay.id << std::endl;
   std::cout << "Name: " << primaryDisplay.name << std::endl;
@@ -24,7 +23,7 @@ int main() {
   std::cout << std::endl;
 
   // Get all displays information
-  std::vector<Display> allDisplays = screenRetriever.GetAllDisplays();
+  std::vector<Display> allDisplays = displayManager.GetAll();
   std::cout << "All Displays Information:" << std::endl;
   for (int i = 0; i < allDisplays.size(); i++) {
     Display& display = allDisplays[i];
@@ -42,8 +41,8 @@ int main() {
   }
 
   // Get cursor position
-  Point cursorPoint = screenRetriever.GetCursorScreenPoint();
-  std::cout << "Current Cursor Position: (" << cursorPoint.x << ", "
-            << cursorPoint.y << ")" << std::endl;
+  Point cursorPosition = displayManager.GetCursorPosition();
+  std::cout << "Current Cursor Position: (" << cursorPosition.x << ", "
+            << cursorPosition.y << ")" << std::endl;
   return 0;
 }

include/nativeapi.h

@@ -1,7 +1,7 @@
 #pragma once
 
 #include "../src/display.h"
+#include "../src/display_manager.h"
 #include "../src/geometry.h"
-#include "../src/screen_retriever.h"
 #include "../src/window.h"
 #include "../src/window_manager.h"

src/display_manager.cpp

@@ -0,0 +1,28 @@
+#include <set>
+
+#include "display_manager.h"
+
+namespace nativeapi {
+
+void DisplayManager::AddListener(DisplayListener* listener) {
+  listeners_.push_back(listener);
+}
+
+void DisplayManager::RemoveListener(DisplayListener* listener) {
+  listeners_.erase(std::remove(listeners_.begin(), listeners_.end(), listener),
+                   listeners_.end());
+}
+
+void DisplayManager::NotifyDisplayAdded(const Display& display) {
+  for (const auto& listener : listeners_) {
+    listener->OnDisplayAdded(display);
+  }
+}
+
+void DisplayManager::NotifyDisplayRemoved(const Display& display) {
+  for (const auto& listener : listeners_) {
+    listener->OnDisplayRemoved(display);
+  }
+}
+
+}  // namespace nativeapi

src/display_manager.h

@@ -0,0 +1,49 @@
+#pragma once
+
+#include <cstdint>
+#include <functional>
+#include <map>
+#include <vector>
+
+#include "display.h"
+#include "geometry.h"
+
+namespace nativeapi {
+
+// DisplayListener is an interface that can be implemented by classes that want
+// to listen for display events.
+class DisplayListener {
+ public:
+  virtual void OnDisplayAdded(const Display& display) = 0;
+  virtual void OnDisplayRemoved(const Display& display) = 0;
+};
+
+// DisplayManager is a singleton that manages all displays on the system.
+class DisplayManager {
+ public:
+  DisplayManager();
+  virtual ~DisplayManager();
+
+  // Get the current cursor position
+  Point GetCursorPosition();
+
+  // Get all displays information
+  std::vector<Display> GetAll();
+
+  // Get the primary display information
+  Display GetPrimary();
+
+  // Add a listener to the display manager
+  void AddListener(DisplayListener* listener);
+
+  // Remove a listener from the display manager
+  void RemoveListener(DisplayListener* listener);
+
+ private:
+  std::vector<Display> displays_;
+  std::vector<DisplayListener*> listeners_;
+  void NotifyDisplayAdded(const Display& display);
+  void NotifyDisplayRemoved(const Display& display);
+};
+
+}  // namespace nativeapi

src/screen_retriever_linux.cpp renamed to src/display_manager_linux.cpp

@@ -1,6 +1,6 @@
 #include <gtk/gtk.h>
 #include <iostream>
-#include "screen_retriever.h"
+#include "display_manager.h"
 
 namespace nativeapi {
 
@@ -30,18 +30,18 @@ static Display CreateDisplayFromGdkMonitor(GdkMonitor* monitor,
   return display;
 }
 
-ScreenRetriever::ScreenRetriever() {
+DisplayManager::DisplayManager() {
   gtk_init(nullptr, nullptr);
   // Constructor implementation
-  std::cout << "ScreenRetriever initialized" << std::endl;
+  std::cout << "DisplayManager initialized" << std::endl;
 }
 
-ScreenRetriever::~ScreenRetriever() {
+DisplayManager::~DisplayManager() {
   // Destructor implementation
-  std::cout << "ScreenRetriever destroyed" << std::endl;
+  std::cout << "DisplayManager destroyed" << std::endl;
 }
 
-Point ScreenRetriever::GetCursorScreenPoint() {
+Point DisplayManager::GetCursorPosition() {
   GdkDisplay* display = gdk_display_get_default();
   GdkSeat* seat = gdk_display_get_default_seat(display);
   GdkDevice* pointer = gdk_seat_get_pointer(seat);
@@ -56,7 +56,7 @@ Point ScreenRetriever::GetCursorScreenPoint() {
   return point;
 }
 
-Display ScreenRetriever::GetPrimaryDisplay() {
+Display DisplayManager::GetPrimary() {
   GdkDisplay* display = gdk_display_get_default();
   GdkMonitor* monitor = gdk_display_get_primary_monitor(display);
 
@@ -71,10 +71,10 @@ Display ScreenRetriever::GetPrimaryDisplay() {
   return CreateDisplayFromGdkMonitor(monitor, true);
 }
 
-std::vector<Display> ScreenRetriever::GetAllDisplays() {
+std::vector<Display> DisplayManager::GetAll() {
   // Empty implementation
   std::vector<Display> displayList;
-  displayList.push_back(GetPrimaryDisplay());
+  displayList.push_back(GetPrimary());
   return displayList;
 }
 

src/screen_retriever_macos.mm renamed to src/display_manager_macos.mm

@@ -1,23 +1,18 @@
 #include <cstring>
 #include <iostream>
+#include <set>
 #include <string>
-#include "screen_retriever.h"
+#include <vector>
+
+#include "display.h"
+#include "display_manager.h"
 
 // Import Cocoa headers
 #import <Cocoa/Cocoa.h>
 
 namespace nativeapi {
 
-// Helper function to convert NSString to char*
-static char* ConvertNSStringToCString(NSString* nsString) {
-  if (nsString == nil) {
-    return strdup("");
-  }
-  const char* cString = [nsString UTF8String];
-  return cString ? strdup(cString) : strdup("");
-}
-
-static Display CreateDisplayFromNSScreen(NSScreen* screen, bool isFirstScreen) {
+static Display CreateDisplayFromNSScreen(NSScreen* screen, bool isPrimary) {
   Display display;
 
   // Get screen details
@@ -29,17 +24,17 @@ static Display CreateDisplayFromNSScreen(NSScreen* screen, bool isFirstScreen) {
   CGDirectDisplayID displayID =
       [[[screen deviceDescription] objectForKey:@"NSScreenNumber"] unsignedIntValue];
   NSString* screenId = [NSString stringWithFormat:@"%@", @(displayID)];
-  display.id = ConvertNSStringToCString(screenId);
+  display.id = [screenId UTF8String];
 
   // Set display name - use localizedName on macOS 10.15+
   NSString* displayName;
   if (@available(macOS 10.15, *)) {
     displayName = [screen localizedName];
   } else {
-    displayName = isFirstScreen ? @"Primary Display"
-                                : [NSString stringWithFormat:@"Display %@", @(displayID)];
+    displayName =
+        isPrimary ? @"Primary Display" : [NSString stringWithFormat:@"Display %@", @(displayID)];
   }
-  display.name = ConvertNSStringToCString(displayName);
+  display.name = [displayName UTF8String];
 
   // Set size and position properties
   display.width = frame.size.width;
@@ -55,57 +50,70 @@ static Display CreateDisplayFromNSScreen(NSScreen* screen, bool isFirstScreen) {
 
 id displayObserver_;
 
-ScreenRetriever::ScreenRetriever() {
-  // Store initial display configuration
-  current_displays_ = GetAllDisplays();
-
+DisplayManager::DisplayManager() {
+  displays_ = GetAll();
   // Set up display configuration change observer
   displayObserver_ = [[NSNotificationCenter defaultCenter]
       addObserverForName:NSApplicationDidChangeScreenParametersNotification
                   object:nil
                    queue:[NSOperationQueue mainQueue]
               usingBlock:^(NSNotification* notification) {
-                HandleDisplayChange();
+                auto old_displays = displays_;
+                auto new_displays = GetAll();
+
+                // Find added displays
+                std::set<std::string> old_ids;
+                for (const auto& d : old_displays)
+                  old_ids.insert(d.id);
+                for (const auto& d : new_displays) {
+                  if (old_ids.find(d.id) == old_ids.end()) {
+                    NotifyDisplayAdded(d);
+                  }
+                }
+
+                // Find removed displays
+                std::set<std::string> new_ids;
+                for (const auto& d : new_displays)
+                  new_ids.insert(d.id);
+                for (const auto& d : old_displays) {
+                  if (new_ids.find(d.id) == new_ids.end()) {
+                    NotifyDisplayRemoved(d);
+                  }
+                }
+
+                displays_ = std::move(new_displays);
               }];
 }
 
-ScreenRetriever::~ScreenRetriever() {
-  // Remove observer
+DisplayManager::~DisplayManager() {
   if (displayObserver_) {
     [[NSNotificationCenter defaultCenter] removeObserver:displayObserver_];
   }
-  // Note: cursor observer is automatically cleaned up when the run loop source is removed
 }
 
-Point ScreenRetriever::GetCursorScreenPoint() {
-  Point point;
-
-  // Get the current mouse position
+Point DisplayManager::GetCursorPosition() {
   NSPoint mouseLocation = [NSEvent mouseLocation];
+  Point point;
   point.x = mouseLocation.x;
   point.y = mouseLocation.y;
-
   return point;
 }
 
-Display ScreenRetriever::GetPrimaryDisplay() {
-  // Get the primary display (first screen)
-  NSArray<NSScreen*>* screens = [NSScreen screens];
-  return CreateDisplayFromNSScreen(screens[0], true);
-}
-
-std::vector<Display> ScreenRetriever::GetAllDisplays() {
+std::vector<Display> DisplayManager::GetAll() {
   std::vector<Display> displayList;
-
-  // Get all screens
   NSArray<NSScreen*>* screens = [NSScreen screens];
-  bool isFirstScreen = true;
+  bool isPrimary = true;
   for (NSScreen* screen in screens) {
-    displayList.push_back(CreateDisplayFromNSScreen(screen, isFirstScreen));
-    isFirstScreen = false;  // Only the first screen is the main screen
+    displayList.push_back(CreateDisplayFromNSScreen(screen, isPrimary));
+    isPrimary = false;  // Only the first NSScreen is the primary display
   }
-
   return displayList;
 }
 
+Display DisplayManager::GetPrimary() {
+  // Get the primary display (first NSScreen)
+  NSArray<NSScreen*>* screens = [NSScreen screens];
+  return CreateDisplayFromNSScreen(screens[0], true);
+}
+
 }  // namespace nativeapi