chore: Implement "display-added" and "display-removed" for macOS

packages/screen_retriever/CHANGELOG.md

@@ -1,6 +1,7 @@
 ## 0.2.0
 
 * Convert to federated plugin
+* Implement "display-added" and "display-removed" for macOS #5
 
 ## 0.1.9
 

packages/screen_retriever/example/lib/pages/home.dart

@@ -4,9 +4,6 @@ import 'package:hotkey_manager/hotkey_manager.dart';
 import 'package:screen_retriever/screen_retriever.dart';
 import 'package:screen_retriever_example/widgets/display_card.dart';
 
-final hotKeyManager = HotKeyManager.instance;
-final screenRetriever = ScreenRetriever.instance;
-
 class _ListSection extends StatelessWidget {
   const _ListSection({required this.title, required this.children});
 
@@ -42,25 +39,39 @@ class HomePage extends StatefulWidget {
   State<HomePage> createState() => _HomePageState();
 }
 
-class _HomePageState extends State<HomePage> {
+class _HomePageState extends State<HomePage> with ScreenListener {
   Display? _primaryDisplay;
   List<Display> _displayList = [];
 
   @override
   void initState() {
+    screenRetriever.addListener(this);
     super.initState();
-    _init();
-  }
-
-  Future<void> _init() async {
-    // 初始化快捷键
     hotKeyManager.unregisterAll();
     hotKeyManager.register(
       HotKey(KeyCode.keyD, modifiers: [KeyModifier.alt]),
       keyDownHandler: (_) {
         _handleGetCursorScreenPoint();
       },
     );
+    _getDisplays();
+  }
+
+  @override
+  void dispose() {
+    screenRetriever.removeListener(this);
+    super.dispose();
+  }
+
+  @override
+  void onScreenEvent(String eventName) {
+    BotToast.showText(
+      text: 'onScreenEvent: $eventName',
+    );
+    _getDisplays();
+  }
+
+  Future<void> _getDisplays() async {
     _primaryDisplay = await screenRetriever.getPrimaryDisplay();
     _displayList = await screenRetriever.getAllDisplays();
     setState(() {});

packages/screen_retriever/lib/src/screen_retriever.dart

@@ -1,3 +1,4 @@
+import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 import 'package:screen_retriever_platform_interface/screen_retriever_platform_interface.dart';
 
@@ -9,6 +10,35 @@ class ScreenRetriever {
 
   ScreenRetrieverPlatform get _platform => ScreenRetrieverPlatform.instance;
 
+  /// Handle screen events from the platform side.
+  void _handleScreenEvent(event) {
+    String type = event['type'] as String;
+    for (var listener in _listeners) {
+      listener.onScreenEvent(type);
+    }
+  }
+
+  final ObserverList<ScreenListener> _listeners =
+      ObserverList<ScreenListener>();
+
+  bool get hasListeners {
+    return _listeners.isNotEmpty;
+  }
+
+  void addListener(ScreenListener listener) {
+    if (!hasListeners) {
+      _platform.onScreenEventReceiver.listen(_handleScreenEvent);
+    }
+    _listeners.add(listener);
+  }
+
+  void removeListener(ScreenListener listener) {
+    _listeners.remove(listener);
+    if (!hasListeners) {
+      _platform.onScreenEventReceiver.listen(null);
+    }
+  }
+
   Future<Offset> getCursorScreenPoint() {
     return _platform.getCursorScreenPoint();
   }
@@ -21,3 +51,5 @@ class ScreenRetriever {
     return _platform.getAllDisplays();
   }
 }
+
+final ScreenRetriever screenRetriever = ScreenRetriever.instance;

packages/screen_retriever/test/screen_retriever_test.dart

@@ -16,6 +16,10 @@ class MockScreenRetrieverPlatform
     with MockPlatformInterfaceMixin
     implements ScreenRetrieverPlatform {
   @override
+  Stream<Map<Object?, Object?>> get onScreenEventReceiver =>
+      throw UnimplementedError();
+
+  @override
   Future<Offset> getCursorScreenPoint() {
     return Future(() => const Offset(10.0, 10.0));
   }

packages/screen_retriever_macos/macos/Classes/ScreenRetrieverMacosPlugin.swift

@@ -48,11 +48,64 @@ extension NSRect {
     }
 }
 
-public class ScreenRetrieverMacosPlugin: NSObject, FlutterPlugin {
+public class ScreenRetrieverMacosPlugin: NSObject, FlutterPlugin,FlutterStreamHandler {
+    private var _eventSink: FlutterEventSink?
+
+    var externalDisplayCount:Int = 0
+
     public static func register(with registrar: FlutterPluginRegistrar) {
         let channel = FlutterMethodChannel(name: "dev.leanflutter.plugins/screen_retriever", binaryMessenger: registrar.messenger)
         let instance = ScreenRetrieverMacosPlugin()
         registrar.addMethodCallDelegate(instance, channel: channel)
+        let eventChannel = FlutterEventChannel(name: "dev.leanflutter.plugins/screen_retriever_event", binaryMessenger: registrar.messenger)
+        eventChannel.setStreamHandler(instance)
+
+        instance.externalDisplayCount = NSScreen.screens.count
+        instance.setupNotificationCenter()
+    }
+
+    public func onListen(withArguments arguments: Any?, eventSink events: @escaping FlutterEventSink) -> FlutterError? {
+        self._eventSink = events
+        return nil;
+    }
+
+    public func onCancel(withArguments arguments: Any?) -> FlutterError? {
+        self._eventSink = nil
+        return nil
+    }
+
+//    public func handleDidFinishLaunching(_ notification: Notification) {
+//        externalDisplayCount = NSScreen.screens.count
+//        setupNotificationCenter()
+//    }
+
+    func setupNotificationCenter() {
+        NotificationCenter.default.addObserver(
+            self,
+            selector: #selector(handleDisplayConnection),
+            name: NSApplication.didChangeScreenParametersNotification,
+            object: nil)
+    }
+
+
+    @objc func handleDisplayConnection(notification: Notification) {
+        if externalDisplayCount < NSScreen.screens.count {
+            _emitEvent("display-added")
+            externalDisplayCount = NSScreen.screens.count
+        } else if externalDisplayCount > NSScreen.screens.count {
+            _emitEvent("display-removed")
+            externalDisplayCount = NSScreen.screens.count
+        }
+    }
+
+    public func _emitEvent(_ eventName: String) {
+        guard let eventSink = self._eventSink else {
+            return
+        }
+        let event: NSDictionary = [
+            "type": eventName,
+        ]
+        eventSink(event)
     }
 
     public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {

packages/screen_retriever_platform_interface/lib/src/screen_listener.dart

@@ -1,5 +1,5 @@
 /// Interface for listening to screen events.
-abstract class ScreenListener {
+abstract mixin class ScreenListener {
   /// Called when a screen event occurs.
   void onScreenEvent(String eventName) {}
 }

packages/screen_retriever_platform_interface/lib/src/screen_retriever_method_channel.dart

@@ -13,6 +13,17 @@ class MethodChannelScreenRetriever extends ScreenRetrieverPlatform {
     'dev.leanflutter.plugins/screen_retriever',
   );
 
+  /// The event channel used to receive events from the native platform.
+  @visibleForTesting
+  final eventChannel = const EventChannel(
+    'dev.leanflutter.plugins/screen_retriever_event',
+  );
+
+  @override
+  Stream<Map<Object?, Object?>> get onScreenEventReceiver {
+    return eventChannel.receiveBroadcastStream().cast<Map<Object?, Object?>>();
+  }
+
   // The default arguments used for [methodChannel.invokeMethod].
   Map<String, dynamic> get _defaultArguments {
     MediaQueryData mediaQueryData = MediaQueryData.fromView(

packages/screen_retriever_platform_interface/lib/src/screen_retriever_platform.dart

@@ -24,6 +24,12 @@ abstract class ScreenRetrieverPlatform extends PlatformInterface {
     _instance = instance;
   }
 
+  Stream<Map<Object?, Object?>> get onScreenEventReceiver {
+    throw UnimplementedError(
+      'onScreenEventReceiver() has not been implemented.',
+    );
+  }
+
   Future<Offset> getCursorScreenPoint() {
     throw UnimplementedError(
       'getCursorScreenPoint() has not been implemented.',

packages/screen_retriever_platform_interface/test/src/screen_retriever_platform_test.dart

@@ -8,6 +8,10 @@ class MockScreenRetrieverPlatform
     with MockPlatformInterfaceMixin
     implements ScreenRetrieverPlatform {
   @override
+  Stream<Map<Object?, Object?>> get onScreenEventReceiver =>
+      throw UnimplementedError();
+
+  @override
   Future<Offset> getCursorScreenPoint() {
     return Future(() => Offset.zero);
   }