enhanced_change_notifier

A handler plugin package that provides a cross-platform solution for handling platform message channel notifications.

How to use

• Create a custom class for the platform handler.

class Handler extends PlatformHandler {
  @override
  Future<dynamic> n2fCallDispatcher(MethodCall call) async {
    print("call.method: ${call.method}, call.arguments: ${call.arguments}");
    switch (call.method) {
      case "LogCallback": //日志回调
        String tag = call.arguments["tag"];
        String message = call.arguments["message"];
        print("$tag: $message");
        break;
    }

    return super.n2fCallDispatcher(call);
  }
}

• Define a custom class for the platform notification.

class FusedLocationCallback extends PlatformNotification {
  int lastUpdatedTimestamp = 0;
  List<Completer> _completers = [];
  Timer? updateLatestLocationTimer;

  FusedLocationCallback() {
    subscribers = {
      "fineLocationCallback":
          fusedLocationResultCallback, // fine location update
      "coarseLocationCallback":
          fusedLocationResultCallback, // coarse location update
    };
  }

  @override
  void dockingOn({Completer? completer}) {
    if (completer != null && !completer.isCompleted) {
      _completers.add(completer);
    }
    _completers = _completers.where((element) => !element.isCompleted).toList();
    docking = true;
  }

  void fusedLocationResultCallback(dynamic callbackJson) {
    Map<String, dynamic>? result = json.decode(callbackJson);
    print("The fused location updated: $result");
    _completers.map((e) => e.complete(0)).toList();
    _completers = [];
  }
}

• Create an instance of the platform handler and set the method call handler.

  import 'package:enhanced_change_notifier/enhanced_change_notifier.dart';

  const MethodChannel _methodChannel = MethodChannel('native.demo.com/messageChannel');
  final GlobalFactory<Handler> handler =
    GlobalFactory(() => Handler());
  _methodChannel.setMethodCallHandler(handler.getInstance().n2fCallDispatcher);

  FusedLocationCallback fusedLocationCallback = FusedLocationCallback();
  List<PlatformNotification> listeners = [fusedLocationCallback];

  handler.getInstance().subscribe(listeners);

  fusedLocationCallback.dockingOn();
  _methodChannel.invokeMethod("locationUpdate");

Additional information

Feel free to file an issue if you have any problem.