Wrapper object to handle cloud messaging in an appropriate way

message_tray.dart

import 'dart:async';
import 'package:firebase_messaging/firebase_messaging.dart';
import 'package:meta/meta.dart';

class MessageTray {
  MessageTray({@required FirebaseMessaging messaging})
      : assert(messaging != null),
        _onMessage = StreamController(),
        _onResume = StreamController(),
        _onLaunch = StreamController() {
    messaging.configure(
      onMessage: (payload) async => _onMessage.sink.add(payload),
      onResume: (payload) async => _onResume.sink.add(payload),
      onLaunch: (payload) async => _onLaunch.sink.add(payload),
    );
  }

  final StreamController<Map<String, dynamic>> _onMessage;

  final StreamController<Map<String, dynamic>> _onResume;

  final StreamController<Map<String, dynamic>> _onLaunch;

  Stream<Map<String, dynamic>> get onMessage => _onMessage.stream;

  Stream<Map<String, dynamic>> get onResume => _onResume.stream;

  Stream<Map<String, dynamic>> get onLaunch => _onLaunch.stream;
}

Saya suka