Flutterでイベントフローを実装するためのもの

route_event.dart

import 'dart:async';

class Router {}

final _controller = StreamController<Router>.broadcast();

/// [Router]イベントを監視するmixin
mixin RouteEventObserver<R extends Router> {
  StreamSubscription<Router>? _subscription;

  void onRouteEventReceived(R router);

  void subscribeToRouteEvent() {
    _subscription = _controller.stream.listen((router) {
      if (router is R) {
        onRouteEventReceived(router);
      }
    });
  }

  void cancelRouteEventSubscription() {
    _subscription?.cancel();
  }
}

/// [Router]イベントを送信するmixin
mixin RouteEventEmitter {
  void publishRouteEvent(Router router) => _controller.add(router);
}