Flutter Notifications and Values

notifications_1.dart

class TimeNotification extends Notification {
  final String time;

  const TimeNotification({this.time});
}

notifications_2.dart

class Timer extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return FlatButton(
      child: Text("Get time!"),
      onPressed: () {
        final time = DateTime.now().toIso8601String();
        TimeNotification(time: time)..dispatch(context);
      },
    );
  }
}

notifications_3.dart

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("ValueListenableBuilder example"),
      ),
      body: NotificationListener<TimeNotification>(
          child: Timer(),
          onNotification: (notification) {
            print(notification.time);
          }),
    );
  }
}