notifications.dart

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