fabiomsr

class MyHomePage extends StatelessWidget {
  final _counter = new ValueNotifier(0);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text("ValueListenableBuilder example"),
        ),
        body: CounterListenableProvider(

fabiomsr

class CounterText extends StatelessWidget {
  @override
  Widget build(BuildContext context) {

    return  ValueListenableBuilder<int>(
        valueListenable: CounterListenableProvider.of(context),
        builder: (context, value, child) {
          return new Text(value.toString());
        });
  }

fabiomsr

static ValueListenable<int> of(BuildContext context) {
    return (context.inheritFromWidgetOfExactType(CounterListenableProvider)
            as CounterListenableProvider)
        .counter;
}

fabiomsr

class CounterListenableProvider extends InheritedWidget {
  final ValueListenable<int> counter;

  CounterListenableProvider({Key key, @required this.counter, Widget child})
      : super(key: key, child: child);

  @override
  bool updateShouldNotify(InheritedWidget oldWidget) {
    return true;
  }

fabiomsr

@override
Widget build(BuildContext context) {
  return Scaffold(
      appBar: AppBar(
        title: Text("ValueListenableBuilder example"),
      ),
      body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[

fabiomsr

class MyHomePage extends StatelessWidget {
  final _counter = new ValueNotifier<int>(0);
}

fabiomsr

class CounterText extends StatelessWidget {
  final ValueListenable<int> _counter;

  CounterText(this._counter);

  @override
  Widget build(BuildContext context) {
    return  ValueListenableBuilder<int>(
        valueListenable: _counter,
        builder: (context, value, child) {

fabiomsr

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

fabiomsr

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);
      },
    );

fabiomsr

class TimeNotification extends Notification {
  final String time;

  const TimeNotification({this.time});
}