notification_dispatcher 0.3.2

Inspired by Apple's NotificationCenter. Passes information around to registered observers.

Inspired by Apple's NotificationCenter. Passes information around to registered observers.

Installing

Add the following line to your pubspec.yaml file.

notification_dispatcher: ^0.3.2

Flutter Example

void main() {
  runApp(const App());
}

class App extends StatefulWidget {
  const App({Key? key}) : super(key: key);

  @override
  State<App> createState() => _AppState();
}

class _AppState extends State<App> {
  int _count = 0;

  @override
  void initState() {
    super.initState();
    NotificationDispatcher.instance.addObserver(
      this,
      name: 'observerName',
      callback: (_) => _incrementCount(),
    );
  }

  @override
  void dispose() {
    NotificationDispatcher.instance.removeObserver(this);
    super.dispose();
  }

  void _incrementCount() {
    setState(() {
      _count++;
    });
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              const Text(
                'You have pushed the button this many times:',
              ),
              Text(
                '$_count',
                style: Theme.of(context).textTheme.headline4,
              ),
            ],
          ),
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: () =>
              NotificationDispatcher.instance.post(name: 'observerName'),
          tooltip: 'Increment',
          child: const Icon(Icons.add),
        ),
      ),
    );
  }
}

Equatable

To set an Equatable-extended class as an observer, use the NotificationDispatcherEquatableObserverMixin mixin and add the instanceKey property to its props property.

class SomeClass extends Equatable with NotificationDispatcherEquatableObserverMixin {
  @override
  List<Object?> get props => [...super.props, instanceKey];
}