rx_notifier 1.1.0

Extension to ValueNotifier by transparently applying functional reactive programming (TFRP)

example/lib/main.dart

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:rx_notifier/rx_notifier.dart';

import 'home_page.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
      ),
      // home: MyHomePage(title: 'Flutter Demo Home Page'),
      home: DefaultTextStyle(style: TextStyle(fontSize: 50), child: HomePage()),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final _counter = RxNotifier<int>(0);
  int get counter => _counter.value;
  set counter(int value) => _counter.value = value;

  _incrementCounter() {
    counter++;
  }

  @override
  void initState() {
    super.initState();
    rxObserver(() {
      print(counter);
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            RxBuilder(
              filter: () => counter != 5,
              builder: (BuildContext context) {
                return Text('$counter');
              },
            ),
            CounterWidget(
              counter: _counter,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

class CounterWidget extends StatelessWidget with RxMixin {
  final ValueListenable<int> counter;

  @override
  bool filter() => counter.value != 3;

  CounterWidget({Key? key, required this.counter}) : super(key: key);
  @override
  Widget build(BuildContext context) {
    return Text('${counter.value}');
  }
}