Flutter Counter With Riverpod

main.dart

// Copyright 2019 the Dart project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license
// that can be found in the LICENSE file.

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

void main() {
  final providerScope = ProviderScope(
    overrides: [],
    child: const MyApp(),
  );
  runApp(providerScope);
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends ConsumerStatefulWidget {
  final String title;

  const MyHomePage({
    super.key,
    required this.title,
  });

  @override
  ConsumerState<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends ConsumerState<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            const Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '${ref.watch(CounterNotifier.provider)}',
              style: Theme.of(context).textTheme.headlineMedium,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: ref.read(CounterNotifier.provider.notifier).increment,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ),
    );
  }
}

class CounterNotifier extends AutoDisposeNotifier<int> {
  static final provider =
      AutoDisposeNotifierProvider<CounterNotifier, int>(CounterNotifier.new);

  @override
  int build() => 0;

  void increment() => state++;
}