main_multi_owner.dart

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';
import 'package:functional_widget_annotation/functional_widget_annotation.dart';
import 'package:hooks_riverpod/hooks_riverpod.dart';
import 'package:state_notifier/state_notifier.dart';

part 'main_multi_owner.g.dart';

class Counter extends StateNotifier<int> {
  Counter() : super(0);

  void increment() => state++;
}

final counterProvider = StateNotifierProvider<Counter>((ref) {
  return Counter();
});

void main() {
  runApp(
    ProviderScope(
      key: ValueKey('1st Scope'),
      child: MyApp(),
    ),
  );
}

@hwidget
Widget myApp() {
  return MaterialApp(
    routes: {
      '/': (_) => FirstPage(),
      'secondPage': (_) => SecondPageWithScope(),
    },
  );
}

@hwidget
Widget firstPage() {
  final context = useContext();
  return Scaffold(
    body: Center(
      child: RaisedButton(
        onPressed: () {
          Navigator.of(context).pushNamed('secondPage');
        },
        child: Text('Next Page'),
      ),
    ),
  );
}

@hwidget
Widget secondPageWithScope() {
  return ProviderScope(
    key: ValueKey('2nd Scope'),
    child: SecondPage(),
  );
}

@hwidget
Widget secondPage() {
  final counter = useProvider(counterProvider);
  return Scaffold(
    appBar: AppBar(title: Text('Second Page')),
    body: Center(
      child: Count(),
    ),
    floatingActionButton: FloatingActionButton(
      onPressed: () {
        counter.increment();
      },
      child: Icon(Icons.add),
    ),
  );
}

@hwidget
Widget count() {
  final count = useProvider(counterProvider.state);

  return Text(count.toString());
}