flutter8.dart

import 'package:provider/provider.dart';

enum Page { counter, settings }

class MyApp extends HookWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    final currentPage = useState(Page.counter);

    return MaterialApp(
      home: Provider.value(value: currentPage, child: MyScaffold()),
    );
  }
}

ValueNotifier<Page> usePage() => useContext().watch<ValueNotifier<Page>>();