import 'package:flutter/cupertino.dart';

void main() => runApp(const SliverNavBarApp());

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

  @override
  Widget build(BuildContext context) {
    return const CupertinoApp(home: SliverNavBarExample());
  }
}

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

  @override
  Widget build(BuildContext context) {
    return CupertinoPageScaffold(
      child: CustomScrollView(
        slivers: [
          CupertinoSliverNavigationBar(largeTitle: Text('Favorites')),
          SliverFillRemaining(
            child: Center(
              child: CupertinoButton.filled(
                onPressed: () => Navigator.push(context, CupertinoPageRoute(builder: (BuildContext context) => NextPage())),
                child: Text('Go to Next Page'),
              ),
            ),
          ),
        ],
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return CupertinoPageScaffold(
      child: CustomScrollView(
        slivers: [
          CupertinoSliverNavigationBar(largeTitle: Text('Page'), previousPageTitle: 'Favorites'),
          SliverFillRemaining(child: Center(child: Text('Page'))),
        ],
      ),
    );
  }
}