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

const String kHeroTag = "hero tag";

void main() => runApp(CupertinoApp(
      title: 'Hero with CupertinoTabScaffold',
      home: HomePage(),
    ));

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return CupertinoTabScaffold(
      tabBar: CupertinoTabBar(
        items: <BottomNavigationBarItem>[
          BottomNavigationBarItem(icon: Icon(Icons.home)),
          BottomNavigationBarItem(icon: Icon(Icons.favorite)),
        ],
      ),
      tabBuilder: (BuildContext context, int index) {
        return CupertinoTabView(
          builder: (BuildContext context) => FirstPage(),
        );
      },
    );
  }
}

class FirstPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return CupertinoPageScaffold(
      navigationBar: CupertinoNavigationBar(),
      child: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Hero(
              tag: kHeroTag,
              child: Container(
                width: 100,
                height: 100,
                color: Colors.red,
              ),
            ),
            RaisedButton(
              onPressed: () {
                Navigator.of(context, rootNavigator: false).push(
                  CupertinoPageRoute(
                    builder: (BuildContext context) => NextPage(),
                  ),
                );
              },
              child: Text("Next in tab"),
            ),
            RaisedButton(
              onPressed: () {
                Navigator.of(context, rootNavigator: true).push(
                  CupertinoPageRoute(
                    builder: (BuildContext context) => NextPage(),
                  ),
                );
              },
              child: Text("Next out tab"),
            ),
          ],
        ),
      ),
    );
  }
}

class NextPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return CupertinoPageScaffold(
      navigationBar: CupertinoNavigationBar(),
      child: Center(
        child: Hero(
          tag: kHeroTag,
          child: Container(
            width: 100,
            height: 100,
            color: Colors.red,
          ),
        ),
      ),
    );
  }
}