Animate a widget across screens

It’s often helpful to guide users through an app as they navigate from screen to screen. A common technique to lead users through an app is to animate a widget from one screen to the next. This creates a visual anchor connecting the two screens.

Use the Hero widget to animate a widget from one screen to the next. This recipe uses the following steps:

  1. Create two screens showing the same image.
  2. Add a Hero widget to the first screen.
  3. Add a Hero widget to the second screen.

1. Create two screens showing the same image

In this example, display the same image on both screens. Animate the image from the first screen to the second screen when the user taps the image. For now, create the visual structure; handle animations in the next steps.

class MainScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Main Screen'),
      ),
      body: GestureDetector(
        onTap: () {
          Navigator.push(context, MaterialPageRoute(builder: (_) {
            return DetailScreen();
          }));
        },
        child: Image.network(
          'https://picsum.photos/250?image=9',
        ),
      ),
    );
  }
}

class DetailScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: GestureDetector(
        onTap: () {
          Navigator.pop(context);
        },
        child: Center(
          child: Image.network(
            'https://picsum.photos/250?image=9',
          ),
        ),
      ),
    );
  }
}

2. Add a Hero widget to the first screen

To connect the two screens together with an animation, wrap the Image widget on both screens in a Hero widget. The Hero widget requires two arguments:

`tag`
An object that identifies the `Hero`. It must be the same on both screens.
`child`
The widget to animate across screens.
Hero(
  tag: 'imageHero',
  child: Image.network(
    'https://picsum.photos/250?image=9',
  ),
);

3. Add a Hero widget to the second screen

To complete the connection with the first screen, wrap the Image on the second screen with a Hero widget that has the same tag as the Hero in the first screen.

After applying the Hero widget to the second screen, the animation between screens just works.

Hero(
  tag: 'imageHero',
  child: Image.network(
    'https://picsum.photos/250?image=9',
  ),
);

Interactive example

import 'package:flutter/material.dart';

void main() => runApp(HeroApp());

class HeroApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Transition Demo',
      home: MainScreen(),
    );
  }
}

class MainScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Main Screen'),
      ),
      body: GestureDetector(
        child: Hero(
          tag: 'imageHero',
          child: Image.network(
            'https://picsum.photos/250?image=9',
          ),
        ),
        onTap: () {
          Navigator.push(context, MaterialPageRoute(builder: (_) {
            return DetailScreen();
          }));
        },
      ),
    );
  }
}

class DetailScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: GestureDetector(
        child: Center(
          child: Hero(
            tag: 'imageHero',
            child: Image.network(
              'https://picsum.photos/250?image=9',
            ),
          ),
        ),
        onTap: () {
          Navigator.pop(context);
        },
      ),
    );
  }
}