letsar/local_hero

local_hero

Pub

A widget which implicitly launches a hero animation when its position changed within the same route.

Overview

Getting started

In the pubspec.yaml of your flutter project, add the following dependency:

dependencies:
  ...
  local_hero:

In your library add the following import:

import 'package:local_hero/local_hero.dart';

Usage

To be animated implicitly, a widget needs to be surrounded by a LocalHero widget with a unique tag:

const LocalHero(
    tag: 'my_widget_tag',
    child: MyWidget(),
),

A LocalHero widget must have a LocalHeroScope ancestor which hosts the animations properties (duration, curve, etc.). At each frame we must have only one LocalHero per tag, per LocalHeroScope.

The following example shows the basic usage of a LocalHero widget:

class _LocalHeroPage extends StatelessWidget {
  const _LocalHeroPage({
    Key key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: LocalHeroScope(
          duration: const Duration(milliseconds: 300),
          curve: Curves.easeInOut,
          child: const _LocalHeroPlayground(),
        ),
      ),
    );
  }
}

class _LocalHeroPlayground extends StatefulWidget {
  const _LocalHeroPlayground({
    Key key,
  }) : super(key: key);

  @override
  _LocalHeroPlaygroundState createState() => _LocalHeroPlaygroundState();
}

class _LocalHeroPlaygroundState extends State<_LocalHeroPlayground> {
  AlignmentGeometry alignment = Alignment.topLeft;

  @override
  Widget build(BuildContext context) {
    return Column(
      children: <Widget>[
        Expanded(
          child: Padding(
            padding: const EdgeInsets.all(8),
            child: Align(
              alignment: alignment,
              child: const LocalHero(
                tag: 'id',
                child: _Box(),
              ),
            ),
          ),
        ),
        RaisedButton(
          onPressed: () {
            setState(() {
              alignment = alignment == Alignment.topLeft
                  ? Alignment.bottomRight
                  : Alignment.topLeft;
            });
          },
          child: const Text('Move'),
        ),
      ],
    );
  }
}

class _Box extends StatelessWidget {
  const _Box({
    Key key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(
      color: Colors.red,
      width: 50,
      height: 50,
    );
  }
}

Example

Sponsoring

I'm working on my packages on my free-time, but I don't have as much time as I would. If this package or any other package I created is helping you, please consider to sponsor me so that I can take time to read the issues, fix bugs, merge pull requests and add features to these packages.

Changelog

Please see the Changelog page to know what's recently changed.

Contributions

Feel free to contribute to this project.

If you find a bug or want a feature, but don't know how to fix/implement it, please fill an issue.
If you fixed a bug or implemented a feature, please send a pull request.