flutter_sidekick

Widgets for creating Hero-like animations between two widgets within the same screen.

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Overview

Features

  • Hero-like animations.
  • Allow you to specify a different animation for each Sidekick.
  • Widget to manage animations between children of two multi-child widgets.

Getting started

In the pubspec.yaml of your flutter project, add the following dependency: The latest version is Pub

dependencies:
  ...
  flutter_sidekick: ^latest_version

In your library add the following import:

import 'package:flutter_sidekick/flutter_sidekick.dart';

For help getting started with Flutter, view the online documentation.

Widgets

Sidekick

The Sidekick widget is heavily inspired by the Hero widget API. To link two sidekicks, the targetTag property of the one denoted as the source must be identical to the tag property of the other one, denoted the target. Then to animate sidekicks, you can use the SidekickController and one of the move function.

The animation below can be created with the following code:

Simple Overview

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

class SimpleExample extends StatefulWidget {
  @override
  _SimpleExampleState createState() => _SimpleExampleState();
}

class _SimpleExampleState extends State<SimpleExample>
    with TickerProviderStateMixin {
  SidekickController controller;

  @override
  void initState() {
    super.initState();
    controller =
        SidekickController(vsync: this, duration: Duration(seconds: 1));
  }

  @override
  void dispose() {
    controller?.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Stack(
      children: <Widget>[
        Positioned(
          top: 20.0,
          left: 20.0,
          width: 100.0,
          height: 100.0,
          child: GestureDetector(
            onTap: () => controller.moveToTarget(context),
            child: Sidekick(
              tag: 'source',
              targetTag: 'target',
              child: Container(
                color: Colors.blue,
              ),
            ),
          ),
        ),
        Positioned(
          bottom: 20.0,
          right: 20.0,
          width: 150.0,
          height: 100.0,
          child: GestureDetector(
            onTap: () => controller.moveToSource(context),
            child: Sidekick(
              tag: 'target',
              child: Container(
                color: Colors.blue,
              ),
            ),
          ),
        ),
      ],
    );
  }
}

SidekickTeamBuilder

The SidekickTeamBuilder widget can be used to create complex layouts, where widgets from one container can be moved to another one, and you want the transition to be animated:

Wrap Overview

import 'package:example/widgets/utils.dart';
import 'package:flutter/material.dart';
import 'package:flutter_sidekick/flutter_sidekick.dart';

class Item {
  Item({
    this.id,
  });
  final int id;
}

class WrapExample extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return SidekickTeamBuilder<Item>(
      initialSourceList: List.generate(20, (i) => Item(id: i)),
      builder: (context, sourceBuilderDelegates, targetBuilderDelegates) {
        return Padding(
          padding: const EdgeInsets.all(8.0),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.center,
            children: <Widget>[
              SizedBox(
                height: 120.0,
                child: Wrap(
                  children: sourceBuilderDelegates
                      .map((builderDelegate) => builderDelegate.build(
                            context,
                            WrapItem(builderDelegate.message, true),
                            animationBuilder: (animation) => CurvedAnimation(
                                  parent: animation,
                                  curve: Curves.ease,
                                ),
                          ))
                      .toList(),
                ),
              ),
              Expanded(
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.center,
                  crossAxisAlignment: CrossAxisAlignment.center,
                  children: <Widget>[
                    CircleButton(
                      text: '>',
                      onPressed: () => SidekickTeamBuilder.of<Item>(context)
                          .moveAll(SidekickFlightDirection.toTarget),
                    ),
                    SizedBox(width: 60.0, height: 60.0),
                    CircleButton(
                      text: '<',
                      onPressed: () => SidekickTeamBuilder.of<Item>(context)
                          .moveAll(SidekickFlightDirection.toSource),
                    ),
                  ],
                ),
              ),
              SizedBox(
                height: 250.0,
                child: Wrap(
                  children: targetBuilderDelegates
                      .map((builderDelegate) => builderDelegate.build(
                            context,
                            WrapItem(builderDelegate.message, false),
                            animationBuilder: (animation) => CurvedAnimation(
                                  parent: animation,
                                  curve: FlippedCurve(Curves.ease),
                                ),
                          ))
                      .toList(),
                ),
              )
            ],
          ),
        );
      },
    );
  }
}

class WrapItem extends StatelessWidget {
  const WrapItem(
    this.item,
    this.isSource,
  ) : size = isSource ? 40.0 : 50.0;
  final bool isSource;
  final double size;
  final Item item;

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: () => SidekickTeamBuilder.of<Item>(context).move(item),
      child: Padding(
        padding: const EdgeInsets.all(2.0),
        child: Container(
          height: size - 4,
          width: size - 4,
          color: _getColor(item.id),
        ),
      ),
    );
  }

  Color _getColor(int index) {
    switch (index % 4) {
      case 0:
        return Colors.blue;
      case 1:
        return Colors.green;
      case 2:
        return Colors.yellow;
      case 3:
        return Colors.red;
    }
    return Colors.indigo;
  }
}

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 new feature, please send a pull request.

Libraries

flutter_sidekick
Widgets for creating Hero-like animations between two widgets within the same screen.

Dart

dart:ui
Built-in types and core primitives for a Flutter application. [...]

Core

dart:async
Support for asynchronous programming, with classes such as Future and Stream. [...]
dart:collection
Classes and utilities that supplement the collection support in dart:core. [...]
dart:convert
Encoders and decoders for converting between different data representations, including JSON and UTF-8. [...]
dart:core
Built-in types, collections, and other core functionality for every Dart program. [...]
dart:developer
Interact with developer tools such as the debugger and inspector. [...]
dart:math
Mathematical constants and functions, plus a random number generator. [...]
dart:typed_data
Lists that efficiently handle fixed sized data (for example, unsigned 8 byte integers) and SIMD numeric types. [...]

VM

dart:io
File, socket, HTTP, and other I/O support for non-web applications. [...]
dart:isolate
Concurrent programming using isolates: independent workers that are similar to threads but don't share memory, communicating only via messages. [...]