fluttie 0.5.0

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fluttie: Lottie for flutter #

Fluttie (github, pub) is a flutter plugin for displaying animations created in Lottie. Even complex animations can be displayed without having to write long custom rendering code. The library can render the animations by piping the output from the Lottie Android library into a Flutter texture.

You can download a small Flutter app for Android showing what Fluttie looks like in action. This app can also be used to easily preview animations from lottiefiles.com, which might be handy when deciding what animations to use.

Please note: At the moment, this plugin does not support iOS devices.

Things to keep in mind when using this: #

  • No iOS support yet
  • Due to a delay between the dart code and the native backend, controlling multiple animations can be a bit laggy. Rendering multiple animations will reduce your app's framerate.
  • Animation widgets need a fixed size for now
  • Do not re-use animations, as this can crash your app. Instead, save the output of loadAnimationFromAsset() and construct a new animation whenever you need to.

Getting Started #

The example included contains a basic, but throughoutly commented, app illustrating how to include, load and show animations in Fluttie.

In order to use animations with fluttie, you will need a json file containing the composition for your animation. You can either export it using an AfterEffects plugin (see instructions) or grab some at lottiefiles.com. A composition is a JSON file that describes everything in your animation, like the different shapes, colors and movements. Place the file in an folder inside your project and add it in the assets part of your pubspec.yaml, like its done here. If you haven't already done so, also add Fluttie to your projects' dependencies:

  fluttie: ^0.3.0

In order to display animations in Flutter, you will have the plugin load a composition first. The plugin will parse the composition file so that it can quickly display the animation later on.

var instance = Fluttie();
var emojiComposition = await instance.loadAnimationFromAsset(
    "assets/animations/emoji.json", //Replace this string with your actual file

In order to actually show the animation on screen, two parts are neccessary: An AnimationController, which controls the instance of the animation and contains methods to pause and resume it, and finally a widget displaying the animation contained by the controller.

// This creates the controller
var emojiAnimation = await instance.prepareAnimation(emojiComposition)

You can also set the duration of your animation and configure looping while preparing the animation by using the optional parameters of prepareAnimation, see the docs fore more details. After having your animation controller ready, you can include it as a widget:

Widget build(BuildContext context) =>

Don't forget to start your animation by calling emojiAnimation.start() on your controller!

Questions and bugs #

As the library is in an early version, there will be things not working like they should. If you encounter a bug, have a question or want some features implemented, please don't hesitate to create an issue. Of course, I would absolutely appreciate any contributions as pull requests.

0.5.0 #

  • Fix build on iOS devices (iOS still isn't supported by this plugin)

0.4.0 #

  • Upgraded to lottie-android 3
  • Call enableMergePathsForKitKatAndAbove()

0.3.2 #

  • Added support for animations with asset images. Thanks to @DeividAndreola for implementing this!

0.3.1 #

  • Simplified logic to handle composition parsing to fix a race condition
  • Temporarily disable this plugin on pre-Lollipop devices. A bug in the Flutter engine could otherwise crash your apps. This will be reverted once a version with a fix lands in flutter beta.

Again, thanks to @kristoffer-zliide for these changes!

0.3 #

  • Updated the Lottie libray used, thus giving you access to the latest features including image support in animations. Thank you, @kristoffer-zliide, for implementing this!

0.2 #

  • Make plugin ready for dart 2.

0.1.2 #

  • Make the plugin only react to activity lifecircle changes that involve the main flutter activity.

0.1.1 #

  • Fix crashes occuring when disposing animations
  • Ability to unpause animations without having to restart them

0.1.0 #

  • Render small animations in high quality by using the preferredSize parameter of Fluttie.prepareAnimation.
  • Reduce resource usage by pausing aimations while the app is in background
  • Implement multithreaded rendering, not yet enabled because of an issue in the Flutter framework.

0.0.1 #

  • First release with basic functionality


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

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

/// An example app showcasing the features of fluttie animations. It should
/// show a emoji animation at the top and a bar of stars below it. When tapping
/// on a star, all the stars to the left should be filled in a beautiful animation.
class MyApp extends StatefulWidget {
  _MyAppState createState() => _MyAppState();

class _MyAppState extends State<MyApp> {

  /// Animation to display a shocked emoji taken from lottiefiles.com
  FluttieAnimationController shockedEmoji;

  /// A list of animations representing the stars shown in a horizontal line.
  /// They will be started when the user tabs on one of them.
  List<FluttieAnimationController> starAnimations = [];
  /// The amount of stars currently selected in the line. Used to compute the
  /// difference on a tap.
  int currentlySelectedStars = 0;

  /// If we're ready to show the animations. Set to true after they have been
  /// loaded by the plugin.
  bool ready = false;

  /// The performance overlay can be triggered by tapping on the icon on the
  /// right-hand side of the toolbar. It can be used to invastigate the
  /// performance impact of running different animations.
  bool showPerformanceOverlay = false;

  initState() {
    /// Load and prepare our animations after this widget has been added

  dispose() {
    /// When this widget gets removed (in this app, that won't happen, but it
    /// can happen for widgets using animations in other situations), we should
    /// free the resources used by our animations.
    starAnimations.forEach((anim) => anim.dispose());

  // async because the plugin will have to do some background-work
  prepareAnimation() async {
    // Checks if the platform we're running on is supported by the animation plugin
    bool canBeUsed = await Fluttie.isAvailable();
    if (!canBeUsed) {
      print("Animations are not supported on this platform");

    var instance = Fluttie();
    // Load our first composition for the emoji animation
    var emojiComposition = await instance.loadAnimationFromAsset(
    // And prepare its animation, which should loop infinitely and take 2s per
    // iteration. Instead of RepeatMode.START_OVER, we could have choosen 
    // REVERSE, which would play the animation in reverse on every second iteration.
    shockedEmoji = await instance.prepareAnimation(emojiComposition,
       duration: const Duration(seconds: 2),
       repeatCount: const RepeatCount.infinite(), repeatMode: RepeatMode.START_OVER);

    // Load the composition for our star animation. Notice how we only have to
    // load the composition once, even though we're using it for 5 animations!
    var composition = await instance.loadAnimationFromAsset(

    // Create the star animation with the default setting. 5 times. The
    // preferredSize needs to be set because the original star animation is quite
    // small. See the documentation for the method prepareAnimation for details.
    for (int i = 0; i < 5; i++) {
        await instance.prepareAnimation(
          composition, preferredSize: Fluttie.kDefaultSize

    // Loading animations may take quite some time. We should check that the
    // widget is still used before updating it, it might have been removed while
    // we were loading our animations!
    if (mounted) {
      setState(() {
        ready = true; // The animations have been loaded, we're ready
        shockedEmoji.start(); //start our looped emoji animation

  void animateStarChange(int updated) {
    /* When the amount of stars that are selected changes, we will have to
       play or stop animations in order to reflect that in the UI. For that, we
       start the animation for each star that was not previously selected but
       should be selected now (i >= old) and (i < currentlySelectedStars).
       If the amount to show has been reduced, we can simply rewind the animation
       to the beginning, as that will show a hollow star not selected.

       Notice how i refers to the index starting at 0, while the amount should
       start at 1.

    setState(() {
      int old = this.currentlySelectedStars;
      currentlySelectedStars = updated;
      for (int i = 0; i < 5; i++) {
        if (i < currentlySelectedStars) { //Star needs to be shown
          if (i >= old) //Star would otherwise already be shown
        } else { //Remove star, reset to beginning
          starAnimations[i].stopAndReset(rewind: true);

  /// Builds a widget animating the star at the specified index.
  Widget buildStar(int i) {
    return Flexible(
      child: GestureDetector(
        onTap: () {
          // Update the amount of stars that have been selected when this star
          // is tapped.
          int amountOfStars = i + 1;
        child: FluttieAnimation(starAnimations[i])

  /// When we're ready to show the animations, this method will create the main
  /// content showcasing them.
  Widget buildStarContent(BuildContext context) {
    return Column(
      children: [
        //Display the emoji animations at the top
        //followed by a row of 5 stars that can be tapped
          mainAxisSize: MainAxisSize.max,
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          children: [
            buildStar(0), buildStar(1), buildStar(2), buildStar(3), buildStar(4)
        // Use a Flexible widget so that the rest will be on the bottom
        Flexible(child: Container()),
        // And display some credits showing where the animations are taken from
          text: TextSpan(
            children: [
                text: "Animations taken from ", 
                style: Theme.of(context).textTheme.body1.copyWith(color: Colors.grey)
                text: "lottiefiles.com",
                style: Theme.of(context).textTheme.body2
        Padding(padding: const EdgeInsets.only(bottom: 10.0)),

  Widget build(BuildContext context) {
    // Display the main content, or - when we're not ready for that yet - a text
    // informing the user that the animations are being prepared.
    Widget content = ready ? buildStarContent(context) : Text("Loading animations");

    return MaterialApp(
      showPerformanceOverlay: this.showPerformanceOverlay,
      home: Scaffold(
        appBar: AppBar(
          title: Text('Fluttie example'),
          actions: [
            // Button to toggle the performance overlay
              icon: const Icon(Icons.build),
              onPressed: () {
                setState(() {
                  showPerformanceOverlay = !showPerformanceOverlay;
        body: Center(child: content)

Use this package as a library

1. Depend on it

Add this to your package's pubspec.yaml file:

  fluttie: ^0.5.0

2. Install it

You can install packages from the command line:

with Flutter:

$ flutter pub get

Alternatively, your editor might support flutter pub get. Check the docs for your editor to learn more.

3. Import it

Now in your Dart code, you can use:

import 'package:fluttie/fluttie.dart';
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We analyzed this package on Apr 4, 2020, and provided a score, details, and suggestions below. Analysis was completed with status completed using:

  • Dart: 2.7.1
  • pana: 0.13.6
  • Flutter: 1.12.13+hotfix.8


Package Constraint Resolved Available
Direct dependencies
Dart SDK >=1.19.0 <3.0.0
flutter 0.0.0
Transitive dependencies
collection 1.14.11 1.14.12
meta 1.1.8
sky_engine 0.0.99
typed_data 1.1.6
vector_math 2.0.8