lottie-ios

Lottie for iOS, MacOS (and Android and React Native)

Lottie is a mobile library for Android and iOS that parses Adobe After Effects animations exported as json with bodymovin and renders the vector animations natively on mobile and through React Native!

For the first time, designers can create and ship beautiful animations without an engineer painstakingly recreating it by hand. Since the animation is backed by JSON they are extremely small in size but can be large in complexity! Animations can be played, resized, looped, sped up, slowed down, reversed, and even interactively scrubbed. Lottie can play or loop just a portion of the animation as well, the possibilities are endless! Animations can even be changed at runtime in various ways! Change the color, position or any keyframable value! Lottie also supports native UIViewController Transitions out of the box!

Here is just a small sampling of the power of Lottie

Using Lottie

Lottie supports iOS 8+ and MacOS 10.10+ Lottie animations can be loaded from any application Bundle or asynchronously from a URL

To bundle JSON just add it and any images that the animation requires to your target in xcode.

The simplest way to use it is with LOTAnimationView:

LOTAnimationView *animation = [LOTAnimationView animationNamed:@"Lottie"];
[self.view addSubview:animation];
[animation playWithCompletion:^(BOOL animationFinished) {
  // Do Something
}];

If you are working with multiple bundles you can use.

LOTAnimationView *animation = [LOTAnimationView animationNamed:@"Lottie" inBundle:[NSBundle YOUR_BUNDLE]];
[self.view addSubview:animation];
[animation playWithCompletion:^(BOOL animationFinished) {
  // Do Something
}];

Or you can load it programmatically from a NSURL

LOTAnimationView *animation = [[LOTAnimationView alloc] initWithContentsOfURL:[NSURL URLWithString:URL]];
[self.view addSubview:animation];

Lottie supports the iOS UIViewContentModes aspectFit, aspectFill and scaleFill

You can also set the animation progress interactively.

CGPoint translation = [gesture getTranslationInView:self.view];
CGFloat progress = translation.y / self.view.bounds.size.height;
animationView.animationProgress = progress;

Or you can play just a portion of the animation:

[lottieAnimation playFromProgress:0.25 toProgress:0.5 withCompletion:^(BOOL animationFinished) {
// Do Something
}];

Want to mask arbitrary views to animation layers in a Lottie View? Easy-peasy as long as you know the name of the layer from After Effects

UIView *snapshot = [self.view snapshotViewAfterScreenUpdates:YES];
[lottieAnimation addSubview:snapshot toLayerNamed:@"AfterEffectsLayerName" applyTransform:NO];

Or how about moving a view with a part of the animation?

UIView *snapshot = [self.view snapshotViewAfterScreenUpdates:YES];
[lottieAnimation addSubview:snapshot toLayerNamed:@"AfterEffectsLayerName" applyTransform:YES];

Want to dynamically change the color of an animation?

[lottieAnimation setValue:[UIColor greenColor] forKeypath:@"Layer 1.Shape 1.Fill 1" atFrame:@0];

Lottie comes with a UIViewController animation-controller for making custom viewController transitions!

#pragma mark -- View Controller Transitioning

- (id<UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented
                                                                  presentingController:(UIViewController *)presenting
                                                                      sourceController:(UIViewController *)source {
  LOTAnimationTransitionController *animationController = [[LOTAnimationTransitionController alloc] initWithAnimationNamed:@"vcTransition1"
                                                                                                          fromLayerNamed:@"outLayer"
                                                                                                            toLayerNamed:@"inLayer"
                                                                                                 applyAnimationTransform:NO];
  return animationController;
}

- (id<UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed {
  LOTAnimationTransitionController *animationController = [[LOTAnimationTransitionController alloc] initWithAnimationNamed:@"vcTransition2"
                                                                                                          fromLayerNamed:@"outLayer"
                                                                                                            toLayerNamed:@"inLayer"
                                                                                                 applyAnimationTransform:NO];
  return animationController;
}

If your animation will be frequently reused, LOTAnimationView has an built in LRU Caching Strategy.

Swift Support

Lottie works just fine in Swift too! Simply import Lottie at the top of your swift class, and use Lottie as follows

let animationView = LOTAnimationView(name: "hamburger")
self.view.addSubview(animationView)

animationView.play(completion: { finished in
    // Do Something
})

Note:

Animation file name should be first added to your project. as for the above code sample, It won't work until you add an animation file called hamburger.json.. let animationView = LOTAnimationView(name: "here_goes_your_json_file_name_without_.json")

MacOS support and Lottie View

Lottie also fully supports MacOS, so you can add animations to your awesome Mac App! In the Example Folder you will find a Lottie Viewer Mac App. Build and run this app to preview Lottie animations straight from your desktop! The app supports play, scrubbing, resizing, and most importantly you can drag and drop JSON files onto the app window to open any animation.

Supported After Effects Features

Keyframe Interpolation

---

• Linear Interpolation
• Bezier Interpolation
• Hold Interpolation
• Rove Across Time
• Spatial Bezier

Solids

---

• Transform Anchor Point
• Transform Position
• Transform Scale
• Transform Rotation
• Transform Opacity

Masks

---

• Path
• Opacity
• Multiple Masks (additive, subtractive and intersection)

Track Mattes

---

• Alpha Matte

Parenting

---

• Multiple Parenting
• Nulls

Shape Layers

---

• Anchor Point
• Position
• Scale
• Rotation
• Opacity
• Path
• Group Transforms (Anchor point, position, scale etc)
• Rectangle (All properties)
• Elipse (All properties)
• Multiple paths in one group
• Even-Odd winding paths
• Reverse Fill Rule

Stroke (shape layer)

---

• Stroke Color
• Stroke Opacity
• Stroke Width
• Line Cap
• Dashes (Now Animated!)

Fill (shape layer)

---

• Fill Color
• Fill Opacity

Trim Paths (shape layer)

---

• Trim Paths Start
• Trim Paths End
• Trim Paths Offset

Repeaters

---

• Supports repeater transforms
• Offset currently not supported.

Gradients

---

• Support for Linear Gradients

Polystar and Polygon

---

• Supported! Theres a known bug if the roundness is greater than 100 percent.

Layer Features

---

• Precomps
• Image Layers
• Shape Layers
• Null Layers
• Solid Layers
• Parenting Layers
• Alpha Matte Layers

Currently Unsupported After Effects Features

• Merge Shapes
• Trim Shapes Individually feature of Trim Paths
• Expressions
• 3d Layer support
• Radial Gradients

Install Lottie

CocoaPods

Add the pod to your podfile

pod 'lottie-ios'

run

pod install

Carthage

Install Carthage (https://github.com/Carthage/Carthage) Add Lottie to your Cartfile

github "airbnb/lottie-ios" "master"

run

carthage update

Try it out

Lottie Uses Cocoapods! Get the Cocoapod or clone this repo and try out the Example App After installing the cocoapod into your project import Lottie with #import <Lottie/Lottie.h>

Try with Carthage. In your application targets “General” tab under the “Linked Frameworks and Libraries” section, drag and drop lottie-ios.framework from the Carthage/Build/iOS directory that carthage update produced.

Community Contributions

• Xamarin bindings
• NativeScript bindings
• Appcelerator Titanium bindings
• MacOS Support added by Alex Pawlowski

Alternatives

1. Build animations by hand. Building animations by hand is a huge time commitment for design and engineering across Android and iOS. It's often hard or even impossible to justify spending so much time to get an animation right.
2. Facebook Keyframes. Keyframes is a wonderful new library from Facebook that they built for reactions. However, Keyframes doesn't support some of Lottie's features such as masks, mattes, trim paths, dash patterns, and more.
3. Gifs. Gifs are more than double the size of a bodymovin JSON and are rendered at a fixed size that can't be scaled up to match large and high density screens.
4. Png sequences. Png sequences are even worse than gifs in that their file sizes are often 30-50x the size of the bodymovin json and also can't be scaled up.

Why is it called Lottie?

Lottie is named after a German film director and the foremost pioneer of silhouette animation. Her best known films are The Adventures of Prince Achmed (1926) – the oldest surviving feature-length animated film, preceding Walt Disney's feature-length Snow White and the Seven Dwarfs (1937) by over ten years The art of Lotte Reineger

Contributing

Contributors are more than welcome. Just upload a PR with a description of your changes.

If you would like to add more JSON files feel free to do so!

Issues or feature requests?

File github issues for anything that is unexpectedly broken. If an After Effects file is not working, please attach it to your issue. Debugging without the original file is much more difficult.

Roadmap (In no particular order)

• Add support for interactive animated transitions
• Animation Breakpoints/Seekpoints