LottieUI allows you to use delightful Lottie animations with SwiftUI without having to give up on the familiar declarative API or the powerful customization settings from the animation framework
To display an animation from a local Lottie JSON file, use the LottieView
component:
LottieView("MyAnimation")
If your JSON is stored on another bundle outside your project's, you can specify the Bundle to load the animation from or provide a file path where the animation file is located:
// Loads an animation from the provided bundle
LottieView("MyAnimation", bundle: DesignSystem.Bundle.main)
// Loads an animation file from the provided path
LottieView(path: "/path/to/animation.json")
For remote animations, LottieUI provides AsyncLottieView, which attemps to download an animation from a remote URL and present it if successful. You can also provide views to be displayed while the donwload is in progress or if the download fails:
let url = URL(string: "https://assets3.lottiefiles.com/packages/lf20_hbdelex6.json")!
AsyncLottieView(url: url) { phase in
switch phase {
case .loading:
ProgressView()
case .error:
ErrorView
case .success(let lottieView):
lottieView
}
}
LottieView allows you to take control of your animations with a set of modifiers that can be applied to a LottieView:
By default, your animation will start playing automatically. To control whether the animation should be playing, use the .play(_:)
modifier:
struct ContentView: View {
@State var isPlaying: Bool = true
var body: some View {
LottieView("MyAnimation")
.play(isPlaying)
}
}
To setup the Loop Mode for your animation, use .loopMode(_:)
struct ContentView: View {
var body: some View {
LottieView("MyAnimation")
.loopMode(.loop)
}
}
To observe the current frame being displayed in the animation and perform an action based on it, use .onFrame(_:)
Warning To make use of the Frame/Progress observers, the animation must be using the
.mainThread
rendering engine. This can be set by using the.renderingEngine(_:)
method
struct ContentView: View {
var body: some View {
LottieView("MyAnimation")
.renderingEngine(.mainThread)
.onFrame { _ in
// Perform action based on current frame
}
}
}
To observe the progress instead, use .onProgress(_:)
:
struct ContentView: View {
var body: some View {
LottieView("MyAnimation")
.renderingEngine(.mainThread)
.onProgress { _ in
// Perform action based on current progress
}
}
}
To set the speed of an animation, use .speed(_:)
:
struct ContentView: View {
var body: some View {
LottieView("MyAnimation")
.speed(2.0)
}
}
LottieUI also supports the new RenderingEngine introduced in Lottie 3.4.0, which can greatly reduce CPU usage when displaying compatible animations
By default, LottieUI uses the .automatic
, which will automatically apply the new rendering engine if an animation is compatible, but you can override it with the .renderingEngine(_:)
modifier:
LottieView("MyAnimation")
.renderingEngine(.coreAnimation)
There are many other options available such as:
.play(fromFrame:to:)
.backgroundBehavior(_:)
.valueProvider(_: keypath:)
For more information check the included documentation in each public component and modifier
In your project's Package.swift
file, add LottieUI
as a dependency:
.package(name: "LottieUI", url: "https://github.com/tfmart/LottieUI", from: "1.0.0")