A library that provides an API that greatly simplifies the process of creating smooth, powerful, and maintainable animations.
This library is listed in the Expo SDK reference because it is included in Expo Go. You may use any library of your choice with development builds.
react-native-reanimated
provides an API that greatly simplifies the process of creating smooth, powerful, and maintainable animations.
Reanimated uses React Native APIs that are incompatible with "Remote JS Debugging" for JavaScriptCore. To use a debugger with your app with
react-native-reanimated
, you'll need to use the Hermes JavaScript engine and the JavaScript Inspector for Hermes.
Android Device | Android Emulator | iOS Device | iOS Simulator | Web |
---|---|---|---|---|
-
npx expo install react-native-reanimated
If you're installing this in a bare React Native app, you should also follow these additional installation instructions.
After the installation completes, you must also add the Babel plugin to babel.config.js:
module.exports = function (api) {
api.cache(true);
return {
presets: ['babel-preset-expo'],
plugins: ['react-native-reanimated/plugin'],
};
};
Next, restart your development server and clear the bundler cache using the command:
-
npx expo start --clear
If you load other Babel plugins, the Reanimated plugin has to be the last item in the plugins array.
For web, you'll have to install the @babel/plugin-proposal-export-namespace-from
Babel plugin and update the babel.config.js to load it:
plugins: [
'@babel/plugin-proposal-export-namespace-from',
'react-native-reanimated/plugin',
],
After you add the Babel plugin, restart your development server and clear the bundler cache using npx expo start --clear
.
The following example shows how to use the react-native-reanimated
library to create a simple animation. For more information on the API and its usage, see react-native-reanimated
documentation.
import Animated, {
useSharedValue,
withTiming,
useAnimatedStyle,
Easing,
} from 'react-native-reanimated';
import { View, Button, StyleSheet } from 'react-native';
export default function AnimatedStyleUpdateExample() {
const randomWidth = useSharedValue(10);
const config = {
duration: 500,
easing: Easing.bezier(0.5, 0.01, 0, 1),
};
const style = useAnimatedStyle(() => {
return {
width: withTiming(randomWidth.value, config),
};
});
return (
<View style={styles.container}>
<Animated.View style={[styles.box, style]} />
<Button
title="toggle"
onPress={() => {
randomWidth.value = Math.random() * 350;
}}
/>
</View>
);
}
const styles = StyleSheet.create({
container: {
flex: 1,
alignItems: 'center',
justifyContent: 'center',
},
box: {
width: 100,
height: 80,
backgroundColor: 'black',
margin: 30,
},
});