React Native Easing Keyframes
Create CSS keyframe-based animations in React Native
Installation
yarn add react-native-easing-keyframes
or
npm install react-native-easing-keyframes
Why do I need this?
Usually in timing animations, the easing function is applied to the entire duration of the animation. With the keyframes
helper from this library, you can control what easing function to use in each keyframe during the animation.
import keyframes from 'react-native-easing-keyframes'
const easeInOut = Easing.bezier(0.42, 0.0, 0.58, 1.0)
const value = new Animated.Value(0)
Animated.timing(value, {
duration: 1200,
toValue: 100,
easing: keyframes({ easing: easeInOut, keyframes: [0, 50, 100] }),
useNativeDriver: true,
})
In the example above, keyframes
will apply the easing function you want to use (easeInOut
) to each keyframe, so easeInOut
will be applied twice, from 0 to 50 and from 50 to 100.
You can also target a specific keyframe and apply a different easing function to it.
Animated.timing(value, {
duration: 1200,
toValue: 100,
easing: keyframes({
easing: easeInOut,
keyframes: [0, 50, 100],
easingsByKeyframe: { 50: Easing.linear },
}),
useNativeDriver: true,
})
API
keyframes
(config: Config) => EasingFunction
This function applies an easing function to each keyframe based on a config.
Config
An object that contains:
keyframes
number[]
And array of keyframes used in the animation.
This array must have at least 3 items. If you're animating from 0
to 100
then the first one should be 0
and the last one should be 100
.
easing
(value: number) => number
| default to Easing.inOut(Easing.ease)
The default easing function that will be used in all keyframes.
easingsByKeyframe
{ [key: number]: EasingFunction }
| defaults to {}
You can specify the easing function you want to use for an individual keyframe. If no easing function
is specified, the value from easing
will be used.
Example
To run the example project, follow these steps:
- Clone the repo
- Run these commands
yarn
cd example
yarn && yarn start