(work in progress, looking for feedback)

react-ease

back to first principles

npm install react-ease react --save

canned animations for react/react-native

(if you're looking for something more dynamic, consider react-springs)

// output floats from 0 to 100 over 0.5 seconds
<Ease from={0} to={100} duration={500}>
  {val => <div>{val}</div>}     // yes, children is a function
</Ease>

// you can tell when it's done
<Ease from={0} to={100} duration={500} delay={500}>
  {(val, done) => <div>animation {done ? 'over!' : 'running...'}</div>}
</Ease>

// you can ease multiple values at once
<Ease from={{left: 0, top: 0}} to={{left: 100, top: 100}} ease='easeInElastic'>
  {val => <div style={val}>move it, move it</div>}
</Ease>

// or if you want more control over each value
<Ease from={0} to={100} duration={500}>{x =>
  <Ease from={0} to={100} duration={200} onProgress={::console.log}>{y =>
    <div style={{left: x, top: y}}>not bad!</div>}
  </Ease>}
</Ease>

// finally, you can chain a bunch of them together
<Chain sequence={[
    {from: {left: 0, top: 0, opacity: 1}, to: {left: 100, top: 100}},
    {from: {left: 50}, to: {top: 50}, ease: 'easeOutCubic'},
    {to: {opacity: 0}, duration: 500, delay: 200}]}
  onProgress={(i, val, done) => done && console.log('done!')}
  repeat={5}>
    {(val, done) => <div style={val}>sweet!</div>}
</Chain>

Ease::props

• from: number/object
• to: number/object
• duration: number (ms)
• ease: string/function ./src.js has a list of available easing functions, or pass in your own
• delay: number (ms)
• onProgress: function - optional callback called on every 'movement'. 'returns' the current value, and a done flag
• repeat: number

Chain::props

• sequence: array
• repeat: number

thanks

• ease-sential, of which react-ease contains a tweaked port