React.js ライブラリ「react-spring」を使用してフェイドアウェイアニメーションを作成する

create-react-app react-app

## 作成したプロジェクトに移動
cd react-app
 
## インストール
npm install react-spring

import React from 'react';
import {useSpring, animated} from 'react-spring'

export const Sample = () => {
    const props = useSpring({
        to: [{opacity: 1, color: '#ffaaee'}, {opacity: 0, color: 'rgb(14,26,19)'}],
        from: {opacity: 0, color: 'red'}
    })
    
    return (
        <animated.div style={props}>フェイドインします</animated.div>
    )
  }


export default Sample

import React from 'react';
import Sample from './sample';
import './App.css';

function App() {
  const style = {
    width: "50%",
    margin: "0 auto",
    marginTop: 150
  };
  return (
    <div className="App">
      <div style={style}>
        <Sample />
      </div>
    </div>
  );
}

export default App;

npm start

import React from 'react';
import { useSpring, animated } from 'react-spring'
import './styles.css'

const calc = (x, y) => [-(y - window.innerHeight / 2) / 20, (x - window.innerWidth / 2) / 20, 1.1]
const trans = (x, y, s) => `perspective(600px) rotateX(${x}deg) rotateY(${y}deg) scale(${s})`

export const Sample = () => {
    const [props, set] = useSpring(() => ({ xys: [0, 0, 1], config: { mass: 5, tension: 350, friction: 40 } }))

    return (
      <animated.div
        class="card"
        onMouseMove={({ clientX: x, clientY: y }) => set({ xys: calc(x, y) })}
        onMouseLeave={() => set({ xys: [0, 0, 1] })}
        style={{ transform: props.xys.interpolate(trans) }}
      />
    )
  }


export default Sample

html,
body,
#root {
  width: 100%;
  height: 100%;
  margin: 0;
  padding: 0;
  background-color: white;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, avenir next, avenir, helvetica neue, helvetica, ubuntu,
    roboto, noto, segoe ui, arial, sans-serif;
  background: transparent;
  -webkit-touch-callout: none;
  -webkit-user-select: none;
  -khtml-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
  cursor: default;
}

#root {
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: #f0f0f0;
}

.card {
  width: 45ch;
  height: 45ch;
  background: grey;
  border-radius: 5px;
  background-image: url(https://cdn.pixabay.com/photo/2020/03/03/15/47/landscape-4899037_1280.jpg);
  background-size: cover;
  background-position: center center;
  box-shadow: 0px 10px 30px -5px rgba(0, 0, 0, 0.3);
  transition: box-shadow 0.5s;
  will-change: transform;
  border: 15px solid white;
}

.card:hover {
  box-shadow: 0px 30px 100px -10px rgba(0, 0, 0, 0.4);
}