使用JavaScript实现按钮的涟漪效果实例代码

<!-- index.html -->
<style>
  @import 'button.css';
  @import 'ripple.css';
</style>

<button class="button-root" id="ripple-example-button" type="button">
  Button
  <!-- 用来装涟漪效果的 DOM 的容器 -->
  <span class="ripple-root"></span>
</button>

/* button.css */
.button-root {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 6px 16px;
  font-size: 0.875rem;
  font-weight: 500;
  line-height: 1.75;
  min-width: 64px;
  margin: 0;
  border-radius: 4px;
  border: 1px solid rgba(25, 118, 210, 0.5);
  cursor: pointer;
  box-sizing: border-box;
  outline: none;
  appearance: none;
  user-select: none;
  color: #1976d2;
  background-color: transparent;
  transition-property: background-color, color, box-shadow, border-color;
  transition-duration: 0.25s;
}

.button-root:hover {
  background-color: rgba(25, 118, 210, 0.04);
  border: 1px solid #1976d2;
}

/* ripple.css */
@keyframes enterKeyframe {
  0% {
    transform: scale(0);
    opacity: 0.1;
  }

  100% {
    transform: scale(1);
    opacity: 0.3;
  }
}

@keyframes exitKeyframe {
  0% {
    opacity: 1;
  }

  100% {
    opacity: 0;
  }
}

@keyframes pulsateKeyframe {
  0% {
    transform: scale(0.9);
  }

  50% {
    transform: scale(0.8);
  }

  100% {
    transform: scale(0.9);
  }
}

.ripple-root {
  display: block;
  position: absolute;
  overflow: hidden;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  pointer-events: none;
  background-color: transparent;
  z-index: 0;
  border-radius: inherit;
}

.ripple-root > .ripple-child {
  position: absolute;
  display: block;
  opacity: 0;
}

.ripple-root > .ripple-child.enter {
  opacity: 0.3;
  transform: scale(1);
  animation: enterKeyframe 550ms ease-in-out;
}

.ripple-root > .ripple-child > .ripple-child-child {
  opacity: 1;
  display: block;
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background-color: currentColor;
}

.ripple-root > .ripple-child.exit > .ripple-child-child {
  opacity: 0;
  animation: exitKeyframe 550ms ease-in-out;
}

.ripple-root > .ripple-child.pulsate > .ripple-child-child {
  position: absolute;
  left: 0;
  top: 0;
  animation: pulsateKeyframe 2500ms ease-in-out 200ms infinite;
}

// ripple.apis.js
export function startRipple(event) {
  const { currentTarget: container } = event
  const { left, top, width, height } = container.getBoundingClientRect()
}

// ripple.apis.js
export function startRipple(event) {
  // ...
  // 效果开始的坐标（相对于 Button）
  let rippleX, rippleY
  // 鼠标当前的坐标
  let clientX = 0, clientY = 0
 
 /**
  * 涟漪效果是否从节点的中心扩散，否则从鼠标点击的位置开始扩散
  * 使用 Tab 键移动焦点的时候，从节点的中心扩散
  */
  let center = false
  let isFocusVisible = false
 
  if (container.matches(':focus-visible')) {
    center = isFocusVisible = true
  } else {
    clientX = event.clientX
    clientY = event.clientY
  }
 
  rippleX = center ? width / 2 : clientX - left
  rippleY = center ? height / 2 : clientY - top
}

// ripple.apis.js
export function startRipple(event) {
  // ...
  // 从鼠标点击的中心位置，构造一个能正好包围当前元素的圆
  const sizeX = Math.max(width - rippleX, rippleX) * 2
  const sizeY = Math.max(height - rippleY, rippleY) * 2
  const diagonal = Math.sqrt(sizeX ** 2 + sizeY ** 2)
}

// ripple.apis.js
const rippleChildren = []

/**
 * 创建以下结构并返回：
 * <span class="ripple-child enter">
 *   <span class="ripple-child-child"></span>
 * </span>
 */
function createRippleChild(rect) {
  const rippleChild = document.createElement('span')
  rippleChild.classList.add('ripple-child', 'enter')
  const rippleChildChild = document.createElement('span')
  rippleChildChild.classList.add('ripple-child-child')
  rippleChild.appendChild(rippleChildChild)

  const { height, left, top, width } = rect
  rippleChild.style.height = height
  rippleChild.style.width = width
  rippleChild.style.top = top
  rippleChild.style.left = left

  rippleChildren.push(rippleChild)

  return rippleChild
}

// ripple.apis.js
export function startRipple(event) {
  // ...
  const rippleChild = createRippleChild({
    width: `${diagonal}px`,
    height: `${diagonal}px`,
    left: `${-diagonal / 2 + rippleX}px`,
    top: `${-diagonal / 2 + rippleY}px`,
  })
  if (isFocusVisible) {
    rippleChild.classList.add('pulsate')
  }
  const rippleRoot = container.querySelector(':scope > .ripple-root')
  rippleRoot.appendChild(rippleChild)
}

// ripple.apis.js
export function stopRipple() {
  const rippleChild = rippleChildren.shift()

  if (!rippleChild) return

  rippleChild.addEventListener('animationend', (event) => {
    if (event.animationName === 'exitKeyframe') {
      rippleChild.remove()
    }
  })
  rippleChild.classList.add('exit')
}

<!-- index.html -->
<style>
  @import 'button.css';
  @import 'ripple.css';
</style>

<script type="module">
  import { startRipple, stopRipple } from 'ripple.apis.js'

  const button = document.querySelector('#ripple-example-button')

  button.addEventListener('mousedown', startRipple)
  button.addEventListener('focus', startRipple)
  button.addEventListener('mouseup', stopRipple)
  button.addEventListener('mouseleave', stopRipple)
  button.addEventListener('blur', stopRipple)
</script>

<button class="button-root" id="ripple-example-button" type="button">
  Button
  <!-- 用来装涟漪效果的 DOM 的容器 -->
  <span class="ripple-root"></span>
</button>