<template>
 <div class="ser_home">
 <ul class="red_packet" id="red_packet">
  <template v-for="(item, index) in liParams">
  <li :style="{ left: item.left, animationDuration: item.durTime, webkitAnimationDuration: item.durTime}" 
 :class="item.cls" :data-index="index" @webkitAnimationEnd="removeDom">
   <a href='javascript:;'>
   <i :style="{ transform: item.transforms, webkitTransform: item.transforms}"></i>
   </a>
  </li>
  </template>
 </ul>
 </div>
</template>


<script>
export default {
 data () {
 return {
  liParams: [],
  timer: null,
  duration: 10000 // 定義時間
 }
 },
 mounted () {
 this.startRedPacket()
 },
 methods: {
 /**
  * 開啟動畫
  */
 startRedPacket() {
  let win = document.documentElement.clientWidth || document.body.clientWidth
  let left = parseInt(Math.random() * (win - 50) + 0);
  
  let rotate = (parseInt(Math.random() * (45 - (-45)) - 45)) + "deg"; // 旋轉(zhuǎn)角度
  let scales = (Math.random() * (12 - 8 + 1) + 8) * 0.1; // 圖片尺寸
  let durTime = (Math.random() * (2.5 - 1.2 + 1) + 1.2) + 's'; // 時間 1.2和1.2這個數(shù)值保持一樣
  console.log(durTime)
  this.liParams.push({left: left+'px', cls: 'move_1', transforms: 'rotate('+ rotate +') scale('+ scales +')', durTime: durTime})


  setTimeout( () => { // 多少時間結(jié)束
  clearTimeout(this.timer)
  return;
  }, this.duration)


  this.timer = setTimeout( () => {
  this.startRedPacket()
  },100) 
 },
 /**
  * 回收dom節(jié)點
  */
 removeDom (e) {
  let target = e.currentTarget;
  document.querySelector('#red_packet').removeChild(target)
 }
 }
}
</script>


<!-- Add "scoped" attribute to limit CSS to this component only -->
<style scoped lang="scss">
.ser_home {
 width: 100%;
 height: 100%;
}
.red_packet {
 display: block;
 position: relative;
 overflow: hidden;
 width: 100%;
 height: 100%;
 i {
 width: 48px;
 height: 69px;
 display: block;
 background: url('/hongbao.png') no-repeat;
 }
 li {
 position: absolute;
 animation: all 3s linear;
 top:-100px;
 z-index: 10;
 &.move_1 {
  -webkit-animation: aim_move 5s linear 1 forwards;
  animation: aim_move 5s linear 1 forwards;
 }
 }
 a {
 display: block;
 }
}


@keyframes aim_move {
 0% {
 -webkit-transform: translateY(0);
 transform: translateY(0);
 }
 100% {
 -webkit-transform: translateY(120vh);
 transform: translateY(120vh);
 }
 }

</style>