<!--
 * @Author: mat
 * @Date: 2019-12-04 14:56:07
 * @LastEditTime: 2019-12-04 16:31:52
 * @LastEditors: Please set LastEditors
 * @Description: 实现数字翻牌动态效果，css 属性 writing-mode: vertical-lr，使数字竖直排版，
        2d移动 transform: translate(-50%, -40%); y值控制移动至哪个数字，transition 
        控制transform属性有动画效果 
 -->
<template>
  <div class="chartNum">
    <div class="box-item">
      <li :class="{'number-item': !isNaN(item), 'mark-item': isNaN(item) }"
        v-for="(item,index) in orderNum"
        :key="index">
          <span v-if="!isNaN(item)">
            <i ref="numberItem">0123456789</i>
          </span>
        <span class="comma" v-else>{{item}}</span>
      </li>
    </div>
  </div>
</template>
<script>
  export default {
    data() {
      return {
        orderNum: ['0', '0', '0', '0', '0', '0', '0', '0'], // 默认订单总数
      }
    },
    mounted(){
      setTimeout(() => {
        this.toOrderNum(12654) // 这里输入数字即可调用
      }, 500);
    },
    methods: {
        // 设置文字滚动
      setNumberTransform () {
       const numberItems = this.$refs.numberItem // 拿到数字的ref，计算元素数量
       const numberArr = this.orderNum.filter(item => !isNaN(item))
       // 结合CSS 对数字字符进行滚动,显示订单数量
       for (let index = 0; index < numberItems.length; index++) {
        const elem = numberItems[index]
        elem.style.transform = `translate(-50%, -${numberArr[index] * 10}%)`
       }
      },
      // 处理总订单数字
      toOrderNum(num) {
       num = num.toString()
       // 把订单数变成字符串
        if (num.length < 8) {
          num = '0' + num // 如未满八位数，添加"0"补位
          this.toOrderNum(num) // 递归添加"0"补位
        } else if (num.length === 8) {
          // 订单数中加入逗号
          // num = num.slice(0, 2) + ',' + num.slice(2, 5) + ',' + num.slice(5, 8)
          this.orderNum = num.split('') // 将其便变成数据，渲染至滚动数组
        } else {
          // 订单总量数字超过八位显示异常
          this.$message.warning('总量数字过大')
        }
        this.setNumberTransform()
      },
    }
  }
</script>
<style scoped lang='scss'>
   /*订单总量滚动数字设置*/
  .box-item {
    position: relative;
    height: 100px;
    font-size: 54px;
    line-height: 41px;
    text-align: center;
    list-style: none;
    color: #2D7CFF;
    writing-mode: vertical-lr;
    text-orientation: upright;
    /*文字禁止编辑*/
    -moz-user-select: none; /*火狐*/
    -webkit-user-select: none; /*webkit浏览器*/
    -ms-user-select: none; /*IE10*/
    -khtml-user-select: none; /*早期浏览器*/
    user-select: none;
    /* overflow: hidden; */
  }
  /* 默认逗号设置 */
  .mark-item {
    width: 10px;
    height: 100px;
    margin-right: 5px;
    line-height: 10px;
    font-size: 48px;
    position: relative;
    & > span {
      position: absolute;
      width: 100%;
      bottom: 0;
      writing-mode: vertical-rl;
      text-orientation: upright;
    }
  }
  /*滚动数字设置*/
  .number-item {
    width: 41px;
    height: 75px;
    /* 背景图片 */
    background: url(/images/text-bg-blue.png) no-repeat center center;
    background-size: 100% 100%;
    // background: #ccc;
    list-style: none;
    margin-right: 5px;
    // background:rgba(250,250,250,1);
    border-radius:4px;
    border:1px solid rgba(221,221,221,1);
    & > span {
      position: relative;
      display: inline-block;
      margin-right: 10px;
      width: 100%;
      height: 100%;
      writing-mode: vertical-rl;
      text-orientation: upright;
      overflow: hidden;
      & > i {
        font-style: normal;
        position: absolute;
        top: 11px;
        left: 50%;
        transform: translate(-50%,0);
        transition: transform 1s ease-in-out;
        letter-spacing: 10px;
      }
    }
  }
  .number-item:last-child {
    margin-right: 0;
  }
</style>