<!--
 * @Author: mat
 * @Date: 2019-12-04 14:56:07
 * @LastEditTime: 2019-12-04 16:31:52
 * @LastEditors: Please set LastEditors
 * @Description: 實現數字翻牌動態效果，css 屬性 writing-mode: vertical-lr，使數字豎直排版，
        2d移動 transform: translate(-50%, -40%); y值控制移動至哪個數字，transition 
        控制transform屬性有動畫效果 
 -->
<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'], // 默認訂單總數
      }
    },
    mounted(){
      setTimeout(() => {
        this.toOrderNum(12654) // 這里輸入數字即可調用
      }, 500);
    },
    methods: {
        // 設置文字滾動
      setNumberTransform () {
       const numberItems = this.$refs.numberItem // 拿到數字的ref，計算元素數量
       const numberArr = this.orderNum.filter(item => !isNaN(item))
       // 結合CSS 對數字字符進行滾動,顯示訂單數量
       for (let index = 0; index < numberItems.length; index++) {
        const elem = numberItems[index]
        elem.style.transform = `translate(-50%, -${numberArr[index] * 10}%)`
       }
      },
      // 處理總訂單數字
      toOrderNum(num) {
       num = num.toString()
       // 把訂單數變成字符串
        if (num.length < 8) {
          num = '0' + num // 如未滿八位數，添加"0"補位
          this.toOrderNum(num) // 遞歸添加"0"補位
        } else if (num.length === 8) {
          // 訂單數中加入逗號
          // num = num.slice(0, 2) + ',' + num.slice(2, 5) + ',' + num.slice(5, 8)
          this.orderNum = num.split('') // 將其便變成數據，渲染至滾動數組
        } else {
          // 訂單總量數字超過八位顯示異常
          this.$message.warning('總量數字過大')
        }
        this.setNumberTransform()
      },
    }
  }
</script>
<style scoped lang='scss'>
   /*訂單總量滾動數字設置*/
  .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;
    /*文字禁止編輯*/
    -moz-user-select: none; /*火狐*/
    -webkit-user-select: none; /*webkit瀏覽器*/
    -ms-user-select: none; /*IE10*/
    -khtml-user-select: none; /*早期瀏覽器*/
    user-select: none;
    /* overflow: hidden; */
  }
  /* 默認逗號設置 */
  .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;
    }
  }
  /*滾動數字設置*/
  .number-item {
    width: 41px;
    height: 75px;
    /* 背景圖片 */
    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>