Vue implements seamless scrolling of lists

<template>
  <div id="box" class="wrapper">
    <div class="contain" id="con1" ref="con1" :class="{anim:animate==true}">
      <List
        v-for="(item,index) in cloudList"
        :key="index"
        :listData="item"
        :index="index"
        :date="date"
      ></List>
    </div>
  </div>
</template>

<style scoped>
.wrapper {
  width: 96vw;
  height: 90vh;
  position: absolute;
  left: 2vw;
  top: 1rem;
  overflow: hidden;
}
.contain > div:nth-child(2n) { //This style is required for my project and has nothing to do with seamless scrolling. Margin-left: 2vw can be ignored;
}
.anim {
  transition: all 0.5s;
  margin-top: -7vh;
}
</style>

<script>
import List from './List';
export default {
  name: 'Contain',
  data () {
    return {
      cloudList: [], //Array used to store list data date: '', //Latest data update date animate: false,
      time: 3000, //Timed scrolling interval setTimeout1: null,
      setInterval1: null
    };
  },
  components:
    List
  },
  methods: {
    // Get json data and update date getCloudListData () {
      const _this = this;
      _this.$api.getCloudListData().then(res => {
        _this.cloudList = res;
      });
      var newDate = new Date();
      _this.date = _this.dateFtt('yyyy-MM-dd hh:mm:ss', newDate);
    },
    // Date format dateFtt (fmt, date) {
      var o = {
        'M+': date.getMonth() + 1, // Month 'd+': date.getDate(), // Day 'h+': date.getHours(), // Hours 'm+': date.getMinutes(), // Minutes 's+': date.getSeconds(), // Seconds 'q+': Math.floor((date.getMonth() + 3) / 3), // Quarter S: date.getMilliseconds() // Milliseconds };
      if (/(y+)/.test(fmt)) {
        fmt = fmt.replace(
          RegExp.$1,
          (date.getFullYear() + '').substr(4 - RegExp.$1.length)
        );
      }
      for (var k in o) {
        if (new RegExp('(' + k + ')').test(fmt)) {
          fmt = fmt.replace(
            RegExp.$1,
            RegExp.$1.length === 1
              ? o[k]
              : ('00' + o[k]).substr(('' + o[k]).length)
          );
        }
      }
      return fmt;
    },
    // Scroll scroll () {
      const _this = this;
      _this.animate = true;
      clearTimeout(_this.setTimeout1);
      _this.setTimeout1 = setTimeout(() => {
        var parent = document.getElementById('con1');
        var first = document.getElementById('con1').children[0];
        var second = document.getElementById('con1').children[1];
        parent.removeChild(first);
        parent.removeChild(second);
        parent.appendChild(first);
        parent.appendChild(second);
        _this.animate = false;
      }, 500);
    }
  },
  created () {
    const _this = this;
    _this.getCloudListData();
    //The timer updates the data every 24 hours setInterval(() => {
      _this.getCloudListData();
    }, 24 * 60 * 60 * 1000);
  },
  mounted () {
    const _this = this;
    var contain = document.getElementById('box');
    _this.setInterval1 = setInterval(_this.scroll, _this.time);
    var setInterval2 = null;
    //Mouse moves into the scrolling area to stop scrolling contain.onmouseenter = function () {
      clearInterval(_this.setInterval1);
      var count = 0;
      // If the mouse does not move for more than ten seconds, start scrolling setInterval2 = setInterval(function () {
        count++;
        if (count === 10) {
          _this.scroll();
          _this.setInterval1 = setInterval(_this.scroll, _this.time);
        }
      }, 1000);
      //Stop scrolling as soon as the mouse moves and set the count to 0
      contain.onmousemove = function () {
        count = 0;
        clearInterval(_this.setInterval1);
      };
    };
    // The mouse moves out of the scrolling area contain.onmouseleave = function () {
      clearInterval(setInterval2);
      clearInterval(_this.setInterval1);
      _this.scroll();
      _this.setInterval1 = setInterval(_this.scroll, _this.time);
    };
  }
};
</script>