Implementation of the function of the vue circular percentage progress bar component

<template>
  <div class="percentloop">
    <div class="circle-left">
      <div ref="leftcontent"></div>
    </div>
    <div class="circle-right">
      <div ref="rightcontent"></div>
    </div>
    <div class="number">
      {{ percent }} %
    </div>
  </div>
</template>

<script>
export default {
  props: {
    percentNum: {
      type: [String, Number],
      default: 0
    },
    speed: { // The recommended value is 0-3
      type: [String, Number],
      default: 1
    }
  },
  data () {
    return {
      percent: 0,
      initDeg: 0,
      timeId: null,
      animation: false
    }
  },
  methods: {
    transformToDeg (percent) {
      let deg = 0
      if (percent >= 100) {
        deg = 360
      } else {
        deg = parseInt(360 * percent / 100)
      }
      return deg
    },
    transformToPercent(deg) {
      let percent = 0
      if (deg >= 360) {
        percent = 100
      } else {
        percent = parseInt(100 * deg / 360)
      }
      return percent
    },
    rotateLeft (deg) { // When the angle is greater than 180, the animation is executed this.$refs.leftcontent.style.transform = 'rotate(' + (deg - 180) + 'deg)'
    },
    rotateRight (deg) { // When the angle is less than 180, the animation is executed this.$refs.rightcontent.style.transform = 'rotate(' + deg + 'deg)'
    },
    goRotate(deg) {
      this.animationing = true
      this.timeId = setInterval(() => {
        if (deg > this.initDeg) { // Incremental animation this.initDeg += Number(this.speed)
          if (this.initDeg >= 180) {
            this.rotateLeft(this.initDeg)
            this.rotateRight(180) // To avoid the situation where the value converted from the percentages passed in twice is not an integer of the step length, which may cause the left and right rotation to fail.
          } else {
            this.rotateRight(this.initDeg)
          }
        } else { // Decrease animation this.initDeg -= Number(this.speed)
          if (this.initDeg >= 180) {
            this.rotateLeft(this.initDeg)
          } else {
            this.rotateLeft(180) // To avoid the situation where the value converted from the percentages passed in twice is not an integer of the step length, which may cause the left and right rotation to fail.
            this.rotateRight(this.initDeg)
          }
        }
        this.percent = this.transformToPercent(this.initDeg) // Percentage data scrolling animation const remainer = Number(deg) - this.initDeg
        if (Math.abs(remainer) < this.speed) {
          this.initDeg += remainer
          if (this.initDeg > 180) {
            this.rotateLeft(deg)
          } else {
            this.rotateRight(deg)
          }
          this.animationFinished()
        }
      }, 10)
    },
    animationFinished () {
      this.percent = this.percentNum // Percentage data scrolling animation this.animationing = false
      clearInterval(this.timeId)
      this.$emit('animationFinished') // callback when animation is completed}
  },
  created () {
    this.goRotate(this.transformToDeg(this.percentNum))
  },
  watch:
    'percentNum': function (val) {
      if (this.animationing) return
      this.goRotate(this.transformToDeg(val))
    }
  }
}
</script>

<style scoped lang="scss">
.percentloop {
  position: relative;
  width: 100%;
  height: 100%;
  border-radius: 50%;
  overflow: hidden;
  .circle-left, .circle-right {
    position: absolute;
    top: 0;
    left: 0;
    width: 50%;
    height: 100%;
    background-color: red;
    overflow: hidden;
    &>div {
      width: 100%;
      height: 100%;
      background-color: #8a8a8a;
      transform-origin: right center;
      /*transition: all .5s linear;*/
    }
  }
  .circle-right {
    left: 50%;
    &>div {
      transform-origin: left center;
    }
  }
  .number {
    position: absolute;
    top: 9%;
    bottom: 9%;
    left: 9%;
    right: 9%;
    background-color: #fff;
    border-radius: 50%;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #000;
  }
}
</style>