<template>
  <view class="number-box">
    <block v-for="(myIndex, index) in indexArr" :key="index">
      <swiper
        class="swiper"
        vertical="true"
        :current="myIndex"
        circular="true"
        v-bind:style="{
          color: color,
          width: myIndex == 10 ? '7px' : width + 'px',
          height: height + 'px',
          lineHeight: height + 'px',
          fontSize: fontSize + 'px'
        }"
      >
        <swiper-item>
          <view class="swiper-item">0</view>
        </swiper-item>
        <swiper-item>
          <view class="swiper-item">1</view>
        </swiper-item>
        <swiper-item>
          <view class="swiper-item">2</view>
        </swiper-item>
        <swiper-item>
          <view class="swiper-item">3</view>
        </swiper-item>
        <swiper-item>
          <view class="swiper-item">4</view>
        </swiper-item>
        <swiper-item>
          <view class="swiper-item">5</view>
        </swiper-item>
        <swiper-item>
          <view class="swiper-item">6</view>
        </swiper-item>
        <swiper-item>
          <view class="swiper-item">7</view>
        </swiper-item>
        <swiper-item>
          <view class="swiper-item">8</view>
        </swiper-item>
        <swiper-item>
          <view class="swiper-item">9</view>
        </swiper-item>
        <swiper-item>
          <view class="swiper-item">.</view>
        </swiper-item>
      </swiper>
    </block>
  </view>
</template>

<script>
export default {
  props: {
    num: [String, Number],
    color: {
      type: String,
      default: '#000000'
    },
    width: {
      type: String,
      default: '15'
    },
    height: {
      type: String,
      default: '15'
    },
    fontSize: {
      type: String,
      default: '15'
    }
  },
  data() {
    return {
      indexArr: []
    };
  },
  created() {
    let { num } = this;
    let arr = new Array(num.toString().length);
    arr.fill(0);
    this.indexArr = arr;
  },
  watch: {
    num: function (val, oldVal) {
      // 处理新老数据长度不一样的情况
      let arr = Array.prototype.slice.apply(this.indexArr);
      let newLen = val.toString().length;
      let oldLen = oldVal.toString().length;
      if (newLen > oldLen) {
        for (let i = 0; i < newLen - oldLen; i++) {
          arr.push(0);
        }
        this.indexArr = arr;
      }
      if (newLen < oldLen) {
        for (let i = 0; i < oldLen - newLen; i++) {
          arr.pop();
        }
        this.indexArr = arr;
      }
      this.numChange(val);
    }
  },
  mounted() {
    //定时器作用：app显示数字滚动
    this._time = setTimeout(() => {
      this.numChange(this.num);
      clearTimeout(this._time);
    }, 100);
  },
  methods: {
    /**
     * 数字改变
     * @value 数字
     */
    numChange(num) {
      this.$nextTick(() => {
        let { indexArr } = this;
        let copyIndexArr = Array.prototype.slice.apply(indexArr);
        let _num = num.toString();
        for (let i = 0; i < _num.length; i++) {
          if (_num[i] === '.') {
            copyIndexArr[i] = 10;
          } else {
            copyIndexArr[i] = Number(_num[i]);
          }
        }
        this.indexArr = copyIndexArr;
      });
    }
  }
};
</script>

<style lang="scss">
.number-box {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
}

.swiper {
  position: relative;
  font-family: PingFangSC-Heavy, PingFang SC;
  text-align: center;
}

.swiper:after {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
}
</style>