<template>
  <div class="drag"
       ref="dragDiv">
    <div class="drag_bg"></div>
    <div class="drag_text">{{confirmWords}}</div>
    <div ref="moveDiv"
         @mousedown="mousedownFn($event)"
         :class="{'handler_ok_bg':confirmSuccess}"
         class="handler handler_bg"
         style="position: absolute;top: 0px;left: 0px;"></div>
  </div>
</template>

<script>
export default {
  data () {
    return {
      beginClientX: 0, /* 距離屏幕左端距離 */
      mouseMoveStata: false, /* 觸發(fā)拖動狀態(tài)  判斷 */
      maxwidth: '', /* 拖動最大寬度，依據(jù)滑塊寬度算出來的 */
      confirmWords: '拖動滑塊驗證', /* 滑塊文字 */
      confirmSuccess: false /* 驗證成功判斷 */
    }
  },
  methods: {
    mousedownFn: function (e) {
      if (!this.confirmSuccess) {
        e.preventDefault && e.preventDefault() // 阻止文字選中等 瀏覽器默認事件
        this.mouseMoveStata = true
        this.beginClientX = e.clientX
      }
    }, // mousedoen 事件
    successFunction () {
      this.confirmSuccess = true
      this.confirmWords = '驗證通過'
      if (window.addEventListener) {
        document.getElementsByTagName('html')[0].removeEventListener('mousemove', this.mouseMoveFn)
        document.getElementsByTagName('html')[0].removeEventListener('mouseup', this.moseUpFn)
      } else {
        document.getElementsByTagName('html')[0].removeEventListener('mouseup', () => { })
      }
      document.getElementsByClassName('drag_text')[0].style.color = '#fff'
      document.getElementsByClassName('handler')[0].style.left = this.maxwidth + 'px'
      document.getElementsByClassName('drag_bg')[0].style.width = this.maxwidth + 'px'
    }, // 驗證成功函數(shù)
    mouseMoveFn (e) {
      if (this.mouseMoveStata) {
        let width = e.clientX - this.beginClientX
        if (width > 0 && width <= this.maxwidth) {
          document.getElementsByClassName('handler')[0].style.left = width + 'px'
          document.getElementsByClassName('drag_bg')[0].style.width = width + 'px'
        } else if (width > this.maxwidth) {
          this.successFunction()
        }
      }
    }, // mousemove事件
    moseUpFn (e) {
      this.mouseMoveStata = false
      var width = e.clientX - this.beginClientX
      if (width < this.maxwidth) {
        document.getElementsByClassName('handler')[0].style.left = 0 + 'px'
        document.getElementsByClassName('drag_bg')[0].style.width = 0 + 'px'
      }
    } // mouseup事件
  },
  mounted () {
    this.maxwidth = this.$refs.dragDiv.clientWidth - this.$refs.moveDiv.clientWidth
    document.getElementsByTagName('html')[0].addEventListener('mousemove', this.mouseMoveFn)
    document.getElementsByTagName('html')[0].addEventListener('mouseup', this.moseUpFn)
  }
}
</script>

<style scoped>
.drag {
  position: relative;
  background-color: #e8e8e8;
  width: 30%;
  height: 34px;
  line-height: 34px;
  text-align: center;
}
.handler {
  width: 40px;
  height: 32px;
  border: 1px solid #ccc;
  cursor: move;
}
.handler_bg {
  background: #fff
    url('data:image/png;base64,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')
    no-repeat center;
}
.handler_ok_bg {
  background: #fff
    url('data:image/png;base64,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')
    no-repeat center;
}
.drag_bg {
  background-color: #7ac23c;
  height: 34px;
  width: 0px;
}
.drag_text {
  position: absolute;
  top: 0px;
  width: 100%;
  text-align: center;
  -moz-user-select: none;
  -webkit-user-select: none;
  user-select: none;
  -o-user-select: none;
  -ms-user-select: none;
}
</style>