<template>
   <div class="delete">
       <div class="slider">
          <div class="content" 
           @touchstart='touchStart'
           @touchmove='touchMove'
           @touchend='touchEnd'
           :style="deleteSlider"
          >
        <!-- 插槽中放具體項(xiàng)目中需要內(nèi)容     -->  
          <slot></slot>
          </div>
          <div class="remove" ref='remove'>
            刪除
          </div>
      </div>
    
   </div>
</template>
 
 
 
<script type="text/ecmascript-6">
 export default {
   data() {
   return {
    startX:0,  //觸摸位置
    endX:0,   //結(jié)束位置
    moveX: 0,  //滑動(dòng)時(shí)的位置
    disX: 0,  //移動(dòng)距離
    deleteSlider: '',//滑動(dòng)時(shí)的效果,使用v-bind:style="deleteSlider"
   }
  
   },
   methods:{
     touchStart(ev){
        ev= ev || event
     //tounches類數(shù)組，等于1時(shí)表示此時(shí)有只有一只手指在觸摸屏幕
  
      if(ev.touches.length == 1){
          // 記錄開始位置
          this.startX = ev.touches[0].clientX;
        }
      },
     touchMove(ev){
        ev = ev || event;
          //獲取刪除按鈕的寬度，此寬度為滑塊左滑的最大距離
        let wd=this.$refs.remove.offsetWidth;
          if(ev.touches.length == 1) {
            // 滑動(dòng)時(shí)距離瀏覽器左側(cè)實(shí)時(shí)距離
            this.moveX = ev.touches[0].clientX
        
            //起始位置減去 實(shí)時(shí)的滑動(dòng)的距離，得到手指實(shí)時(shí)偏移距離
            this.disX = this.startX - this.moveX;
          console.log(this.disX)
            // 如果是向右滑動(dòng)或者不滑動(dòng)，不改變滑塊的位置
            if(this.disX < 0 || this.disX == 0) {
              this.deleteSlider = "transform:translateX(0px)";
            // 大于0，表示左滑了，此時(shí)滑塊開始滑動(dòng) 
            }else if (this.disX > 0) {
               //具體滑動(dòng)距離我取的是 手指偏移距離*5。
              this.deleteSlider = "transform:translateX(-" + this.disX*5 + "px)";
              
              // 最大也只能等于刪除按鈕寬度 
              if (this.disX*5 >=wd) {
                this.deleteSlider = "transform:translateX(-" +wd+ "px)";
               
              }
            }
          }
       },
     touchEnd(ev){
       ev = ev || event;
       let wd=this.$refs.remove.offsetWidth;
       if (ev.changedTouches.length == 1) {
          let endX = ev.changedTouches[0].clientX;
           
            this.disX = this.startX - endX;
            console.log(this.disX)
            //如果距離小于刪除按鈕一半,強(qiáng)行回到起點(diǎn)
            
            if ((this.disX*5) < (wd/2)) {
             
              this.deleteSlider = "transform:translateX(0px)";
            }else{
              //大于一半 滑動(dòng)到最大值
               this.deleteSlider = "transform:translateX(-"+wd+ "px)";
            }
          }
        }   
   }
   }
</script>       
 
<style scoped lang="less">
  .slider{
    width: 100%;
    height:100px;
    position: relative;
     user-select: none;
    .content{
      position: absolute;
      left: 0;
      right: 0;
      top: 0;
      bottom: 0;
      background:green;
      z-index: 100;
      //  設(shè)置過渡動(dòng)畫
      transition: 0.3s;
       
    }
    .remove{
      position: absolute;
      width:200px;
      height:100px;
      background:red;
      right: 0;
      top: 0;
      color:#fff;
      text-align: center;
      font-size: 40px;
      line-height: 100px;
    }
  }
 
</style>