<!-- 侧滑删除 组件 -->

<template>

  <div class="delete">

    <div class="slider">

      <div class="content"

        @touchstart='touchStart'

        @touchmove='touchMove'

        @touchend='touchEnd'

        :style="deleteSlider"

      >

        <!-- 插槽中放具体项目中需要内容 -->

        <slot></slot>

      </div>

      <div class="remove active" ref='remove' @click="handleClick">删除</div>

    </div>

  </div>

</template>

<script>

  export default {

    props:{

      propE: {

        type: Object,

        default: function () {

        }

      }

    },

    data() {

      return {

        startX:0,  //触摸位置

        endX:0,   //结束位置

        moveX: 0,  //滑动时的位置

        disX: 0,  //移动距离

        deleteSlider: '',//滑动时的效果,使用v-bind:style="deleteSlider"

      }

    },

    methods:{

      handleClick (v) {

        this.$emit('msg-from-child', this.val)

        this.deleteSlider = "transform:translateX(0px)";

      },

      touchStart(ev){

        console.log(ev)

        ev= ev || event;

        //tounches类数组，等于1时表示此时有只有一只手指在触摸屏幕

        if(ev.touches.length == 1){

          // 记录开始位置

          this.startX = ev.touches[0].clientX;

        }

      },

      touchMove(ev){

        ev = ev || event;

        //获取删除按钮的宽度，此宽度为滑块左滑的最大距离

        let wd=this.$refs.remove.offsetWidth;

        if(ev.touches.length == 1) {

          // 滑动时距离浏览器左侧实时距离

          this.moveX = ev.touches[0].clientX;

          //起始位置减去 实时的滑动的距离，得到手指实时偏移距离

          this.disX = this.startX - this.moveX;

          // 如果是向右滑动或者不滑动，不改变滑块的位置

          if(this.disX < 0 || this.disX == 0) {

            this.deleteSlider = "transform:translateX(0px)";

          // 大于0，表示左滑了，此时滑块开始滑动

          }else if (this.disX > 0) {

            //具体滑动距离我取的是 手指偏移距离*5。

            this.deleteSlider = "transform:translateX(-" + this.disX*5 + "px)";

            // 最大也只能等于删除按钮宽度

            if (this.disX*5 >=wd) {

              this.deleteSlider = "transform:translateX(-" +wd+ "px)";

            }

          }

        }

      },

      touchEnd(ev){

        ev = ev || event;

        console.log(ev)

        let wd=this.$refs.remove.offsetWidth;

        if (ev.changedTouches.length == 1) {

          let endX = ev.changedTouches[0].clientX;

          this.disX = this.startX - endX;

          //如果距离小于删除按钮一半,强行回到起点

          if ((this.disX*5) < (wd/2)) {

            this.deleteSlider = "transform:translateX(0px)";

          }else{

            //大于一半 滑动到最大值

            this.deleteSlider = "transform:translateX(-"+wd+ "px)";

          }

        }

      }

    }

  }

</script>

<style lang="less" scoped>

  .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;

      // 设置过渡动画

      transition: 0.3s;

    }

    .remove{

      position: absolute;

      width:100px;

      height:100px;

      background:red;

      right: 0;

      top: 0;

      color:#fff;

      text-align: center;

      font-size: 32px;

      line-height: 100px;

    }

  }

</style>