<template>
    <div id="SlideBar" class="box">
        <div class="item" ref="slide" :style="slideStyle" @touchstart="start($event)" @touchmove="move($event)" @touchend="end($event)">
          <img src="../../../static/lun.1.jpg" alt="">
          <div class="right">
            
          </div>
        </div>
        <div class="btn" ref="btn">
            <button>编辑</button>
            <button style="background:#387ef5;color:#fff">收藏</button>
        </div>
    </div>
</template>
<script>
    export default {
        name: 'SlideBar',
        props: {

        },
        data (){
            return {
                flag: false,
                startX: 0,
                endX: 0,
                slideStyle: {
                    left: 0,
                    transition: 'none'
                }
            }
        },
        methods: {
            start (e){  //记录开始滑动屏幕的X轴的位置
                this.flag = true;
                this.startX = e.touches[0].clientX;
                this.endX = this.$refs.slide.offsetLeft;
                this.slideStyle.transition = 'none';
            },
            move (e){
                if(this.flag){
                    // 处理鼠标移动的逻辑
                    var moveX = this.endX + (e.touches[0].clientX - this.startX);  //计算滑动的距离
                    if(Math.abs(moveX) >= this.$refs.btn.offsetWidth && moveX < 0){  //判断滑动的距离是否大于class:btn的宽度
                        moveX = (Math.abs(moveX) - this.$refs.btn.offsetWidth) * 0.1; // 0.3阻力系数
                        this.slideStyle.left = - this.$refs.btn.offsetWidth - moveX + 'px';
                    }else if(moveX >= 0){  //滑动距离是否大于等于0
                        this.slideStyle.left = 0 + 'px';  //大于等于0让class:item等于0
                    }else{
                        this.slideStyle.left = moveX + 'px';  //小于0让class:item等于滑动的距离
                    }
                }
            },
            end (e){
                if(this.flag){
                    this.flag = false;
                    // endX = slide.offsetLeft;
                    var moveX = e.changedTouches[0].clientX - this.startX;  //计算滑动的距离
                    this.slideStyle.transition = 'left .3s';
                    var btnWidth = this.$refs.btn.offsetWidth;  //class:btn的宽度
                    if(moveX < 0){
                        if(Math.abs(moveX) >= btnWidth / 2 || Math.abs(this.$refs.slide.offsetLeft) >= this.$refs.btn.offsetWidth){ //是否大于class:btn宽度的一半
                            this.slideStyle.left = - btnWidth + 'px';  //左滑超过class:btn宽度的一半就滑回去
                        }else if(Math.abs(moveX) < btnWidth / 2){  //小于class:btn宽度的一半
                            this.slideStyle.left = 0 + 'px';  //左滑没有超过class:btn宽度的一半回原位
                        }
                    }else if(moveX > 0 && this.endX != 0){
                        if(Math.abs(moveX) >= btnWidth / 2){
                            this.slideStyle.left = 0 + 'px';  //右滑超过class:btn宽度的一半就滑回去
                        }else if(Math.abs(moveX) < btnWidth / 2){
                            this.slideStyle.left = - btnWidth + 'px';  //右滑没有超过class:btn宽度的一半回原位
                        }
                    }
                }
            }
        },
        mounted (){
            var _this = this;
            // 使用js的现代事件监听transition过渡结束
            this.$refs.slide.addEventListener('transitionend',function(){
                _this.endX = this.offsetLeft;
            })
        }
    }
</script>
<style>
.box{
    position:relative;
    border-bottom:0.026667rem solid #666666;
}
.btn{
  height:100%;
  position:absolute;
  right:0;
  top:0;
  background:red;
  display:flex;
}
button{
  width:1.6rem;
  height:100%;
  background:#f8f8f8;
  border:none;
}
.item{
  padding:0.266667rem;
  display:flex;
  position:relative;
  background:#fff;
  z-index: 2;
  box-shadow: 0.026667rem 0 0.053333rem #ddd;
}
.item img{
  width:2.133333rem;
  height:2.133333rem;
  margin-right:0.4rem;
  border-radius: 0.133333rem;
}

.item .title{
  font-size:0.48rem;
  float: left;
}
.item .text{
  font-size:0.426667rem;
  color:#888;
  float: left;
  margin: 0 1.33rem;
}
.item .price{
  color:#888;
  float: left;
  margin: 0 1.33rem;
}
</style>

效果图：