Vue练习六十：08_02_自定义滚动条(缺键盘左右箭头功能)

<template>
  <div id="app">
    <div id="box" ref="box" @mouseover="handleBoxOver">
      <div class="list" ref="list">
        <ul :style="styleObject" ref="ul" >
          <li ref="li"><img src="./assets/lesson8/1.jpg"><p>iPhone 4</p></li>
          <li><img src="./assets/lesson8/2.jpg"><p>iPad 2</p></li>
          <li><img src="./assets/lesson8/3.jpg"><p>iPod touch</p></li>
          <li><img src="./assets/lesson8/4.jpg"><p>iPod classic</p></li>
          <li><img src="./assets/lesson8/5.jpg"><p>iPod shuffle</p></li>
          <li><img src="./assets/lesson8/6.jpg"><p>iPod nano</p></li>
          <li><img src="./assets/lesson8/7.jpg"><p>MacBook Air</p></li>
          <li><img src="./assets/lesson8/8.jpg"><p>MacBook Pro</p></li>
          <li><img src="./assets/lesson8/9.jpg"><p>Mac mini</p></li>
          <li><img src="./assets/lesson8/10.jpg"><p>Mac Pro</p></li>
        </ul>
      </div>
      <div class="scrollBar">
        <div class="barL" ref="barL" :class="{barLStop:isLStop}" @mouseover="handleBarLOver"  @mouseout="handleOut" @keyup="handleOut"></div>
        <div class="barM" ref="barM" @click="hadlebarMClick">
          <div class="bar" @mousedown="handleBarDown" ref="bar" @click="handleBarClick">
            <div class="l"></div>
            <div class="r"></div>
          </div>
        </div>
        <div class="barR" ref="barR" :class="{barRStop:isRStop}" @mouseover="handleBarROver" @mouseout="handleOut" @keyup="handleOut"></div>
      </div>
    </div>
    <dl id="desc">
      <dt>功能说明：</dt>
        <dd>① 拖动滚动条，图片列表缓冲滑动至目标点；</dd>
        <dd>② 滚动条两端鼠标移入自动滑动；</dd>
        <dd>③ 滚动条滑动到两端自动更换为停止标识；</dd>
        <dd>④ 点击滚动条黑色背景区，滚动条及图片列表缓冲滑动至目标点；</dd>
        <dd>⑤ 支持键盘左右键；</dd>
        <dd>⑥ 支持鼠标滚轮。</dd>
        <dd class="ta-r">QQ:21314130, By — Ferris</dd>
    </dl>
  </div>
</template>
<script>
function getStyle(obj, attr)
{
    return parseFloat(obj.currentStyle ? obj.currentStyle[attr] : getComputedStyle(obj, null)[attr])
}
export default {
  data(){
    return{
      oBox:null,
      oList:null,
      oUl:null,
      oLi:null,
      oBarL:null,
      oBarM:null,
      oBarR:null,
      oBar:null,
      maxL:0,
      iMarginRight:0,
      tiemr:null,
      iScale:0,
      disX:0,
      isLStop:false,
      isRStop:false,
      li_width:0,
      bar_left:0,
    }
  },
  computed:{
    styleObject(){
      var width = (this.li_width + this.iMarginRight) * 10 + ‘px‘;
      return{
        width:width
      }
    }
  },
  methods:{
    init(){
      this.oBox = this.$refs.box;
      this.oList = this.$refs.list;
      this.oUl = this.$refs.ul;
      this.oLi = this.$refs.li;
      this.oBarL = this.$refs.barL;
      this.oBarM = this.$refs.barM;
      this.oBarR = this.$refs.barR;
      this.oBar = this.$refs.bar;
      this.maxL = this.oBarM.offsetWidth - this.oBar.offsetWidth;
      this.iMarginRight = getStyle(this.oLi, "marginRight");
      this.li_width = this.$refs.li.offsetWidth;
      this.bar_left = this.$refs.bar.offsetLeft;

      this.isStop();

    },
    handleBarDown(e){
      var _this = this;
      this.disX = e.clientX - this.oBar.offsetLeft;
      document.onmousemove = function(e){
        var iL = e.clientX - _this.disX;
        iL <= 0 && (iL = 0);
        iL >= _this.maxL && (iL = _this.maxL);
        _this.oBar.style.left = iL + ‘px‘;
        _this.iScale = iL / _this.maxL;
        return false;
      };
      document.onmouseup = function(){
        _this.startMove(_this.oUl, parseInt((_this.oList.offsetWidth + _this.iMarginRight - _this.oUl.offsetWidth) * _this.iScale));
        _this.isStop();
        document.onmousemove = null;
        document.onmouseup = null;
      };
      return false;
    },
    handleBarClick(e){
      e.cancelBubble = true;
    },
    handleBarLOver(){
      var _this = this;
      var iSpeed = -5;
      this.tiemr = setInterval(function(){
        _this.togetherMove(getStyle(_this.oBar, "left") + iSpeed, 1);
      },30);
    },
    handleBarROver(){
      var _this = this;
      var iSpeed = 5;
      this.tiemr = setInterval(function(){
        _this.togetherMove(getStyle(_this.oBar, "left") + iSpeed, 1);
      },30);
    },
    handleOut(){
      clearInterval(this.tiemr);
    },
    hadlebarMClick(e){
      var iTarget = e.clientX - this.oBox.offsetLeft - this.oBarM.offsetLeft - this.oBar.offsetWidth / 2;
      this.togetherMove(iTarget);
    },
    handleBoxOver(){
      var _this = this;
      function mouseWheel(e){
        var delta = e.wheelDelta ? e.wheelDelta : -e.detail * 40;
        var iTarget = delta > 0 ? -50 : 50;
        _this.togetherMove(_this.oBar.offsetLeft + iTarget);
      }
      this.oBox.addEventListener("mousewheel",mouseWheel);
      this.oBarM.addEventListener("DOMMouseScroll",mouseWheel);      
    },
    togetherMove(iTarget, buffer){
      var _this = this;
      if(iTarget <= 0){
        this.tiemr && clearInterval(this.tiemr);
        iTarget = 0;
      }
      else if(iTarget >= this.maxL){
        this.tiemr && clearInterval(this.tiemr);
        iTarget = this.maxL;
      }
      this.iScale = iTarget / this.maxL;
      this.startMove(this.oUl,parseInt((this.oList.offsetWidth + this.iMarginRight -_this.oUl.offsetWidth) * this.iScale),
      function(){
        _this.isStop()
      },buffer);
      this.startMove(this.oBar, iTarget, function(){_this.isStop()},buffer);
    },
    isStop(){
      this.oBarL.className = ‘barL‘;
      this.oBarR.className = ‘barR‘;
      var _this = this;
      switch(this.oBar.offsetLeft){
        case 0:
          _this.oBarL.classList.contains(‘barLStop‘) || (this.oBarL.classList.add(‘barLStop‘))
          break;
        case _this.maxL:
          _this.oBarR.classList.contains(‘barRStop‘) || (_this.oBarR.classList.add(‘barRStop‘))
          break;
      }
    },
    startMove(obj, iTarget, fnEnd, buffer){
      var _this = this;
      clearTimeout(obj.timer);
      obj.timer = setInterval(function(){
        _this.doMove(obj,iTarget,fnEnd,buffer);
      },25)
    },
    doMove(obj, iTarget, fnEnd, buffer){
      var iLeft = getStyle(obj,"left");
      var iSpeed = (iTarget - iLeft) / (buffer || 5);
      iSpeed = iSpeed > 0 ? Math.ceil(iSpeed) : Math.floor(iSpeed);
      iLeft == iTarget ? (clearInterval(obj.timer), fnEnd && fnEnd()) : obj.style.left = iLeft + iSpeed + "px"
    }
  },
  mounted(){
    this.init();
    this.isStop();
  }
}
</script>
<style>
body,div,ul,li,p{
  margin: 0;
  padding: 0;
}
body{
  background: #3e3e3e;
  font: 14px/1.5 \5fae\8f6f\96c5\9ed1;;
}
#box{
  width: 600px ;
  margin: 20px auto;
}
.list{
  position: relative;
  width: 600px;
  height: 144px;
  margin-bottom: 10px;
  overflow: hidden;
  border-radius: 8px;
}
.list ul{
  position: absolute;
  top:0;
  left: 0;
  height: 144px;
}
.list li{
  display: inline;  
  float: left;
  width: 144px;
  height: 144px;
  list-style:none;
  background: #000;
  margin-right: 8px;
  border-radius: 8px;
}
.list li img{
  float: left;
  width: 124px;
  height: 100px;
  border-radius: 5px;
  margin: 10px 0 0 10px;
}
.list li p{
  float: left;
  color: #fff;
  width: 100%;
  text-align: center;
  line-height: 34px;
}
.scrollBar{
  position: relative;
  height: 19px;
  background: #0a0a0a;
  overflow: hidden;
}
.scrollBar .barL, .scrollBar .barR, .scrollBar .barLStop, .scrollBar .barRStop{
  position: absolute;
  top:0;
  width: 28px;
  height: 19px;
  cursor: pointer;
  background: url(./assets/lesson8/03.gif) no-repeat;
}
.scrollBar .barL{
  left: 0;
}
.scrollBar .barR{
  right: 0;
  background-position: right 0;
}
.scrollBar .barLStop{
  left: 0;
  background-position: 0 -19px;
  cursor:default;
}
.scrollBar .barRStop{
  right: 0;
  background-position: right -19px;
  cursor: default;
}
.scrollBar .barM{
  position: relative;
  height: 15px;
  border: 1px so   #545454;
  border-width: 1px 0;
  margin: 0 28px;
  padding: 1px 0;
  z-index: 1;
  cursor: pointer;
}
.scrollBar .bar{
  position: absolute;
  top:1px;
  left: 0;
  width: 150px;
  height: 15px;
  cursor: e-resize;
  background: url(./assets/lesson8/01.gif) repeat-x;
}
.scrollBar .bar .l, .scrollBar .bar .r{
  position: absolute;
  top:0;
  width: 6px;
  height: 15px;
  background: url(./assets/lesson8/02.gif) no-repeat;
}
.scrollBar .bar .l{
  left: -6px;
}
.scrollBar .bar .r{
  right: -6px;
  background-position: right 0;
}
#desc{
  color: #ccc;
  width: 578px;
  padding: 10px;
  margin: 0 auto;
  line-height: 2;
  border: 1px dashed #666;;
}
#desc dd{
  margin-left: 2rem;
}
.ta-r{
  text-align: right;
}
</style>