Vue有趣的可旋转转盘组件

使用 vue 编写的一个可旋转组件，如图

• 布局

  • 用卡片数量均分360度圆，使用绝对定位分布在外部容器上，自身通过rotate旋转

          computedCardPosStyle(index){     let deg = index * this.unitCardDeg;     let absDeg = Math.abs((deg + this.turnRotate) % 360);     let z_index = absDeg > 180 ? Math.ceil(absDeg-180): Math.ceil(180-absDeg);     return {         width: this.cardWidth + "px",         height: this.cardHeight + "px",         top: -Math.cos(deg*Math.PI/180)*this.turntableR + "px",         left: Math.sin(deg*Math.PI/180)*this.turntableR + "px",         transform: `translate(-50%, -50%) rotate(${deg}deg)`,         zIndex: z_index     } }, 

  • 外部容器定位于浏览器窗口之下，露出正上方部分出来

     <div      class="container"     :style="{         width: `${turntableR*2 + cardWidth}px`,         height: `${turntableR*2 + cardHeight}px`,         left: `${screenWidth/2 - turntableR-cardWidth/2}px`,         top: `${             outerWrap? -(1-wrapScale)*(turntableR+cardHeight/2) + screenHeight - wrapScale*(cardHeight + bottomPos + cardHeight*reletiveTop):              -(1-wrapScale)*(turntableR+cardHeight/2)         }px`,         transform: `scale(${wrapScale})`,     }"     ref="container" >  ...</div> 

• 圆盘的转动

  • onmousedown、onmouseup 用来判断鼠标是否处于按下状态，并且清空上一次拖动的数据
  • 圆盘的转动以横向滑动的总距离更新角度

  • 针对圆盘如何转动，设计按每一个小的间隔时间（如20ms），叠加一次总体滑动的距离

    handleMouseDown(e){    e.preventDefault();    clearInterval(this.UDLMactionTimer);    this.mouseIsDown = true;    this.startX = e.clientX || e.touches[0].clientX;    this.endX = e.clientX || e.touches[0].clientX;},handleMouseUp(e){    e.preventDefault();    this.mouseIsDown = false;    clearInterval(this.timer);    clearInterval(this.UDLMactionTimer);    this.timer = null;    this.startX = 0;    this.endX = 0;    if(this.lastSpeed) this.UDLMaction();},handleMouseMove(e){    e.preventDefault();    this.endX = e.clientX || e.touches[0].clientX;    if(!this.mouseIsDown) return;    if(!this.timer){        this.timer = setInterval(() => {            let moveGap = this.endX - this.startX;            this.lastSpeed = moveGap/this.timeGap;            this.xGap += moveGap;            this.direction = moveGap > 0 ? 1 : -1;            this.startX = this.endX;        }, this.timeGap);    }},mounted(){let container_dom = this.outerWrap ? this.$refs.outerWrap : this.$refs.container;container_dom.addEventListener('mousedown', this.handleMouseDown.bind(this));container_dom.addEventListener('mouseup', this.handleMouseUp.bind(this));container_dom.addEventListener('mouseleave', this.handleMouseUp.bind(this));container_dom.addEventListener('mousemove', this.handleMouseMove.bind(this));container_dom.addEventListener('touchstart', this.handleMouseDown.bind(this));container_dom.addEventListener('touchend', this.handleMouseUp.bind(this));container_dom.addEventListener('touchcancel', this.handleMouseUp.bind(this));container_dom.addEventListener('touchmove', this.handleMouseMove.bind(this));window.addEventListener('resize', this.responseContainerScale.bind(this));window.addEventListener('load', this.responseContainerScale.bind(this));},beforeDestroy(){    let container_dom = this.outerWrap ? this.$refs.outerWrap : this.$refs.container;    container_dom.removeEventListener('mousedown', this.handleMouseDown.bind(this));    container_dom.removeEventListener('mouseup', this.handleMouseUp.bind(this));    container_dom.removeEventListener('mouseleave', this.handleMouseUp.bind(this));    container_dom.removeEventListener('mousemove', this.handleMouseMove.bind(this));    container_dom.removeEventListener('touchstart', this.handleMouseDown.bind(this));    container_dom.removeEventListener('touchend', this.handleMouseUp.bind(this));    container_dom.removeEventListener('touchcancel', this.handleMouseUp.bind(this));    container_dom.removeEventListener('touchmove', this.handleMouseMove.bind(this));    window.removeEventListener('resize', this.responseContainerScale.bind(this));}

• 旋转效果平滑

  如果没有滑动惯性，当滑动完之后，无论滑动的时候速度如何的快，在松开鼠标后转盘立刻停下，使得效果非常生硬。所以在滑动完成之后，利用最后时刻的滑动速度，让转盘做匀减速运动直至速度为0，并且在速度为0时，在设计缓慢细小的匀速滑动，最后呈现出来的效果就比较平滑了。UDLMaction(){       let a = -this.reduceSpeed*this.direction;       this.UDLMactionTimer = setInterval(() => {           this.lastSpeed = (this.lastSpeed + a)*this.direction >= 0? this.lastSpeed + a: 0;           this.xGap += (this.lastSpeed) * this.timeGap;           if(!this.lastSpeed){               this.moreDynamic();               return clearInterval(this.UDLMactionTimer);           }       }, this.timeGap);   },   moreDynamic(){       let time = 10;       let timer = setInterval(() => {           this.xGap += this.direction*3;           if(--time <= 0) clearInterval(timer);       }, 20)   },   

• demo地址： https://github.com/tanf1995/m...

• 请教

  本来设想的是通过prop来传递卡片的内部结构和数组数据，例如传递一个渲染函数，通过react可以轻松的实现,但是vue这招行不通。请问如何能够做到这点呢？react伪代码如下

     <Component       renderItem={item => <Child propName={item.props} data={item.data} />}   >   </Component>