Vue有趣的可旋转转盘组件

jiezi

6 年前

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>
```

使用 vue 编写的一个可旋转组件，如图