SVG Slider - 仅沿SVG路径移动点

时间:2016-09-05 12:43:12

标签: javascript html svg

我创建了一个圆形SVG滑块但是我仍然在正确定位点时遇到问题。 看看Codepen上的当前结果:

HTML:

    <svg version="1.1" id="slider" width="300px" height="150px"> 
       <path id="sliderPath" stroke="red" stroke-width="5" d="M10,100a147,147,0,1,1,280,1"/>
       <circle id="dot" fill="white" cx="10" cy="100" r="14" /> 
    </svg>

JS:

var sliderPath = document.getElementById("sliderPath"),
box = sliderPath.getBBox(),
dot = document.getElementById("dot"),
W = box.width,
pathLength = sliderPath.getTotalLength();

Draggable.create(
    document.createElement('div'),
      { 
        type:'x',
        throwProps:true,
        bounds: { minX:0, maxX:W },
        trigger:dot,
        overshootTolerance:0,
        onDrag:update,
        onThrowUpdate:update
});

function update(){ 
  // Get x and y for dot.
  var P = sliderPath.getPointAtLength(this.x / W * pathLength);
  // Set dot.
  TweenLite.set(dot,{attr:{cx:P.x,cy:P.y}});
};

http://codepen.io/Yheeky/pen/xEbAbR

您可以开始拖动点并从左向右移动鼠标。这很有效,但是我需要更直接地设置点位置,使得点位置等于鼠标位置,但仅沿着路径。 为了得到这样的结果,我需要改变什么?

提前致谢!

1 个答案:

答案 0 :(得分:0)

下面的示例显示了水平条路径。条形的路径长度和sliderPath比率的路径长度用于沿着sliderPath移动点。

这个例子有点时髦,因为我移动了svg所以它完全可见,但你应该知道它是如何工作的。

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<!DOCTYPE HTML>
<html>
<head>
  <title>Slider@Semi Circle</title>
</head>
<body>
<div style='position:absolute;top:200px;left:200px;'>
<svg overflow=visible version="1.1" id="slider" width="300px" height="150px">
<path onmousedown=moveDotStart(evt) onmousemove=moveDot(evt) onmouseup=moveDotEnd(evt) onmouseout=moveDotEnd(evt) id="slideBar" stroke=lime opacity=.3 stroke-width=30 d="M10,100 L290,100" />
<path id="sliderPath" stroke="red" fill="none" stroke-width="5" d="M10,100a147,147,0,1,1,280,1"/>
<circle pointer-events="none"  id="dot" fill="blue" cx="10" cy="100" r="14" />
</svg>
</div>

<script>
var MoveDot=false
function moveDotStart(evt)
{
   MoveDot=true
}
function moveDot(evt)
{
    if(MoveDot==true)
    {
        var pathLength=sliderPath.getTotalLength()
        var barLength=slideBar.getTotalLength()
        var xCursor=evt.clientX-10-200
        var moveRatio=xCursor/barLength
        var dotPathLength=moveRatio*pathLength
        var dotPnt=sliderPath.getPointAtLength(dotPathLength)
        dot.setAttribute("cx",dotPnt.x)
        dot.setAttribute("cy",dotPnt.y)
    }

}

function moveDotEnd(evt)
{
  MoveDot=false
}
</script>
</body>
</html>
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