Javascript ISC滚动缩放因子计算

我有个问题，真的希望有人能帮我解决

JSFiddle：

HTML:

JavaScript:

var myScroll = new IScroll('#wrapper', {
        mouseWheel: true,
        keyBindings: true,
        wheelAction: 'zoom',
        scrollbars: true,
        scrollX: true,
        scrollY: true,
        zoomMin: 0.1,
        zoom: true, 
        mouseWheelSpeed: 20,
});


var zoomFactor = 0.4;  //need to calculate this somehow

$('#btn').on('click', function() {

    myScroll.zoom(myScroll.scale - zoomFactor);

});

所以基本上我想要的是iScroll（）缩小，以便显示它的所有内容。问题是它的内容大小不是固定的（可以是700x300、2000x3000、200x900等等）

---

感谢您抽出时间使用此方法，如果我理解正确，您希望重置内容，我在两个维度（宽度与高度）上都实现了此功能，如果您只需要其中一个，请修改拟合系数以返回维度的准确百分比（无最大值，只需选择一个即可返回），小提琴：

#wrapper {
    width: 500px;
    height: 500px;
    border: 1px solid black; 
    overflow: hidden;
    position: relative;
}

#content {
    width: 700px;
    height: 300px;
    background-color: blue;
}

var myScroll = new IScroll('#wrapper', {
        mouseWheel: true,
        keyBindings: true,
        wheelAction: 'zoom',
        scrollbars: true,
        scrollX: true,
        scrollY: true,
        zoomMin: 0.1,
        zoom: true, 
        mouseWheelSpeed: 20,
});


var zoomFactor = 0.4;  //need to calculate this somehow

$('#btn').on('click', function() {

    myScroll.zoom(myScroll.scale - zoomFactor);

});

//get wrapper dimensions
var wrap = {
    H : $('#wrapper').height(),
    W : $('#wrapper').width()
}
//get content dimensions
var content = {
    H : $('#content').height(),
    W : $('#content').width(),
   };

var myScroll = new IScroll('#wrapper', {
        mouseWheel: true,
        keyBindings: true,
        wheelAction: 'zoom',
        scrollbars: true,
        scrollX: true,
        scrollY: true,
        zoomMin: 0.1,
        zoom: true, 
        mouseWheelSpeed: 20,
});
//compute reset zoom factor
var fitFactor = function ()
{
    //compute witch dimension is larger width vs height
    h = content.H / wrap.H;//zoom factor for height
    w = content.W/ wrap.W;//zoom factor for width
    //get max between zoom factores, remove percents
    renderedFactor = Math.max(h, w);
    //return scale factor
    return  1/renderedFactor;
};

$('#btn').on('click', function() {
    myScroll.zoom(fitFactor());
 });