jQuery UI的问题

//Monkey-patching getComputedStyle to work around the following 
//WebKit Safari bug: 
//https://bugs.webkit.org/show_bug.cgi?id=105979 
(function() { 
    //tolerate small variations caused by zoom scaling 
    var delta = 0.05; 
    function close_enough(x, y) { 
     var diff = x - y; 
     return delta > diff && diff > -delta; 
    } 

    //Set up a reference element to measure 
    //undesired variations from browser zooming 
    var expected_left = 100; 
    var body = document.getElementsByTagName("body")[0]; 
    var ref_node = document.createElement("div"); 
    body.appendChild(ref_node); 
    ref_node.style.position = "relative"; 
    ref_node.style.left = expected_left + "px"; 
    ref_node.style.height = "0"; 

    var native = window.getComputedStyle; 

    window.getComputedStyle = function(elt) { 
    //Bug only affects relative positioning. 
    //Only intervene if the element is concerned. 
    var styles = native(elt); 
    if("relative" !== styles.position) { 
     return styles; 
    } 

    //Measure undesired variation from reference element 
    var ref_styles = native(ref_node); 
    var ref_left = parseFloat(ref_styles.left); 

    if(close_enough(expected_left, ref_left)) { 
     return styles; 
    } 

    var proportion = ref_left/expected_left; 

    //Copy styles 
    //Use an object implementing the CSSStyleDeclaration interface. 
    var cloned = document.createElement("div").style; 
    var attr; 
    for(var ii=0; ii < styles.length; ++ii){ 
     attr = styles[ii]; 
     cloned[attr] = styles[attr]; 
    } 

    //correct styles 
    var property_names = ["top", "right", "bottom", "left"]; 
    for(var ii = 0; ii < property_names.length; ++ii) { 
     var prop_name = property_names[ii]; 
     if(prop_name in cloned) { 
       cloned[prop_name] = (parseFloat(cloned[prop_name])/proportion) + "px"; 
     }   
    } 

    return cloned; 
    } 
})();

来源

2014-12-08 15:43:50