(function ($) {(function ($) {Expose support flag. Aids in unit testing.
$.support.getBoundingClientRect = "getBoundingClientRect" in document.documentElement;Gets the window containing the specified element.
function getWindow(elem) {
return $.isWindow(elem) ?
elem :
elem.nodeType === 9 ?
elem.defaultView || elem.parentWindow :
false;
}Returns a rect for the first element in the jQuery object.
$.fn.clientRect = function () {
var rect = {
top: 0,
left: 0,
width: 0,
height: 0,
bottom: 0,
right: 0
};
if (this.length === 0) {
return rect;
}
var elem = this[0];
var doc = elem.ownerDocument;
var docElem = doc.documentElement;
var box;Make sure we’re not dealing with a disconnected DOM node
if (!$.contains(docElem, elem)) {
return rect;
}Make modern browsers wicked fast
if ($.support.getBoundingClientRect) {This is derived from the internals of jQuery.fn.offset
try {
box = elem.getBoundingClientRect();
} catch (e) {OldIE throws an exception when trying to get a client rect for an element that hasn’t been rendered, or isn’t in the DOM. For consistency, return a 0 rect.
}
if (!box) {
return rect;
}TODO needs a unit test to verify the returned rect always has the same properties (i.e. bottom, right) If the rect has no area, it needs no further processing
if (box.right === box.left &&
box.top === box.bottom) {
return rect;
}Handles some quirks in the oldIE box model, including some bizarre behavior around the starting coordinates.
var win = getWindow(doc);
rect.top = box.top + (win.pageYOffset || docElem.scrollTop) - (docElem.clientTop || 0);
rect.left = box.left + (win.pageXOffset || docElem.scrollLeft) - (docElem.clientLeft || 0);
rect.width = box.right - box.left;
rect.height = box.bottom - box.top;
} else {Support ancient browsers by falling back to jQuery.outerWidth/Height()
if (this.css("display") == "none") {
return rect;
}
rect = this.offset();
rect.width = this.outerWidth();
rect.height = this.outerHeight();
}
rect.bottom = rect.top + rect.height;
rect.right = rect.left + rect.width;
return rect;
};
})(jQuery);