Hacking at 0300

Updated 2012-12-26 with a much better algorithm for detecting stylesheet loading.

So let's say I want to create elements that match a jQuery UI theme (in my case, I was using a <canvas> element and wanted to copy colors). I could try to parse the CSS file directly, but that runs afoul of the same-origin security problem (I use Google's CDN to get the jQuery UI stylesheets, as in http://ajax.googleapis.com/ajax/libs/jqueryui/1.7.0/themes/smoothness/jquery-ui.css). I could go through the document stylesheets to find the relevant styles, but there's an easier way; just create an element with the desired classes and query that:

var background = $('<div class="ui-state-default">').css('background-color');