jquery_animate_auto_from_max_width_height.js

/* 
 * Original Source: http://darcyclarke.me/development/fix-jquerys-animate-to-allow-auto-values-2/
 *
 * This is an addition to Darcy Clark's animateAuto function that allows you to animate a div with
 * a set max-width/height growing to full height/width. In my use case, I had a div with a height
 * larger than its default max-height. I wanted to animate the growth from the set max-height to the
 * actual height. This addition to Darcy's function simply turns off the max-height/width and immediately
 * sets the actual height of the div to the previous max-height/width. Then it animates to auto like normal.
 * Also, the speed variable can optionally be a function of height or width or both.
 */
 
jQuery.fn.animateAuto = function(prop, speed, callback){
    var elem, height, width;
    return this.each(function(i, el){
        var el = jQuery(el),
            height0 = el.height()+"px",
            width0 = el.width()+"px",
            elem = el.clone().css({"height":"auto","width":"auto"}).appendTo("body"),
            height = elem.css("height"),
            width = elem.css("width");
        el.css({"max-height": "none", "max-width": "none", "height": height0, "width": width0});
        elem.remove();

        var _speed = function() {return speed;};
        if (isFunction(speed)) _speed = function(x) {return speed(x);};
        if(prop === "height")
            el.animate({"height":height}, _speed(height), callback);
        else if(prop === "width")
            el.animate({"width":width}, _speed(width), callback);
        else if(prop === "both")
            el.animate({"width":width,"height":height}, _speed(width, height), callback);
    });
};