/*
 * jQuery Animate From To plugin 1.0
 *
 * Copyright (c) 2011 Emil Stenstrom <http://friendlybit.com>
 *
 * Dual licensed under the MIT and GPL licenses:
 * http://www.opensource.org/licenses/mit-license.php
 * http://www.gnu.org/licenses/gpl.html                 
 */
(function($) {
	$.fn.animate_from_to = function(targetElm, options){
		return this.each(function(){
			animate_from_to(this, targetElm, options);
		});
	};

	$.extend({
		animate_from_to: animate_from_to
	});

	function animate_from_to(sourceElm, targetElm, options) {

        var source = $(sourceElm).eq(0),
            target = $(targetElm).eq(0);

        var defaults = {
            pixels_per_second: 500,
            initial_css: {
                "opacity": 0.6,
                "position": "absolute",
                "top": source.offset().top,
                "left": source.offset().left,
                "height": source.height(),
                "width": source.width(),
                "z-index": 100000
            },
            callback: function(){ return; }
        }
        if (options && options.initial_css) {
            options.initial_css = $.extend({}, defaults.initial_css, options.initial_css);
        }
        options = $.extend({}, defaults, options);

        var dy = source.offset().top + source.width()/2 - target.offset().top,
            dx = source.offset().left + source.height()/2 - target.offset().left,
            pixel_distance = Math.floor(Math.sqrt(Math.pow(dx, 2) + Math.pow(dy, 2))),
            duration = (pixel_distance/options.pixels_per_second)*1000,

            shadow = $('<div><img src="' + sourceElm.src + '"/></div>')
                .css(options.initial_css)
                .appendTo('body')
                .animate({
                    top: target.offset().top,
                    left: target.offset().left
                }, {
                    duration: duration
                })
                .animate({
                    opacity: 0
                }, {
                    duration: 100,
                    complete: function(){
                        shadow.remove();
                        return options.callback();
                    }
                });
	}
})(jQuery);