/**
* Copyright (c) 2008, Ben XO <me@ben-xo.com>
* 
* Dual licensed under the MIT (MIT-LICENSE.txt)
* and GPL (GPL-LICENSE.txt) licenses.
* 
* 
* This is a jQuery plugin that allows events to be handled in reverse order of
* binding - add events to the head of the queue rather than the end.
* 
* Particularly useful if you apply your "do"s in a modular order and wish to 
* apply your "undo"s in reverse order.
* 
* It adds the following two methods:
* 
* reverse(event): reverses the order that functions attached to <event> are 
*                 applied to this element.
* 
* stack( event, data, fn ): just like bind(), except adds to the front of the 
*                           event queue instead of the end.
*                           
* Also, every event method (.click(), .focus(), .resize(), .submit(), etc - 
* 21 methods in all) can take an extra parameter "reverse" that controls if 
* the event is added to the front or end of the event queue. For example:
* 
* $("body").click(function() { alert("1"); });
* $("body").click(function() { alert("2"); });
* $("body").click(function() { alert("3"); }, true);
* 
* ... will show "3", "1" then "2" when the document is clicked.
* 
* @version 0.3
*/

jQuery.fn.extend({

    // reverse the order of events bound to an element
    reverse: function (event) {
        var events = this.data("events");
        if (events != undefined && events[event] != undefined) {
            // can't reverse what's not there
            var reverseEvent = new Array;
            for (var e in events[event]) {
                reverseEvent.unshift(events[event][e]);
            }
            events[event] = reverseEvent;
        }
        return this;
    },

    // add an event to the front of an event queue rather than the back
    // we do this by reversing the queue, adding, then reversing again
    stack: function (event, data, fn) {
        return this
			.reverse(event)
			.bind(event, data, fn)
			.reverse(event)
		;
    },

    hover: function (fnOver, fnOut, reverse) {
        if (reverse) {
            return this
				.stack('mouseenter', fnOver)
				.stack('mouseleave', fnOut)
			;
        } else {
            return this
				.bind('mouseenter', fnOver)
				.bind('mouseleave', fnOut)
			;
        }
    }
});

// every event handler - blur(), focus(), click() etc now has a 2nd param which
// if true will add the passed function to the beginning of the event list 
// instead of the end
jQuery.each(("blur,focus,load,resize,scroll,unload,click,dblclick," +
	"mousedown,mouseup,mousemove,mouseover,mouseout,change,select," +
	"submit,keydown,keypress,keyup,error").split(","), function (i, name) {

	    // Handle event binding
	    jQuery.fn[name] = function (fn, reverse) {
	        if (fn) {
	            return reverse ?
				this.stack(name, fn) :
				this.bind(name, fn)
			;
	        } else {
	            return this.trigger(name);
	        }
	    };
	});