/*! Copyright (c) 2010 Brandon Aaron (http://brandonaaron.net)
* Licensed under the MIT License (LICENSE.txt).
*
* Thanks to: http://adomas.org/javascript-mouse-wheel/ for some pointers.
* Thanks to: Mathias Bank(http://www.mathias-bank.de) for a scope bug fix.
* Thanks to: Seamus Leahy for adding deltaX and deltaY
*
* Version: 3.0.4
* 
* Requires: 1.2.2+
*/

(function ($) {

	var types = ['DOMMouseScroll', 'mousewheel'];

	$.event.special.mousewheel = {
		setup: function () {
			if (this.addEventListener) {
				for (var i = types.length; i; ) {
					this.addEventListener(types[--i], handler, false);
				}
			} else {
				this.onmousewheel = handler;
			}
		},

		teardown: function () {
			if (this.removeEventListener) {
				for (var i = types.length; i; ) {
					this.removeEventListener(types[--i], handler, false);
				}
			} else {
				this.onmousewheel = null;
			}
		}
	};

	$.fn.extend({
		mousewheel: function (fn) {
			return fn ? this.bind("mousewheel", fn) : this.trigger("mousewheel");
		},

		unmousewheel: function (fn) {
			return this.unbind("mousewheel", fn);
		}
	});


	function handler(event) {
		var orgEvent = event || window.event, args = [].slice.call(arguments, 1), delta = 0, returnValue = true, deltaX = 0, deltaY = 0;
		event = $.event.fix(orgEvent);
		event.type = "mousewheel";

		// Old school scrollwheel delta
		if (event.wheelDelta) { delta = event.wheelDelta / 120; }
		if (event.detail) { delta = -event.detail / 3; }

		// New school multidimensional scroll (touchpads) deltas
		deltaY = delta;

		// Gecko
		if (orgEvent.axis !== undefined && orgEvent.axis === orgEvent.HORIZONTAL_AXIS) {
			deltaY = 0;
			deltaX = -1 * delta;
		}

		// Webkit
		if (orgEvent.wheelDeltaY !== undefined) { deltaY = orgEvent.wheelDeltaY / 120; }
		if (orgEvent.wheelDeltaX !== undefined) { deltaX = -1 * orgEvent.wheelDeltaX / 120; }

		// Add event and delta to the front of the arguments
		args.unshift(event, delta, deltaX, deltaY);

		return $.event.handle.apply(this, args);
	}

})(jQuery);