/* Copyright (c) 2006 Brandon Aaron (brandon.aaron@gmail.com || http://brandonaaron.net)
 * Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)
 * and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
 * 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.
 *
 * $LastChangedDate: 2007-12-20 09:02:08 -0600 (Thu, 20 Dec 2007) $
 * $Rev: 4265 $
 *
 * Version: 3.0
 * 
 * Requires: $ 1.2.2+
 */

(function($) {
	$.event.special.mousewheel = {
		setup: function() {
			var handler = $.event.special.mousewheel.handler;
			
			// Fix pageX, pageY, clientX and clientY for mozilla
			if ( $.browser.mozilla )
				$(this).bind('mousemove.mousewheel', function(event) {
					$.data(this, 'mwcursorposdata', {
						pageX: event.pageX,
						pageY: event.pageY,
						clientX: event.clientX,
						clientY: event.clientY
					});
				});
		
			if ( this.addEventListener )
				this.addEventListener( ($.browser.mozilla ? 'DOMMouseScroll' : 'mousewheel'), handler, false);
			else
				this.onmousewheel = handler;
		},
		teardown: function() {
			var handler = $.event.special.mousewheel.handler;
			
			$(this).unbind('mousemove.mousewheel');
			
			if ( this.removeEventListener )
				this.removeEventListener( ($.browser.mozilla ? 'DOMMouseScroll' : 'mousewheel'), handler, false);
			else
				this.onmousewheel = function(){};
			
			$.removeData(this, 'mwcursorposdata');
		},
		handler: function(event) {
			var args = Array.prototype.slice.call( arguments, 1 );
			
			event = $.event.fix(event || window.event);
			// Get correct pageX, pageY, clientX and clientY for mozilla
			$.extend( event, $.data(this, 'mwcursorposdata') || {} );
			var delta = 0, returnValue = true;
			
			if ( event.wheelDelta ) delta = event.wheelDelta/120;
			if ( event.detail     ) delta = -event.detail/3;
			if ( $.browser.opera  ) delta = -event.wheelDelta;
			
			event.data  = event.data || {};
			event.type  = "mousewheel";
			
			// Add delta to the front of the arguments
			args.unshift(delta);
			// Add event to the front of the arguments
			args.unshift(event);
	
			return $.event.handle.apply(this, args);
		}
	};
	$.fn.extend({
		mousewheel: function(fn) {
			return fn ? this.bind("mousewheel", fn) : this.trigger("mousewheel");
		},
		unmousewheel: function(fn) {
			return this.unbind("mousewheel", fn);
		}
	});
})(jQuery);