/* 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);