/* 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+
*/

jQuery(function() {

jQuery.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);
      }
   };

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

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

});