/* 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);