/*! Copyright (c) 2009 Brandon Aaron (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.
*
* Version: 3.0.2
* 
* 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 args = [].slice.call(arguments, 1), delta = 0, returnValue = true;

        event = $.event.fix(event || window.event);
        event.type = "mousewheel";

        if (event.wheelDelta) delta = event.wheelDelta / 120;
        if (event.detail) delta = -event.detail / 3;

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

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

})(jQuery);