/* 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);