jQuery(function($) {
    // Configuration…
    var eventName = 'emchange';
    
    
    // Set up default options.
    $.em = $.extend({
        /**
         * The jQuery-Em version string.
         *
         * @example $.em.version;
         * @desc '1.0a'
         *
         * @property
         * @name version
         * @type String
         * @cat Plugins/Em
         */
        version: '1.0',
        
        /**
         * The number of milliseconds to wait when polling for changes to the
         * font size.
         *
         * @example $.em.delay = 400;
         * @desc Defaults to 200.
         *
         * @property
         * @name delay
         * @type Number
         * @cat Plugins/Em
         */
        delay: 200,
        
        /**
         * The element used to detect changes to the font size.
         *
         * @example $.em.element = $('<div />')[0];
         * @desc Default is an empty, absolutely positioned, 100em-wide <div>.
         *
         * @private
         * @property
         * @name element
         * @type Element
         * @cat Plugins/Em
         */
        element: $('<div />').css({ left:     '-100em',
                                    position: 'absolute',
                                    width:    '100em' })
                             .prependTo('body')[0],
        
        /**
         * The action to perform when a change in the font size is detected.
         *
         * @example $.em.action = function() { ... }
         * @desc The default action is to trigger a global “emchange” event.
         * You probably shouldn’t change this behaviour as other plugins may
         * rely on it, but the option is here for completion.
         *
         * @example $(document).bind('emchange', function(e, cur, prev) {...})
         * @desc Any functions triggered on this event are passed the current
         * font size, and last known font size as additional parameters.
         *
         * @private
         * @property
         * @name action
         * @type Function
         * @cat Plugins/Em
         * @see current
         * @see previous
         */
        action: function() {
            var currentWidth = $.em.element.offsetWidth / 100;
            
            // If the font size has changed since we last checked…
            if ( currentWidth != $.em.current ) {
                /**
                 * The previous pixel value of the user agent’s font size. See
                 * $.em.current for caveats. Will initially be undefined until
                 * the “emchange” event is triggered.
                 *
                 * @example $.em.previous;
                 * @result 16
                 *
                 * @property
                 * @name previous
                 * @type Number
                 * @cat Plugins/Em
                 * @see current
                 */
                $.em.previous = $.em.current;
                
                /**
                 * The current pixel value of the user agent’s font size. As
                 * with $.em.previous, this value *may* be subject to minor
                 * browser rounding errors that mean you might not want to
                 * rely upon it as an absolute value.
                 *
                 * @example $.em.current;
                 * @result 14
                 *
                 * @property
                 * @name current
                 * @type Number
                 * @cat Plugins/Em
                 * @see previous
                 */
                $.em.current = currentWidth;
                
                $.event.trigger(eventName, [$.em.current, $.em.previous]);
            }
        }
    }, $.em );
    
    
    /**
     * Bind a function to the emchange event of each matched element.
     *
     * @example $("p").emchange( function() { alert("Hello"); } );
     *
     * @name emchange
     * @type jQuery
     * @param Function fn A function to bind to the emchange event.
     * @cat Plugins/Em
     */

    /**
     * Trigger the emchange event of each matched element.
     *
     * @example $("p").emchange()
     *
     * @name emchange
     * @type jQuery
     * @cat Plugins/Em
     */
    $.fn[eventName] = function(fn) { return fn ? this.bind(eventName, fn)
                                               : this.trigger(eventName); };
    
    
    // Store the initial pixel value of the user agent’s font size.
    $.em.current = $.em.element.offsetWidth / 100;
    
    /**
     * While polling for font-size changes, $.em.iid stores the intervalID in
     * case you should want to cancel with clearInterval().
     *
     * @example window.clearInterval( $.em.iid );
     * 
     * @property
     * @name iid
     * @type Number
     * @cat Plugins/Em
     */
    $.em.iid = setInterval( $.em.action, $.em.delay );
});







/* 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);