"

From 2013.igem.org

/*! Copyright (c) 2013 Brandon Aaron (http://brandonaaron.net)

* Licensed under the MIT License (LICENSE.txt).
*
* 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.
* Thanks to: Seamus Leahy for adding deltaX and deltaY
*
* Version: 3.1.3
*
* Requires: 1.2.2+
*/

(function (factory) {

   if ( typeof define === 'function' && define.amd ) {
       // AMD. Register as an anonymous module.
       define(['jquery'], factory);
   } else if (typeof exports === 'object') {
       // Node/CommonJS style for Browserify
       module.exports = factory;
   } else {
       // Browser globals
       factory(jQuery);
   }

}(function ($) {

   var toFix = ['wheel', 'mousewheel', 'DOMMouseScroll', 'MozMousePixelScroll'];
   var toBind = 'onwheel' in document || document.documentMode >= 9 ? ['wheel'] : ['mousewheel', 'DomMouseScroll', 'MozMousePixelScroll'];
   var lowestDelta, lowestDeltaXY;

   if ( $.event.fixHooks ) {
       for ( var i = toFix.length; i; ) {
           $.event.fixHooks[ toFix[--i] ] = $.event.mouseHooks;
       }
   }

   $.event.special.mousewheel = {
       setup: function() {
           if ( this.addEventListener ) {
               for ( var i = toBind.length; i; ) {
                   this.addEventListener( toBind[--i], handler, false );
               }
           } else {
               this.onmousewheel = handler;
           }
       },

       teardown: function() {
           if ( this.removeEventListener ) {
               for ( var i = toBind.length; i; ) {
                   this.removeEventListener( toBind[--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 orgEvent = event || window.event,
           args = [].slice.call(arguments, 1),
           delta = 0,
           deltaX = 0,
           deltaY = 0,
           absDelta = 0,
           absDeltaXY = 0,
           fn;
       event = $.event.fix(orgEvent);
       event.type = "mousewheel";

       // Old school scrollwheel delta
       if ( orgEvent.wheelDelta ) { delta = orgEvent.wheelDelta; }
       if ( orgEvent.detail )     { delta = orgEvent.detail * -1; }

       // New school wheel delta (wheel event)
       if ( orgEvent.deltaY ) {
           deltaY = orgEvent.deltaY * -1;
           delta  = deltaY;
       }
       if ( orgEvent.deltaX ) {
           deltaX = orgEvent.deltaX;
           delta  = deltaX * -1;
       }

       // Webkit
       if ( orgEvent.wheelDeltaY !== undefined ) { deltaY = orgEvent.wheelDeltaY; }
       if ( orgEvent.wheelDeltaX !== undefined ) { deltaX = orgEvent.wheelDeltaX * -1; }

       // Look for lowest delta to normalize the delta values
       absDelta = Math.abs(delta);
       if ( !lowestDelta || absDelta < lowestDelta ) { lowestDelta = absDelta; }
       absDeltaXY = Math.max(Math.abs(deltaY), Math.abs(deltaX));
       if ( !lowestDeltaXY || absDeltaXY < lowestDeltaXY ) { lowestDeltaXY = absDeltaXY; }

       // Get a whole value for the deltas
       fn = delta > 0 ? 'floor' : 'ceil';
       delta  = Math[fn](delta / lowestDelta);
       deltaX = Math[fn](deltaX / lowestDeltaXY);
       deltaY = Math[fn](deltaY / lowestDeltaXY);

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

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

}));