/*! Copyright (c) 2013 Brandon Aaron (http://brandon.aaron.sh)

 * Licensed under the MIT License (LICENSE.txt).

 *

 * Version: 3.1.6

 *

 * Requires: jQuery 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'],

        toBind = ( 'onwheel' in document || document.documentMode >= 9 ) ?

                    ['wheel'] : ['mousewheel', 'DomMouseScroll', 'MozMousePixelScroll'],

        slice  = Array.prototype.slice,

        nullLowestDeltaTimeout, lowestDelta;

    if ( $.event.fixHooks ) {

        for ( var i = toFix.length; i; ) {

            $.event.fixHooks[ toFix[--i] ] = $.event.mouseHooks;

        }

    }

    $.event.special.mousewheel = {

        version: '3.1.6',

        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;

        event = $.event.fix(orgEvent);

        event.type = 'mousewheel';

        // Old school scrollwheel delta

        if ( 'detail'      in orgEvent ) { deltaY = orgEvent.detail * -1;      }

        if ( 'wheelDelta'  in orgEvent ) { deltaY = orgEvent.wheelDelta;       }

        if ( 'wheelDeltaY' in orgEvent ) { deltaY = orgEvent.wheelDeltaY;      }

        if ( 'wheelDeltaX' in orgEvent ) { deltaX = orgEvent.wheelDeltaX * -1; }

        // Firefox < 17 horizontal scrolling related to DOMMouseScroll event

        if ( 'axis' in orgEvent && orgEvent.axis === orgEvent.HORIZONTAL_AXIS ) {

            deltaX = deltaY * -1;

            deltaY = 0;

        }

        // Set delta to be deltaY or deltaX if deltaY is 0 for backwards compatabilitiy

        delta = deltaY === 0 ? deltaX : deltaY;

        // New school wheel delta (wheel event)

        if ( 'deltaY' in orgEvent ) {

          deltaY = orgEvent.deltaY * -1;

          delta  = deltaY;

        }

        if ( 'deltaX' in orgEvent ) {

          deltaX = orgEvent.deltaX;

          if ( deltaY === 0 ) { delta  = deltaX * -1; }

        }

        // No change actually happened, no reason to go any further

        if ( deltaY === 0 && deltaX === 0 ) { return; }

        // Store lowest absolute delta to normalize the delta values

        absDelta = Math.max( Math.abs(deltaY), Math.abs(deltaX) );

        if ( !lowestDelta || absDelta < lowestDelta ) {

          lowestDelta = absDelta;

        }

        // Get a whole, normalized value for the deltas

        delta  = Math[ delta  >= 1 ? 'floor' : 'ceil' ](delta  / lowestDelta);

        deltaX = Math[ deltaX >= 1 ? 'floor' : 'ceil' ](deltaX / lowestDelta);

        deltaY = Math[ deltaY >= 1 ? 'floor' : 'ceil' ](deltaY / lowestDelta);

        // Add information to the event object

        event.deltaX = deltaX;

        event.deltaY = deltaY;

        event.deltaFactor = lowestDelta;

        // Add event and delta to the front of the arguments

        args.unshift(event, delta, deltaX, deltaY);

        // Clearout lowestDelta after sometime to better

        // handle multiple device types that give different

        // a different lowestDelta

        // Ex: trackpad = 3 and mouse wheel = 120

        if (nullLowestDeltaTimeout) { clearTimeout(nullLowestDeltaTimeout); }

        nullLowestDeltaTimeout = setTimeout(nullLowestDelta, 200);

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

    }

    function nullLowestDelta() {

      lowestDelta = null;

    }

}));