/*! copyright (c) 2013 brandon aaron (http://brandon.aaron.sh)
 * licensed under the mit license (license.txt).
 *
 * version: 3.1.9
 *
 * 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;
        }
    }

    var special = $.event.special.mousewheel = {
        version: '3.1.9',

        setup: function() {
            if ( this.addeventlistener ) {
                for ( var i = tobind.length; i; ) {
                    this.addeventlistener( tobind[--i], handler, false );
                }
            } else {
                this.onmousewheel = handler;
            }
            // store the line height and page height for this particular element
            $.data(this, 'mousewheel-line-height', special.getlineheight(this));
            $.data(this, 'mousewheel-page-height', special.getpageheight(this));
        },

        teardown: function() {
            if ( this.removeeventlistener ) {
                for ( var i = tobind.length; i; ) {
                    this.removeeventlistener( tobind[--i], handler, false );
                }
            } else {
                this.onmousewheel = null;
            }
        },

        getlineheight: function(elem) {
            return parseint($(elem)['offsetparent' in $.fn ? 'offsetparent' : 'parent']().css('fontsize'), 10);
        },

        getpageheight: function(elem) {
            return $(elem).height();
        },

        settings: {
            adjustolddeltas: true
        }
    };

    $.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; }

        // need to convert lines and pages to pixels if we aren't already in pixels
        // there are three delta modes:
        //   * deltamode 0 is by pixels, nothing to do
        //   * deltamode 1 is by lines
        //   * deltamode 2 is by pages
        if ( orgevent.deltamode === 1 ) {
            var lineheight = $.data(this, 'mousewheel-line-height');
            delta  *= lineheight;
            deltay *= lineheight;
            deltax *= lineheight;
        } else if ( orgevent.deltamode === 2 ) {
            var pageheight = $.data(this, 'mousewheel-page-height');
            delta  *= pageheight;
            deltay *= pageheight;
            deltax *= pageheight;
        }

        // store lowest absolute delta to normalize the delta values
        absdelta = math.max( math.abs(deltay), math.abs(deltax) );

        if ( !lowestdelta || absdelta < lowestdelta ) {
            lowestdelta = absdelta;

            // adjust older deltas if necessary
            if ( shouldadjustolddeltas(orgevent, absdelta) ) {
                lowestdelta /= 40;
            }
        }

        // adjust older deltas if necessary
        if ( shouldadjustolddeltas(orgevent, absdelta) ) {
            // divide all the things by 40!
            delta  /= 40;
            deltax /= 40;
            deltay /= 40;
        }

        // 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;
        // go ahead and set deltamode to 0 since we converted to pixels
        // although this is a little odd since we overwrite the deltax/y
        // properties with normalized deltas.
        event.deltamode = 0;

        // 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;
    }

    function shouldadjustolddeltas(orgevent, absdelta) {
        // if this is an older event and the delta is divisable by 120,
        // then we are assuming that the browser is treating this as an
        // older mouse wheel event and that we should divide the deltas
        // by 40 to try and get a more usable deltafactor.
        // side note, this actually impacts the reported scroll distance
        // in older browsers and can cause scrolling to be slower than native.
        // turn this off by setting $.event.special.mousewheel.settings.adjustolddeltas to false.
        return special.settings.adjustolddeltas && orgevent.type === 'mousewheel' && absdelta % 120 === 0;
    }

}));