/*! Copyright © 2013 Brandon Aaron (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;
}

}));