jquery-ui/external/jquery.mousewheel.js

/*! 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: 3.1.0
 *
 * Requires: 1.2.2+
 */

(function (factory) {
    if (typeof define === 'function' && define.amd) {
        // AMD. Register as an anonymous module.
        define(['jquery'], factory);
    } else {
        // Browser globals
        factory(jQuery);
    }
}(function ($) {

    var toFix = ['wheel', 'mousewheel', 'DOMMouseScroll'];
    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;
        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; }

        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; }

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

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

}));