cesiumDemo/Source/Core/KeyboardEventModifier.js

import freezeObject from './freezeObject.js';

    /**
     * This enumerated type is for representing keyboard modifiers. These are keys
     * that are held down in addition to other event types.
     *
     * @exports KeyboardEventModifier
     */
    var KeyboardEventModifier = {
        /**
         * Represents the shift key being held down.
         *
         * @type {Number}
         * @constant
         */
        SHIFT : 0,

        /**
         * Represents the control key being held down.
         *
         * @type {Number}
         * @constant
         */
        CTRL : 1,

        /**
         * Represents the alt key being held down.
         *
         * @type {Number}
         * @constant
         */
        ALT : 2
    };
export default freezeObject(KeyboardEventModifier);