Source: Widgets/HomeButton/HomeButton.js

/*global define*/
define([
        '../../Core/defined',
        '../../Core/defineProperties',
        '../../Core/destroyObject',
        '../../Core/DeveloperError',
        '../../ThirdParty/knockout',
        '../getElement',
        './HomeButtonViewModel'
    ], function(
        defined,
        defineProperties,
        destroyObject,
        DeveloperError,
        knockout,
        getElement,
        HomeButtonViewModel) {
    'use strict';

    /**
     * A single button widget for returning to the default camera view of the current scene.
     *
     * @alias HomeButton
     * @constructor
     *
     * @param {Element|String} container The DOM element or ID that will contain the widget.
     * @param {Scene} scene The Scene instance to use.
     * @param {Number} [duration] The time, in seconds, it takes to complete the camera flight home.
     */
    function HomeButton(container, scene, duration) {
        //>>includeStart('debug', pragmas.debug);
        if (!defined(container)) {
            throw new DeveloperError('container is required.');
        }
        //>>includeEnd('debug');

        container = getElement(container);

        var viewModel = new HomeButtonViewModel(scene, duration);

        viewModel._svgPath = 'M14,4l-10,8.75h20l-4.25-3.7188v-4.6562h-2.812v2.1875l-2.938-2.5625zm-7.0938,9.906v10.094h14.094v-10.094h-14.094zm2.1876,2.313h3.3122v4.25h-3.3122v-4.25zm5.8442,1.281h3.406v6.438h-3.406v-6.438z';

        var element = document.createElement('button');
        element.type = 'button';
        element.className = 'cesium-button cesium-toolbar-button cesium-home-button';
        element.setAttribute('data-bind', '\
attr: { title: tooltip },\
click: command,\
cesiumSvgPath: { path: _svgPath, width: 28, height: 28 }');

        container.appendChild(element);

        knockout.applyBindings(viewModel, element);

        this._container = container;
        this._viewModel = viewModel;
        this._element = element;
    }

    defineProperties(HomeButton.prototype, {
        /**
         * Gets the parent container.
         * @memberof HomeButton.prototype
         *
         * @type {Element}
         */
        container : {
            get : function() {
                return this._container;
            }
        },

        /**
         * Gets the view model.
         * @memberof HomeButton.prototype
         *
         * @type {HomeButtonViewModel}
         */
        viewModel : {
            get : function() {
                return this._viewModel;
            }
        }
    });

    /**
     * @returns {Boolean} true if the object has been destroyed, false otherwise.
     */
    HomeButton.prototype.isDestroyed = function() {
        return false;
    };

    /**
     * Destroys the widget.  Should be called if permanently
     * removing the widget from layout.
     */
    HomeButton.prototype.destroy = function() {
        knockout.cleanNode(this._element);
        this._container.removeChild(this._element);

        return destroyObject(this);
    };

    return HomeButton;
});