Add existing to tracked

node_modules/@cesium/widgets/Source/FullscreenButton/FullscreenButtonViewModel.js

@@ -0,0 +1,144 @@
+import {
+  defined,
+  destroyObject,
+  DeveloperError,
+  Fullscreen,
+  getElement,
+} from "@cesium/engine";
+import knockout from "../ThirdParty/knockout.js";
+import createCommand from "../createCommand.js";
+
+/**
+ * The view model for {@link FullscreenButton}.
+ * @alias FullscreenButtonViewModel
+ * @constructor
+ *
+ * @param {Element|string} [fullscreenElement=document.body] The element or id to be placed into fullscreen mode.
+ * @param {Element|string} [container] The DOM element or ID that will contain the widget.
+ */
+function FullscreenButtonViewModel(fullscreenElement, container) {
+  if (!defined(container)) {
+    container = document.body;
+  }
+
+  container = getElement(container);
+
+  const that = this;
+
+  const tmpIsFullscreen = knockout.observable(Fullscreen.fullscreen);
+  const tmpIsEnabled = knockout.observable(Fullscreen.enabled);
+  const ownerDocument = container.ownerDocument;
+
+  /**
+   * Gets whether or not fullscreen mode is active.  This property is observable.
+   *
+   * @type {boolean}
+   */
+  this.isFullscreen = undefined;
+  knockout.defineProperty(this, "isFullscreen", {
+    get: function () {
+      return tmpIsFullscreen();
+    },
+  });
+
+  /**
+   * Gets or sets whether or not fullscreen functionality should be enabled.  This property is observable.
+   *
+   * @type {boolean}
+   * @see Fullscreen.enabled
+   */
+  this.isFullscreenEnabled = undefined;
+  knockout.defineProperty(this, "isFullscreenEnabled", {
+    get: function () {
+      return tmpIsEnabled();
+    },
+    set: function (value) {
+      tmpIsEnabled(value && Fullscreen.enabled);
+    },
+  });
+
+  /**
+   * Gets the tooltip.  This property is observable.
+   *
+   * @type {string}
+   */
+  this.tooltip = undefined;
+  knockout.defineProperty(this, "tooltip", function () {
+    if (!this.isFullscreenEnabled) {
+      return "Full screen unavailable";
+    }
+    return tmpIsFullscreen() ? "Exit full screen" : "Full screen";
+  });
+
+  this._command = createCommand(
+    function () {
+      if (Fullscreen.fullscreen) {
+        Fullscreen.exitFullscreen();
+      } else {
+        Fullscreen.requestFullscreen(that._fullscreenElement);
+      }
+    },
+    knockout.getObservable(this, "isFullscreenEnabled"),
+  );
+
+  this._fullscreenElement = getElement(fullscreenElement) ?? ownerDocument.body;
+
+  this._callback = function () {
+    tmpIsFullscreen(Fullscreen.fullscreen);
+  };
+  ownerDocument.addEventListener(Fullscreen.changeEventName, this._callback);
+}
+
+Object.defineProperties(FullscreenButtonViewModel.prototype, {
+  /**
+   * Gets or sets the HTML element to place into fullscreen mode when the
+   * corresponding button is pressed.
+   * @memberof FullscreenButtonViewModel.prototype
+   *
+   * @type {Element}
+   */
+  fullscreenElement: {
+    //TODO:@exception {DeveloperError} value must be a valid HTML Element.
+    get: function () {
+      return this._fullscreenElement;
+    },
+    set: function (value) {
+      //>>includeStart('debug', pragmas.debug);
+      if (!(value instanceof Element)) {
+        throw new DeveloperError("value must be a valid Element.");
+      }
+      //>>includeEnd('debug');
+
+      this._fullscreenElement = value;
+    },
+  },
+
+  /**
+   * Gets the Command to toggle fullscreen mode.
+   * @memberof FullscreenButtonViewModel.prototype
+   *
+   * @type {Command}
+   */
+  command: {
+    get: function () {
+      return this._command;
+    },
+  },
+});
+
+/**
+ * @returns {boolean} true if the object has been destroyed, false otherwise.
+ */
+FullscreenButtonViewModel.prototype.isDestroyed = function () {
+  return false;
+};
+
+/**
+ * Destroys the view model.  Should be called to
+ * properly clean up the view model when it is no longer needed.
+ */
+FullscreenButtonViewModel.prototype.destroy = function () {
+  document.removeEventListener(Fullscreen.changeEventName, this._callback);
+  destroyObject(this);
+};
+export default FullscreenButtonViewModel;