Function visor

tfjs-vis/src/visor.ts:40–82

()

 * @doc {heading: 'Visor & Surfaces'}
 */
export function visor(): Visor {
  if (typeof document === 'undefined') {
    throw new Error(
        'No document defined. This library needs a browser/dom to work');
  }

  if (document.getElementById(VISOR_CONTAINER_ID) && visorSingleton != null) {
    return visorSingleton;
  }

  // Create the container
  let visorEl = document.getElementById(VISOR_CONTAINER_ID);

  if (visorEl == null) {
    visorEl = document.createElement('div');
    visorEl.id = VISOR_CONTAINER_ID;
    document.body.appendChild(visorEl);
  }

  let renderRoot: Element;
  function renderVisor(
      domNode: HTMLElement,
      surfaceList: Map<string, SurfaceInfoStrict>): VisorComponent {
    let visorInstance: VisorComponent = null;
    renderRoot = VisorComponent.render(domNode, renderRoot, {
      ref: (r: VisorComponent) => visorInstance = r,
      surfaceList: Array.from(surfaceList.values()),
    });
    // Side effect of VisorComponent.render() is to assign visorInstance
    return visorInstance;
  }

  // TODO: consider changing this type. Possibly lift into top level state
  // object
  const surfaceList: Map<string, SurfaceInfoStrict> = new Map();
  const visorComponentInstance: VisorComponent =
      renderVisor(visorEl, surfaceList);

  visorSingleton =
      new Visor(visorComponentInstance, visorEl, surfaceList, renderVisor);

  return visorSingleton;
}

/**
 * An instance of the visor. An instance of this class is created using the