jtBaseApp/node_modules/@cesium/engine/Source/DataSources/DataSource.js

import DeveloperError from "../Core/DeveloperError.js";

/**
 * Defines the interface for data sources, which turn arbitrary data into a
 * {@link EntityCollection} for generic consumption. This object is an interface
 * for documentation purposes and is not intended to be instantiated directly.
 * @alias DataSource
 * @constructor
 *
 * @see Entity
 * @see DataSourceDisplay
 */
function DataSource() {
  DeveloperError.throwInstantiationError();
}

Object.defineProperties(DataSource.prototype, {
  /**
   * Gets a human-readable name for this instance.
   * @memberof DataSource.prototype
   * @type {string}
   */
  name: {
    get: DeveloperError.throwInstantiationError,
  },
  /**
   * Gets the preferred clock settings for this data source.
   * @memberof DataSource.prototype
   * @type {DataSourceClock}
   */
  clock: {
    get: DeveloperError.throwInstantiationError,
  },
  /**
   * Gets the collection of {@link Entity} instances.
   * @memberof DataSource.prototype
   * @type {EntityCollection}
   */
  entities: {
    get: DeveloperError.throwInstantiationError,
  },
  /**
   * Gets a value indicating if the data source is currently loading data.
   * @memberof DataSource.prototype
   * @type {boolean}
   */
  isLoading: {
    get: DeveloperError.throwInstantiationError,
  },
  /**
   * Gets an event that will be raised when the underlying data changes.
   * @memberof DataSource.prototype
   * @type {Event}
   */
  changedEvent: {
    get: DeveloperError.throwInstantiationError,
  },
  /**
   * Gets an event that will be raised if an error is encountered during processing.
   * @memberof DataSource.prototype
   * @type {Event<function(this, RequestErrorEvent)>}
   */
  errorEvent: {
    get: DeveloperError.throwInstantiationError,
  },
  /**
   * Gets an event that will be raised when the value of isLoading changes.
   * @memberof DataSource.prototype
   * @type {Event<function(this, boolean)>}
   */
  loadingEvent: {
    get: DeveloperError.throwInstantiationError,
  },
  /**
   * Gets whether or not this data source should be displayed.
   * @memberof DataSource.prototype
   * @type {boolean}
   */
  show: {
    get: DeveloperError.throwInstantiationError,
  },

  /**
   * Gets or sets the clustering options for this data source. This object can be shared between multiple data sources.
   *
   * @memberof DataSource.prototype
   * @type {EntityCluster}
   */
  clustering: {
    get: DeveloperError.throwInstantiationError,
  },
});

/**
 * Updates the data source to the provided time.  This function is optional and
 * is not required to be implemented.  It is provided for data sources which
 * retrieve data based on the current animation time or scene state.
 * If implemented, update will be called by {@link DataSourceDisplay} once a frame.
 *
 * @param {JulianDate} time The simulation time.
 * @returns {boolean} True if this data source is ready to be displayed at the provided time, false otherwise.
 */
DataSource.prototype.update = function (time) {
  DeveloperError.throwInstantiationError();
};

/**
 * @private
 */
DataSource.setLoading = function (dataSource, isLoading) {
  if (dataSource._isLoading !== isLoading) {
    if (isLoading) {
      dataSource._entityCollection.suspendEvents();
    } else {
      dataSource._entityCollection.resumeEvents();
    }
    dataSource._isLoading = isLoading;
    dataSource._loading.raiseEvent(dataSource, isLoading);
  }
};
export default DataSource;