SingleTileImageryProvider.js

import Credit from "../Core/Credit.js";
import defaultValue from "../Core/defaultValue.js";
import defined from "../Core/defined.js";
import DeveloperError from "../Core/DeveloperError.js";
import Event from "../Core/Event.js";
import GeographicTilingScheme from "../Core/GeographicTilingScheme.js";
import Rectangle from "../Core/Rectangle.js";
import Resource from "../Core/Resource.js";
import RuntimeError from "../Core/RuntimeError.js";
import TileProviderError from "../Core/TileProviderError.js";
import ImageryProvider from "./ImageryProvider.js";

/**
 * @typedef {Object} SingleTileImageryProvider.ConstructorOptions
 *
 * Initialization options for the SingleTileImageryProvider constructor
 *
 * @property {Resource|String} url The url for the tile.
 * @property {Rectangle} [rectangle=Rectangle.MAX_VALUE] The rectangle, in radians, covered by the image.
 * @property {Credit|String} [credit] A credit for the data source, which is displayed on the canvas.
 * @property {Ellipsoid} [ellipsoid] The ellipsoid.  If not specified, the WGS84 ellipsoid is used.
 */

/**
 * Provides a single, top-level imagery tile.  The single image is assumed to use a
 * {@link GeographicTilingScheme}.
 *
 * @alias SingleTileImageryProvider
 * @constructor
 *
 * @param {SingleTileImageryProvider.ConstructorOptions} options Object describing initialization options
 *
 * @see ArcGisMapServerImageryProvider
 * @see BingMapsImageryProvider
 * @see GoogleEarthEnterpriseMapsProvider
 * @see OpenStreetMapImageryProvider
 * @see TileMapServiceImageryProvider
 * @see WebMapServiceImageryProvider
 * @see WebMapTileServiceImageryProvider
 * @see UrlTemplateImageryProvider
 */
function SingleTileImageryProvider(options) {
  options = defaultValue(options, defaultValue.EMPTY_OBJECT);
  //>>includeStart('debug', pragmas.debug);
  if (!defined(options.url)) {
    throw new DeveloperError("options.url is required.");
  }
  //>>includeEnd('debug');

  /**
   * The default alpha blending value of this provider, with 0.0 representing fully transparent and
   * 1.0 representing fully opaque.
   *
   * @type {Number|undefined}
   * @default undefined
   */
  this.defaultAlpha = undefined;

  /**
   * The default alpha blending value on the night side of the globe of this provider, with 0.0 representing fully transparent and
   * 1.0 representing fully opaque.
   *
   * @type {Number|undefined}
   * @default undefined
   */
  this.defaultNightAlpha = undefined;

  /**
   * The default alpha blending value on the day side of the globe of this provider, with 0.0 representing fully transparent and
   * 1.0 representing fully opaque.
   *
   * @type {Number|undefined}
   * @default undefined
   */
  this.defaultDayAlpha = undefined;

  /**
   * The default brightness of this provider.  1.0 uses the unmodified imagery color.  Less than 1.0
   * makes the imagery darker while greater than 1.0 makes it brighter.
   *
   * @type {Number|undefined}
   * @default undefined
   */
  this.defaultBrightness = undefined;

  /**
   * The default contrast of this provider.  1.0 uses the unmodified imagery color.  Less than 1.0 reduces
   * the contrast while greater than 1.0 increases it.
   *
   * @type {Number|undefined}
   * @default undefined
   */
  this.defaultContrast = undefined;

  /**
   * The default hue of this provider in radians. 0.0 uses the unmodified imagery color.
   *
   * @type {Number|undefined}
   * @default undefined
   */
  this.defaultHue = undefined;

  /**
   * The default saturation of this provider. 1.0 uses the unmodified imagery color. Less than 1.0 reduces the
   * saturation while greater than 1.0 increases it.
   *
   * @type {Number|undefined}
   * @default undefined
   */
  this.defaultSaturation = undefined;

  /**
   * The default gamma correction to apply to this provider.  1.0 uses the unmodified imagery color.
   *
   * @type {Number|undefined}
   * @default undefined
   */
  this.defaultGamma = undefined;

  /**
   * The default texture minification filter to apply to this provider.
   *
   * @type {TextureMinificationFilter}
   * @default undefined
   */
  this.defaultMinificationFilter = undefined;

  /**
   * The default texture magnification filter to apply to this provider.
   *
   * @type {TextureMagnificationFilter}
   * @default undefined
   */
  this.defaultMagnificationFilter = undefined;

  const resource = Resource.createIfNeeded(options.url);

  const rectangle = defaultValue(options.rectangle, Rectangle.MAX_VALUE);
  const tilingScheme = new GeographicTilingScheme({
    rectangle: rectangle,
    numberOfLevelZeroTilesX: 1,
    numberOfLevelZeroTilesY: 1,
    ellipsoid: options.ellipsoid,
  });
  this._tilingScheme = tilingScheme;
  this._resource = resource;
  this._image = undefined;
  this._texture = undefined;
  this._tileWidth = 0;
  this._tileHeight = 0;

  this._errorEvent = new Event();

  this._ready = false;

  let credit = options.credit;
  if (typeof credit === "string") {
    credit = new Credit(credit);
  }
  this._credit = credit;

  const that = this;
  let error;

  function success(image) {
    that._image = image;
    that._tileWidth = image.width;
    that._tileHeight = image.height;
    that._ready = true;
    TileProviderError.reportSuccess(that._errorEvent);
    return Promise.resolve(true);
  }

  function failure(e) {
    const message = `Failed to load image ${resource.url}.`;
    error = TileProviderError.reportError(
      error,
      that,
      that._errorEvent,
      message,
      0,
      0,
      0
    );
    if (error.retry) {
      return doRequest();
    }
    return Promise.reject(new RuntimeError(message));
  }

  function doRequest() {
    return ImageryProvider.loadImage(null, resource)
      .then(success)
      .catch(failure);
  }

  this._readyPromise = doRequest();
}

Object.defineProperties(SingleTileImageryProvider.prototype, {
  /**
   * Gets the URL of the single, top-level imagery tile.
   * @memberof SingleTileImageryProvider.prototype
   * @type {String}
   * @readonly
   */
  url: {
    get: function () {
      return this._resource.url;
    },
  },

  /**
   * Gets the proxy used by this provider.
   * @memberof SingleTileImageryProvider.prototype
   * @type {Proxy}
   * @readonly
   */
  proxy: {
    get: function () {
      return this._resource.proxy;
    },
  },

  /**
   * Gets the width of each tile, in pixels. This function should
   * not be called before {@link SingleTileImageryProvider#ready} returns true.
   * @memberof SingleTileImageryProvider.prototype
   * @type {Number}
   * @readonly
   */
  tileWidth: {
    get: function () {
      //>>includeStart('debug', pragmas.debug);
      if (!this._ready) {
        throw new DeveloperError(
          "tileWidth must not be called before the imagery provider is ready."
        );
      }
      //>>includeEnd('debug');

      return this._tileWidth;
    },
  },

  /**
   * Gets the height of each tile, in pixels.  This function should
   * not be called before {@link SingleTileImageryProvider#ready} returns true.
   * @memberof SingleTileImageryProvider.prototype
   * @type {Number}
   * @readonly
   */
  tileHeight: {
    get: function () {
      //>>includeStart('debug', pragmas.debug);
      if (!this._ready) {
        throw new DeveloperError(
          "tileHeight must not be called before the imagery provider is ready."
        );
      }
      //>>includeEnd('debug');

      return this._tileHeight;
    },
  },

  /**
   * Gets the maximum level-of-detail that can be requested.  This function should
   * not be called before {@link SingleTileImageryProvider#ready} returns true.
   * @memberof SingleTileImageryProvider.prototype
   * @type {Number|undefined}
   * @readonly
   */
  maximumLevel: {
    get: function () {
      //>>includeStart('debug', pragmas.debug);
      if (!this._ready) {
        throw new DeveloperError(
          "maximumLevel must not be called before the imagery provider is ready."
        );
      }
      //>>includeEnd('debug');

      return 0;
    },
  },

  /**
   * Gets the minimum level-of-detail that can be requested.  This function should
   * not be called before {@link SingleTileImageryProvider#ready} returns true.
   * @memberof SingleTileImageryProvider.prototype
   * @type {Number}
   * @readonly
   */
  minimumLevel: {
    get: function () {
      //>>includeStart('debug', pragmas.debug);
      if (!this._ready) {
        throw new DeveloperError(
          "minimumLevel must not be called before the imagery provider is ready."
        );
      }
      //>>includeEnd('debug');

      return 0;
    },
  },

  /**
   * Gets the tiling scheme used by this provider.  This function should
   * not be called before {@link SingleTileImageryProvider#ready} returns true.
   * @memberof SingleTileImageryProvider.prototype
   * @type {TilingScheme}
   * @readonly
   */
  tilingScheme: {
    get: function () {
      //>>includeStart('debug', pragmas.debug);
      if (!this._ready) {
        throw new DeveloperError(
          "tilingScheme must not be called before the imagery provider is ready."
        );
      }
      //>>includeEnd('debug');

      return this._tilingScheme;
    },
  },

  /**
   * Gets the rectangle, in radians, of the imagery provided by this instance.  This function should
   * not be called before {@link SingleTileImageryProvider#ready} returns true.
   * @memberof SingleTileImageryProvider.prototype
   * @type {Rectangle}
   * @readonly
   */
  rectangle: {
    get: function () {
      return this._tilingScheme.rectangle;
    },
  },

  /**
   * Gets the tile discard policy.  If not undefined, the discard policy is responsible
   * for filtering out "missing" tiles via its shouldDiscardImage function.  If this function
   * returns undefined, no tiles are filtered.  This function should
   * not be called before {@link SingleTileImageryProvider#ready} returns true.
   * @memberof SingleTileImageryProvider.prototype
   * @type {TileDiscardPolicy}
   * @readonly
   */
  tileDiscardPolicy: {
    get: function () {
      //>>includeStart('debug', pragmas.debug);
      if (!this._ready) {
        throw new DeveloperError(
          "tileDiscardPolicy must not be called before the imagery provider is ready."
        );
      }
      //>>includeEnd('debug');

      return undefined;
    },
  },

  /**
   * Gets an event that is raised when the imagery provider encounters an asynchronous error.  By subscribing
   * to the event, you will be notified of the error and can potentially recover from it.  Event listeners
   * are passed an instance of {@link TileProviderError}.
   * @memberof SingleTileImageryProvider.prototype
   * @type {Event}
   * @readonly
   */
  errorEvent: {
    get: function () {
      return this._errorEvent;
    },
  },

  /**
   * Gets a value indicating whether or not the provider is ready for use.
   * @memberof SingleTileImageryProvider.prototype
   * @type {Boolean}
   * @readonly
   */
  ready: {
    get: function () {
      return this._ready;
    },
  },

  /**
   * Gets a promise that resolves to true when the provider is ready for use.
   * @memberof SingleTileImageryProvider.prototype
   * @type {Promise.<Boolean>}
   * @readonly
   */
  readyPromise: {
    get: function () {
      return this._readyPromise;
    },
  },

  /**
   * Gets the credit to display when this imagery provider is active.  Typically this is used to credit
   * the source of the imagery.  This function should not be called before {@link SingleTileImageryProvider#ready} returns true.
   * @memberof SingleTileImageryProvider.prototype
   * @type {Credit}
   * @readonly
   */
  credit: {
    get: function () {
      return this._credit;
    },
  },

  /**
   * Gets a value indicating whether or not the images provided by this imagery provider
   * include an alpha channel.  If this property is false, an alpha channel, if present, will
   * be ignored.  If this property is true, any images without an alpha channel will be treated
   * as if their alpha is 1.0 everywhere.  When this property is false, memory usage
   * and texture upload time are reduced.
   * @memberof SingleTileImageryProvider.prototype
   * @type {Boolean}
   * @readonly
   */
  hasAlphaChannel: {
    get: function () {
      return true;
    },
  },
});

/**
 * Gets the credits to be displayed when a given tile is displayed.
 *
 * @param {Number} x The tile X coordinate.
 * @param {Number} y The tile Y coordinate.
 * @param {Number} level The tile level;
 * @returns {Credit[]} The credits to be displayed when the tile is displayed.
 *
 * @exception {DeveloperError} <code>getTileCredits</code> must not be called before the imagery provider is ready.
 */
SingleTileImageryProvider.prototype.getTileCredits = function (x, y, level) {
  return undefined;
};

/**
 * Requests the image for a given tile.  This function should
 * not be called before {@link SingleTileImageryProvider#ready} returns true.
 *
 * @param {Number} x The tile X coordinate.
 * @param {Number} y The tile Y coordinate.
 * @param {Number} level The tile level.
 * @param {Request} [request] The request object. Intended for internal use only.
 * @returns {Promise.<ImageryTypes>|undefined} The resolved image
 *
 * @exception {DeveloperError} <code>requestImage</code> must not be called before the imagery provider is ready.
 */
SingleTileImageryProvider.prototype.requestImage = function (
  x,
  y,
  level,
  request
) {
  //>>includeStart('debug', pragmas.debug);
  if (!this._ready) {
    throw new DeveloperError(
      "requestImage must not be called before the imagery provider is ready."
    );
  }
  //>>includeEnd('debug');

  if (!defined(this._image)) {
    return;
  }

  return Promise.resolve(this._image);
};

/**
 * Picking features is not currently supported by this imagery provider, so this function simply returns
 * undefined.
 *
 * @param {Number} x The tile X coordinate.
 * @param {Number} y The tile Y coordinate.
 * @param {Number} level The tile level.
 * @param {Number} longitude The longitude at which to pick features.
 * @param {Number} latitude  The latitude at which to pick features.
 * @return {undefined} Undefined since picking is not supported.
 */
SingleTileImageryProvider.prototype.pickFeatures = function (
  x,
  y,
  level,
  longitude,
  latitude
) {
  return undefined;
};
export default SingleTileImageryProvider;