text: 'use strict';
  
  var CanvasImageryProvider = (function CanvasImageryProviderClosure() {
  
          /**
           * Provides a Single Canvas imagery tile.  The image is assumed to use a
           * {@link GeographicTilingScheme}.
           *
           * @alias CanvasImageryProvider
           * @constructor
           *
           * @param {canvas} Canvas for the tile.
           * @param {Object} options Object with the following properties:
           * @param {Credit|String} [options.credit] A credit for the data source, which is displayed on the canvas.
       *
           * @see ArcGisMapServerImageryProvider
           * @see BingMapsImageryProvider
           * @see GoogleEarthImageryProvider
           * @see OpenStreetMapImageryProvider
           * @see TileMapServiceImageryProvider
           * @see WebMapServiceImageryProvider
           */
          var CanvasImageryProvider = function(canvas, options) {
              if (options === undefined) {
                  options = {};
          }
          
                  //>>includeStart('debug', pragmas.debug);
                  if (canvas === undefined) {
                          throw new DeveloperError('canvas is required.');
                  }
                  //>>includeEnd('debug');
  
          this._canvas = canvas;
  
                  this._errorEvent = new Event('CanvasImageryProviderStatus');
  
                  this._ready = false;
          
                  var credit = options.credit;
                  if (typeof credit === 'string') {
                          credit = new Credit(credit);
                  }
                  this._credit = credit;
          };
  
          CanvasImageryProvider.prototype = {
                  /**
                   * Gets the width of each tile, in pixels. This function should
                   * not be called before {@link CanvasImageryProvider#ready} returns true.
                   * @memberof CanvasImageryProvider.prototype
                   * @type {Number}
                   * @readonly
                   */
                  get tileWidth() {
                          //>>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._canvas.width;
                  },
  
                  /**
                   * Gets the height of each tile, in pixels.  This function should
                   * not be called before {@link CanvasImageryProvider#ready} returns true.
                   * @memberof CanvasImageryProvider.prototype
                   * @type {Number}
                   * @readonly
                   */
                  get tileHeight() {
                          //>>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._canvas.height;
                  },
  
                  /**
                   * Gets the maximum level-of-detail that can be requested.  This function should
                   * not be called before {@link CanvasImageryProvider#ready} returns true.
                   * @memberof CanvasImageryProvider.prototype
                   * @type {Number}
                   * @readonly
                   */
                  get maximumLevel() {
                          //>>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 CanvasImageryProvider#ready} returns true.
                   * @memberof CanvasImageryProvider.prototype
                   * @type {Number}
                   * @readonly
                   */
                  get minimumLevel() {
                          //>>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 CanvasImageryProvider#ready} returns true.
                   * @memberof CanvasImageryProvider.prototype
                   * @type {TilingScheme}
                   * @readonly
                   */
                  get tilingScheme() {
                          //>>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 CanvasImageryProvider#ready} returns true.
                   * @memberof CanvasImageryProvider.prototype
                   * @type {Rectangle}
                   * @readonly
                   */
                  get rectangle() {
                          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 CanvasImageryProvider#ready} returns true.
                   * @memberof CanvasImageryProvider.prototype
                   * @type {TileDiscardPolicy}
                   * @readonly
                   */
                  get tileDiscardPolicy() {
                          //>>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 CanvasImageryProvider.prototype
                   * @type {Event}
                   * @readonly
                   */
                  get errorEvent() {
                          return this._errorEvent;
                  },
  
                  /**
                   * Gets a value indicating whether or not the provider is ready for use.
                   * @memberof CanvasImageryProvider.prototype
                   * @type {Boolean}
                   * @readonly
                   */
                  get ready() {
                          return this._ready;
                  },
  
                  /**
                   * 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 CanvasImageryProvider#ready} returns true.
                   * @memberof CanvasImageryProvider.prototype
                   * @type {Credit}
                   * @readonly
                   */
                  get credit() {
                          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 CanvasImageryProvider.prototype
                   * @type {Boolean}
                   * @readonly
                   */
                  get hasAlphaChannel() {
                          return true;
                  }
          };
      
      CanvasImageryProvider.prototype.setRectangle =
          function setRectangle(rectangle) {
          
          this._tilingScheme = new Cesium.GeographicTilingScheme({
              rectangle: rectangle,
              numberOfLevelZeroTilesX: 1,
              numberOfLevelZeroTilesY: 1
          });
          
          if (!this._ready) {
              this._ready = true;
              Cesium.TileProviderError.handleSuccess(this._errorEvent);
          }
      },
      
      CanvasImageryProvider.prototype.getTileWidth = function getTileWidth() {
          return this.tileWidth;
      };
      
      CanvasImageryProvider.prototype.getTileHeight = function getTileHeight() {
          return this.tileHeight;
      };
      
      CanvasImageryProvider.prototype.getMaximumLevel = function getMaximumLevel() {
          return this.maximumLevel;
      };
      
      CanvasImageryProvider.prototype.getMinimumLevel = function getMinimumLevel() {
          return this.minimumLevel;
      };
      
      CanvasImageryProvider.prototype.isReady = function isReady() {
          return this.ready;
      };
      
      CanvasImageryProvider.prototype.getCredit = function getCredit() {
          return this.credit;
      };
      
      CanvasImageryProvider.prototype.getRectangle = function getRectangle() {
          return this.tilingScheme.rectangle;
      };
  
      CanvasImageryProvider.prototype.getTilingScheme = function getTilingScheme() {
          return this.tilingScheme;
      };
  
      CanvasImageryProvider.prototype.getTileDiscardPolicy = function getTileDiscardPolicy() {
          return this.tileDiscardPolicy;
      };
      
      CanvasImageryProvider.prototype.getErrorEvent = function getErrorEvent() {
          return this.errorEvent;
      };
      
      CanvasImageryProvider.prototype.getHasAlphaChannel = function getHasAlphaChannel() {
          return this.hasAlphaChannel;
      };
      
          /**
           * 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.
           */
          CanvasImageryProvider.prototype.getTileCredits = function(x, y, level) {
                  return undefined;
          };
  
          /**
           * Requests the image for a given tile.  This function should
           * not be called before {@link CanvasImageryProvider#ready} returns true.
           *
           * @param {Number} x The tile X coordinate.
           * @param {Number} y The tile Y coordinate.
           * @param {Number} level The tile level.
           * @returns {Promise} A promise for the image that will resolve when the image is available, or
           *          undefined if there are too many active requests to the server, and the request
           *          should be retried later.  The resolved image may be either an
           *          Image or a Canvas DOM object.
           *
           * @exception {DeveloperError} <code>requestImage</code> must not be called before the imagery provider is ready.
           */
          CanvasImageryProvider.prototype.requestImage = function(x, y, level) {
                  //>>includeStart('debug', pragmas.debug);
                  if (!this._ready) {
                          throw new DeveloperError('requestImage must not be called before the imagery provider is ready.');
                  }
                  //>>includeEnd('debug');
          
          return this._canvas;
          };
  
          /**
           * 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 {Promise} A promise for the picked features that will resolve when the asynchronous
           *                   picking completes.  The resolved value is an array of {@link ImageryLayerFeatureInfo}
           *                   instances.  The array may be empty if no features are found at the given location.
           *                   It may also be undefined if picking is not supported.
           */
          CanvasImageryProvider.prototype.pickFeatures = function() {
                  return undefined;
          };
      
          return CanvasImageryProvider;
  })();