/*global define*/
define([
'../Core/Credit',
'../Core/defaultValue',
'../Core/defined',
'../Core/defineProperties',
'../Core/DeveloperError',
'../Core/Event',
'../Core/Rectangle',
'../Core/WebMercatorTilingScheme',
'./ImageryProvider'
], function(
Credit,
defaultValue,
defined,
defineProperties,
DeveloperError,
Event,
Rectangle,
WebMercatorTilingScheme,
ImageryProvider) {
"use strict";
var trailingSlashRegex = /\/$/;
var defaultCredit = new Credit('MapQuest, Open Street Map and contributors, CC-BY-SA');
/**
* Provides tiled imagery hosted by OpenStreetMap or another provider of Slippy tiles. Please be aware
* that a default-constructed instance of this class will connect to OpenStreetMap's volunteer-run
* servers, so you must conform to their
* {@link http://wiki.openstreetmap.org/wiki/Tile_usage_policy|Tile Usage Policy}.
*
* @alias OpenStreetMapImageryProvider
* @constructor
*
* @param {Object} [options] Object with the following properties:
* @param {String} [options.url='//a.tile.openstreetmap.org'] The OpenStreetMap server url.
* @param {String} [options.fileExtension='png'] The file extension for images on the server.
* @param {Object} [options.proxy] A proxy to use for requests. This object is expected to have a getURL function which returns the proxied URL.
* @param {Rectangle} [options.rectangle=Rectangle.MAX_VALUE] The rectangle of the layer.
* @param {Number} [options.minimumLevel=0] The minimum level-of-detail supported by the imagery provider.
* @param {Number} [options.maximumLevel=18] The maximum level-of-detail supported by the imagery provider.
* @param {Credit|String} [options.credit='MapQuest, Open Street Map and contributors, CC-BY-SA'] A credit for the data source, which is displayed on the canvas.
*
* @see ArcGisMapServerImageryProvider
* @see BingMapsImageryProvider
* @see SingleTileImageryProvider
* @see TileMapServiceImageryProvider
* @see WebMapServiceImageryProvider
*
* @see {@link http://wiki.openstreetmap.org/wiki/Main_Page|OpenStreetMap Wiki}
* @see {@link http://www.w3.org/TR/cors/|Cross-Origin Resource Sharing}
*
* @example
* // OpenStreetMap tile provider
* var osm = new Cesium.OpenStreetMapImageryProvider({
* url : '//a.tile.openstreetmap.org/'
* });
*/
var OpenStreetMapImageryProvider = function OpenStreetMapImageryProvider(options) {
options = defaultValue(options, {});
var url = defaultValue(options.url, '//a.tile.openstreetmap.org/');
if (!trailingSlashRegex.test(url)) {
url = url + '/';
}
this._url = url;
this._fileExtension = defaultValue(options.fileExtension, 'png');
this._proxy = options.proxy;
this._tileDiscardPolicy = options.tileDiscardPolicy;
this._tilingScheme = new WebMercatorTilingScheme();
this._tileWidth = 256;
this._tileHeight = 256;
this._minimumLevel = defaultValue(options.minimumLevel, 0);
this._maximumLevel = defaultValue(options.maximumLevel, 18);
this._rectangle = defaultValue(options.rectangle, this._tilingScheme.rectangle);
// Check the number of tiles at the minimum level. If it's more than four,
// throw an exception, because starting at the higher minimum
// level will cause too many tiles to be downloaded and rendered.
var swTile = this._tilingScheme.positionToTileXY(Rectangle.southwest(this._rectangle), this._minimumLevel);
var neTile = this._tilingScheme.positionToTileXY(Rectangle.northeast(this._rectangle), this._minimumLevel);
var tileCount = (Math.abs(neTile.x - swTile.x) + 1) * (Math.abs(neTile.y - swTile.y) + 1);
if (tileCount > 4) {
throw new DeveloperError('The imagery provider\'s rectangle and minimumLevel indicate that there are ' + tileCount + ' tiles at the minimum level. Imagery providers with more than four tiles at the minimum level are not supported.');
}
this._errorEvent = new Event();
this._ready = true;
var credit = defaultValue(options.credit, defaultCredit);
if (typeof credit === 'string') {
credit = new Credit(credit);
}
this._credit = credit;
};
function buildImageUrl(imageryProvider, x, y, level) {
var url = imageryProvider._url + level + '/' + x + '/' + y + '.' + imageryProvider._fileExtension;
var proxy = imageryProvider._proxy;
if (defined(proxy)) {
url = proxy.getURL(url);
}
return url;
}
defineProperties(OpenStreetMapImageryProvider.prototype, {
/**
* Gets the URL of the service hosting the imagery.
* @memberof OpenStreetMapImageryProvider.prototype
* @type {String}
* @readonly
*/
url : {
get : function() {
return this._url;
}
},
/**
* Gets the proxy used by this provider.
* @memberof OpenStreetMapImageryProvider.prototype
* @type {Proxy}
* @readonly
*/
proxy : {
get : function() {
return this._proxy;
}
},
/**
* Gets the width of each tile, in pixels. This function should
* not be called before {@link OpenStreetMapImageryProvider#ready} returns true.
* @memberof OpenStreetMapImageryProvider.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 OpenStreetMapImageryProvider#ready} returns true.
* @memberof OpenStreetMapImageryProvider.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 OpenStreetMapImageryProvider#ready} returns true.
* @memberof OpenStreetMapImageryProvider.prototype
* @type {Number}
* @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 this._maximumLevel;
}
},
/**
* Gets the minimum level-of-detail that can be requested. This function should
* not be called before {@link OpenStreetMapImageryProvider#ready} returns true.
* @memberof OpenStreetMapImageryProvider.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 this._minimumLevel;
}
},
/**
* Gets the tiling scheme used by this provider. This function should
* not be called before {@link OpenStreetMapImageryProvider#ready} returns true.
* @memberof OpenStreetMapImageryProvider.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 OpenStreetMapImageryProvider#ready} returns true.
* @memberof OpenStreetMapImageryProvider.prototype
* @type {Rectangle}
* @readonly
*/
rectangle : {
get : function() {
//>>includeStart('debug', pragmas.debug);
if (!this._ready) {
throw new DeveloperError('rectangle must not be called before the imagery provider is ready.');
}
//>>includeEnd('debug');
return this._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 OpenStreetMapImageryProvider#ready} returns true.
* @memberof OpenStreetMapImageryProvider.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 this._tileDiscardPolicy;
}
},
/**
* 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 OpenStreetMapImageryProvider.prototype
* @type {Event}
* @readonly
*/
errorEvent : {
get : function() {
return this._errorEvent;
}
},
/**
* Gets a value indicating whether or not the provider is ready for use.
* @memberof OpenStreetMapImageryProvider.prototype
* @type {Boolean}
* @readonly
*/
ready : {
get : function() {
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 OpenStreetMapImageryProvider#ready} returns true.
* @memberof OpenStreetMapImageryProvider.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 OpenStreetMapImageryProvider.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.
*/
OpenStreetMapImageryProvider.prototype.getTileCredits = function(x, y, level) {
return undefined;
};
/**
* Requests the image for a given tile. This function should
* not be called before {@link OpenStreetMapImageryProvider#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.
*/
OpenStreetMapImageryProvider.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');
var url = buildImageUrl(this, x, y, level);
return ImageryProvider.loadImage(this, url);
};
/**
* 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.
*/
OpenStreetMapImageryProvider.prototype.pickFeatures = function() {
return undefined;
};
return OpenStreetMapImageryProvider;
});