Files
openlayers/src/ol/source/Stamen.js
2018-04-25 08:21:11 +02:00

149 lines
3.4 KiB
JavaScript

/**
* @module ol/source/Stamen
*/
import {inherits} from '../index.js';
import {ATTRIBUTION as OSM_ATTRIBUTION} from '../source/OSM.js';
import XYZ from '../source/XYZ.js';
/**
* @const
* @type {Array.<string>}
*/
const ATTRIBUTIONS = [
'Map tiles by <a href="https://stamen.com/">Stamen Design</a>, ' +
'under <a href="https://creativecommons.org/licenses/by/3.0/">CC BY' +
' 3.0</a>.',
OSM_ATTRIBUTION
];
/**
* @type {Object.<string, {extension: string, opaque: boolean}>}
*/
const LayerConfig = {
'terrain': {
extension: 'jpg',
opaque: true
},
'terrain-background': {
extension: 'jpg',
opaque: true
},
'terrain-labels': {
extension: 'png',
opaque: false
},
'terrain-lines': {
extension: 'png',
opaque: false
},
'toner-background': {
extension: 'png',
opaque: true
},
'toner': {
extension: 'png',
opaque: true
},
'toner-hybrid': {
extension: 'png',
opaque: false
},
'toner-labels': {
extension: 'png',
opaque: false
},
'toner-lines': {
extension: 'png',
opaque: false
},
'toner-lite': {
extension: 'png',
opaque: true
},
'watercolor': {
extension: 'jpg',
opaque: true
}
};
/**
* @type {Object.<string, {minZoom: number, maxZoom: number}>}
*/
const ProviderConfig = {
'terrain': {
minZoom: 4,
maxZoom: 18
},
'toner': {
minZoom: 0,
maxZoom: 20
},
'watercolor': {
minZoom: 1,
maxZoom: 16
}
};
/**
* @typedef {Object} Options
* @property {number} [cacheSize=2048] Cache size.
* @property {string} [layer] Layer.
* @property {number} [minZoom] Minimum zoom.
* @property {number} [maxZoom] Maximum zoom.
* @property {boolean} [opaque] Whether the layer is opaque.
* @property {boolean} [reprojectionErrorThreshold=0.5] Maximum allowed reprojection error (in pixels).
* Higher values can increase reprojection performance, but decrease precision.
* @property {module:ol/Tile~LoadFunction} [tileLoadFunction]
* Optional function to load a tile given a URL. The default is
* ```js
* function(imageTile, src) {
* imageTile.getImage().src = src;
* };
* ```
* @property {string} [url] URL template. Must include `{x}`, `{y}` or `{-y}`, and `{z}` placeholders.
* @property {boolean} [wrapX=true] Whether to wrap the world horizontally.
*/
/**
* @classdesc
* Layer source for the Stamen tile server.
*
* @constructor
* @extends {module:ol/source/XYZ~XYZ}
* @param {module:ol/source/Stamen~Options=} options Stamen options.
* @api
*/
const Stamen = function(options) {
const i = options.layer.indexOf('-');
const provider = i == -1 ? options.layer : options.layer.slice(0, i);
const providerConfig = ProviderConfig[provider];
const layerConfig = LayerConfig[options.layer];
const url = options.url !== undefined ? options.url :
'https://stamen-tiles-{a-d}.a.ssl.fastly.net/' + options.layer +
'/{z}/{x}/{y}.' + layerConfig.extension;
XYZ.call(this, {
attributions: ATTRIBUTIONS,
cacheSize: options.cacheSize,
crossOrigin: 'anonymous',
maxZoom: options.maxZoom != undefined ? options.maxZoom : providerConfig.maxZoom,
minZoom: options.minZoom != undefined ? options.minZoom : providerConfig.minZoom,
opaque: layerConfig.opaque,
reprojectionErrorThreshold: options.reprojectionErrorThreshold,
tileLoadFunction: options.tileLoadFunction,
url: url,
wrapX: options.wrapX
});
};
inherits(Stamen, XYZ);
export default Stamen;