Files
openlayers/src/ol/source/XYZ.js
2021-07-09 11:32:26 +01:00

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5.1 KiB
JavaScript

/**
* @module ol/source/XYZ
*/
import TileImage from './TileImage.js';
import {createXYZ, extentFromProjection} from '../tilegrid.js';
/**
* @typedef {Object} Options
* @property {import("./Source.js").AttributionLike} [attributions] Attributions.
* @property {boolean} [attributionsCollapsible=true] Attributions are collapsible.
* @property {number} [cacheSize] Initial tile cache size. Will auto-grow to hold at least the number of tiles in the viewport.
* @property {null|string} [crossOrigin] The `crossOrigin` attribute for loaded images. Note that
* you must provide a `crossOrigin` value if you want to access pixel data with the Canvas renderer.
* See https://developer.mozilla.org/en-US/docs/Web/HTML/CORS_enabled_image for more detail.
* @property {boolean} [imageSmoothing=true] Enable image smoothing.
* @property {boolean} [opaque=false] Whether the layer is opaque.
* @property {import("../proj.js").ProjectionLike} [projection='EPSG:3857'] Projection.
* @property {number} [reprojectionErrorThreshold=0.5] Maximum allowed reprojection error (in pixels).
* Higher values can increase reprojection performance, but decrease precision.
* @property {number} [maxZoom=42] Optional max zoom level. Not used if `tileGrid` is provided.
* @property {number} [minZoom=0] Optional min zoom level. Not used if `tileGrid` is provided.
* @property {number} [maxResolution] Optional tile grid resolution at level zero. Not used if `tileGrid` is provided.
* @property {import("../tilegrid/TileGrid.js").default} [tileGrid] Tile grid.
* @property {import("../Tile.js").LoadFunction} [tileLoadFunction] Optional function to load a tile given a URL. The default is
* ```js
* function(imageTile, src) {
* imageTile.getImage().src = src;
* };
* ```
* @property {number} [tilePixelRatio=1] The pixel ratio used by the tile service.
* For example, if the tile service advertizes 256px by 256px tiles but actually sends 512px
* by 512px images (for retina/hidpi devices) then `tilePixelRatio`
* should be set to `2`.
* @property {number|import("../size.js").Size} [tileSize=[256, 256]] The tile size used by the tile service.
* Not used if `tileGrid` is provided.
* @property {import("../Tile.js").UrlFunction} [tileUrlFunction] Optional function to get
* tile URL given a tile coordinate and the projection.
* Required if `url` or `urls` are not provided.
* @property {string} [url] URL template. Must include `{x}`, `{y}` or `{-y}`,
* and `{z}` placeholders. A `{?-?}` template pattern, for example `subdomain{a-f}.domain.com`,
* may be used instead of defining each one separately in the `urls` option.
* @property {Array<string>} [urls] An array of URL templates.
* @property {boolean} [wrapX=true] Whether to wrap the world horizontally.
* @property {number} [transition=250] Duration of the opacity transition for rendering.
* To disable the opacity transition, pass `transition: 0`.
* @property {number|import("../array.js").NearestDirectionFunction} [zDirection=0]
* Choose whether to use tiles with a higher or lower zoom level when between integer
* zoom levels. See {@link module:ol/tilegrid/TileGrid~TileGrid#getZForResolution}.
*/
/**
* @classdesc
* Layer source for tile data with URLs in a set XYZ format that are
* defined in a URL template. By default, this follows the widely-used
* Google grid where `x` 0 and `y` 0 are in the top left. Grids like
* TMS where `x` 0 and `y` 0 are in the bottom left can be used by
* using the `{-y}` placeholder in the URL template, so long as the
* source does not have a custom tile grid. In this case
* a `tileUrlFunction` can be used, such as:
* ```js
* tileUrlFunction: function(coordinate) {
* return 'http://mapserver.com/' + coordinate[0] + '/' +
* coordinate[1] + '/' + (-coordinate[2] - 1) + '.png';
* }
* ```
* @api
*/
class XYZ extends TileImage {
/**
* @param {Options} [opt_options] XYZ options.
*/
constructor(opt_options) {
const options = opt_options || {};
const projection =
options.projection !== undefined ? options.projection : 'EPSG:3857';
const tileGrid =
options.tileGrid !== undefined
? options.tileGrid
: createXYZ({
extent: extentFromProjection(projection),
maxResolution: options.maxResolution,
maxZoom: options.maxZoom,
minZoom: options.minZoom,
tileSize: options.tileSize,
});
super({
attributions: options.attributions,
cacheSize: options.cacheSize,
crossOrigin: options.crossOrigin,
imageSmoothing: options.imageSmoothing,
opaque: options.opaque,
projection: projection,
reprojectionErrorThreshold: options.reprojectionErrorThreshold,
tileGrid: tileGrid,
tileLoadFunction: options.tileLoadFunction,
tilePixelRatio: options.tilePixelRatio,
tileUrlFunction: options.tileUrlFunction,
url: options.url,
urls: options.urls,
wrapX: options.wrapX !== undefined ? options.wrapX : true,
transition: options.transition,
attributionsCollapsible: options.attributionsCollapsible,
zDirection: options.zDirection,
});
}
}
export default XYZ;