openlayers
Version:
Build tools and sources for developing OpenLayers based mapping applications
164 lines (138 loc) • 4.18 kB
JavaScript
// FIXME check order of async callbacks
/**
* @see http://mapbox.com/developers/api/
*/
goog.provide('ol.source.TileJSON');
goog.require('ol');
goog.require('ol.Attribution');
goog.require('ol.TileUrlFunction');
goog.require('ol.extent');
goog.require('ol.net');
goog.require('ol.proj');
goog.require('ol.source.State');
goog.require('ol.source.TileImage');
goog.require('ol.tilegrid');
/**
* @classdesc
* Layer source for tile data in TileJSON format.
*
* @constructor
* @extends {ol.source.TileImage}
* @param {olx.source.TileJSONOptions} options TileJSON options.
* @api stable
*/
ol.source.TileJSON = function(options) {
/**
* @type {TileJSON}
* @private
*/
this.tileJSON_ = null;
ol.source.TileImage.call(this, {
attributions: options.attributions,
cacheSize: options.cacheSize,
crossOrigin: options.crossOrigin,
projection: ol.proj.get('EPSG:3857'),
reprojectionErrorThreshold: options.reprojectionErrorThreshold,
state: ol.source.State.LOADING,
tileLoadFunction: options.tileLoadFunction,
wrapX: options.wrapX !== undefined ? options.wrapX : true
});
if (options.jsonp) {
ol.net.jsonp(options.url, this.handleTileJSONResponse.bind(this),
this.handleTileJSONError.bind(this));
} else {
var client = new XMLHttpRequest();
client.addEventListener('load', this.onXHRLoad_.bind(this));
client.addEventListener('error', this.onXHRError_.bind(this));
client.open('GET', options.url);
client.send();
}
};
ol.inherits(ol.source.TileJSON, ol.source.TileImage);
/**
* @private
* @param {Event} event The load event.
*/
ol.source.TileJSON.prototype.onXHRLoad_ = function(event) {
var client = /** @type {XMLHttpRequest} */ (event.target);
// status will be 0 for file:// urls
if (!client.status || client.status >= 200 && client.status < 300) {
var response;
try {
response = /** @type {TileJSON} */(JSON.parse(client.responseText));
} catch (err) {
this.handleTileJSONError();
return;
}
this.handleTileJSONResponse(response);
} else {
this.handleTileJSONError();
}
};
/**
* @private
* @param {Event} event The error event.
*/
ol.source.TileJSON.prototype.onXHRError_ = function(event) {
this.handleTileJSONError();
};
/**
* @return {TileJSON} The tilejson object.
* @api
*/
ol.source.TileJSON.prototype.getTileJSON = function() {
return this.tileJSON_;
};
/**
* @protected
* @param {TileJSON} tileJSON Tile JSON.
*/
ol.source.TileJSON.prototype.handleTileJSONResponse = function(tileJSON) {
var epsg4326Projection = ol.proj.get('EPSG:4326');
var sourceProjection = this.getProjection();
var extent;
if (tileJSON.bounds !== undefined) {
var transform = ol.proj.getTransformFromProjections(
epsg4326Projection, sourceProjection);
extent = ol.extent.applyTransform(tileJSON.bounds, transform);
}
if (tileJSON.scheme !== undefined) {
ol.DEBUG && console.assert(tileJSON.scheme == 'xyz', 'tileJSON-scheme is "xyz"');
}
var minZoom = tileJSON.minzoom || 0;
var maxZoom = tileJSON.maxzoom || 22;
var tileGrid = ol.tilegrid.createXYZ({
extent: ol.tilegrid.extentFromProjection(sourceProjection),
maxZoom: maxZoom,
minZoom: minZoom
});
this.tileGrid = tileGrid;
this.tileUrlFunction =
ol.TileUrlFunction.createFromTemplates(tileJSON.tiles, tileGrid);
if (tileJSON.attribution !== undefined && !this.getAttributions()) {
var attributionExtent = extent !== undefined ?
extent : epsg4326Projection.getExtent();
/** @type {Object.<string, Array.<ol.TileRange>>} */
var tileRanges = {};
var z, zKey;
for (z = minZoom; z <= maxZoom; ++z) {
zKey = z.toString();
tileRanges[zKey] =
[tileGrid.getTileRangeForExtentAndZ(attributionExtent, z)];
}
this.setAttributions([
new ol.Attribution({
html: tileJSON.attribution,
tileRanges: tileRanges
})
]);
}
this.tileJSON_ = tileJSON;
this.setState(ol.source.State.READY);
};
/**
* @protected
*/
ol.source.TileJSON.prototype.handleTileJSONError = function() {
this.setState(ol.source.State.ERROR);
};