Files
openlayers/src/ol/source/tilejsonsource.js

161 lines
3.8 KiB
JavaScript

// FIXME add some error checking
// FIXME check order of async callbacks
// FIXME use minzoom when supported
/**
* @see http://mapbox.com/developers/api/
*/
goog.provide('ol.source.TileJSON');
goog.provide('ol.tilejson');
goog.require('goog.asserts');
goog.require('goog.net.jsloader');
goog.require('ol.Attribution');
goog.require('ol.Extent');
goog.require('ol.TileCoord');
goog.require('ol.TileRange');
goog.require('ol.TileUrlFunction');
goog.require('ol.projection');
goog.require('ol.source.ImageTileSource');
goog.require('ol.tilegrid.XYZ');
/**
* @typedef {{uri: string}}
*/
ol.source.TileJSONOptions;
/**
* @private
* @type {Array.<TileJSON>}
*/
ol.tilejson.grids_ = [];
/**
* @param {TileJSON} tileJSON Tile JSON.
*/
var grid = function(tileJSON) {
ol.tilejson.grids_.push(tileJSON);
};
goog.exportSymbol('grid', grid);
/**
* @constructor
* @extends {ol.source.ImageTileSource}
* @param {ol.source.TileJSONOptions} tileJsonOptions TileJSON optios.
*/
ol.source.TileJSON = function(tileJsonOptions) {
goog.base(this, {
projection: ol.projection.getFromCode('EPSG:3857')
});
/**
* @private
* @type {boolean}
*/
this.ready_ = false;
/**
* @private
* @type {!goog.async.Deferred}
*/
this.deferred_ =
goog.net.jsloader.load(tileJsonOptions.uri, {cleanupWhenDone: true});
this.deferred_.addCallback(this.handleTileJSONResponse, this);
};
goog.inherits(ol.source.TileJSON, ol.source.ImageTileSource);
/**
* @protected
*/
ol.source.TileJSON.prototype.handleTileJSONResponse = function() {
var tileJSON = ol.tilejson.grids_.pop();
var epsg4326Projection = ol.projection.getFromCode('EPSG:4326');
var epsg4326Extent, extent;
if (goog.isDef(tileJSON.bounds)) {
var bounds = tileJSON.bounds;
epsg4326Extent = new ol.Extent(
bounds[0], bounds[1], bounds[2], bounds[3]);
extent = epsg4326Extent.transform(
ol.projection.getTransform(epsg4326Projection, this.getProjection()));
this.setExtent(extent);
} else {
epsg4326Extent = null;
extent = null;
}
var scheme = goog.isDef(tileJSON.scheme) || 'xyz';
if (goog.isDef(tileJSON.scheme)) {
goog.asserts.assert(tileJSON.scheme == 'xyz');
}
var minZoom = tileJSON.minzoom || 0;
goog.asserts.assert(minZoom === 0); // FIXME
var maxZoom = tileJSON.maxzoom || 22;
var tileGrid = new ol.tilegrid.XYZ({
maxZoom: maxZoom
});
this.tileGrid = tileGrid;
this.tileUrlFunction = ol.TileUrlFunction.withTileCoordTransform(
function(tileCoord) {
if (tileCoord.z < minZoom || maxZoom < tileCoord.z) {
return null;
}
var n = 1 << tileCoord.z;
var y = -tileCoord.y - 1;
if (y < 0 || n <= y) {
return null;
}
var x = goog.math.modulo(tileCoord.x, n);
if (!goog.isNull(extent)) {
var tileExtent = tileGrid.getTileCoordExtent(
new ol.TileCoord(tileCoord.z, x, tileCoord.y));
if (!tileExtent.intersects(extent)) {
return null;
}
}
return new ol.TileCoord(tileCoord.z, x, y);
},
ol.TileUrlFunction.createFromTemplates(tileJSON.tiles));
if (goog.isDef(tileJSON.attribution)) {
var attributionExtent = goog.isNull(extent) ?
epsg4326Projection.getExtent() : extent;
/** @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(tileJSON.attribution, tileRanges)
]);
}
this.ready_ = true;
this.dispatchLoadEvent();
};
/**
* @inheritDoc
*/
ol.source.TileJSON.prototype.isReady = function() {
return this.ready_;
};