Added ol.source.TileUTFGrid

2014-09-25 19:19:55 +02:00
parent d62ad47338
commit 794c7950c8
2 changed files with 233 additions and 0 deletions
--- a/src/ol/source/tileutfgridsource.js
+++ b/src/ol/source/tileutfgridsource.js
@@ -0,0 +1,226 @@
+goog.provide('ol.source.TileUTFGrid');
+
+goog.require('goog.net.Jsonp');
+goog.require('ol.Attribution');
+goog.require('ol.Tile');
+goog.require('ol.TileState');
+goog.require('ol.TileUrlFunction');
+goog.require('ol.extent');
+goog.require('ol.proj');
+goog.require('ol.source.Tile');
+goog.require('ol.tilegrid.TileGrid');
+goog.require('ol.tilegrid.XYZ');
+
+
+
+/**
+ * @classdesc
+ * TODO: desc
+ * TODO: caching
+ * TODO: getTilePixelSize ?
+ *
+ * @constructor
+ * @extends {ol.source.Tile}
+ * @param {olx.source.TileUTFGridOptions} options Source options.
+ * @api
+ */
+ol.source.TileUTFGrid = function(options) {
+  goog.base(this, {
+    projection: ol.proj.get('EPSG:3857'),
+    state: ol.source.State.LOADING
+  });
+
+  /**
+   * @protected
+   * @type {ol.TileCache}
+   */
+  this.tileCache = new ol.TileCache();
+
+  var request = new goog.net.Jsonp(options.url);
+  request.send(undefined, goog.bind(this.handleTileJSONResponse, this));
+};
+goog.inherits(ol.source.TileUTFGrid, ol.source.Tile);
+
+
+/**
+ * @inheritDoc
+ */
+ol.source.TileUTFGrid.prototype.canExpireCache = function() {
+  return this.tileCache.canExpireCache();
+};
+
+
+/**
+ * @inheritDoc
+ */
+ol.source.TileUTFGrid.prototype.expireCache = function(usedTiles) {
+  this.tileCache.expireCache(usedTiles);
+};
+
+
+/**
+ * TODO: very similar to ol.source.TileJSON#handleTileJSONResponse
+ * @protected
+ * @param {TileJSON} tileJSON Tile JSON.
+ */
+ol.source.TileUTFGrid.prototype.handleTileJSONResponse = function(tileJSON) {
+
+  var epsg4326Projection = ol.proj.get('EPSG:4326');
+
+  var sourceProjection = this.getProjection();
+  var extent;
+  if (goog.isDef(tileJSON.bounds)) {
+    var transform = ol.proj.getTransformFromProjections(
+        epsg4326Projection, sourceProjection);
+    extent = ol.extent.applyTransform(tileJSON.bounds, transform);
+  }
+
+  if (goog.isDef(tileJSON.scheme)) {
+    goog.asserts.assert(tileJSON.scheme == 'xyz');
+  }
+  var minZoom = tileJSON.minzoom || 0;
+  var maxZoom = tileJSON.maxzoom || 22;
+  var tileGrid = new ol.tilegrid.XYZ({
+    extent: ol.tilegrid.extentFromProjection(sourceProjection),
+    maxZoom: maxZoom,
+    minZoom: minZoom
+  });
+  this.tileGrid = tileGrid;
+
+  this.tileUrlFunction = ol.TileUrlFunction.withTileCoordTransform(
+      tileGrid.createTileCoordTransform({
+        extent: extent
+      }),
+      ol.TileUrlFunction.createFromTemplates(tileJSON.grids));
+
+  if (goog.isDef(tileJSON.attribution)) {
+    var attributionExtent = goog.isDef(extent) ?
+        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.setState(ol.source.State.READY);
+
+};
+
+
+/**
+ * @inheritDoc
+ */
+ol.source.TileUTFGrid.prototype.getTile =
+    function(z, x, y, pixelRatio, projection) {
+  var tileCoordKey = this.getKeyZXY(z, x, y);
+  if (this.tileCache.containsKey(tileCoordKey)) {
+    return /** @type {!ol.Tile} */ (this.tileCache.get(tileCoordKey));
+  } else {
+    goog.asserts.assert(projection);
+    var tileCoord = [z, x, y];
+    var tileUrl = this.tileUrlFunction(tileCoord, pixelRatio, projection);
+    var tile = new ol.source.TileUTFGridTile_(
+        tileCoord,
+        goog.isDef(tileUrl) ? ol.TileState.IDLE : ol.TileState.EMPTY,
+        goog.isDef(tileUrl) ? tileUrl : '');
+    this.tileCache.set(tileCoordKey, tile);
+    return tile;
+  }
+};
+
+
+/**
+ * @inheritDoc
+ */
+ol.source.TileUTFGrid.prototype.useTile = function(z, x, y) {
+  var tileCoordKey = this.getKeyZXY(z, x, y);
+  if (this.tileCache.containsKey(tileCoordKey)) {
+    this.tileCache.get(tileCoordKey);
+  }
+};
+
+
+
+/**
+ * @constructor
+ * @extends {ol.Tile}
+ * @param {ol.TileCoord} tileCoord Tile coordinate.
+ * @param {ol.TileState} state State.
+ * @param {string} src Image source URI.
+ * @private
+ */
+ol.source.TileUTFGridTile_ = function(tileCoord, state, src) {
+
+  goog.base(this, tileCoord, state);
+
+  /**
+   * @private
+   * @type {string}
+   */
+  this.src_ = src;
+
+  /**
+   * @private
+   * @type {?Object}
+   */
+  this.data_ = null;
+};
+goog.inherits(ol.source.TileUTFGridTile_, ol.Tile);
+
+
+/**
+ * @inheritDoc
+ */
+ol.source.TileUTFGridTile_.prototype.getImage = goog.nullFunction;
+
+
+/**
+ * @inheritDoc
+ */
+ol.source.TileUTFGridTile_.prototype.getKey = function() {
+  return this.src_;
+};
+
+
+/**
+ * @private
+ */
+ol.source.TileUTFGridTile_.prototype.handleError_ = function() {
+  this.state = ol.TileState.ERROR;
+  this.changed();
+};
+
+
+/**
+ * @param {Object} json
+ * @private
+ */
+ol.source.TileUTFGridTile_.prototype.handleLoad_ = function(json) {
+  this.data_ = json;
+
+  this.state = ol.TileState.EMPTY;
+  this.changed();
+};
+
+
+/**
+ * Load not yet loaded URI.
+ */
+ol.source.TileUTFGridTile_.prototype.load = function() {
+  if (this.state == ol.TileState.IDLE) {
+    this.state = ol.TileState.LOADING;
+    var request = new goog.net.Jsonp(this.src_);
+    request.send(undefined, goog.bind(this.handleLoad_, this),
+                 goog.bind(this.handleError_, this));
+  }
+};