Factor out ImageTile and ImageTileSource

2013-01-05 16:26:58 +01:00
parent 9194a4b4eb
commit 97d83666a6
10 changed files with 284 additions and 190 deletions
@@ -0,0 +1,95 @@
+goog.provide('ol.source.ImageTileSource');
+goog.provide('ol.source.ImageTileSourceOptions');
+
+goog.require('ol.Attribution');
+goog.require('ol.Extent');
+goog.require('ol.ImageTile');
+goog.require('ol.Projection');
+goog.require('ol.TileCoord');
+goog.require('ol.TileUrlFunction');
+goog.require('ol.TileUrlFunctionType');
+goog.require('ol.source.TileSource');
+goog.require('ol.tilegrid.TileGrid');
+
+
+/**
+ * @typedef {{attributions: (Array.<ol.Attribution>|undefined),
+ *            crossOrigin: (null|string|undefined),
+ *            extent: (ol.Extent|undefined),
+ *            projection: (ol.Projection|undefined),
+ *            tileGrid: (ol.tilegrid.TileGrid|undefined),
+ *            tileUrlFunction: (ol.TileUrlFunctionType|undefined)}}
+ */
+ol.source.ImageTileSourceOptions;
+
+
+
+/**
+ * @constructor
+ * @extends {ol.source.TileSource}
+ * @param {ol.source.ImageTileSourceOptions} options Options.
+ */
+ol.source.ImageTileSource = function(options) {
+
+  goog.base(this, {
+    attributions: options.attributions,
+    extent: options.extent,
+    projection: options.projection,
+    tileGrid: options.tileGrid
+  });
+
+  /**
+   * @protected
+   * @type {ol.TileUrlFunctionType}
+   */
+  this.tileUrlFunction = goog.isDef(options.tileUrlFunction) ?
+      options.tileUrlFunction :
+      ol.TileUrlFunction.nullTileUrlFunction;
+
+  /**
+   * @private
+   * @type {?string}
+   */
+  this.crossOrigin_ =
+      goog.isDef(options.crossOrigin) ? options.crossOrigin : 'anonymous';
+
+  /**
+   * @private
+   * @type {Object.<string, ol.ImageTile>}
+   * FIXME will need to expire elements from this cache
+   * FIXME see elemoine's work with goog.structs.LinkedMap
+   */
+  this.tileCache_ = {};
+
+};
+goog.inherits(ol.source.ImageTileSource, ol.source.TileSource);
+
+
+/**
+ * @inheritDoc
+ */
+ol.source.ImageTileSource.prototype.getTile = function(tileCoord) {
+  var key = tileCoord.toString();
+  if (goog.object.containsKey(this.tileCache_, key)) {
+    return this.tileCache_[key];
+  } else {
+    var tileUrl = this.getTileCoordUrl(tileCoord);
+    var tile;
+    if (goog.isDef(tileUrl)) {
+      tile = new ol.ImageTile(tileCoord, tileUrl, this.crossOrigin_);
+    } else {
+      tile = null;
+    }
+    this.tileCache_[key] = tile;
+    return tile;
+  }
+};
+
+
+/**
+ * @param {ol.TileCoord} tileCoord Tile coordinate.
+ * @return {string|undefined} Tile URL.
+ */
+ol.source.ImageTileSource.prototype.getTileCoordUrl = function(tileCoord) {
+  return this.tileUrlFunction(tileCoord);
+};