Add ol.source.DebugTileSource

src/ol/source/debugtilesource.js

@@ -0,0 +1,125 @@
+goog.provide('ol.source.DebugTileSource');
+goog.provide('ol.source.DebugTileSourceOptions');
+
+goog.require('ol.Tile');
+goog.require('ol.TileCoord');
+goog.require('ol.source.TileSource');
+goog.require('ol.tilegrid.TileGrid');
+
+
+
+/**
+ * @constructor
+ * @extends {ol.Tile}
+ * @param {ol.TileCoord} tileCoord Tile coordinate.
+ * @param {ol.tilegrid.TileGrid} tileGrid Tile grid.
+ * @private
+ */
+ol.DebugTile_ = function(tileCoord, tileGrid) {
+
+  goog.base(this, tileCoord);
+
+  this.state = ol.TileState.LOADED;
+
+  var tileSize = tileGrid.getTileSize();
+
+  /**
+   * @private
+   * @type {HTMLCanvasElement}
+   */
+  this.canvas_ = /** @type {HTMLCanvasElement} */
+      (goog.dom.createElement(goog.dom.TagName.CANVAS));
+  this.canvas_.width = tileSize.width;
+  this.canvas_.height = tileSize.height;
+
+  var context = this.canvas_.getContext('2d');
+
+  context.strokeStyle = 'black';
+  context.strokeRect(0.5, 0.5, tileSize.width + 0.5, tileSize.height + 0.5);
+
+  context.fillStyle = 'black';
+  context.textAlign = 'center';
+  context.textBaseline = 'middle';
+  context.font = '24px sans-serif';
+  context.fillText(
+      tileCoord.toString(), tileSize.width / 2, tileSize.height / 2);
+
+  /**
+   * @private
+   * @type {Object.<number, HTMLCanvasElement>}
+   */
+  this.canvasByContext_ = {};
+
+};
+goog.inherits(ol.DebugTile_, ol.Tile);
+
+
+/**
+ * @inheritDoc
+ */
+ol.DebugTile_.prototype.getImage = function(opt_context) {
+  if (goog.isDef(opt_context)) {
+    var canvas;
+    var key = goog.getUid(opt_context);
+    if (key in this.canvasByContext_) {
+      return this.canvasByContext_[key];
+    } else if (goog.object.isEmpty(this.canvasByContext_)) {
+      canvas = this.canvas_;
+    } else {
+      canvas = /** @type {HTMLCanvasElement} */ (this.canvas_.cloneNode(false));
+    }
+    this.canvasByContext_[key] = canvas;
+    return canvas;
+  } else {
+    return this.canvas_;
+  }
+};
+
+
+/**
+ * @typedef {{extent: (ol.Extent|undefined),
+ *            projection: (ol.Projection|undefined),
+ *            tileGrid: (ol.tilegrid.TileGrid|undefined)}}
+ */
+ol.source.DebugTileSourceOptions;
+
+
+
+/**
+ * @constructor
+ * @extends {ol.source.TileSource}
+ * @param {ol.source.DebugTileSourceOptions} options Options.
+ */
+ol.source.DebugTileSource = function(options) {
+
+  goog.base(this, {
+    extent: options.extent,
+    projection: options.projection,
+    tileGrid: options.tileGrid
+  });
+
+  /**
+   * @private
+   * @type {Object.<string, ol.DebugTile_>}
+   * FIXME will need to expire elements from this cache
+   * FIXME see elemoine's work with goog.structs.LinkedMap
+   */
+  this.tileCache_ = {};
+
+};
+goog.inherits(ol.source.DebugTileSource, ol.source.TileSource);
+
+
+/**
+ * @inheritDoc
+ */
+ol.source.DebugTileSource.prototype.getTile = function(tileCoord) {
+  var key = tileCoord.toString();
+  if (goog.object.containsKey(this.tileCache_, key)) {
+    return this.tileCache_[key];
+  } else {
+    var tile = new ol.DebugTile_(tileCoord, this.tileGrid);
+    this.tileCache_[key] = tile;
+    return tile;
+  }
+};