Be more strict with {Element} types

src/ol/renderer/canvas/canvasmaprenderer.js

@@ -33,9 +33,10 @@ ol.renderer.canvas.Map = function(container, map) {
 
   /**
    * @private
-   * @type {Element}
+   * @type {HTMLCanvasElement}
    */
-  this.canvas_ = goog.dom.createElement(goog.dom.TagName.CANVAS);
+  this.canvas_ = /** @type {HTMLCanvasElement} */
+      (goog.dom.createElement(goog.dom.TagName.CANVAS));
   this.canvas_.height = container.clientHeight;
   this.canvas_.width = container.clientWidth;
   this.canvas_.className = ol.css.CLASS_UNSELECTABLE;
@@ -57,7 +58,8 @@ ol.renderer.canvas.Map = function(container, map) {
    * @private
    * @type {CanvasRenderingContext2D}
    */
-  this.context_ = this.canvas_.getContext('2d');
+  this.context_ = /** @type {CanvasRenderingContext2D} */
+      (this.canvas_.getContext('2d'));
 
 };
 goog.inherits(ol.renderer.canvas.Map, ol.renderer.Map);

src/ol/renderer/maprenderer.js

@@ -93,7 +93,7 @@ ol.renderer.Map.prototype.disposeInternal = function() {
 
 
 /**
- * @return {Element} Canvas.
+ * @return {HTMLCanvasElement} Canvas.
  */
 ol.renderer.Map.prototype.getCanvas = goog.functions.NULL;
 

src/ol/renderer/webgl/webglmaprenderer.js

@@ -70,9 +70,10 @@ ol.renderer.webgl.Map = function(container, map) {
 
   /**
    * @private
-   * @type {Element}
+   * @type {HTMLCanvasElement}
    */
-  this.canvas_ = goog.dom.createElement(goog.dom.TagName.CANVAS);
+  this.canvas_ = /** @type {HTMLCanvasElement} */
+      (goog.dom.createElement(goog.dom.TagName.CANVAS));
   this.canvas_.height = container.clientHeight;
   this.canvas_.width = container.clientWidth;
   this.canvas_.className = ol.css.CLASS_UNSELECTABLE;

src/ol/webgl/webgl.js

@@ -28,7 +28,7 @@ ol.webgl.WebGLContextEventType = {
 
 
 /**
- * @param {Element} canvas Canvas.
+ * @param {HTMLCanvasElement} canvas Canvas.
  * @param {Object=} opt_attributes Attributes.
  * @return {WebGLRenderingContext} WebGL rendering context.
  */
@@ -38,7 +38,7 @@ ol.webgl.getContext = function(canvas, opt_attributes) {
     try {
       context = canvas.getContext(ol.webgl.CONTEXT_IDS_[i], opt_attributes);
       if (!goog.isNull(context)) {
-        return context;
+        return /** @type {!WebGLRenderingContext} */ (context);
       }
     } catch (e) {
     }
@@ -57,7 +57,8 @@ ol.webgl.SUPPORTED = (function() {
     return false;
   }
   try {
-    var canvas = goog.dom.createElement(goog.dom.TagName.CANVAS);
+    var canvas = /** @type {HTMLCanvasElement} */
+        (goog.dom.createElement(goog.dom.TagName.CANVAS));
     return !goog.isNull(ol.webgl.getContext(canvas));
   } catch (e) {
     return false;