Image source refactoring

src/ol/imagecanvas.js

@@ -0,0 +1,38 @@
+goog.provide('ol.ImageCanvas');
+
+goog.require('ol.ImageBase');
+goog.require('ol.ImageState');
+
+
+
+/**
+ * @constructor
+ * @extends {ol.ImageBase}
+ * @param {ol.Extent} extent Extent.
+ * @param {number} resolution Resolution.
+ * @param {number} pixelRatio Pixel ratio.
+ * @param {Array.<ol.Attribution>} attributions Attributions.
+ * @param {HTMLCanvasElement} canvas Canvas.
+ */
+ol.ImageCanvas = function(extent, resolution, pixelRatio, attributions,
+    canvas) {
+
+  goog.base(this, extent, resolution, pixelRatio, ol.ImageState.LOADED,
+      attributions);
+
+  /**
+   * @private
+   * @type {HTMLCanvasElement}
+   */
+  this.canvas_ = canvas;
+
+};
+goog.inherits(ol.ImageCanvas, ol.ImageBase);
+
+
+/**
+ * @inheritDoc
+ */
+ol.ImageCanvas.prototype.getImageElement = function(opt_context) {
+  return this.canvas_;
+};