Load erroneous image in ol.Image#load and ol.ImageTile#load

src/ol/image.js

@@ -122,10 +122,13 @@ ol.Image.prototype.handleImageLoad_ = function() {
 
 
 /**
- * Load not yet loaded URI.
+ * Load the image or retry if loading previously failed.
+ * Loading is taken care of by the tile queue, and calling this method is
+ * only needed for preloading or for reloading in case of an error.
+ * @api
  */
 ol.Image.prototype.load = function() {
-  if (this.state == ol.ImageState.IDLE) {
+  if (this.state == ol.ImageState.IDLE || this.state == ol.ImageState.ERROR) {
     this.state = ol.ImageState.LOADING;
     this.changed();
     goog.asserts.assert(!this.imageListenerKeys_,

src/ol/imagetile.js

@@ -137,10 +137,13 @@ ol.ImageTile.prototype.handleImageLoad_ = function() {
 
 
 /**
- * Load not yet loaded URI.
+ * Load the image or retry if loading previously failed.
+ * Loading is taken care of by the tile queue, and calling this method is
+ * only needed for preloading or for reloading in case of an error.
+ * @api
  */
 ol.ImageTile.prototype.load = function() {
-  if (this.state == ol.TileState.IDLE) {
+  if (this.state == ol.TileState.IDLE || this.state == ol.TileState.ERROR) {
     this.state = ol.TileState.LOADING;
     this.changed();
     goog.asserts.assert(!this.imageListenerKeys_,

src/ol/tile.js

@@ -107,6 +107,9 @@ ol.Tile.prototype.getState = function() {
 
 
 /**
- * FIXME empty description for jsdoc
+ * Load the image or retry if loading previously failed.
+ * Loading is taken care of by the tile queue, and calling this method is
+ * only needed for preloading or for reloading in case of an error.
+ * @api
  */
 ol.Tile.prototype.load = goog.abstractMethod;

test/spec/ol/imagetile.test.js

@@ -0,0 +1,65 @@
+goog.provide('ol.test.ImageTile');
+
+describe('ol.ImageTile', function() {
+
+  describe('#load()', function() {
+
+    it('can load idle tile', function(done) {
+      var tileCoord = [0, 0, 0];
+      var state = ol.TileState.IDLE;
+      var src = 'spec/ol/data/osm-0-0-0.png';
+      var tileLoadFunction = ol.source.Image.defaultImageLoadFunction;
+      var tile = new ol.ImageTile(tileCoord, state, src, null, tileLoadFunction);
+
+      var previousState = tile.getState()
+
+      ol.events.listen(tile, ol.events.EventType.CHANGE, function(event) {
+        var state = tile.getState();
+        if (previousState == ol.TileState.IDLE) {
+          expect(state).to.be(ol.TileState.LOADING);
+        } else if (previousState == ol.TileState.LOADING) {
+          expect(state).to.be(ol.TileState.LOADED);
+          done();
+        } else {
+          expect().fail();
+        }
+        previousState = state;
+      });
+
+      tile.load();
+    });
+
+    it('can load error tile', function(done) {
+      var tileCoord = [0, 0, 0];
+      var state = ol.TileState.ERROR;
+      var src = 'spec/ol/data/osm-0-0-0.png';
+      var tileLoadFunction = ol.source.Image.defaultImageLoadFunction;
+      var tile = new ol.ImageTile(tileCoord, state, src, null, tileLoadFunction);
+
+      var previousState = tile.getState()
+
+      ol.events.listen(tile, ol.events.EventType.CHANGE, function(event) {
+        var state = tile.getState();
+        if (previousState == ol.TileState.ERROR) {
+          expect(state).to.be(ol.TileState.LOADING);
+        } else if (previousState == ol.TileState.LOADING) {
+          expect(state).to.be(ol.TileState.LOADED);
+          done();
+        } else {
+          expect().fail();
+        }
+        previousState = state;
+      });
+
+      tile.load();
+    });
+
+  });
+
+});
+
+goog.require('ol.events');
+goog.require('ol.events.EventType');
+goog.require('ol.source.Image');
+goog.require('ol.ImageTile');
+goog.require('ol.TileState');