From c1abe4a550166d211d9f75d5963d6190250e6a6f Mon Sep 17 00:00:00 2001
From: oterral <olivier.terral@swisstopo.ch>
Date: Fri, 19 May 2017 15:57:59 +0200
Subject: [PATCH] Force state of error tiles when usInterimTilesOnError is
 false

---
 src/ol/imagetile.js                 |  9 +++++++++
 src/ol/renderer/canvas/tilelayer.js |  4 ++++
 src/ol/tile.js                      |  7 +++++++
 src/ol/vectorimagetile.js           |  9 ---------
 src/ol/vectortile.js                |  9 ---------
 test/spec/ol/imagetile.test.js      | 19 +++++++++++++++++++
 6 files changed, 39 insertions(+), 18 deletions(-)

diff --git a/src/ol/imagetile.js b/src/ol/imagetile.js
index a474374a01..424856e5fd 100644
--- a/src/ol/imagetile.js
+++ b/src/ol/imagetile.js
@@ -94,6 +94,7 @@ ol.ImageTile.prototype.getKey = function() {
  */
 ol.ImageTile.prototype.handleImageError_ = function() {
   this.state = ol.TileState.ERROR;
+  this.image_ = ol.ImageTile.blankImage;
   this.unlistenImage_();
   this.changed();
 };
@@ -143,3 +144,11 @@ ol.ImageTile.prototype.unlistenImage_ = function() {
   this.imageListenerKeys_.forEach(ol.events.unlistenByKey);
   this.imageListenerKeys_ = null;
 };
+
+
+/**
+ * A blank image.
+ * @type {Image}
+ */
+ol.ImageTile.blankImage = new Image();
+ol.ImageTile.blankImage.src = 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7';
diff --git a/src/ol/renderer/canvas/tilelayer.js b/src/ol/renderer/canvas/tilelayer.js
index 100ec2fcd1..3690c00107 100644
--- a/src/ol/renderer/canvas/tilelayer.js
+++ b/src/ol/renderer/canvas/tilelayer.js
@@ -144,6 +144,10 @@ ol.renderer.canvas.TileLayer.prototype.prepareFrame = function(frameState, layer
   for (x = tileRange.minX; x <= tileRange.maxX; ++x) {
     for (y = tileRange.minY; y <= tileRange.maxY; ++y) {
       tile = tileSource.getTile(z, x, y, pixelRatio, projection);
+      // When useInterimTilesOnError is false, we consider the error tile as loaded.
+      if (tile.getState() == ol.TileState.ERROR && !this.getLayer().getUseInterimTilesOnError()) {
+        tile.setState(ol.TileState.LOADED);
+      }
       if (!this.isDrawableTile_(tile)) {
         tile = tile.getInterimTile();
       }
diff --git a/src/ol/tile.js b/src/ol/tile.js
index 4d1628bea4..9a1bfe7e84 100644
--- a/src/ol/tile.js
+++ b/src/ol/tile.js
@@ -145,6 +145,13 @@ ol.Tile.prototype.getState = function() {
   return this.state;
 };
 
+/**
+ * @param {ol.TileState} state State.
+ */
+ol.Tile.prototype.setState = function(state) {
+  this.state = state;
+  this.changed();
+};
 
 /**
  * Load the image or retry if loading previously failed.
diff --git a/src/ol/vectorimagetile.js b/src/ol/vectorimagetile.js
index 7ac49ab936..7a3371d3df 100644
--- a/src/ol/vectorimagetile.js
+++ b/src/ol/vectorimagetile.js
@@ -243,15 +243,6 @@ ol.VectorImageTile.prototype.load = function() {
 };
 
 
-/**
- * @param {ol.TileState} tileState Tile state.
- */
-ol.VectorImageTile.prototype.setState = function(tileState) {
-  this.state = tileState;
-  this.changed();
-};
-
-
 /**
  * Sets the loader for a tile.
  * @param {ol.VectorTile} tile Vector tile.
diff --git a/src/ol/vectortile.js b/src/ol/vectortile.js
index 11fa1f8f05..4976e90156 100644
--- a/src/ol/vectortile.js
+++ b/src/ol/vectortile.js
@@ -161,15 +161,6 @@ ol.VectorTile.prototype.setReplayGroup = function(key, replayGroup) {
 };
 
 
-/**
- * @param {ol.TileState} tileState Tile state.
- */
-ol.VectorTile.prototype.setState = function(tileState) {
-  this.state = tileState;
-  this.changed();
-};
-
-
 /**
  * Set the feature loader for reading this tile's features.
  * @param {ol.FeatureLoader} loader Feature loader.
diff --git a/test/spec/ol/imagetile.test.js b/test/spec/ol/imagetile.test.js
index 1a73392c50..6b6bdb5ce3 100644
--- a/test/spec/ol/imagetile.test.js
+++ b/test/spec/ol/imagetile.test.js
@@ -61,6 +61,25 @@ describe('ol.ImageTile', function() {
       tile.load();
     });
 
+    it('loads an empty image on error ', function(done) {
+      var tileCoord = [0, 0, 0];
+      var state = ol.TileState.IDLE;
+      var src = 'spec/ol/data/osm-0-0-99.png';
+      var tileLoadFunction = ol.source.Image.defaultImageLoadFunction;
+      var tile = new ol.ImageTile(tileCoord, state, src, null, tileLoadFunction);
+
+      ol.events.listen(tile, ol.events.EventType.CHANGE, function(event) {
+        var state = tile.getState();
+        if (state == ol.TileState.ERROR) {
+          expect(state).to.be(ol.TileState.ERROR);
+          expect(tile.image_).to.be(ol.ImageTile.blankImage);
+          done();
+        }
+      });
+
+      tile.load();
+    });
+
   });
 
 });