[ol.layer.TileLayer] add a getTileSize function

src/ol/layer/TileLayer.js

@@ -108,6 +108,14 @@ ol.layer.TileLayer.prototype.getExtent = function() {
     return null;
 };
 
+/**
+ * Get tile size.
+ * @return {Array.<number>}
+ */
+ol.layer.TileLayer.prototype.getTileSize = function() {
+    return [this.tileWidth_, this.tileHeight_];
+};
+
 /**
  * Get tile origin.
  * @return {Array.<number>}

test/spec/ol/layer/TileLayer.test.js

@@ -9,6 +9,19 @@ describe('ol.layer.TileLayer', function() {
 
     });
 
+    describe('get tile size', function() {
+        var layer;
+
+        beforeEach(function() {
+            layer = new ol.layer.TileLayer();
+        });
+
+        it('returns tile size', function() {
+            var tilesize = layer.getTileSize();
+            expect(tilesize).toEqual([256, 256]);
+        });
+    });
+
     describe('get tile origin', function() {
         var layer;