Add ol.TileBounds.getSize

src/ol/tilebounds.js

@@ -1,6 +1,7 @@
 goog.provide('ol.TileBounds');
 
 goog.require('goog.asserts');
+goog.require('goog.math.Size');
 goog.require('ol.Rectangle');
 goog.require('ol.TileCoord');
 
@@ -71,3 +72,12 @@ ol.TileBounds.prototype.forEachTileCoord = function(z, f, opt_obj) {
     }
   }
 };
+
+
+/**
+ * @return {goog.math.Size} Size.
+ */
+ol.TileBounds.prototype.getSize = function() {
+  return new goog.math.Size(
+      this.maxX - this.minX + 1, this.maxY - this.minY + 1);
+};

src/ol/tilebounds_test.js

@@ -76,3 +76,11 @@ function testForEachTileCoord() {
   assertEquals(3, tileCoords[3].y);
 
 }
+
+
+function testSize() {
+  var tileBounds = new ol.TileBounds(0, 1, 2, 4);
+  var size = tileBounds.getSize();
+  assertEquals(3, size.width);
+  assertEquals(4, size.height);
+}