Add ol.ImageUrlFunction

src/imageurlfunction.js

@@ -0,0 +1,40 @@
+goog.provide('ol.ImageUrlFunction');
+goog.provide('ol.ImageUrlFunctionType');
+
+goog.require('ol.Extent');
+goog.require('ol.Size');
+
+
+/**
+ * @typedef {function(ol.Extent, ol.Size): (string|undefined)}
+ */
+ol.ImageUrlFunctionType;
+
+
+/**
+ * @param {string} baseUrl Base URL (may have query data).
+ * @return {ol.ImageUrlFunctionType} Image URL function.
+ */
+ol.ImageUrlFunction.createBboxParam = function(baseUrl) {
+  return function(extent, size) {
+    // FIXME Projection dependant axis order.
+    var bboxValue = [
+      extent.minX, extent.minY, extent.maxX, extent.maxY
+    ].join(',');
+    return goog.uri.utils.appendParams(baseUrl,
+        'BBOX', bboxValue,
+        'HEIGHT', size.height,
+        'WIDTH', size.width);
+  };
+};
+
+
+/**
+ * @param {ol.Extent} extent Extent.
+ * @param {ol.Size} size Size.
+ * @return {string|undefined} Image URL.
+ */
+ol.ImageUrlFunction.nullImageUrlFunction =
+    function(extent, size) {
+  return undefined;
+};