Update wmts-hidpi, add nicer-api-docs

nicer-api-docs/closure-library/closure/goog/labs/net/image.js

@@ -0,0 +1,93 @@
+// Copyright 2012 The Closure Library Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS-IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/**
+ * @fileoverview Simple image loader, used for preloading.
+ * @author nnaze@google.com (Nathan Naze)
+ */
+
+goog.provide('goog.labs.net.image');
+
+goog.require('goog.events.EventHandler');
+goog.require('goog.events.EventType');
+goog.require('goog.net.EventType');
+goog.require('goog.result.SimpleResult');
+goog.require('goog.userAgent');
+
+
+/**
+ * Loads a single image.  Useful for preloading images. May be combined with
+ * goog.result.combine to preload many images.
+ *
+ * @param {string} uri URI of the image.
+ * @param {(Image|function(): !Image)=} opt_image If present, instead of
+ *     creating a new Image instance the function will use the passed Image
+ *     instance or the result of calling the Image factory respectively. This
+ *     can be used to control exactly how Image instances are created, for
+ *     example if they should be created in a particular document element, or
+ *     have fields that will trigger CORS image fetches.
+ * @return {!goog.result.Result} An asyncronous result that will succeed
+ *     if the image successfully loads or error if the image load fails.
+ */
+goog.labs.net.image.load = function(uri, opt_image) {
+  var image;
+  if (!goog.isDef(opt_image)) {
+    image = new Image();
+  } else if (goog.isFunction(opt_image)) {
+    image = opt_image();
+  } else {
+    image = opt_image;
+  }
+
+  // IE's load event on images can be buggy.  Instead, we wait for
+  // readystatechange events and check if readyState is 'complete'.
+  // See:
+  // http://msdn.microsoft.com/en-us/library/ie/ms536957(v=vs.85).aspx
+  // http://msdn.microsoft.com/en-us/library/ie/ms534359(v=vs.85).aspx
+  var loadEvent = goog.userAgent.IE ? goog.net.EventType.READY_STATE_CHANGE :
+      goog.events.EventType.LOAD;
+
+  var result = new goog.result.SimpleResult();
+
+  var handler = new goog.events.EventHandler();
+  handler.listen(
+      image,
+      [loadEvent, goog.net.EventType.ABORT, goog.net.EventType.ERROR],
+      function(e) {
+
+        // We only registered listeners for READY_STATE_CHANGE for IE.
+        // If readyState is now COMPLETE, the image has loaded.
+        // See related comment above.
+        if (e.type == goog.net.EventType.READY_STATE_CHANGE &&
+            image.readyState != goog.net.EventType.COMPLETE) {
+          return;
+        }
+
+        // At this point, we know whether the image load was successful
+        // and no longer care about image events.
+        goog.dispose(handler);
+
+        // Whether the image successfully loaded.
+        if (e.type == loadEvent) {
+          result.setValue(image);
+        } else {
+          result.setError();
+        }
+      });
+
+  // Initiate the image request.
+  image.src = uri;
+
+  return result;
+};