Loads local resources from current locale subtree if available, if not it fal...

chrome/browser/image_loading_tracker.h

-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef CHROME_BROWSER_IMAGE_LOADING_TRACKER_H_
-#define CHROME_BROWSER_IMAGE_LOADING_TRACKER_H_
-
-#include "base/ref_counted.h"
-
-class FilePath;
-class SkBitmap;
-
-// The views need to load their icons asynchronously but might be deleted before
-// the images have loaded. This class stays alive while the request is in
-// progress (manages its own lifetime) and keeps track of whether the view still
-// cares about the icon loading.
-class ImageLoadingTracker
-  : public base::RefCountedThreadSafe<ImageLoadingTracker> {
- public:
-  class Observer {
-   public:
-    // Will be called when the image with the given index has loaded.
-    // The |image| is owned by the tracker, so the observer should make a copy
-    // if they need to access it after this call.
-    virtual void OnImageLoaded(SkBitmap* image, size_t index) = 0;
-  };
-
-  ImageLoadingTracker(Observer* observer, size_t image_count)
-    : observer_(observer), image_count_(image_count), posted_count_(0) {
-    AddRef();  // We hold on to a reference to ourself to make sure we don't
-               // get deleted until we get a response from image loading (see
-               // ImageLoadingDone).
-  }
-  ~ImageLoadingTracker() {}
-
-  // If there are remaining images to be loaded, the observing object should
-  // call this method on its destruction, so that the tracker will not attempt
-  // to make any more callbacks to it.
-  void StopTrackingImageLoad() {
-    observer_ = NULL;
-  }
-
-  // Specify path of image to load.  This method must be called a number of
-  // times equal to the |image_count| arugment to the constructor.  Calling it
-  // any more or less than that is an error.
-  void PostLoadImageTask(FilePath path);
-
- private:
-  class LoadImageTask;
-
-  // When an image has finished loaded and scaled on the file thread, it is
-  // posted back to this method on the original thread.  This method then calls
-  // the observer's OnImageLoaded and deletes the ImageLoadingTracker if it was
-  // the last image in the list.
-  // |image| may be null if the file failed to decode.
-  void OnImageLoaded(SkBitmap* image, size_t index);
-
-  // The view that is waiting for the image to load.
-  Observer* observer_;
-
-  // The number of images this ImageTracker should keep track of.  This is
-  // decremented as each image finishes loading, and the tracker will delete
-  // itself when it reaches zero.
-  size_t image_count_;
-
-  // The number of tasks that have been posted so far.
-  size_t posted_count_;
-
-  DISALLOW_COPY_AND_ASSIGN(ImageLoadingTracker);
-};
-
-#endif  // CHROME_BROWSER_IMAGE_LOADING_TRACKER_H_