Implement mediaGalleriesPrivate api to notify extensions about gallery changed events.

chrome/browser/extensions/api/media_galleries_private/gallery_watch_manager.h

+// Copyright (c) 2012 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.
+
+// Manages all the gallery file watchers for the associated profile. This class
+// lives on the file thread. This class is instantiated per profile. This
+// is temporary and will be moved to a permanent, public place in the near
+// future. Please refer to crbug.com/166950 for more details.
+
+#ifndef CHROME_BROWSER_EXTENSIONS_API_MEDIA_GALLERIES_PRIVATE_GALLERY_WATCH_MANAGER_H_
+#define CHROME_BROWSER_EXTENSIONS_API_MEDIA_GALLERIES_PRIVATE_GALLERY_WATCH_MANAGER_H_
+
+#include <map>
+#include <string>
+
+#include "base/file_path.h"
+#include "base/memory/weak_ptr.h"
+#include "chrome/browser/media_gallery/media_galleries_preferences.h"
+
+namespace extensions {
+
+class MediaGalleriesPrivateEventRouter;
+
+class GalleryWatchManager {
+ public:
+  // Returns the GalleryWatchManager for |profile_id|, creating it if it is not
+  // yet created.
+  static GalleryWatchManager* GetForProfile(void* profile_id);
+
+  // Returns true if an GalleryWatchManager already exists for the specified
+  // |profile_id|.
+  static bool HasForProfile(void* profile_id);
+
+  // Notifies about the profile shutdown event.
+  static void OnProfileShutdown(void* profile_id);
+
+  // Initiates a gallery watch operation for the extension specified by
+  // the |extension_id|. |gallery_id| specifies the gallery identifier and
+  // |watch_path| specifies the absolute path of the gallery. Returns true,
+  // if the watch was set successfully.
+  bool StartGalleryWatch(
+      chrome::MediaGalleryPrefId gallery_id,
+      const FilePath& watch_path,
+      const std::string& extension_id,
+      base::WeakPtr<MediaGalleriesPrivateEventRouter> event_router);
+
+  // Cancels the gallery watch operation for the extension specified by the
+  // |extension_id|. |watch_path| specifies the absolute path of the gallery.
+  void StopGalleryWatch(const FilePath& watch_path,
+                        const std::string& extension_id);
+
+  // Handles the extension unloaded/uninstalled/destroyed event.
+  void OnExtensionDestroyed(const std::string& extension_id);
+
+ private:
+  class GalleryFilePathWatcher;
+  typedef std::map<FilePath, GalleryFilePathWatcher* > WatcherMap;
+
+  // Use GetForProfile().
+  explicit GalleryWatchManager();

[Lei Zhang, 2013/01/04 22:56:28]

nit: no need for explicit.

[kmadhusu, 2013/01/04 23:41:02]

Done.

+  ~GalleryWatchManager();
+
+  // Deletes the gallery watchers.
+  void DeleteAllWatchers();
+
+  // Removes the GalleryFilePathWatcher entry associated with the given
+  // |watch_path|.
+  void RemoveGalleryFilePathWatcherEntry(const FilePath& watch_path);
+
+  // Map to manage the gallery file path watchers.
+  // Key: Gallery watch path.
+  // Value: GalleryFilePathWatcher*.
+  WatcherMap gallery_watchers_;
+
+  DISALLOW_COPY_AND_ASSIGN(GalleryWatchManager);
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_MEDIA_GALLERIES_PRIVATE_GALLERY_WATCH_MANAGER_H_