Media Galleries: Add MediaGalleriesPreferences::GalleryChangeObserver class.

chrome/browser/media_gallery/media_galleries_preferences.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.
 
 #ifndef CHROME_BROWSER_MEDIA_GALLERY_MEDIA_GALLERIES_PREFERENCES_H_
 #define CHROME_BROWSER_MEDIA_GALLERY_MEDIA_GALLERIES_PREFERENCES_H_
 
 #include <map>
 #include <set>
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/file_path.h"
+#include "base/observer_list.h"
 #include "base/string16.h"
 #include "chrome/browser/profiles/profile_keyed_service.h"
 
 class PrefServiceSyncable;
 class Profile;
 
 namespace base {
 class DictionaryValue;
 }
 
@@ skipping 44 matching lines @@
 };
 
 typedef std::map<MediaGalleryPrefId, MediaGalleryPrefInfo>
     MediaGalleriesPrefInfoMap;
 typedef std::set<MediaGalleryPrefId> MediaGalleryPrefIdSet;
 
 // A class to manage the media gallery preferences.  There is one instance per
 // user profile.
 class MediaGalleriesPreferences : public ProfileKeyedService {
  public:
+  class GalleryChangeObserver {
+    public:
+     virtual void OnGalleryChanged(MediaGalleriesPreferences* pref) {}
+
+    protected:
+     virtual ~GalleryChangeObserver();
+  };
+
   explicit MediaGalleriesPreferences(Profile* profile);
   virtual ~MediaGalleriesPreferences();
 
+  void AddGalleryChangeObserver(GalleryChangeObserver* observer);
+  void RemoveGalleryChangeObserver(GalleryChangeObserver* observer);
+
   // Lookup a media gallery and fill in information about it and return true.
   // If the media gallery does not already exist, fill in as much of the
   // MediaGalleryPrefInfo struct as we can and return false.
   // TODO(vandebo) figure out if we want this to be async, in which case:
   // void LookUpGalleryByPath(FilePath&path, callback(const MediaGalleryInfo&))
   bool LookUpGalleryByPath(const FilePath& path,
                            MediaGalleryPrefInfo* gallery) const;
 
   MediaGalleryPrefIdSet LookUpGalleriesByDeviceId(
       const std::string& device_id) const;
 
   // Teaches the registry about a new gallery.
+  // Returns the gallery's pref id.
   MediaGalleryPrefId AddGallery(const std::string& device_id,
                                 const string16& display_name,
                                 const FilePath& relative_path,
                                 bool user_added);
 
   // Teach the registry about a user added registry simply from the path.
+  // Returns the gallery's pref id.
   MediaGalleryPrefId AddGalleryByPath(const FilePath& path);
 
   // Removes the gallery identified by |id| from the store.
   void ForgetGalleryById(MediaGalleryPrefId id);
 
   MediaGalleryPrefIdSet GalleriesForExtension(
       const extensions::Extension& extension) const;
 
   void SetGalleryPermissionForExtension(const extensions::Extension& extension,
                                         MediaGalleryPrefId pref_id,
@@ skipping 14 matching lines @@
   static bool APIHasBeenUsed(Profile* profile);
 
  private:
   typedef std::map<std::string /*device id*/, MediaGalleryPrefIdSet>
       DeviceIdPrefIdsMap;
 
   // Populates the default galleries if this is a fresh profile.
   void AddDefaultGalleriesIfFreshProfile();
 
   // Builds |known_galleries_| from the persistent store.
-  void InitFromPrefs();
+  // Notifies GalleryChangeObservers if |notify_observers| is true.
+  void InitFromPrefs(bool notify_observers);
+
+  // Notifies |gallery_change_observers_| about changes in |known_galleries_|.
+  void NotifyChangeObservers();
+
+  extensions::ExtensionPrefs* GetExtensionPrefs() const;
 
   // The profile that owns |this|.
   Profile* profile_;
 
   // An in-memory cache of known galleries.
   MediaGalleriesPrefInfoMap known_galleries_;
 
   // A mapping from device id to the set of gallery pref ids on that device.
   // All pref ids in |device_map_| are also in |known_galleries_|.
   DeviceIdPrefIdsMap device_map_;
 
-  extensions::ExtensionPrefs* GetExtensionPrefs() const;
+  ObserverList<GalleryChangeObserver> gallery_change_observers_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaGalleriesPreferences);
 };
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_MEDIA_GALLERY_MEDIA_GALLERIES_PREFERENCES_H_