drive: Introduce DriveSystemServiceObserver

chrome/browser/chromeos/drive/drive_system_service.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_CHROMEOS_DRIVE_DRIVE_SYSTEM_SERVICE_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_SYSTEM_SERVICE_H_
 
 #include <string>
 
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
 #include "base/memory/weak_ptr.h"
+#include "base/observer_list.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "chrome/browser/chromeos/drive/drive_file_error.h"
 #include "chrome/browser/chromeos/drive/drive_file_system_util.h"
 #include "chrome/browser/profiles/profile_keyed_service.h"
 #include "chrome/browser/profiles/profile_keyed_service_factory.h"
 #include "sync/notifier/invalidation_handler.h"
 
 namespace base {
 class FilePath;
 }
 
 namespace google_apis {
 class DriveServiceInterface;
 }
 
 namespace drive {
 
 class DriveCache;
 class DriveDownloadHandler;
 class DriveFileSystemInterface;
 class DriveFileSystemProxy;
 class DriveWebAppsRegistry;
 class DriveSyncClient;
 class DrivePrefetcher;
 class DriveResourceMetadata;
 class EventLogger;
 class FileWriteHelper;
 class StaleCacheFilesRemover;
 
+// Interface for classes that need to observe events from DriveSystemService.
+// All events are notified on UI thread.
+class DriveSystemServiceObserver {
+ public:
+  // Triggered when the file system is mounted.
+  virtual void OnFileSystemMounted() {
+  }
+
+  // Triggered when the file system is being unmounted.
+  virtual void OnFileSystemBeingUnmounted() {
+  }
+
+ protected:
+  virtual ~DriveSystemServiceObserver() {}
+};
+
 // DriveSystemService runs the Drive system, including the Drive file system
 // implementation for the file manager, and some other sub systems.
 //
 // The class is essentially a container that manages lifetime of the objects
 // that are used to run the Drive system. The DriveSystemService object is
 // created per-profile.
 class DriveSystemService : public ProfileKeyedService,
                            public syncer::InvalidationHandler {
  public:
   // test_drive_service, test_cache_root and test_file_system are used by tests
   // to inject customized instances.
   // Pass NULL or the empty value when not interested.
   DriveSystemService(Profile* profile,
                      google_apis::DriveServiceInterface* test_drive_service,
                      const base::FilePath& test_cache_root,
                      DriveFileSystemInterface* test_file_system);
   virtual ~DriveSystemService();
 
   // Initializes the object. This function should be called before any
   // other functions.
   void Initialize();
 
   // ProfileKeyedService override:
   virtual void Shutdown() OVERRIDE;
 
+  // Adds and removes the observer.
+  void AddObserver(DriveSystemServiceObserver* observer);
+  void RemoveObserver(DriveSystemServiceObserver* observer);
+
   google_apis::DriveServiceInterface* drive_service() {
     return drive_service_.get();
   }
 
   DriveCache* cache() { return cache_.get(); }
   DriveFileSystemInterface* file_system() { return file_system_.get(); }
   FileWriteHelper* file_write_helper() { return file_write_helper_.get(); }
   DriveDownloadHandler* download_handler() { return download_handler_.get(); }
   DriveWebAppsRegistry* webapps_registry() { return webapps_registry_.get(); }
   EventLogger* event_logger() { return event_logger_.get(); }
@@ skipping 67 matching lines @@
   scoped_ptr<DriveWebAppsRegistry> webapps_registry_;
   scoped_ptr<DriveResourceMetadata, util::DestroyHelper> resource_metadata_;
   scoped_ptr<DriveFileSystemInterface> file_system_;
   scoped_ptr<FileWriteHelper> file_write_helper_;
   scoped_ptr<DriveDownloadHandler> download_handler_;
   scoped_ptr<DriveSyncClient> sync_client_;
   scoped_ptr<DrivePrefetcher> prefetcher_;
   scoped_ptr<StaleCacheFilesRemover> stale_cache_files_remover_;
   scoped_refptr<DriveFileSystemProxy> file_system_proxy_;
 
+  ObserverList<DriveSystemServiceObserver> observers_;
+
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate its weak pointers before any other members are destroyed.
   base::WeakPtrFactory<DriveSystemService> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(DriveSystemService);
 };
 
 // Singleton that owns all DriveSystemServices and associates them with
 // Profiles.
 class DriveSystemServiceFactory : public ProfileKeyedServiceFactory {
  public:
@@ skipping 39 matching lines @@
   // ProfileKeyedServiceFactory:
   virtual ProfileKeyedService* BuildServiceInstanceFor(
       Profile* profile) const OVERRIDE;
 
   FactoryCallback factory_for_test_;
 };
 
 }  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_SYSTEM_SERVICE_H_