Make NotificationService an interface in the content namespace, and switch callers to use it. Mov...

content/common/notification_service.h

-// Copyright (c) 2011 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.
-
-// This file describes a central switchboard for notifications that might
-// happen in various parts of the application, and allows users to register
-// observers for various classes of events that they're interested in.
-
-#ifndef CONTENT_COMMON_NOTIFICATION_SERVICE_H_
-#define CONTENT_COMMON_NOTIFICATION_SERVICE_H_
-#pragma once
-
-#include <map>
-
-#include "base/observer_list.h"
-#include "content/common/content_export.h"
-#include "content/public/browser/notification_details.h"
-#include "content/public/browser/notification_source.h"
-
-namespace content {
-class NotificationObserver;
-class NotificationRegistrar;
-}
-
-class CONTENT_EXPORT NotificationService {
- public:
-  // Returns the NotificationService object for the current thread, or NULL if
-  // none.
-  static NotificationService* current();
-
-  // Normally instantiated when the thread is created.  Not all threads have
-  // a NotificationService.  Only one instance should be created per thread.
-  NotificationService();
-  ~NotificationService();
-
-  // Synchronously posts a notification to all interested observers.
-  // Source is a reference to a NotificationSource object representing
-  // the object originating the notification (can be
-  // NotificationService::AllSources(), in which case
-  // only observers interested in all sources will be notified).
-  // Details is a reference to an object containing additional data about
-  // the notification.  If no additional data is needed, NoDetails() is used.
-  // There is no particular order in which the observers will be notified.
-  void Notify(int type,
-              const content::NotificationSource& source,
-              const content::NotificationDetails& details);
-
-  // Returns a NotificationSource that represents all notification sources
-  // (for the purpose of registering an observer for events from all sources).
-  static content::Source<void> AllSources() {
-    return content::Source<void>(NULL);
-  }
-
-  // Returns the same value as AllSources(). This function has semantic
-  // differences to the programmer: We have checked that this AllSources()
-  // usage is safe in the face of multiple profiles. Objects that were
-  // singletons now will always have multiple instances, one per browser
-  // context.
-  //
-  // Some usage is safe, where the Source is checked to see if it's a member of
-  // a container before use. But, we want the number of AllSources() calls to
-  // drop to almost nothing, because most usages are not multiprofile safe and
-  // were done because it was easier to listen to everything.
-  static content::Source<void> AllBrowserContextsAndSources() {
-    return content::Source<void>(NULL);
-  }
-
-  // Returns a NotificationDetails object that represents a lack of details
-  // associated with a notification.  (This is effectively a null pointer.)
-  static content::Details<void> NoDetails() {
-    return content::Details<void>(NULL);
-  }
-
- private:
-  friend class content::NotificationRegistrar;
-
-  typedef ObserverList<content::NotificationObserver> NotificationObserverList;
-  typedef std::map<uintptr_t, NotificationObserverList*> NotificationSourceMap;
-  typedef std::map<int, NotificationSourceMap> NotificationObserverMap;
-  typedef std::map<int, int> NotificationObserverCount;
-
-  // Convenience function to determine whether a source has a
-  // NotificationObserverList in the given map;
-  static bool HasKey(const NotificationSourceMap& map,
-                     const content::NotificationSource& source);
-
-  // NOTE: Rather than using this directly, you should use a
-  // NotificationRegistrar.
-  //
-  // Registers a NotificationObserver to be called whenever a matching
-  // notification is posted.  Observer is a pointer to an object subclassing
-  // NotificationObserver to be notified when an event matching the other two
-  // parameters is posted to this service.  Type is the type of events to be
-  // notified about (or content::NOTIFICATION_ALL to receive events of all
-  // types).
-  // Source is a NotificationSource object (created using
-  // "Source<classname>(pointer)"), if this observer only wants to
-  // receive events from that object, or NotificationService::AllSources()
-  // to receive events from all sources.
-  //
-  // A given observer can be registered only once for each combination of
-  // type and source.  If the same object is registered more than once,
-  // it must be removed for each of those combinations of type and source later.
-  //
-  // The caller retains ownership of the object pointed to by observer.
-  void AddObserver(content::NotificationObserver* observer,
-                   int type, const content::NotificationSource& source);
-
-  // NOTE: Rather than using this directly, you should use a
-  // NotificationRegistrar.
-  //
-  // Removes the object pointed to by observer from receiving notifications
-  // that match type and source.  If no object matching the parameters is
-  // currently registered, this method is a no-op.
-  void RemoveObserver(content::NotificationObserver* observer,
-                      int type, const content::NotificationSource& source);
-
-  // Keeps track of the observers for each type of notification.
-  // Until we get a prohibitively large number of notification types,
-  // a simple array is probably the fastest way to dispatch.
-  NotificationObserverMap observers_;
-
-#ifndef NDEBUG
-  // Used to check to see that AddObserver and RemoveObserver calls are
-  // balanced.
-  NotificationObserverCount observer_counts_;
-#endif
-
-  DISALLOW_COPY_AND_ASSIGN(NotificationService);
-};
-
-#endif  // CONTENT_COMMON_NOTIFICATION_SERVICE_H_