// Copyright (c) 2010 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_PREFS_PREF_NOTIFIER_IMPL_H_
#define CHROME_BROWSER_PREFS_PREF_NOTIFIER_IMPL_H_
#pragma once
#include <string>
#include "base/hash_tables.h"
#include "base/observer_list.h"
#include "base/threading/non_thread_safe.h"
#include "chrome/browser/prefs/pref_notifier.h"
class PrefService;
class NotificationObserver;
// The PrefNotifier implementation used by the PrefService.
class PrefNotifierImpl : public PrefNotifier,
public base::NonThreadSafe {
public:
explicit PrefNotifierImpl(PrefService* pref_service);
virtual ~PrefNotifierImpl();
// If the pref at the given path changes, we call the observer's Observe
// method with PREF_CHANGED.
void AddPrefObserver(const char* path, NotificationObserver* obs);
void RemovePrefObserver(const char* path, NotificationObserver* obs);
// PrefNotifier overrides.
virtual void OnPreferenceChanged(const std::string& pref_name);
virtual void OnInitializationCompleted();
protected:
// A map from pref names to a list of observers. Observers get fired in the
// order they are added. These should only be accessed externally for unit
// testing.
typedef ObserverList<NotificationObserver> NotificationObserverList;
typedef base::hash_map<std::string, NotificationObserverList*>
PrefObserverMap;
const PrefObserverMap* pref_observers() const { return &pref_observers_; }
private:
// For the given pref_name, fire any observer of the pref. Virtual so it can
// be mocked for unit testing.
virtual void FireObservers(const std::string& path);
// Weak reference; the notifier is owned by the PrefService.
PrefService* pref_service_;
PrefObserverMap pref_observers_;
DISALLOW_COPY_AND_ASSIGN(PrefNotifierImpl);
};
#endif // CHROME_BROWSER_PREFS_PREF_NOTIFIER_IMPL_H_