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1 // Copyright 2013 The Chromium Authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 #ifndef COMPONENTS_SYNCABLE_PREFS_SYNCED_PREF_CHANGE_REGISTRAR_H_ | |
6 #define COMPONENTS_SYNCABLE_PREFS_SYNCED_PREF_CHANGE_REGISTRAR_H_ | |
7 | |
8 #include <map> | |
9 #include <string> | |
10 | |
11 #include "base/callback.h" | |
12 #include "base/macros.h" | |
13 #include "components/syncable_prefs/pref_service_syncable.h" | |
14 #include "components/syncable_prefs/synced_pref_observer.h" | |
15 | |
16 namespace syncable_prefs { | |
17 | |
18 // Manages the registration of one or more SyncedPrefObservers on a | |
19 // PrefServiceSyncable. This is modeled after base::PrefChangeRegistrar, and | |
20 // it should be used whenever it's necessary to determine whether a pref change | |
21 // has come from sync or from some other mechanism (managed, UI, external, etc.) | |
22 class SyncedPrefChangeRegistrar : public SyncedPrefObserver { | |
23 public: | |
24 // Registered callbacks may optionally take a path argument. | |
25 // The boolean argument indicates whether (true) or not (false) | |
26 // the change was a result of syncing. | |
27 typedef base::Callback<void(bool)> ChangeCallback; | |
28 typedef base::Callback<void(const std::string&, bool)> NamedChangeCallback; | |
29 | |
30 explicit SyncedPrefChangeRegistrar(PrefServiceSyncable* pref_service); | |
31 virtual ~SyncedPrefChangeRegistrar(); | |
32 | |
33 // Register an observer callback for sync change events on the pref at | |
34 // |path|. Only one callback may be registered per pref. | |
35 void Add(const char* path, const ChangeCallback& callback); | |
36 void Add(const char* path, const NamedChangeCallback& callback); | |
37 | |
38 // Remove the registered observer for |path|. | |
39 void Remove(const char* path); | |
40 | |
41 // Remove all registered observers. | |
42 void RemoveAll(); | |
43 | |
44 // Indicates whether or not an observer is already registered for |path|. | |
45 bool IsObserved(const char* path) const; | |
46 | |
47 private: | |
48 // SyncedPrefObserver implementation | |
49 void OnSyncedPrefChanged(const std::string& path, bool from_sync) override; | |
50 | |
51 typedef std::map<std::string, NamedChangeCallback> ObserverMap; | |
52 | |
53 PrefServiceSyncable* pref_service_; | |
54 ObserverMap observers_; | |
55 | |
56 DISALLOW_COPY_AND_ASSIGN(SyncedPrefChangeRegistrar); | |
57 }; | |
58 | |
59 } // namespace syncable_prefs | |
60 | |
61 #endif // COMPONENTS_SYNCABLE_PREFS_SYNCED_PREF_CHANGE_REGISTRAR_H_ | |
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