base/prefs/pref_filter.h

   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 BASE_PREFS_PREF_FILTER_H_
   6 #define BASE_PREFS_PREF_FILTER_H_
   7
   8 #include <string>
   9
  10 #include "base/prefs/base_prefs_export.h"
  11
  12 namespace base {
  13 class DictionaryValue;
  14 class Value;
  15 }  // namespace base
  16
  17 // Filters preferences as they are loaded from disk or updated at runtime.
  18 // Currently supported only by JsonPrefStore.
  19 class BASE_PREFS_EXPORT PrefFilter {
  20  public:
  21   virtual ~PrefFilter() {}
  22
  23   // Receives notification when the pref store data has been loaded but before
  24   // Observers are notified.
  25   // Changes made by a PrefFilter during FilterOnLoad do not result in
  26   // notifications to |PrefStore::Observer|s.
  27   virtual void FilterOnLoad(base::DictionaryValue* pref_store_contents) = 0;
  28
  29   // Receives notification when a pref store value is changed, before Observers
  30   // are notified.
  31   virtual void FilterUpdate(const std::string& path) = 0;
  32
  33   // Receives notification when the pref store is about to serialize data
  34   // contained in |pref_store_contents| to a string.
  35   virtual void FilterSerializeData(
  36       const base::DictionaryValue* pref_store_contents) = 0;
  37 };
  38
  39 #endif  // BASE_PREFS_PREF_FILTER_H_