1// Copyright 2014 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_WRITEABLE_PREF_STORE_H_
6#define BASE_PREFS_WRITEABLE_PREF_STORE_H_
7
8#include <string>
9
10#include "base/basictypes.h"
11#include "base/prefs/pref_store.h"
12
13namespace base {
14class Value;
15}
16
17// A pref store that can be written to as well as read from.
18class BASE_PREFS_EXPORT WriteablePrefStore : public PrefStore {
19 public:
20  WriteablePrefStore() {}
21
22  // Sets a |value| for |key| in the store. Assumes ownership of |value|, which
23  // must be non-NULL.
24  virtual void SetValue(const std::string& key, base::Value* value) = 0;
25
26  // Removes the value for |key|.
27  virtual void RemoveValue(const std::string& key) = 0;
28
29  // Equivalent to PrefStore::GetValue but returns a mutable value.
30  virtual bool GetMutableValue(const std::string& key,
31                               base::Value** result) = 0;
32
33  // Triggers a value changed notification. This function needs to be called
34  // if one retrieves a list or dictionary with GetMutableValue and change its
35  // value. SetValue takes care of notifications itself. Note that
36  // ReportValueChanged will trigger notifications even if nothing has changed.
37  virtual void ReportValueChanged(const std::string& key) = 0;
38
39  // Same as SetValue, but doesn't generate notifications. This is used by
40  // PrefService::GetMutableUserPref() in order to put empty entries
41  // into the user pref store. Using SetValue is not an option since existing
42  // tests rely on the number of notifications generated.
43  virtual void SetValueSilently(const std::string& key, base::Value* value) = 0;
44
45 protected:
46  virtual ~WriteablePrefStore() {}
47
48 private:
49  DISALLOW_COPY_AND_ASSIGN(WriteablePrefStore);
50};
51
52#endif  // BASE_PREFS_WRITEABLE_PREF_STORE_H_
53