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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #ifndef BASE_PREFS_PREF_REGISTRY_H_ | 5 // TODO(brettw) remove this forwarding header when prefs is completely moved to |
6 #define BASE_PREFS_PREF_REGISTRY_H_ | 6 // components. |
7 | 7 #include "components/prefs/pref_registry.h" |
8 #include <stdint.h> | |
9 | |
10 #include "base/containers/hash_tables.h" | |
11 #include "base/macros.h" | |
12 #include "base/memory/ref_counted.h" | |
13 #include "base/prefs/base_prefs_export.h" | |
14 #include "base/prefs/pref_value_map.h" | |
15 | |
16 namespace base { | |
17 class Value; | |
18 } | |
19 | |
20 class DefaultPrefStore; | |
21 class PrefStore; | |
22 | |
23 // Preferences need to be registered with a type and default value | |
24 // before they are used. | |
25 // | |
26 // The way you use a PrefRegistry is that you register all required | |
27 // preferences on it (via one of its subclasses), then pass it as a | |
28 // construction parameter to PrefService. | |
29 // | |
30 // Currently, registrations after constructing the PrefService will | |
31 // also work, but this is being deprecated. | |
32 class BASE_PREFS_EXPORT PrefRegistry : public base::RefCounted<PrefRegistry> { | |
33 public: | |
34 // Registration flags that can be specified which impact how the pref will | |
35 // behave or be stored. This will be passed in a bitmask when the pref is | |
36 // registered. Subclasses of PrefRegistry can specify their own flags. Care | |
37 // must be taken to ensure none of these overlap with the flags below. | |
38 enum PrefRegistrationFlags : uint32_t { | |
39 // No flags are specified. | |
40 NO_REGISTRATION_FLAGS = 0, | |
41 | |
42 // The first 8 bits are reserved for subclasses of PrefRegistry to use. | |
43 | |
44 // This marks the pref as "lossy". There is no strict time guarantee on when | |
45 // a lossy pref will be persisted to permanent storage when it is modified. | |
46 LOSSY_PREF = 1 << 8, | |
47 }; | |
48 | |
49 typedef PrefValueMap::const_iterator const_iterator; | |
50 typedef base::hash_map<std::string, uint32_t> PrefRegistrationFlagsMap; | |
51 | |
52 PrefRegistry(); | |
53 | |
54 // Retrieve the set of registration flags for the given preference. The return | |
55 // value is a bitmask of PrefRegistrationFlags. | |
56 uint32_t GetRegistrationFlags(const std::string& pref_name) const; | |
57 | |
58 // Gets the registered defaults. | |
59 scoped_refptr<PrefStore> defaults(); | |
60 | |
61 // Allows iteration over defaults. | |
62 const_iterator begin() const; | |
63 const_iterator end() const; | |
64 | |
65 // Changes the default value for a preference. Takes ownership of |value|. | |
66 // | |
67 // |pref_name| must be a previously registered preference. | |
68 void SetDefaultPrefValue(const std::string& pref_name, base::Value* value); | |
69 | |
70 protected: | |
71 friend class base::RefCounted<PrefRegistry>; | |
72 virtual ~PrefRegistry(); | |
73 | |
74 // Used by subclasses to register a default value and registration flags for | |
75 // a preference. |flags| is a bitmask of |PrefRegistrationFlags|. | |
76 void RegisterPreference(const std::string& path, | |
77 base::Value* default_value, | |
78 uint32_t flags); | |
79 | |
80 scoped_refptr<DefaultPrefStore> defaults_; | |
81 | |
82 // A map of pref name to a bitmask of PrefRegistrationFlags. | |
83 PrefRegistrationFlagsMap registration_flags_; | |
84 | |
85 private: | |
86 DISALLOW_COPY_AND_ASSIGN(PrefRegistry); | |
87 }; | |
88 | |
89 #endif // BASE_PREFS_PREF_REGISTRY_H_ | |
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