base/prefs/pref_value_map.h

   1 // Copyright (c) 2011 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_VALUE_MAP_H_
   6 #define BASE_PREFS_PREF_VALUE_MAP_H_
   7
   8 #include <map>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/basictypes.h"
  13 #include "base/prefs/base_prefs_export.h"
  14
  15 namespace base {
  16 class Value;
  17 }
  18
  19 // A generic string to value map used by the PrefStore implementations.
  20 class BASE_PREFS_EXPORT PrefValueMap {
  21  public:
  22   typedef std::map<std::string, base::Value*>::iterator iterator;
  23   typedef std::map<std::string, base::Value*>::const_iterator const_iterator;
  24
  25   PrefValueMap();
  26   virtual ~PrefValueMap();
  27
  28   // Gets the value for |key| and stores it in |value|. Ownership remains with
  29   // the map. Returns true if a value is present. If not, |value| is not
  30   // touched.
  31   bool GetValue(const std::string& key, const base::Value** value) const;
  32   bool GetValue(const std::string& key, base::Value** value);
  33
  34   // Sets a new |value| for |key|. Takes ownership of |value|, which must be
  35   // non-NULL. Returns true if the value changed.
  36   bool SetValue(const std::string& key, base::Value* value);
  37
  38   // Removes the value for |key| from the map. Returns true if a value was
  39   // removed.
  40   bool RemoveValue(const std::string& key);
  41
  42   // Clears the map.
  43   void Clear();
  44
  45   // Swaps the contents of two maps.
  46   void Swap(PrefValueMap* other);
  47
  48   iterator begin();
  49   iterator end();
  50   const_iterator begin() const;
  51   const_iterator end() const;
  52
  53   // Gets a boolean value for |key| and stores it in |value|. Returns true if
  54   // the value was found and of the proper type.
  55   bool GetBoolean(const std::string& key, bool* value) const;
  56
  57   // Sets the value for |key| to the boolean |value|.
  58   void SetBoolean(const std::string& key, bool value);
  59
  60   // Gets a string value for |key| and stores it in |value|. Returns true if
  61   // the value was found and of the proper type.
  62   bool GetString(const std::string& key, std::string* value) const;
  63
  64   // Sets the value for |key| to the string |value|.
  65   void SetString(const std::string& key, const std::string& value);
  66
  67   // Gets an int value for |key| and stores it in |value|. Returns true if
  68   // the value was found and of the proper type.
  69   bool GetInteger(const std::string& key, int* value) const;
  70
  71   // Sets the value for |key| to the int |value|.
  72   void SetInteger(const std::string& key, const int value);
  73
  74   // Compares this value map against |other| and stores all key names that have
  75   // different values in |differing_keys|. This includes keys that are present
  76   // only in one of the maps.
  77   void GetDifferingKeys(const PrefValueMap* other,
  78                         std::vector<std::string>* differing_keys) const;
  79
  80  private:
  81   typedef std::map<std::string, base::Value*> Map;
  82
  83   Map prefs_;
  84
  85   DISALLOW_COPY_AND_ASSIGN(PrefValueMap);
  86 };
  87
  88 #endif  // BASE_PREFS_PREF_VALUE_MAP_H_