chrome/browser/chromeos/settings/cros_settings.h

   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
   3 // found in the LICENSE file.
   4
   5 #ifndef CHROME_BROWSER_CHROMEOS_SETTINGS_CROS_SETTINGS_H_
   6 #define CHROME_BROWSER_CHROMEOS_SETTINGS_CROS_SETTINGS_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/callback_forward.h"
  12 #include "base/callback_list.h"
  13 #include "base/containers/hash_tables.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/threading/non_thread_safe.h"
  16 #include "chromeos/settings/cros_settings_names.h"
  17 #include "chromeos/settings/cros_settings_provider.h"
  18
  19 namespace base {
  20 class DictionaryValue;
  21 class ListValue;
  22 class Value;
  23 }
  24
  25 namespace chromeos {
  26
  27 class DeviceSettingsService;
  28
  29 // This class manages per-device/global settings.
  30 class CrosSettings : public base::NonThreadSafe {
  31  public:
  32   // Manage singleton instance.
  33   static void Initialize();
  34   static bool IsInitialized();
  35   static void Shutdown();
  36   static CrosSettings* Get();
  37
  38   // Creates a device settings service instance. This is meant for unit tests,
  39   // production code uses the singleton returned by Get() above.
  40   explicit CrosSettings(DeviceSettingsService* device_settings_service);
  41   virtual ~CrosSettings();
  42
  43   // Helper function to test if the given |path| is a valid cros setting.
  44   static bool IsCrosSettings(const std::string& path);
  45
  46   // Sets |in_value| to given |path| in cros settings.
  47   void Set(const std::string& path, const base::Value& in_value);
  48
  49   // Returns setting value for the given |path|.
  50   const base::Value* GetPref(const std::string& path) const;
  51
  52   // Requests all providers to fetch their values from a trusted store, if they
  53   // haven't done so yet. Returns true if the cros settings returned by |this|
  54   // are trusted during the current loop cycle; otherwise returns false, and
  55   // |callback| will be invoked later when trusted values become available.
  56   // PrepareTrustedValues() should be tried again in that case.
  57   virtual CrosSettingsProvider::TrustedStatus PrepareTrustedValues(
  58       const base::Closure& callback) const;
  59
  60   // Convenience forms of Set().  These methods will replace any existing
  61   // value at that |path|, even if it has a different type.
  62   void SetBoolean(const std::string& path, bool in_value);
  63   void SetInteger(const std::string& path, int in_value);
  64   void SetDouble(const std::string& path, double in_value);
  65   void SetString(const std::string& path, const std::string& in_value);
  66
  67   // Convenience functions for manipulating lists. Note that the following
  68   // functions employs a read, modify and write pattern. If underlying settings
  69   // provider updates its value asynchronously such as DeviceSettingsProvider,
  70   // value cache they read from might not be fresh and multiple calls to those
  71   // function would lose data. See http://crbug.com/127215
  72   void AppendToList(const std::string& path, const base::Value* value);
  73   void RemoveFromList(const std::string& path, const base::Value* value);
  74
  75   // These are convenience forms of Get().  The value will be retrieved
  76   // and the return value will be true if the |path| is valid and the value at
  77   // the end of the path can be returned in the form specified.
  78   bool GetBoolean(const std::string& path, bool* out_value) const;
  79   bool GetInteger(const std::string& path, int* out_value) const;
  80   bool GetDouble(const std::string& path, double* out_value) const;
  81   bool GetString(const std::string& path, std::string* out_value) const;
  82   bool GetList(const std::string& path,
  83                const base::ListValue** out_value) const;
  84   bool GetDictionary(const std::string& path,
  85                      const base::DictionaryValue** out_value) const;
  86
  87   // Helper function for the whitelist op. Implemented here because we will need
  88   // this in a few places. The functions searches for |email| in the pref |path|
  89   // It respects whitelists so foo@bar.baz will match *@bar.baz too.
  90   bool FindEmailInList(const std::string& path, const std::string& email) const;
  91
  92   // Adding/removing of providers.
  93   bool AddSettingsProvider(CrosSettingsProvider* provider);
  94   bool RemoveSettingsProvider(CrosSettingsProvider* provider);
  95
  96   // Add an observer Callback for changes for the given |path|.
  97   typedef base::CallbackList<void(void)>::Subscription ObserverSubscription;
  98   scoped_ptr<ObserverSubscription> AddSettingsObserver(
  99       const std::string& path,
 100       const base::Closure& callback);
 101
 102   // Returns the provider that handles settings with the |path| or prefix.
 103   CrosSettingsProvider* GetProvider(const std::string& path) const;
 104
 105  private:
 106   friend class CrosSettingsTest;
 107
 108   // Fires system setting change callback.
 109   void FireObservers(const std::string& path);
 110
 111   // List of ChromeOS system settings providers.
 112   std::vector<CrosSettingsProvider*> providers_;
 113
 114   // A map from settings names to a list of observers. Observers get fired in
 115   // the order they are added.
 116   typedef base::hash_map<std::string, base::CallbackList<void(void)>*>
 117       SettingsObserverMap;
 118   SettingsObserverMap settings_observers_;
 119
 120   DISALLOW_COPY_AND_ASSIGN(CrosSettings);
 121 };
 122
 123 // Helper class for tests. Initializes the CrosSettings singleton on
 124 // construction and tears it down again on destruction.
 125 class ScopedTestCrosSettings {
 126  public:
 127   ScopedTestCrosSettings();
 128   ~ScopedTestCrosSettings();
 129
 130  private:
 131   DISALLOW_COPY_AND_ASSIGN(ScopedTestCrosSettings);
 132 };
 133
 134 }  // namespace chromeos
 135
 136 #endif  // CHROME_BROWSER_CHROMEOS_SETTINGS_CROS_SETTINGS_H_