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 EXTENSIONS_BROWSER_EXTENSION_PREF_VALUE_MAP_H_ 6 #define EXTENSIONS_BROWSER_EXTENSION_PREF_VALUE_MAP_H_ 7 8 #include <map> 9 #include <set> 10 #include <string> 11 12 #include "base/observer_list.h" 13 #include "base/prefs/pref_value_map.h" 14 #include "base/time/time.h" 15 #include "base/values.h" 16 #include "components/keyed_service/core/keyed_service.h" 17 #include "extensions/browser/extension_prefs_scope.h" 18 19 // Non-persistent data container that is shared by ExtensionPrefStores. All 20 // extension pref values (incognito and regular) are stored herein and 21 // provided to ExtensionPrefStores. 22 // 23 // The semantics of the ExtensionPrefValueMap are: 24 // - A regular setting applies to regular browsing sessions as well as incognito 25 // browsing sessions. 26 // - An incognito setting applies only to incognito browsing sessions, not to 27 // regular ones. It takes precedence over a regular setting set by the same 28 // extension. 29 // - A regular-only setting applies only to regular browsing sessions, not to 30 // incognito ones. It takes precedence over a regular setting set by the same 31 // extension. 32 // - If two different extensions set a value for the same preference (and both 33 // values apply to the regular/incognito browsing session), the extension that 34 // was installed later takes precedence, regardless of whether the settings 35 // are regular, incognito or regular-only. 36 // 37 // The following table illustrates the behavior: 38 // A.reg | A.reg_only | A.inc | B.reg | B.reg_only | B.inc | E.reg | E.inc 39 // 1 | - | - | - | - | - | 1 | 1 40 // 1 | 2 | - | - | - | - | 2 | 1 41 // 1 | - | 3 | - | - | - | 1 | 3 42 // 1 | 2 | 3 | - | - | - | 2 | 3 43 // 1 | - | - | 4 | - | - | 4 | 4 44 // 1 | 2 | 3 | 4 | - | - | 4 | 4 45 // 1 | - | - | - | 5 | - | 5 | 1 46 // 1 | - | 3 | 4 | 5 | - | 5 | 4 47 // 1 | - | - | - | - | 6 | 1 | 6 48 // 1 | 2 | - | 4 | - | 6 | 4 | 6 49 // 1 | 2 | 3 | - | 5 | 6 | 5 | 6 50 // 51 // A = extension A, B = extension B, E = effective value 52 // .reg = regular value 53 // .reg_only = regular-only value 54 // .inc = incognito value 55 // Extension B has higher precedence than A. 56 class ExtensionPrefValueMap : public KeyedService { 57 public: 58 // Observer interface for monitoring ExtensionPrefValueMap. 59 class Observer { 60 public: 61 // Called when the value for the given |key| set by one of the extensions 62 // changes. This does not necessarily mean that the effective value has 63 // changed. 64 virtual void OnPrefValueChanged(const std::string& key) = 0; 65 // Notification about the ExtensionPrefValueMap being fully initialized. 66 virtual void OnInitializationCompleted() = 0; 67 // Called when the ExtensionPrefValueMap is being destroyed. When called, 68 // observers must unsubscribe. 69 virtual void OnExtensionPrefValueMapDestruction() = 0; 70 71 protected: ~Observer()72 virtual ~Observer() {} 73 }; 74 75 ExtensionPrefValueMap(); 76 virtual ~ExtensionPrefValueMap(); 77 78 // KeyedService implementation. 79 virtual void Shutdown() OVERRIDE; 80 81 // Set an extension preference |value| for |key| of extension |ext_id|. 82 // Takes ownership of |value|. 83 // Note that regular extension pref values need to be reported to 84 // incognito and to regular ExtensionPrefStores. 85 // Precondition: the extension must be registered. 86 void SetExtensionPref(const std::string& ext_id, 87 const std::string& key, 88 extensions::ExtensionPrefsScope scope, 89 base::Value* value); 90 91 // Remove the extension preference value for |key| of extension |ext_id|. 92 // Precondition: the extension must be registered. 93 void RemoveExtensionPref(const std::string& ext_id, 94 const std::string& key, 95 extensions::ExtensionPrefsScope scope); 96 97 // Returns true if currently no extension with higher precedence controls the 98 // preference. If |incognito| is true and the extension does not have 99 // incognito permission, CanExtensionControlPref returns false. 100 // Note that this function does does not consider the existence of 101 // policies. An extension is only really able to control a preference if 102 // PrefService::Preference::IsExtensionModifiable() returns true as well. 103 bool CanExtensionControlPref(const std::string& extension_id, 104 const std::string& pref_key, 105 bool incognito) const; 106 107 // Removes all "incognito session only" preference values. 108 void ClearAllIncognitoSessionOnlyPreferences(); 109 110 // Returns true if an extension identified by |extension_id| controls the 111 // preference. This means this extension has set a preference value and no 112 // other extension with higher precedence overrides it. If |from_incognito| 113 // is not NULL, looks at incognito preferences first, and |from_incognito| is 114 // set to true if the effective pref value is coming from the incognito 115 // preferences, false if it is coming from the normal ones. 116 // Note that the this function does does not consider the existence of 117 // policies. An extension is only really able to control a preference if 118 // PrefService::Preference::IsExtensionModifiable() returns true as well. 119 bool DoesExtensionControlPref(const std::string& extension_id, 120 const std::string& pref_key, 121 bool* from_incognito) const; 122 123 // Returns the ID of the extension that currently controls this preference 124 // for a regular profile. Incognito settings are ignored. 125 // Returns an empty string if this preference is not controlled by an 126 // extension. 127 std::string GetExtensionControllingPref(const std::string& pref_key) const; 128 129 // Tell the store it's now fully initialized. 130 void NotifyInitializationCompleted(); 131 132 // Registers the time when an extension |ext_id| is installed. 133 void RegisterExtension(const std::string& ext_id, 134 const base::Time& install_time, 135 bool is_enabled, 136 bool is_incognito_enabled); 137 138 // Deletes all entries related to extension |ext_id|. 139 void UnregisterExtension(const std::string& ext_id); 140 141 // Hides or makes the extension preference values of the specified extension 142 // visible. 143 void SetExtensionState(const std::string& ext_id, bool is_enabled); 144 145 // Sets whether the extension has permission to access incognito state. 146 void SetExtensionIncognitoState(const std::string& ext_id, 147 bool is_incognito_enabled); 148 149 // Adds an observer and notifies it about the currently stored keys. 150 void AddObserver(Observer* observer); 151 152 void RemoveObserver(Observer* observer); 153 154 const base::Value* GetEffectivePrefValue(const std::string& key, 155 bool incognito, 156 bool* from_incognito) const; 157 158 private: 159 struct ExtensionEntry; 160 161 typedef std::map<std::string, ExtensionEntry*> ExtensionEntryMap; 162 163 const PrefValueMap* GetExtensionPrefValueMap( 164 const std::string& ext_id, 165 extensions::ExtensionPrefsScope scope) const; 166 167 PrefValueMap* GetExtensionPrefValueMap( 168 const std::string& ext_id, 169 extensions::ExtensionPrefsScope scope); 170 171 // Returns all keys of pref values that are set by the extension of |entry|, 172 // regardless whether they are set for incognito or regular pref values. 173 void GetExtensionControlledKeys(const ExtensionEntry& entry, 174 std::set<std::string>* out) const; 175 176 // Returns an iterator to the extension which controls the preference |key|. 177 // If |incognito| is true, looks at incognito preferences first. In that case, 178 // if |from_incognito| is not NULL, it is set to true if the effective pref 179 // value is coming from the incognito preferences, false if it is coming from 180 // the normal ones. 181 ExtensionEntryMap::const_iterator GetEffectivePrefValueController( 182 const std::string& key, 183 bool incognito, 184 bool* from_incognito) const; 185 186 void NotifyOfDestruction(); 187 void NotifyPrefValueChanged(const std::string& key); 188 void NotifyPrefValueChanged(const std::set<std::string>& keys); 189 190 // Mapping of which extension set which preference value. The effective 191 // preferences values (i.e. the ones with the highest precedence) 192 // are stored in ExtensionPrefStores. 193 ExtensionEntryMap entries_; 194 195 // In normal Profile shutdown, Shutdown() notifies observers that we are 196 // being destroyed. In tests, it isn't called, so the notification must 197 // be done in the destructor. This bit tracks whether it has been done yet. 198 bool destroyed_; 199 200 ObserverList<Observer, true> observers_; 201 202 DISALLOW_COPY_AND_ASSIGN(ExtensionPrefValueMap); 203 }; 204 205 #endif // EXTENSIONS_BROWSER_EXTENSION_PREF_VALUE_MAP_H_ 206