Fix for Bug 50726 "Save extension list and "winning" prefs from extensions"

chrome/browser/extensions/extension_pref_store.h

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_PREF_STORE_H_
-#define CHROME_BROWSER_EXTENSIONS_EXTENSION_PREF_STORE_H_
-#pragma once
-
-#include <list>
-#include <map>
-#include <string>
-#include <utility>
-#include <vector>
-
-#include "base/basictypes.h"
-#include "base/scoped_ptr.h"
-#include "base/stl_util-inl.h"
-#include "chrome/browser/prefs/pref_notifier.h"
-#include "chrome/common/notification_observer.h"
-#include "chrome/common/notification_registrar.h"
-#include "chrome/common/pref_store.h"
-
-class DictionaryValue;
-class Extension;
-class PrefService;
-class Profile;
-class Value;
-
-// This PrefStore keeps track of preferences set by extensions: for example,
-// proxy settings. A stack of relevant extensions is stored in order of
-// their addition to this PrefStore. For each preference, the last-added
-// enabled extension that tries to set it overrules any others.
-class ExtensionPrefStore : public PrefStore,
-                           public NotificationObserver {
- public:
-  // Maps preference paths to their values.
-  typedef std::map<const char*, Value*> PrefValueMap;
-
-  // The type passed as Details for an EXTENSION_PREF_CHANGED notification.
-  // The nested pairs are <extension, <pref_path, pref_value> >. This is here,
-  // rather than in (say) notification_type.h, to keep the dependency on
-  // std::pair out of the many places that include notification_type.h.
-  typedef std::pair<const Extension*, std::pair<const char*, Value*> >
-      ExtensionPrefDetails;
-
-  ExtensionPrefStore(Profile* profile, PrefNotifier::PrefStoreType type);
-  virtual ~ExtensionPrefStore();
-
-  // Begins tracking the preference and value an extension wishes to set. This
-  // must be called each time an extension API tries to set a preference.
-  // The ExtensionPrefStore will take ownership of the |pref_value|.
-  virtual void InstallExtensionPref(const Extension* extension,
-                                    const char* pref_path,
-                                    Value* pref_value);
-
-  // Removes an extension and all its preference settings from this PrefStore.
-  // This must be called when an extension is uninstalled or disabled.
-  virtual void UninstallExtension(const Extension* extension);
-
-  // PrefStore methods:
-  virtual DictionaryValue* prefs() const { return prefs_.get(); }
-
-  virtual PrefReadError ReadPrefs() { return PREF_READ_ERROR_NONE; }
-
- protected:
-  // Returns a vector of the extension IDs in the extension_stack_.
-  // This should only be accessed by subclasses for unit-testing.
-  void GetExtensionIDs(std::vector<std::string>* result);
-
-  // Returns the applicable pref service from the profile (if we have one) or
-  // the browser's local state. This should only be accessed or overridden by
-  // subclasses for unit-testing.
-  virtual PrefService* GetPrefService();
-
- private:
-  // Associates an extension with the prefs it sets. Owns the pref values.
-  struct ExtensionPrefs {
-    ExtensionPrefs(const Extension* extension, PrefValueMap* values);
-    ~ExtensionPrefs();
-
-    const Extension* extension;
-    PrefValueMap* pref_values;
-  };
-
-  // A pseudo-stack of extensions and their preferences. Extensions are always
-  // added to the head, but may be removed from the middle.
-  typedef std::list<ExtensionPrefs*> ExtensionStack;
-
-  // Applies the highest-priority extension's setting for the given preference
-  // path to the |prefs_| store, or clears the setting there if no extensions
-  // wish to control it.
-  void UpdateOnePref(const char* path);
-
-  // Updates each preference in the key set of the |pref_values| map.
-  void UpdatePrefs(const PrefValueMap* pref_values);
-
-  // Registers this as an observer for relevant notifications.
-  void RegisterObservers();
-
-  // Responds to observed notifications.
-  void Observe(NotificationType type,
-               const NotificationSource& source,
-               const NotificationDetails& details);
-
-  // A cache of the highest-priority values for each preference that any
-  // extension is controlling, for quick read access. Owns the stored values.
-  scoped_ptr<DictionaryValue> prefs_;
-
-  ExtensionStack extension_stack_;
-
-  NotificationRegistrar notification_registrar_;
-
-  // Weak reference to the profile whose extensions we're interested in. May be
-  // NULL (for the local-state preferences), in which case we watch all
-  // extensions.
-  Profile* profile_;
-
-  // My PrefStore type, assigned by the PrefValueStore.
-  PrefNotifier::PrefStoreType type_;
-
-  DISALLOW_COPY_AND_ASSIGN(ExtensionPrefStore);
-};
-
-#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_PREF_STORE_H_