chrome/browser/content_settings/content_settings_pref_provider.h

// Copyright (c) 2012 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_CONTENT_SETTINGS_CONTENT_SETTINGS_PREF_PROVIDER_H_
#define CHROME_BROWSER_CONTENT_SETTINGS_CONTENT_SETTINGS_PREF_PROVIDER_H_

// A content settings provider that takes its settings out of the pref service.

#include <vector>

#include "base/basictypes.h"
#include "base/prefs/pref_change_registrar.h"
#include "base/synchronization/lock.h"
#include "chrome/browser/content_settings/content_settings_observable_provider.h"
#include "chrome/browser/content_settings/content_settings_origin_identifier_value_map.h"
#include "chrome/browser/content_settings/content_settings_utils.h"

class PrefService;

namespace base {
class DictionaryValue;
}

namespace user_prefs {
class PrefRegistrySyncable;
}

namespace content_settings {

// Content settings provider that provides content settings from the user
// preference.
class PrefProvider : public ObservableProvider {
 public:
  static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);

  PrefProvider(PrefService* prefs, bool incognito);
  virtual ~PrefProvider();

  // ProviderInterface implementations.
  virtual RuleIterator* GetRuleIterator(
      ContentSettingsType content_type,
      const ResourceIdentifier& resource_identifier,
      bool incognito) const OVERRIDE;

  virtual bool SetWebsiteSetting(
      const ContentSettingsPattern& primary_pattern,
      const ContentSettingsPattern& secondary_pattern,
      ContentSettingsType content_type,
      const ResourceIdentifier& resource_identifier,
      base::Value* value) OVERRIDE;

  virtual void ClearAllContentSettingsRules(
      ContentSettingsType content_type) OVERRIDE;

  virtual void ShutdownOnUIThread() OVERRIDE;

 private:
  friend class DeadlockCheckerThread;  // For testing.
  // Reads all content settings exceptions from the preference and load them
  // into the |value_map_|. The |value_map_| is cleared first if |overwrite| is
  // true.
  void ReadContentSettingsFromPref(bool overwrite);

  // Callback for changes in the pref with the same name.
  void OnContentSettingsPatternPairsChanged();

  // Update the preference that stores content settings exceptions and syncs the
  // value to the obsolete preference. When calling this function, |lock_|
  // should not be held, since this function will send out notifications of
  // preference changes.
  void UpdatePref(
      const ContentSettingsPattern& primary_pattern,
      const ContentSettingsPattern& secondary_pattern,
      ContentSettingsType content_type,
      const ResourceIdentifier& resource_identifier,
      const base::Value* value);

  // Migrate the old media setting into new mic/camera content settings.
  void MigrateObsoleteMediaContentSetting();

  static void CanonicalizeContentSettingsExceptions(
      base::DictionaryValue* all_settings_dictionary);

  // In the debug mode, asserts that |lock_| is not held by this thread. It's
  // ok if some other thread holds |lock_|, as long as it will eventually
  // release it.
  void AssertLockNotHeld() const;

  // Weak; owned by the Profile and reset in ShutdownOnUIThread.
  PrefService* prefs_;

  bool is_incognito_;

  PrefChangeRegistrar pref_change_registrar_;

  // Whether we are currently updating preferences, this is used to ignore
  // notifications from the preferences service that we triggered ourself.
  bool updating_preferences_;

  OriginIdentifierValueMap value_map_;

  OriginIdentifierValueMap incognito_value_map_;

  // Used around accesses to the value map objects to guarantee thread safety.
  mutable base::Lock lock_;

  DISALLOW_COPY_AND_ASSIGN(PrefProvider);
};

}  // namespace content_settings

#endif  // CHROME_BROWSER_CONTENT_SETTINGS_CONTENT_SETTINGS_PREF_PROVIDER_H_