chrome/browser/speech/chrome_speech_recognition_preferences.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_SPEECH_CHROME_SPEECH_RECOGNITION_PREFERENCES_H_
   6 #define CHROME_BROWSER_SPEECH_CHROME_SPEECH_RECOGNITION_PREFERENCES_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/memory/singleton.h"
  12 #include "base/prefs/pref_change_registrar.h"
  13 #include "base/synchronization/lock.h"
  14 #include "base/threading/non_thread_safe.h"
  15 #include "chrome/browser/profiles/profile_keyed_service.h"
  16 #include "chrome/browser/profiles/profile_keyed_service_factory.h"
  17 #include "content/public/browser/speech_recognition_preferences.h"
  18
  19 class PrefRegistrySyncable;
  20 class PrefService;
  21
  22 namespace base {
  23 class ListValue;
  24 }
  25
  26 // Utility class that handles persistent storage of speech recognition
  27 // preferences. Instances of this class must be obtained exclusively through the
  28 // method ChromeSpeechRecognitionPreferences::GetForProfile(...), so that
  29 // preferences are handled within the Profile (if not NULL). The internal
  30 // factory class also handles ownership and lifetime of the
  31 // ChromeSpeechRecognitionPreferences instances (through the inner Service
  32 // class), allowing them to be used in a detached mode (no persistent storage)
  33 // even when a Profile is not available (or has been shutdown).
  34
  35 class ChromeSpeechRecognitionPreferences
  36     : public content::SpeechRecognitionPreferences {
  37  public:
  38   static void InitializeFactory();
  39   static scoped_refptr<ChromeSpeechRecognitionPreferences> GetForProfile(
  40       Profile* profile);
  41
  42   // content::SpeechRecognitionPreferences implementation.
  43   // Called by both Content (on IO thread) and Chrome (on UI thread).
  44   virtual bool FilterProfanities() const OVERRIDE;
  45
  46   // Called only by Chrome (on UI thread).
  47   void SetFilterProfanities(bool filter_profanities);
  48   void ToggleFilterProfanities();
  49   bool ShouldShowSecurityNotification(const std::string& context_name) const;
  50   void SetHasShownSecurityNotification(const std::string& context_name);
  51
  52  private:
  53   // The two classes below are needed to handle storage of speech recognition
  54   // preferences in profile preferences, according to the Chromium Profile
  55   // Architecture document entitled "The New Way: ProfileKeyedServiceFactory".
  56
  57   // Singleton that manages instantiation of ChromeSpeechRecognitionPreferences
  58   // handling its association with Profiles.
  59   class Factory : public ProfileKeyedServiceFactory {
  60    public:
  61     static Factory* GetInstance();
  62     scoped_refptr<ChromeSpeechRecognitionPreferences> GetForProfile(
  63         Profile* profile);
  64
  65    private:
  66     friend struct DefaultSingletonTraits<Factory>;
  67
  68     Factory();
  69     virtual ~Factory();
  70
  71     // ProfileKeyedServiceFactory methods:
  72     virtual ProfileKeyedService* BuildServiceInstanceFor(Profile* profile)
  73         const OVERRIDE;
  74     virtual void RegisterUserPrefs(PrefRegistrySyncable* registry) OVERRIDE;
  75     virtual bool ServiceRedirectedInIncognito() const OVERRIDE;
  76     virtual bool ServiceIsNULLWhileTesting() const OVERRIDE;
  77     virtual bool ServiceIsCreatedWithProfile() const OVERRIDE;
  78
  79     DISALLOW_COPY_AND_ASSIGN(Factory);
  80   };
  81
  82   // This wrapper handles the binding between ChromeSpeechRecognitionPreferences
  83   // instances (which can have a longer lifetime, since they are refcounted) and
  84   // ProfileKeyedService (which lifetime depends on the Profile service). Upon
  85   // profile shutdown, the ChromeSpeechRecognitionPreferences instance is
  86   // detached from profile, meaning that after that point its clients can still
  87   // use it, but preferences will no longer be kept in sync with the profile.
  88   class Service : public ProfileKeyedService {
  89    public:
  90     explicit Service(Profile* profile);
  91     virtual ~Service();
  92
  93     // ProfileKeyedService implementation.
  94     virtual void Shutdown() OVERRIDE;
  95
  96     scoped_refptr<ChromeSpeechRecognitionPreferences> GetPreferences() const;
  97
  98    private:
  99     scoped_refptr<ChromeSpeechRecognitionPreferences> preferences_;
 100
 101     DISALLOW_COPY_AND_ASSIGN(Service);
 102   };
 103
 104   explicit ChromeSpeechRecognitionPreferences(Profile* profile);
 105   virtual ~ChromeSpeechRecognitionPreferences();
 106
 107   void DetachFromProfile();
 108   void ReloadFilterProfanities();
 109   void ReloadNotificationsShown();
 110
 111   Profile* profile_;  // NULL when detached.
 112   scoped_ptr<PrefChangeRegistrar> pref_change_registrar_;
 113   bool filter_profanities_;
 114   scoped_ptr<base::ListValue> notifications_shown_;
 115
 116   // Lock used to ensure exclusive access to preference variables that are
 117   // accessed by both threads (note: mutable is required to keep getters const).
 118   mutable base::Lock preferences_lock_;
 119
 120   DISALLOW_COPY_AND_ASSIGN(ChromeSpeechRecognitionPreferences);
 121 };
 122
 123 #endif  // CHROME_BROWSER_SPEECH_CHROME_SPEECH_RECOGNITION_PREFERENCES_H_