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/public/pref_change_registrar.h"
  13 #include "base/prefs/public/pref_observer.h"
  14 #include "base/synchronization/lock.h"
  15 #include "base/threading/non_thread_safe.h"
  16 #include "chrome/browser/profiles/profile_keyed_service.h"
  17 #include "chrome/browser/profiles/profile_keyed_service_factory.h"
  18 #include "content/public/browser/speech_recognition_preferences.h"
  19
  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 PrefObserver {
  38  public:
  39   static void InitializeFactory();
  40   static scoped_refptr<ChromeSpeechRecognitionPreferences> GetForProfile(
  41       Profile* profile);
  42
  43   // PrefObserver implementation.
  44   virtual void OnPreferenceChanged(PrefServiceBase* service,
  45                                    const std::string& pref_name) OVERRIDE;
  46
  47
  48   // content::SpeechRecognitionPreferences implementation.
  49   // Called by both Content (on IO thread) and Chrome (on UI thread).
  50   virtual bool FilterProfanities() const OVERRIDE;
  51
  52   // Called only by Chrome (on UI thread).
  53   void SetFilterProfanities(bool filter_profanities);
  54   void ToggleFilterProfanities();
  55   bool ShouldShowSecurityNotification(const std::string& context_name) const;
  56   void SetHasShownSecurityNotification(const std::string& context_name);
  57
  58  private:
  59   // The two classes below are needed to handle storage of speech recognition
  60   // preferences in profile preferences, according to the Chromium Profile
  61   // Architecture document entitled "The New Way: ProfileKeyedServiceFactory".
  62
  63   // Singleton that manages instantiation of ChromeSpeechRecognitionPreferences
  64   // handling its association with Profiles.
  65   class Factory : public ProfileKeyedServiceFactory {
  66    public:
  67     static Factory* GetInstance();
  68     scoped_refptr<ChromeSpeechRecognitionPreferences> GetForProfile(
  69         Profile* profile);
  70
  71    private:
  72     friend struct DefaultSingletonTraits<Factory>;
  73
  74     Factory();
  75     virtual ~Factory();
  76
  77     // ProfileKeyedServiceFactory methods:
  78     virtual ProfileKeyedService* BuildServiceInstanceFor(Profile* profile)
  79         const OVERRIDE;
  80     virtual void RegisterUserPrefs(PrefService* prefs) OVERRIDE;
  81     virtual bool ServiceRedirectedInIncognito() const OVERRIDE;
  82     virtual bool ServiceIsNULLWhileTesting() const OVERRIDE;
  83     virtual bool ServiceIsCreatedWithProfile() const OVERRIDE;
  84
  85     DISALLOW_COPY_AND_ASSIGN(Factory);
  86   };
  87
  88   // This wrapper handles the binding between ChromeSpeechRecognitionPreferences
  89   // instances (which can have a longer lifetime, since they are refcounted) and
  90   // ProfileKeyedService (which lifetime depends on the Profile service). Upon
  91   // profile shutdown, the ChromeSpeechRecognitionPreferences instance is
  92   // detached from profile, meaning that after that point its clients can still
  93   // use it, but preferences will no longer be kept in sync with the profile.
  94   class Service : public ProfileKeyedService {
  95    public:
  96     explicit Service(Profile* profile);
  97     virtual ~Service();
  98
  99     // ProfileKeyedService implementation.
 100     virtual void Shutdown() OVERRIDE;
 101
 102     scoped_refptr<ChromeSpeechRecognitionPreferences> GetPreferences() const;
 103
 104    private:
 105     scoped_refptr<ChromeSpeechRecognitionPreferences> preferences_;
 106
 107     DISALLOW_COPY_AND_ASSIGN(Service);
 108   };
 109
 110   explicit ChromeSpeechRecognitionPreferences(Profile* profile);
 111   virtual ~ChromeSpeechRecognitionPreferences();
 112
 113   void DetachFromProfile();
 114   void ReloadPreference(const std::string& key);
 115
 116   Profile* profile_;  // NULL when detached.
 117   scoped_ptr<PrefChangeRegistrar> pref_change_registrar_;
 118   bool filter_profanities_;
 119   scoped_ptr<base::ListValue> notifications_shown_;
 120
 121   // Lock used to ensure exclusive access to preference variables that are
 122   // accessed by both threads (note: mutable is required to keep getters const).
 123   mutable base::Lock preferences_lock_;
 124
 125   DISALLOW_COPY_AND_ASSIGN(ChromeSpeechRecognitionPreferences);
 126 };
 127
 128 #endif  // CHROME_BROWSER_SPEECH_CHROME_SPEECH_RECOGNITION_PREFERENCES_H_