content/browser/speech/speech_recognition_manager_impl.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 CONTENT_BROWSER_SPEECH_SPEECH_RECOGNITION_MANAGER_IMPL_H_
   6 #define CONTENT_BROWSER_SPEECH_SPEECH_RECOGNITION_MANAGER_IMPL_H_
   7
   8 #include <map>
   9 #include <string>
  10
  11 #include "base/basictypes.h"
  12 #include "base/callback.h"
  13 #include "base/compiler_specific.h"
  14 #include "base/memory/weak_ptr.h"
  15 #include "content/browser/renderer_host/media/media_stream_requester.h"
  16 #include "content/public/browser/speech_recognition_event_listener.h"
  17 #include "content/public/browser/speech_recognition_manager.h"
  18 #include "content/public/browser/speech_recognition_session_config.h"
  19 #include "content/public/browser/speech_recognition_session_context.h"
  20 #include "content/public/common/speech_recognition_error.h"
  21
  22 namespace media {
  23 class AudioManager;
  24 }
  25
  26 namespace content {
  27 class BrowserMainLoop;
  28 class MediaStreamManager;
  29 class MediaStreamUIProxy;
  30 class SpeechRecognitionManagerDelegate;
  31 class SpeechRecognizer;
  32
  33 // This is the manager for speech recognition. It is a single instance in
  34 // the browser process and can serve several requests. Each recognition request
  35 // corresponds to a session, initiated via |CreateSession|.
  36 //
  37 // In any moment, the manager has a single session known as the primary session,
  38 // |primary_session_id_|.
  39 // This is the session that is capturing audio, waiting for user permission,
  40 // etc. There may also be other, non-primary, sessions living in parallel that
  41 // are waiting for results but not recording audio.
  42 //
  43 // The SpeechRecognitionManager has the following responsibilities:
  44 //  - Handles requests received from various render views and makes sure only
  45 //    one of them accesses the audio device at any given time.
  46 //  - Handles the instantiation of SpeechRecognitionEngine objects when
  47 //    requested by SpeechRecognitionSessions.
  48 //  - Relays recognition results/status/error events of each session to the
  49 //    corresponding listener (demuxing on the base of their session_id).
  50 //  - Relays also recognition results/status/error events of every session to
  51 //    the catch-all snoop listener (optionally) provided by the delegate.
  52 class CONTENT_EXPORT SpeechRecognitionManagerImpl :
  53     public NON_EXPORTED_BASE(SpeechRecognitionManager),
  54     public SpeechRecognitionEventListener {
  55  public:
  56   // Returns the current SpeechRecognitionManagerImpl or NULL if the call is
  57   // issued when it is not created yet or destroyed (by BrowserMainLoop).
  58   static SpeechRecognitionManagerImpl* GetInstance();
  59
  60   // SpeechRecognitionManager implementation.
  61   int CreateSession(const SpeechRecognitionSessionConfig& config) override;
  62   void StartSession(int session_id) override;
  63   void AbortSession(int session_id) override;
  64   void AbortAllSessionsForRenderProcess(int render_process_id) override;
  65   void AbortAllSessionsForRenderView(int render_process_id,
  66                                      int render_view_id) override;
  67   void StopAudioCaptureForSession(int session_id) override;
  68   const SpeechRecognitionSessionConfig& GetSessionConfig(
  69       int session_id) const override;
  70   SpeechRecognitionSessionContext GetSessionContext(
  71       int session_id) const override;
  72   int GetSession(int render_process_id,
  73                  int render_view_id,
  74                  int request_id) const override;
  75   bool HasAudioInputDevices() override;
  76   base::string16 GetAudioInputDeviceModel() override;
  77   void ShowAudioInputSettings() override;
  78
  79   // SpeechRecognitionEventListener methods.
  80   void OnRecognitionStart(int session_id) override;
  81   void OnAudioStart(int session_id) override;
  82   void OnEnvironmentEstimationComplete(int session_id) override;
  83   void OnSoundStart(int session_id) override;
  84   void OnSoundEnd(int session_id) override;
  85   void OnAudioEnd(int session_id) override;
  86   void OnRecognitionEnd(int session_id) override;
  87   void OnRecognitionResults(int session_id,
  88                             const SpeechRecognitionResults& result) override;
  89   void OnRecognitionError(int session_id,
  90                           const SpeechRecognitionError& error) override;
  91   void OnAudioLevelsChange(int session_id,
  92                            float volume,
  93                            float noise_volume) override;
  94
  95   SpeechRecognitionManagerDelegate* delegate() const { return delegate_.get(); }
  96
  97  protected:
  98   // BrowserMainLoop is the only one allowed to istantiate and free us.
  99   friend class BrowserMainLoop;
 100   // Needed for dtor.
 101   friend struct base::DefaultDeleter<SpeechRecognitionManagerImpl>;
 102   SpeechRecognitionManagerImpl(media::AudioManager* audio_manager,
 103                                MediaStreamManager* media_stream_manager);
 104   ~SpeechRecognitionManagerImpl() override;
 105
 106  private:
 107   // Data types for the internal Finite State Machine (FSM).
 108   enum FSMState {
 109     SESSION_STATE_IDLE = 0,
 110     SESSION_STATE_CAPTURING_AUDIO,
 111     SESSION_STATE_WAITING_FOR_RESULT,
 112     SESSION_STATE_MAX_VALUE = SESSION_STATE_WAITING_FOR_RESULT
 113   };
 114
 115   enum FSMEvent {
 116     EVENT_ABORT = 0,
 117     EVENT_START,
 118     EVENT_STOP_CAPTURE,
 119     EVENT_AUDIO_ENDED,
 120     EVENT_RECOGNITION_ENDED,
 121     EVENT_MAX_VALUE = EVENT_RECOGNITION_ENDED
 122   };
 123
 124   struct Session {
 125     Session();
 126     ~Session();
 127
 128     int id;
 129     bool abort_requested;
 130     bool listener_is_active;
 131     SpeechRecognitionSessionConfig config;
 132     SpeechRecognitionSessionContext context;
 133     scoped_refptr<SpeechRecognizer> recognizer;
 134     scoped_ptr<MediaStreamUIProxy> ui;
 135   };
 136
 137   // Callback issued by the SpeechRecognitionManagerDelegate for reporting
 138   // asynchronously the result of the CheckRecognitionIsAllowed call.
 139   void RecognitionAllowedCallback(int session_id,
 140                                   bool ask_user,
 141                                   bool is_allowed);
 142
 143   // Callback to get back the result of a media request. |devices| is an array
 144   // of devices approved to be used for the request, |devices| is empty if the
 145   // users deny the request.
 146   void MediaRequestPermissionCallback(int session_id,
 147                                       const MediaStreamDevices& devices,
 148                                       scoped_ptr<MediaStreamUIProxy> stream_ui);
 149
 150   // Entry point for pushing any external event into the session handling FSM.
 151   void DispatchEvent(int session_id, FSMEvent event);
 152
 153   // Defines the behavior of the session handling FSM, selecting the appropriate
 154   // transition according to the session, its current state and the event.
 155   void ExecuteTransitionAndGetNextState(Session* session,
 156                                         FSMState session_state,
 157                                         FSMEvent event);
 158
 159   // Retrieves the state of the session, enquiring directly the recognizer.
 160   FSMState GetSessionState(int session_id) const;
 161
 162   // The methods below handle transitions of the session handling FSM.
 163   void SessionStart(const Session& session);
 164   void SessionAbort(const Session& session);
 165   void SessionStopAudioCapture(const Session& session);
 166   void ResetCapturingSessionId(const Session& session);
 167   void SessionDelete(Session* session);
 168   void NotFeasible(const Session& session, FSMEvent event);
 169
 170   bool SessionExists(int session_id) const;
 171   Session* GetSession(int session_id) const;
 172   SpeechRecognitionEventListener* GetListener(int session_id) const;
 173   SpeechRecognitionEventListener* GetDelegateListener() const;
 174   int GetNextSessionID();
 175
 176   media::AudioManager* audio_manager_;
 177   MediaStreamManager* media_stream_manager_;
 178   typedef std::map<int, Session*> SessionsTable;
 179   SessionsTable sessions_;
 180   int primary_session_id_;
 181   int last_session_id_;
 182   bool is_dispatching_event_;
 183   scoped_ptr<SpeechRecognitionManagerDelegate> delegate_;
 184
 185   // Used for posting asynchronous tasks (on the IO thread) without worrying
 186   // about this class being destroyed in the meanwhile (due to browser shutdown)
 187   // since tasks pending on a destroyed WeakPtr are automatically discarded.
 188   base::WeakPtrFactory<SpeechRecognitionManagerImpl> weak_factory_;
 189 };
 190
 191 }  // namespace content
 192
 193 #endif  // CONTENT_BROWSER_SPEECH_SPEECH_RECOGNITION_MANAGER_IMPL_H_