Adding key press detection in the browser process.

media/audio/audio_input_controller.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 MEDIA_AUDIO_AUDIO_INPUT_CONTROLLER_H_
 #define MEDIA_AUDIO_AUDIO_INPUT_CONTROLLER_H_
 
 #include <string>
 #include "base/atomicops.h"
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/lock.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/thread.h"
 #include "base/timer/timer.h"
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_manager_base.h"
+#include "media/audio/key_press_monitor.h"
 
 // An AudioInputController controls an AudioInputStream and records data
 // from this input stream. The two main methods are Record() and Close() and
 // they are both executed on the audio thread which is injected by the two
 // alternative factory methods, Create() or CreateLowLatency().
 //
 // All public methods of AudioInputController are non-blocking.
 //
 // Here is a state diagram for the AudioInputController:
 //
@@ skipping 38 matching lines @@
 //
 // The audio thread itself is owned by the AudioManager that the
 // AudioInputController holds a reference to.  When performing tasks on the
 // audio thread, the controller must not add or release references to the
 // AudioManager or itself (since it in turn holds a reference to the manager).
 //
 namespace media {
 
 class MEDIA_EXPORT AudioInputController
     : public base::RefCountedThreadSafe<AudioInputController>,
-      public AudioInputStream::AudioInputCallback {
+      public AudioInputStream::AudioInputCallback,
+      public KeyPressMonitor::KeyPressListener {
  public:
   // An event handler that receives events from the AudioInputController. The
   // following methods are all called on the audio thread.
   class MEDIA_EXPORT EventHandler {
    public:
     virtual void OnCreated(AudioInputController* controller) = 0;
     virtual void OnRecording(AudioInputController* controller) = 0;
     virtual void OnError(AudioInputController* controller) = 0;
     virtual void OnData(AudioInputController* controller, const uint8* data,
                         uint32 size) = 0;
 
    protected:
     virtual ~EventHandler() {}
   };
 
   // A synchronous writer interface used by AudioInputController for
   // synchronous writing.
   class SyncWriter {
    public:
     virtual ~SyncWriter() {}
 
     // Notify the synchronous writer about the number of bytes in the
     // soundcard which has been recorded.
     virtual void UpdateRecordedBytes(uint32 bytes) = 0;
 
     // Write certain amount of data from |data|. This method returns
     // number of written bytes.
-    virtual uint32 Write(const void* data, uint32 size, double volume) = 0;
+    virtual uint32 Write(const void* data,
+                         uint32 size,
+                         double volume,
+                         bool key_pressed) = 0;
 
     // Close this synchronous writer.
     virtual void Close() = 0;
   };
 
   // AudioInputController::Create() can use the currently registered Factory
   // to create the AudioInputController. Factory is intended for testing only.
   class Factory {
    public:
-    virtual AudioInputController* Create(AudioManager* audio_manager,
-                                         EventHandler* event_handler,
-                                         AudioParameters params) = 0;
+    virtual AudioInputController* Create(
+        AudioManager* audio_manager,
+        EventHandler* event_handler,
+        AudioParameters params,
+        KeyPressMonitor* key_press_monitor) = 0;
+
    protected:
     virtual ~Factory() {}
   };
 
   // Factory method for creating an AudioInputController.
   // The audio device will be created on the audio thread, and when that is
   // done, the event handler will receive an OnCreated() call from that same
   // thread. |device_id| is the unique ID of the audio device to be opened.
   static scoped_refptr<AudioInputController> Create(
       AudioManager* audio_manager,
       EventHandler* event_handler,
       const AudioParameters& params,
-      const std::string& device_id);
+      const std::string& device_id,
+      KeyPressMonitor* key_press_monitor);
 
   // Sets the factory used by the static method Create(). AudioInputController
   // does not take ownership of |factory|. A value of NULL results in an
   // AudioInputController being created directly.
   static void set_factory_for_testing(Factory* factory) { factory_ = factory; }
   AudioInputStream* stream_for_testing() { return stream_; }
 
   // Factory method for creating an AudioInputController for low-latency mode.
   // The audio device will be created on the audio thread, and when that is
   // done, the event handler will receive an OnCreated() call from that same
   // thread.
   static scoped_refptr<AudioInputController> CreateLowLatency(
       AudioManager* audio_manager,
       EventHandler* event_handler,
       const AudioParameters& params,
       const std::string& device_id,
       // External synchronous writer for audio controller.
-      SyncWriter* sync_writer);
+      SyncWriter* sync_writer,
+      KeyPressMonitor* key_press_monitor);
 
   // Factory method for creating an AudioInputController for low-latency mode,
   // taking ownership of |stream|.  The stream will be opened on the audio
   // thread, and when that is done, the event handler will receive an
   // OnCreated() call from that same thread.
   static scoped_refptr<AudioInputController> CreateForStream(
       const scoped_refptr<base::MessageLoopProxy>& message_loop,
       EventHandler* event_handler,
       AudioInputStream* stream,
       // External synchronous writer for audio controller.
-      SyncWriter* sync_writer);
+      SyncWriter* sync_writer,
+      KeyPressMonitor* key_press_monitor);
 
   // Starts recording using the created audio input stream.
   // This method is called on the creator thread.
   virtual void Record();
 
   // Closes the audio input stream. The state is changed and the resources
   // are freed on the audio thread. |closed_task| is then executed on the thread
   // that called Close().
   // Callbacks (EventHandler and SyncWriter) must exist until |closed_task|
   // is called.
@@ skipping 12 matching lines @@
 
   // AudioInputCallback implementation. Threading details depends on the
   // device-specific implementation.
   virtual void OnData(AudioInputStream* stream, const uint8* src, uint32 size,
                       uint32 hardware_delay_bytes, double volume) OVERRIDE;
   virtual void OnClose(AudioInputStream* stream) OVERRIDE;
   virtual void OnError(AudioInputStream* stream) OVERRIDE;
 
   bool LowLatencyMode() const { return sync_writer_ != NULL; }
 
+  // Impl of KeyPressListener.
+  virtual void OnKeyPressed() OVERRIDE;
+
  protected:
   friend class base::RefCountedThreadSafe<AudioInputController>;
 
   // Internal state of the source.
   enum State {
     kEmpty,
     kCreated,
     kRecording,
     kClosed,
     kError
   };
 
-  AudioInputController(EventHandler* handler, SyncWriter* sync_writer);
+  AudioInputController(EventHandler* handler,
+                       SyncWriter* sync_writer,
+                       KeyPressMonitor* key_press_monitor);
   virtual ~AudioInputController();
 
   // Methods called on the audio thread (owned by the AudioManager).
   void DoCreate(AudioManager* audio_manager, const AudioParameters& params,
                 const std::string& device_id);
   void DoCreateForStream(AudioInputStream* stream_to_control,
                          bool enable_nodata_timer);
   void DoRecord();
   void DoClose();
   void DoReportError();
@@ skipping 44 matching lines @@
 
   base::Lock lock_;
 
   // SyncWriter is used only in low-latency mode for synchronous writing.
   SyncWriter* sync_writer_;
 
   static Factory* factory_;
 
   double max_volume_;
 
+  KeyPressMonitor* key_press_monitor_;
+
+  // True if any key has been pressed after the last OnData call.
+  bool key_pressed_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioInputController);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_INPUT_CONTROLLER_H_