pc/dtmfsender.h

/*
 *  Copyright 2012 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#ifndef PC_DTMFSENDER_H_
#define PC_DTMFSENDER_H_

#include <string>

#include "api/dtmfsenderinterface.h"
#include "api/mediastreaminterface.h"
#include "api/proxy.h"
#include "rtc_base/constructormagic.h"
#include "rtc_base/messagehandler.h"
#include "rtc_base/refcount.h"

// DtmfSender is the native implementation of the RTCDTMFSender defined by
// the WebRTC W3C Editor's Draft.
// http://dev.w3.org/2011/webrtc/editor/webrtc.html

namespace rtc {
class Thread;
}

namespace webrtc {

// This interface is called by DtmfSender to talk to the actual audio channel
// to send DTMF.
class DtmfProviderInterface {
 public:
  // Returns true if the audio sender is capable of sending DTMF. Otherwise
  // returns false.
  virtual bool CanInsertDtmf() = 0;
  // Sends DTMF |code|.
  // The |duration| indicates the length of the DTMF tone in ms.
  // Returns true on success and false on failure.
  virtual bool InsertDtmf(int code, int duration) = 0;
  // Returns a |sigslot::signal0<>| signal. The signal should fire before
  // the provider is destroyed.
  virtual sigslot::signal0<>* GetOnDestroyedSignal() = 0;

 protected:
  virtual ~DtmfProviderInterface() {}
};

class DtmfSender
    : public DtmfSenderInterface,
      public sigslot::has_slots<>,
      public rtc::MessageHandler {
 public:
  // |track| is only there for backwards compatibility, since there's a track
  // accessor method.
  static rtc::scoped_refptr<DtmfSender> Create(
      AudioTrackInterface* track,
      rtc::Thread* signaling_thread,
      DtmfProviderInterface* provider);

  // Implements DtmfSenderInterface.
  void RegisterObserver(DtmfSenderObserverInterface* observer) override;
  void UnregisterObserver() override;
  bool CanInsertDtmf() override;
  bool InsertDtmf(const std::string& tones,
                  int duration,
                  int inter_tone_gap) override;
  const AudioTrackInterface* track() const override;
  std::string tones() const override;
  int duration() const override;
  int inter_tone_gap() const override;

 protected:
  DtmfSender(AudioTrackInterface* track,
             rtc::Thread* signaling_thread,
             DtmfProviderInterface* provider);
  virtual ~DtmfSender();

 private:
  DtmfSender();

  // Implements MessageHandler.
  void OnMessage(rtc::Message* msg) override;

  // The DTMF sending task.
  void DoInsertDtmf();

  void OnProviderDestroyed();

  void StopSending();

  rtc::scoped_refptr<AudioTrackInterface> track_;
  DtmfSenderObserverInterface* observer_;
  rtc::Thread* signaling_thread_;
  DtmfProviderInterface* provider_;
  std::string tones_;
  int duration_;
  int inter_tone_gap_;

  RTC_DISALLOW_COPY_AND_ASSIGN(DtmfSender);
};

// Define proxy for DtmfSenderInterface.
BEGIN_SIGNALING_PROXY_MAP(DtmfSender)
  PROXY_SIGNALING_THREAD_DESTRUCTOR()
  PROXY_METHOD1(void, RegisterObserver, DtmfSenderObserverInterface*)
  PROXY_METHOD0(void, UnregisterObserver)
  PROXY_METHOD0(bool, CanInsertDtmf)
  PROXY_METHOD3(bool, InsertDtmf, const std::string&, int, int)
  PROXY_CONSTMETHOD0(const AudioTrackInterface*, track)
  PROXY_CONSTMETHOD0(std::string, tones)
  PROXY_CONSTMETHOD0(int, duration)
  PROXY_CONSTMETHOD0(int, inter_tone_gap)
END_PROXY_MAP()

// Get DTMF code from the DTMF event character.
bool GetDtmfCode(char tone, int* code);

}  // namespace webrtc

#endif  // PC_DTMFSENDER_H_