content/browser/speech/speech_recognition_dispatcher_host.h

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_SPEECH_SPEECH_RECOGNITION_DISPATCHER_HOST_H_
#define CONTENT_BROWSER_SPEECH_SPEECH_RECOGNITION_DISPATCHER_HOST_H_

#include <memory>
#include <string>

#include "base/memory/weak_ptr.h"
#include "content/public/browser/browser_message_filter.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/speech_recognition_event_listener.h"
#include "mojo/public/cpp/bindings/pending_receiver.h"
#include "mojo/public/cpp/bindings/pending_remote.h"
#include "mojo/public/cpp/bindings/remote.h"
#include "third_party/blink/public/mojom/speech/speech_recognizer.mojom.h"

namespace network {
class PendingSharedURLLoaderFactory;
}

namespace url {
class Origin;
}

namespace content {

class SpeechRecognitionSession;
class SpeechRecognitionManager;

// SpeechRecognitionDispatcherHost is an implementation of the SpeechRecognizer
// interface that allows a RenderFrame to start a speech recognition session
// in the browser process, by communicating with SpeechRecognitionManager.
class SpeechRecognitionDispatcherHost : public blink::mojom::SpeechRecognizer {
 public:
  SpeechRecognitionDispatcherHost(int render_process_id, int render_frame_id);

  SpeechRecognitionDispatcherHost(const SpeechRecognitionDispatcherHost&) =
      delete;
  SpeechRecognitionDispatcherHost& operator=(
      const SpeechRecognitionDispatcherHost&) = delete;

  ~SpeechRecognitionDispatcherHost() override;
  static void Create(
      int render_process_id,
      int render_frame_id,
      mojo::PendingReceiver<blink::mojom::SpeechRecognizer> receiver);
  base::WeakPtr<SpeechRecognitionDispatcherHost> AsWeakPtr();

  // blink::mojom::SpeechRecognizer implementation
  void Start(
      blink::mojom::StartSpeechRecognitionRequestParamsPtr params) override;

 private:
  static void StartRequestOnUI(
      base::WeakPtr<SpeechRecognitionDispatcherHost>
          speech_recognition_dispatcher_host,
      int render_process_id,
      int render_frame_id,
      blink::mojom::StartSpeechRecognitionRequestParamsPtr params);
  void StartSessionOnIO(
      blink::mojom::StartSpeechRecognitionRequestParamsPtr params,
      int embedder_render_process_id,
      int embedder_render_frame_id,
      const url::Origin& origin,
      bool filter_profanities,
      std::unique_ptr<network::PendingSharedURLLoaderFactory>
          pending_shared_url_loader_factory,
      const std::string& accept_language);

  const int render_process_id_;
  const int render_frame_id_;

  // Used for posting asynchronous tasks (on the IO thread) without worrying
  // about this class being destroyed in the meanwhile (due to browser shutdown)
  // since tasks pending on a destroyed WeakPtr are automatically discarded.
  base::WeakPtrFactory<SpeechRecognitionDispatcherHost> weak_factory_{this};
};

// SpeechRecognitionSession implements the
// blink::mojom::SpeechRecognitionSession interface for a particular session. It
// also acts as a proxy for events sent from SpeechRecognitionManager, and
// forwards the events to the renderer using a
// mojo::Remote<SpeechRecognitionSessionClient> (that is passed from the render
// process).
class SpeechRecognitionSession : public blink::mojom::SpeechRecognitionSession,
                                 public SpeechRecognitionEventListener {
 public:
  explicit SpeechRecognitionSession(
      mojo::PendingRemote<blink::mojom::SpeechRecognitionSessionClient> client);
  ~SpeechRecognitionSession() override;
  base::WeakPtr<SpeechRecognitionSession> AsWeakPtr();

  void SetSessionId(int session_id) { session_id_ = session_id; }

  // blink::mojom::SpeechRecognitionSession implementation.
  void Abort() override;
  void StopCapture() override;

  // SpeechRecognitionEventListener methods.
  void OnRecognitionStart(int session_id) override;
  void OnAudioStart(int session_id) override;
  void OnEnvironmentEstimationComplete(int session_id) override;
  void OnSoundStart(int session_id) override;
  void OnSoundEnd(int session_id) override;
  void OnAudioEnd(int session_id) override;
  void OnRecognitionEnd(int session_id) override;
  void OnRecognitionResults(
      int session_id,
      const std::vector<blink::mojom::SpeechRecognitionResultPtr>& results)
      override;
  void OnRecognitionError(
      int session_id,
      const blink::mojom::SpeechRecognitionError& error) override;
  void OnAudioLevelsChange(int session_id,
                           float volume,
                           float noise_volume) override;

 private:
  void ConnectionErrorHandler();

  int session_id_;
  mojo::Remote<blink::mojom::SpeechRecognitionSessionClient> client_;
  bool stopped_;

  base::WeakPtrFactory<SpeechRecognitionSession> weak_factory_{this};
};

}  // namespace content

#endif  // CONTENT_BROWSER_SPEECH_SPEECH_RECOGNITION_DISPATCHER_HOST_H_