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_GOOGLE_ONE_SHOT_REMOTE_ENGINE_H_
6#define CONTENT_BROWSER_SPEECH_GOOGLE_ONE_SHOT_REMOTE_ENGINE_H_
7
8#include <string>
9
10#include "base/basictypes.h"
11#include "base/memory/ref_counted.h"
12#include "base/memory/scoped_ptr.h"
13#include "content/browser/speech/audio_encoder.h"
14#include "content/browser/speech/speech_recognition_engine.h"
15#include "content/common/content_export.h"
16#include "net/url_request/url_fetcher_delegate.h"
17
18namespace net {
19class URLRequestContextGetter;
20}
21
22namespace content {
23
24// Implements a SpeechRecognitionEngine by means of remote interaction with
25// Google speech recognition webservice.
26class CONTENT_EXPORT GoogleOneShotRemoteEngine
27    : public NON_EXPORTED_BASE(SpeechRecognitionEngine),
28      public net::URLFetcherDelegate {
29 public:
30  // Duration of each audio packet.
31  static const int kAudioPacketIntervalMs;
32  // ID passed to URLFetcher::Create(). Used for testing.
33  static int url_fetcher_id_for_tests;
34
35  explicit GoogleOneShotRemoteEngine(net::URLRequestContextGetter* context);
36  virtual ~GoogleOneShotRemoteEngine();
37
38  // SpeechRecognitionEngine methods.
39  virtual void SetConfig(const SpeechRecognitionEngineConfig& config) OVERRIDE;
40  virtual void StartRecognition() OVERRIDE;
41  virtual void EndRecognition() OVERRIDE;
42  virtual void TakeAudioChunk(const AudioChunk& data) OVERRIDE;
43  virtual void AudioChunksEnded() OVERRIDE;
44  virtual bool IsRecognitionPending() const OVERRIDE;
45  virtual int GetDesiredAudioChunkDurationMs() const OVERRIDE;
46
47  // net::URLFetcherDelegate methods.
48  virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
49
50 private:
51  SpeechRecognitionEngineConfig config_;
52  scoped_ptr<net::URLFetcher> url_fetcher_;
53  scoped_refptr<net::URLRequestContextGetter> url_context_;
54  scoped_ptr<AudioEncoder> encoder_;
55
56  DISALLOW_COPY_AND_ASSIGN(GoogleOneShotRemoteEngine);
57};
58
59}  // namespace content
60
61#endif  // CONTENT_BROWSER_SPEECH_GOOGLE_ONE_SHOT_REMOTE_ENGINE_H_
62