root/content/browser/speech/speech_recognizer_impl_android.cc

DEFINITIONS

1. state_
2. StartRecognition
3. StartRecognitionOnUIThread
4. AbortRecognition
5. StopAudioCapture
6. IsActive
7. IsCapturingAudio
8. OnAudioStart
9. OnSoundStart
10. OnSoundEnd
11. OnAudioEnd
12. OnRecognitionResults
13. OnRecognitionResultsOnIOThread
14. OnRecognitionError
15. OnRecognitionEnd
16. RegisterSpeechRecognizer

// Copyright 2013 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.

#include "content/browser/speech/speech_recognizer_impl_android.h"

#include "base/android/jni_android.h"
#include "base/android/jni_array.h"
#include "base/android/jni_string.h"
#include "base/android/scoped_java_ref.h"
#include "base/bind.h"
#include "base/strings/utf_string_conversions.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/speech_recognition_event_listener.h"
#include "content/public/browser/speech_recognition_manager.h"
#include "content/public/browser/speech_recognition_session_config.h"
#include "content/public/common/speech_recognition_grammar.h"
#include "content/public/common/speech_recognition_result.h"
#include "jni/SpeechRecognition_jni.h"

using base::android::AppendJavaStringArrayToStringVector;
using base::android::AttachCurrentThread;
using base::android::ConvertUTF8ToJavaString;
using base::android::GetApplicationContext;
using base::android::JavaFloatArrayToFloatVector;

namespace content {

SpeechRecognizerImplAndroid::SpeechRecognizerImplAndroid(
    SpeechRecognitionEventListener* listener,
    int session_id)
    : SpeechRecognizer(listener, session_id),
      state_(STATE_IDLE) {
}

SpeechRecognizerImplAndroid::~SpeechRecognizerImplAndroid() { }

void SpeechRecognizerImplAndroid::StartRecognition(
    const std::string& device_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  // TODO(xians): Open the correct device for speech on Android.
  BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, base::Bind(
      &SpeechRecognitionEventListener::OnRecognitionStart,
      base::Unretained(listener()),
      session_id()));
  SpeechRecognitionSessionConfig config =
      SpeechRecognitionManager::GetInstance()->GetSessionConfig(session_id());
  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, base::Bind(
      &content::SpeechRecognizerImplAndroid::StartRecognitionOnUIThread, this,
      config.language, config.continuous, config.interim_results));
}

void SpeechRecognizerImplAndroid::StartRecognitionOnUIThread(
    std::string language, bool continuous, bool interim_results) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  JNIEnv* env = AttachCurrentThread();
  j_recognition_.Reset(Java_SpeechRecognition_createSpeechRecognition(env,
      GetApplicationContext(), reinterpret_cast<intptr_t>(this)));
  Java_SpeechRecognition_startRecognition(env, j_recognition_.obj(),
      ConvertUTF8ToJavaString(env, language).obj(), continuous,
      interim_results);
}

void SpeechRecognizerImplAndroid::AbortRecognition() {
  if (BrowserThread::CurrentlyOn(BrowserThread::IO)) {
    state_ = STATE_IDLE;
    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, base::Bind(
        &content::SpeechRecognizerImplAndroid::AbortRecognition, this));
    return;
  }
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  JNIEnv* env = AttachCurrentThread();
  if (!j_recognition_.is_null())
    Java_SpeechRecognition_abortRecognition(env, j_recognition_.obj());
}

void SpeechRecognizerImplAndroid::StopAudioCapture() {
  if (BrowserThread::CurrentlyOn(BrowserThread::IO)) {
    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, base::Bind(
        &content::SpeechRecognizerImplAndroid::StopAudioCapture, this));
    return;
  }
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  JNIEnv* env = AttachCurrentThread();
  if (!j_recognition_.is_null())
    Java_SpeechRecognition_stopRecognition(env, j_recognition_.obj());
}

bool SpeechRecognizerImplAndroid::IsActive() const {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  return state_ != STATE_IDLE;
}

bool SpeechRecognizerImplAndroid::IsCapturingAudio() const {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  return state_ == STATE_CAPTURING_AUDIO;
}

void SpeechRecognizerImplAndroid::OnAudioStart(JNIEnv* env, jobject obj) {
  if (BrowserThread::CurrentlyOn(BrowserThread::UI)) {
    BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, base::Bind(
        &SpeechRecognizerImplAndroid::OnAudioStart, this,
        static_cast<JNIEnv*>(NULL), static_cast<jobject>(NULL)));
    return;
  }
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  state_ = STATE_CAPTURING_AUDIO;
  listener()->OnAudioStart(session_id());
}

void SpeechRecognizerImplAndroid::OnSoundStart(JNIEnv* env, jobject obj) {
  if (BrowserThread::CurrentlyOn(BrowserThread::UI)) {
    BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, base::Bind(
        &SpeechRecognizerImplAndroid::OnSoundStart, this,
        static_cast<JNIEnv*>(NULL), static_cast<jobject>(NULL)));
    return;
  }
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  listener()->OnSoundStart(session_id());
}

void SpeechRecognizerImplAndroid::OnSoundEnd(JNIEnv* env, jobject obj) {
  if (BrowserThread::CurrentlyOn(BrowserThread::UI)) {
    BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, base::Bind(
        &SpeechRecognizerImplAndroid::OnSoundEnd, this,
        static_cast<JNIEnv*>(NULL), static_cast<jobject>(NULL)));
    return;
  }
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  listener()->OnSoundEnd(session_id());
}

void SpeechRecognizerImplAndroid::OnAudioEnd(JNIEnv* env, jobject obj) {
  if (BrowserThread::CurrentlyOn(BrowserThread::UI)) {
    BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, base::Bind(
        &SpeechRecognizerImplAndroid::OnAudioEnd, this,
        static_cast<JNIEnv*>(NULL), static_cast<jobject>(NULL)));
    return;
  }
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  if (state_ == STATE_CAPTURING_AUDIO)
    state_ = STATE_AWAITING_FINAL_RESULT;
  listener()->OnAudioEnd(session_id());
}

void SpeechRecognizerImplAndroid::OnRecognitionResults(JNIEnv* env, jobject obj,
    jobjectArray strings, jfloatArray floats, jboolean provisional) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  std::vector<base::string16> options;
  AppendJavaStringArrayToStringVector(env, strings, &options);
  std::vector<float> scores(options.size(), 0.0);
  if (floats != NULL)
    JavaFloatArrayToFloatVector(env, floats, &scores);
  SpeechRecognitionResults results;
  results.push_back(SpeechRecognitionResult());
  SpeechRecognitionResult& result = results.back();
  CHECK_EQ(options.size(), scores.size());
  for (size_t i = 0; i < options.size(); ++i) {
    result.hypotheses.push_back(SpeechRecognitionHypothesis(
        options[i], static_cast<double>(scores[i])));
  }
  result.is_provisional = provisional;
  BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, base::Bind(
      &SpeechRecognizerImplAndroid::OnRecognitionResultsOnIOThread,
      this, results));
}

void SpeechRecognizerImplAndroid::OnRecognitionResultsOnIOThread(
    SpeechRecognitionResults const &results) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  listener()->OnRecognitionResults(session_id(), results);
}

void SpeechRecognizerImplAndroid::OnRecognitionError(JNIEnv* env,
    jobject obj, jint error) {
  if (BrowserThread::CurrentlyOn(BrowserThread::UI)) {
    BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, base::Bind(
        &SpeechRecognizerImplAndroid::OnRecognitionError, this,
        static_cast<JNIEnv*>(NULL), static_cast<jobject>(NULL), error));
    return;
  }
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  SpeechRecognitionErrorCode code =
      static_cast<SpeechRecognitionErrorCode>(error);
  listener()->OnRecognitionError(session_id(), SpeechRecognitionError(code));
}

void SpeechRecognizerImplAndroid::OnRecognitionEnd(JNIEnv* env,
    jobject obj) {
  if (BrowserThread::CurrentlyOn(BrowserThread::UI)) {
    BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, base::Bind(
        &SpeechRecognizerImplAndroid::OnRecognitionEnd, this,
        static_cast<JNIEnv*>(NULL), static_cast<jobject>(NULL)));
    return;
  }
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  state_ = STATE_IDLE;
  listener()->OnRecognitionEnd(session_id());
}

// static
bool SpeechRecognizerImplAndroid::RegisterSpeechRecognizer(JNIEnv* env) {
  return RegisterNativesImpl(env);
}

}  // namespace content