third_party/WebKit/public/web/WebSpeechRecognizerClient.h

/*
 * Copyright (C) 2012 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef WebSpeechRecognizerClient_h
#define WebSpeechRecognizerClient_h

#include "../platform/WebVector.h"

namespace blink {

class WebSpeechRecognitionResult;
class WebSpeechRecognitionHandle;
class WebString;

// A client for reporting progress on speech recognition for a specific handle.
class WebSpeechRecognizerClient {
 public:
  enum ErrorCode {
    OtherError = 0,
    NoSpeechError = 1,
    AbortedError = 2,
    AudioCaptureError = 3,
    NetworkError = 4,
    NotAllowedError = 5,
    ServiceNotAllowedError = 6,
    BadGrammarError = 7,
    LanguageNotSupportedError = 8
  };

  // These methods correspond to the events described in the spec:
  // http://speech-javascript-api-spec.googlecode.com/git/speechapi.html#speechreco-events

  // To be called when the embedder has started to capture audio.
  virtual void didStartAudio(const WebSpeechRecognitionHandle&) = 0;

  // To be called when some sound, possibly speech, has been detected.
  // This is expected to be called after didStartAudio.
  virtual void didStartSound(const WebSpeechRecognitionHandle&) = 0;

  // To be called when sound is no longer detected.
  // This is expected to be called after didEndSpeech.
  virtual void didEndSound(const WebSpeechRecognitionHandle&) = 0;

  // To be called when audio capture has stopped.
  // This is expected to be called after didEndSound.
  virtual void didEndAudio(const WebSpeechRecognitionHandle&) = 0;

  // To be called when the speech recognizer provides new results.
  // - newFinalResults contains zero or more final results that are new since
  // the last time the function was called.
  // - currentInterimResults contains zero or more inteirm results that
  // replace the interim results that were reported the last time this
  // function was called.
  virtual void didReceiveResults(
      const WebSpeechRecognitionHandle&,
      const WebVector<WebSpeechRecognitionResult>& newFinalResults,
      const WebVector<WebSpeechRecognitionResult>& currentInterimResults) = 0;

  // To be called when the speech recognizer returns a final result with no
  // recognizion hypothesis.
  virtual void didReceiveNoMatch(const WebSpeechRecognitionHandle&,
                                 const WebSpeechRecognitionResult&) = 0;

  // To be called when a speech recognition error occurs.
  virtual void didReceiveError(const WebSpeechRecognitionHandle&,
                               const WebString& message,
                               ErrorCode) = 0;

  // To be called when the recognizer has begun to listen to the audio with
  // the intention of recognizing.
  virtual void didStart(const WebSpeechRecognitionHandle&) = 0;

  // To be called when the recognition session has ended. This must always be
  // called, no matter the reason for the end.
  virtual void didEnd(const WebSpeechRecognitionHandle&) = 0;

 protected:
  virtual ~WebSpeechRecognizerClient() {}
};

}  // namespace blink

#endif  // WebSpeechRecognizerClient_h