Source/WebCore/Modules/speech/SpeechRecognizer.h

/*
 * Copyright (C) 2020 Apple 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:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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 APPLE INC. AND ITS CONTRIBUTORS ``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 APPLE INC. OR ITS 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 (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include "SpeechRecognitionCaptureSource.h"
#include "SpeechRecognitionConnectionClientIdentifier.h"
#include "SpeechRecognitionError.h"
#include <wtf/UniqueRef.h>

#if HAVE(SPEECHRECOGNIZER)
#include <CoreMedia/CMTime.h>
#include <wtf/RetainPtr.h>
OBJC_CLASS WebSpeechRecognizerTask;
#endif

namespace WebCore {

class SpeechRecognitionRequest;
class SpeechRecognitionUpdate;

class SpeechRecognizer : public CanMakeWeakPtr<SpeechRecognizer> {
    WTF_MAKE_FAST_ALLOCATED;
public:
    using DelegateCallback = Function<void(const SpeechRecognitionUpdate&)>;
    WEBCORE_EXPORT explicit SpeechRecognizer(DelegateCallback&&, UniqueRef<SpeechRecognitionRequest>&&);

#if ENABLE(MEDIA_STREAM)
    WEBCORE_EXPORT void start(Ref<RealtimeMediaSource>&&, bool mockSpeechRecognitionEnabled);
#endif
    WEBCORE_EXPORT void abort(std::optional<SpeechRecognitionError>&& = std::nullopt);
    WEBCORE_EXPORT void stop();
    WEBCORE_EXPORT void prepareForDestruction();

    WEBCORE_EXPORT SpeechRecognitionConnectionClientIdentifier clientIdentifier() const;
    SpeechRecognitionCaptureSource* source() { return m_source.get(); }

    void setInactive() { m_state = State::Inactive; }

private:
    enum class State {
        Inactive,
        Running,
        Stopping,
        Aborting
    };

#if ENABLE(MEDIA_STREAM)
    void startCapture(Ref<RealtimeMediaSource>&&);
#endif
    void stopCapture();
    void dataCaptured(const WTF::MediaTime&, const PlatformAudioData&, const AudioStreamDescription&, size_t sampleCount);
    bool startRecognition(bool mockSpeechRecognitionEnabled, SpeechRecognitionConnectionClientIdentifier, const String& localeIdentifier, bool continuous, bool interimResults, uint64_t alternatives);
    void abortRecognition();
    void stopRecognition();

    DelegateCallback m_delegateCallback;
    UniqueRef<SpeechRecognitionRequest> m_request;
    std::unique_ptr<SpeechRecognitionCaptureSource> m_source;
    State m_state { State::Inactive };

#if HAVE(SPEECHRECOGNIZER)
    RetainPtr<WebSpeechRecognizerTask> m_task;
    CMTime m_currentAudioSampleTime;
#endif
};

} // namespace WebCore