Source/WebCore/dom/InternalObserver.h

/*
 * Copyright (C) 2024 Keith Cirkel <webkit@keithcirkel.co.uk>. 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 "ActiveDOMObject.h"
#include <wtf/RefCounted.h>

namespace JSC {
class AbstractSlotVisitor;
class JSValue;
} // namespace JSC

namespace WebCore {

class InternalObserver : public ActiveDOMObject, public RefCounted<InternalObserver> {
public:
    void ref() const final { RefCounted::ref(); }
    void deref() const final { RefCounted::deref(); }

    virtual ~InternalObserver() = default;

    virtual void next(JSC::JSValue) = 0;
    virtual void complete()
    {
        m_active = false;
    }

    virtual void error(JSC::JSValue);

    virtual void visitAdditionalChildren(JSC::AbstractSlotVisitor&) const = 0;

protected:
    bool m_active { true };

    InternalObserver(ScriptExecutionContext& context)
        : ActiveDOMObject(&context)
    {
    }

    // ActiveDOMObject
    void stop() override { }
    bool virtualHasPendingActivity() const override { return m_active; }
};

} // namespace WebCore