Source/WebCore/dom/MutationObserverInterestGroup.h

/*
 * Copyright (C) 2011 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.
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 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
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 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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#pragma once

#include "Document.h"
#include "MutationObserver.h"
#include <memory>
#include <wtf/HashMap.h>

namespace WebCore {

class QualifiedName;

class MutationObserverInterestGroup {
    WTF_MAKE_FAST_ALLOCATED;
public:
    MutationObserverInterestGroup(HashMap<Ref<MutationObserver>, MutationRecordDeliveryOptions>&&, MutationRecordDeliveryOptions);

    static std::unique_ptr<MutationObserverInterestGroup> createForChildListMutation(Node& target)
    {
        if (!target.document().hasMutationObserversOfType(MutationObserver::ChildList))
            return nullptr;

        MutationRecordDeliveryOptions oldValueFlag = 0;
        return createIfNeeded(target, MutationObserver::ChildList, oldValueFlag);
    }

    static std::unique_ptr<MutationObserverInterestGroup> createForCharacterDataMutation(Node& target)
    {
        if (!target.document().hasMutationObserversOfType(MutationObserver::CharacterData))
            return nullptr;

        return createIfNeeded(target, MutationObserver::CharacterData, MutationObserver::CharacterDataOldValue);
    }

    static std::unique_ptr<MutationObserverInterestGroup> createForAttributesMutation(Node& target, const QualifiedName& attributeName)
    {
        if (!target.document().hasMutationObserversOfType(MutationObserver::Attributes))
            return nullptr;

        return createIfNeeded(target, MutationObserver::Attributes, MutationObserver::AttributeOldValue, &attributeName);
    }

    bool isOldValueRequested() const;
    void enqueueMutationRecord(Ref<MutationRecord>&&);

private:
    static std::unique_ptr<MutationObserverInterestGroup> createIfNeeded(Node& target, MutationObserver::MutationType, MutationRecordDeliveryOptions oldValueFlag, const QualifiedName* attributeName = nullptr);

    bool hasOldValue(MutationRecordDeliveryOptions options) const { return options & m_oldValueFlag; }

    HashMap<Ref<MutationObserver>, MutationRecordDeliveryOptions> m_observers;
    MutationRecordDeliveryOptions m_oldValueFlag;
};

} // namespace WebCore