Source/core/dom/MutationObserverInterestGroup.h

/*
 * Copyright (C) 2011 Google Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
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 *
 *     * 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
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 * in the documentation and/or other materials provided with the
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 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#ifndef MutationObserverInterestGroup_h
#define MutationObserverInterestGroup_h

#include "core/dom/Document.h"
#include "core/dom/MutationObserver.h"
#include "core/dom/Node.h"
#include "core/dom/QualifiedName.h"
#include "wtf/HashMap.h"
#include "wtf/PassOwnPtr.h"

namespace WebCore {

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

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

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

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

    static PassOwnPtr<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();
    void enqueueMutationRecord(PassRefPtr<MutationRecord>);

private:
    static PassOwnPtr<MutationObserverInterestGroup> createIfNeeded(Node& target, MutationObserver::MutationType, MutationRecordDeliveryOptions oldValueFlag, const QualifiedName* attributeName = 0);
    MutationObserverInterestGroup(HashMap<MutationObserver*, MutationRecordDeliveryOptions>& observers, MutationRecordDeliveryOptions oldValueFlag);

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

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

}

#endif // MutationObserverInterestGroup_h