root/Source/core/dom/MutationObserverInterestGroup.cpp

DEFINITIONS

1. createIfNeeded
2. isOldValueRequested
3. enqueueMutationRecord

/*
 * 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
 * met:
 *
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 * notice, this list of conditions and the following disclaimer.
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 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#include "config.h"

#include "core/dom/MutationObserverInterestGroup.h"

#include "core/dom/MutationRecord.h"

namespace WebCore {

PassOwnPtr<MutationObserverInterestGroup> MutationObserverInterestGroup::createIfNeeded(Node& target, MutationObserver::MutationType type, MutationRecordDeliveryOptions oldValueFlag, const QualifiedName* attributeName)
{
    ASSERT((type == MutationObserver::Attributes && attributeName) || !attributeName);
    HashMap<MutationObserver*, MutationRecordDeliveryOptions> observers;
    target.getRegisteredMutationObserversOfType(observers, type, attributeName);
    if (observers.isEmpty())
        return nullptr;

    return adoptPtr(new MutationObserverInterestGroup(observers, oldValueFlag));
}

MutationObserverInterestGroup::MutationObserverInterestGroup(HashMap<MutationObserver*, MutationRecordDeliveryOptions>& observers, MutationRecordDeliveryOptions oldValueFlag)
    : m_oldValueFlag(oldValueFlag)
{
    ASSERT(!observers.isEmpty());
    m_observers.swap(observers);
}

bool MutationObserverInterestGroup::isOldValueRequested()
{
    for (HashMap<MutationObserver*, MutationRecordDeliveryOptions>::iterator iter = m_observers.begin(); iter != m_observers.end(); ++iter) {
        if (hasOldValue(iter->value))
            return true;
    }
    return false;
}

void MutationObserverInterestGroup::enqueueMutationRecord(PassRefPtr<MutationRecord> prpMutation)
{
    RefPtr<MutationRecord> mutation = prpMutation;
    RefPtr<MutationRecord> mutationWithNullOldValue;
    for (HashMap<MutationObserver*, MutationRecordDeliveryOptions>::iterator iter = m_observers.begin(); iter != m_observers.end(); ++iter) {
        MutationObserver* observer = iter->key;
        if (hasOldValue(iter->value)) {
            observer->enqueueMutationRecord(mutation);
            continue;
        }
        if (!mutationWithNullOldValue) {
            if (mutation->oldValue().isNull())
                mutationWithNullOldValue = mutation;
            else
                mutationWithNullOldValue = MutationRecord::createWithNullOldValue(mutation).get();
        }
        observer->enqueueMutationRecord(mutationWithNullOldValue);
    }
}

} // namespace WebCore