Source/WebCore/dom/ScopedEventQueue.cpp

/*
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 * in the documentation and/or other materials provided with the
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 *
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#include "config.h"
#include "ScopedEventQueue.h"

#include "Event.h"
#include "Node.h"
#include <wtf/NeverDestroyed.h>

namespace WebCore {

ScopedEventQueue& ScopedEventQueue::singleton()
{
    static NeverDestroyed<ScopedEventQueue> scopedEventQueue;
    return scopedEventQueue;
}

void ScopedEventQueue::enqueueEvent(Ref<Event>&& event)
{
    ASSERT(is<Node>(event->target()));
    auto& target = downcast<Node>(*event->target());
    ScopedEvent scopedEvent = { WTFMove(event), target };
    if (m_scopingLevel)
        m_queuedEvents.append(WTFMove(scopedEvent));
    else
        dispatchEvent(scopedEvent);
}

void ScopedEventQueue::dispatchEvent(const ScopedEvent& event) const
{
    event.target->dispatchEvent(event.event);
}

void ScopedEventQueue::dispatchAllEvents()
{
    auto queuedEvents = std::exchange(m_queuedEvents, { });
    for (auto& queuedEvent : queuedEvents)
        dispatchEvent(queuedEvent);
}

void ScopedEventQueue::incrementScopingLevel()
{
    ++m_scopingLevel;
}

void ScopedEventQueue::decrementScopingLevel()
{
    ASSERT(m_scopingLevel);
    --m_scopingLevel;
    if (!m_scopingLevel)
        dispatchAllEvents();
}

}