Source/WebCore/dom/ScopedEventQueue.cpp

/*
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#include "config.h"
#include "ScopedEventQueue.h"

#include "Event.h"
#include "EventDispatcher.h"
#include "EventTarget.h"
#include <wtf/RefPtr.h>

namespace WebCore {

ScopedEventQueue::ScopedEventQueue()
    : m_scopingLevel(0)
{
}

ScopedEventQueue::~ScopedEventQueue()
{
    ASSERT(!m_scopingLevel);
    ASSERT(!m_queuedEvents.size());
}

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

void ScopedEventQueue::enqueueEvent(PassRefPtr<Event> event)
{
    if (m_scopingLevel)
        m_queuedEvents.append(event);
    else
        dispatchEvent(event);
}

void ScopedEventQueue::dispatchEvent(PassRefPtr<Event> event) const
{
    ASSERT(event->target());
    // Store the target in a local variable to avoid possibly dereferencing a nullified PassRefPtr after it's passed on.
    Node* node = event->target()->toNode();
    EventDispatcher::dispatchEvent(node, event);
}

void ScopedEventQueue::dispatchAllEvents()
{
    Vector<RefPtr<Event>> queuedEvents = std::move(m_queuedEvents);
    for (size_t i = 0; i < queuedEvents.size(); i++)
        dispatchEvent(queuedEvents[i].release());
}

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

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

}