Source/WebCore/dom/PseudoElement.cpp

/*
 * Copyright (C) 2012 Google Inc. All rights reserved.
 * Copyright (C) 2017 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
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 *
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#include "config.h"
#include "PseudoElement.h"

#include "ContentData.h"
#include "DocumentTimeline.h"
#include "InspectorInstrumentation.h"
#include "KeyframeEffectStack.h"
#include "RenderElement.h"
#include "RenderImage.h"
#include "RenderQuote.h"
#include "StyleResolver.h"
#include <wtf/IsoMallocInlines.h>

namespace WebCore {

WTF_MAKE_ISO_ALLOCATED_IMPL(PseudoElement);

const QualifiedName& pseudoElementTagName()
{
    static NeverDestroyed<QualifiedName> name(nullAtom(), "<pseudo>", nullAtom());
    return name;
}

PseudoElement::PseudoElement(Element& host, PseudoId pseudoId)
    : Element(pseudoElementTagName(), host.document(), CreatePseudoElement)
    , m_hostElement(&host)
    , m_pseudoId(pseudoId)
{
    ASSERT(pseudoId == PseudoId::Before || pseudoId == PseudoId::After);
    setHasCustomStyleResolveCallbacks();
}

PseudoElement::~PseudoElement()
{
    ASSERT(!m_hostElement);
}

Ref<PseudoElement> PseudoElement::create(Element& host, PseudoId pseudoId)
{
    auto pseudoElement = adoptRef(*new PseudoElement(host, pseudoId));

    InspectorInstrumentation::pseudoElementCreated(host.document().page(), pseudoElement.get());

    return pseudoElement;
}

void PseudoElement::clearHostElement()
{
    InspectorInstrumentation::pseudoElementDestroyed(document().page(), *this);

    Styleable::fromElement(*this).elementWasRemoved();
    
    m_hostElement = nullptr;
}

bool PseudoElement::rendererIsNeeded(const RenderStyle& style)
{
    if (pseudoElementRendererIsNeeded(&style))
        return true;

    if (m_hostElement) {
        if (auto* stack = m_hostElement->keyframeEffectStack(pseudoId()))
            return stack->requiresPseudoElement();
    }
    return false;
}

} // namespace