Source/WebCore/dom/ElementAncestorIterator.h

/*
 * Copyright (C) 2013-2020 Apple Inc. All rights reserved.
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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#pragma once

#include "ElementIterator.h"

namespace WebCore {

template<typename> class ElementAncestorRange;

// Range for iterating an element and its ancestors.
template<typename ElementType> ElementAncestorRange<ElementType> lineageOfType(Element& first);
template<typename ElementType> ElementAncestorRange<const ElementType> lineageOfType(const Element& first);

// Range for iterating a node's element ancestors.
template<typename ElementType> ElementAncestorRange<ElementType> ancestorsOfType(Node& descendant);
template<typename ElementType> ElementAncestorRange<const ElementType> ancestorsOfType(const Node& descendant);

template <typename ElementType>
class ElementAncestorIterator : public ElementIterator<ElementType> {
public:
    explicit ElementAncestorIterator(ElementType* = nullptr);
    ElementAncestorIterator& operator++();
};

template <typename ElementType>
class ElementAncestorRange {
public:
    explicit ElementAncestorRange(ElementType* first);
    ElementAncestorIterator<ElementType> begin() const;
    static constexpr std::nullptr_t end() { return nullptr; }
    ElementType* first() const { return m_first; }

private:
    ElementType* const m_first;
};

// ElementAncestorIterator

template <typename ElementType>
inline ElementAncestorIterator<ElementType>::ElementAncestorIterator(ElementType* current)
    : ElementIterator<ElementType>(nullptr, current)
{
}

template <typename ElementType>
inline ElementAncestorIterator<ElementType>& ElementAncestorIterator<ElementType>::operator++()
{
    ElementIterator<ElementType>::traverseAncestor();
    return *this;
}

// ElementAncestorRange

template <typename ElementType>
inline ElementAncestorRange<ElementType>::ElementAncestorRange(ElementType* first)
    : m_first(first)
{
}

template <typename ElementType>
inline ElementAncestorIterator<ElementType> ElementAncestorRange<ElementType>::begin() const
{
    return ElementAncestorIterator<ElementType>(m_first);
}

// Standalone functions

template<> inline ElementAncestorRange<Element> lineageOfType<Element>(Element& first)
{
    return ElementAncestorRange<Element>(&first);
}

template <typename ElementType>
inline ElementAncestorRange<ElementType> lineageOfType(Element& first)
{
    if (is<ElementType>(first))
        return ElementAncestorRange<ElementType>(&downcast<ElementType>(first));
    return ancestorsOfType<ElementType>(first);
}

template<> inline ElementAncestorRange<const Element> lineageOfType<Element>(const Element& first)
{
    return ElementAncestorRange<const Element>(&first);
}

template <typename ElementType>
inline ElementAncestorRange<const ElementType> lineageOfType(const Element& first)
{
    if (is<ElementType>(first))
        return ElementAncestorRange<const ElementType>(&downcast<ElementType>(first));
    return ancestorsOfType<ElementType>(first);
}

template <typename ElementType>
inline ElementAncestorRange<ElementType> ancestorsOfType(Node& descendant)
{
    return ElementAncestorRange<ElementType>(findElementAncestorOfType<ElementType>(descendant));
}

template <typename ElementType>
inline ElementAncestorRange<const ElementType> ancestorsOfType(const Node& descendant)
{
    return ElementAncestorRange<const ElementType>(findElementAncestorOfType<const ElementType>(descendant));
}

} // namespace WebCore