Source/WebCore/html/CollectionTraversalInlines.h

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#pragma once

#include <WebCore/CollectionTraversal.h>
#include <WebCore/ElementChildIteratorInlines.h>
#include <WebCore/HTMLOptionsCollectionInlines.h>
#include <WebCore/TypedElementDescendantIteratorInlines.h>

namespace WebCore {

// CollectionTraversal::Descendants

template <typename CollectionClass>
inline auto CollectionTraversal<CollectionTraversalType::Descendants>::begin(const CollectionClass& collection, ContainerNode& rootNode) -> Iterator
{
    auto it = descendantsOfType<Element>(rootNode).begin();
    while (it && !collection.elementMatches(*it))
        ++it;
    // Drop iterator assertions because HTMLCollections / NodeList use a fine-grained invalidation scheme.
    it.dropAssertions();
    return it;
}

template <typename CollectionClass>
inline auto CollectionTraversal<CollectionTraversalType::Descendants>::last(const CollectionClass& collection, ContainerNode& rootNode) -> Iterator
{
    Iterator it { rootNode, ElementTraversal::lastWithin(rootNode) };
    while (it && !collection.elementMatches(*it))
        --it;
    // Drop iterator assertions because HTMLCollections / NodeList use a fine-grained invalidation scheme.
    it.dropAssertions();
    return it;
}

template <typename CollectionClass>
inline void CollectionTraversal<CollectionTraversalType::Descendants>::traverseForward(const CollectionClass& collection, Iterator& current, unsigned count, unsigned& traversedCount)
{
    ASSERT(collection.elementMatches(*current));
    for (traversedCount = 0; traversedCount < count; ++traversedCount) {
        do {
            ++current;
            if (!current)
                return;
        } while (!collection.elementMatches(*current));
    }
}

template <typename CollectionClass>
inline void CollectionTraversal<CollectionTraversalType::Descendants>::traverseBackward(const CollectionClass& collection, Iterator& current, unsigned count)
{
    ASSERT(collection.elementMatches(*current));
    for (; count; --count) {
        do {
            --current;
            if (!current)
                return;
        } while (!collection.elementMatches(*current));
    }
}

// CollectionTraversal::WeakPtrDescendants

template <typename CollectionClass>
inline auto CollectionTraversal<CollectionTraversalType::WeakPtrDescendants>::begin(const CollectionClass& collection, ContainerNode& rootNode) -> Iterator
{
    auto it = descendantsOfType<Element>(rootNode).begin();
    while (it && !collection.elementMatches(*it))
        ++it;
    if (!it)
        return nullptr;
    return WeakPtr { *it };
}

template <typename CollectionClass>
inline auto CollectionTraversal<CollectionTraversalType::WeakPtrDescendants>::last(const CollectionClass& collection, ContainerNode& rootNode) -> Iterator
{
    ElementDescendantIterator<Element> it { rootNode, ElementTraversal::lastWithin(rootNode) };
    while (it && !collection.elementMatches(*it))
        --it;
    if (!it)
        return nullptr;
    return WeakPtr { *it };
}

template <typename CollectionClass>
inline void CollectionTraversal<CollectionTraversalType::WeakPtrDescendants>::traverseForward(const CollectionClass& collection, Iterator& current, unsigned count, unsigned& traversedCount)
{
    ASSERT(collection.elementMatches(*current));
    ElementDescendantIterator<Element> iterator { collection.rootNode(), current.get() };
    for (traversedCount = 0; traversedCount < count; ++traversedCount) {
        do {
            ++iterator;
            if (!iterator) {
                current = nullptr;
                return;
            }
        } while (!collection.elementMatches(*iterator));
    }
    if (iterator)
        current = *iterator;
    else
        current = nullptr;
}

template <typename CollectionClass>
inline void CollectionTraversal<CollectionTraversalType::WeakPtrDescendants>::traverseBackward(const CollectionClass& collection, Iterator& current, unsigned count)
{
    ASSERT(collection.elementMatches(*current));
    ElementDescendantIterator<Element> iterator { collection.rootNode(), current.get() };
    for (; count; --count) {
        do {
            --iterator;
            if (!iterator) {
                current = nullptr;
                return;
            }
        } while (!collection.elementMatches(*iterator));
    }
    if (iterator)
        current = *iterator;
    else
        current = nullptr;
}

// CollectionTraversal::ChildrenOnly

template <typename CollectionClass>
inline auto CollectionTraversal<CollectionTraversalType::ChildrenOnly>::begin(const CollectionClass& collection, ContainerNode& rootNode) -> Iterator
{
    auto it = childrenOfType<Element>(rootNode).begin();
    while (it && !collection.elementMatches(*it))
        ++it;
    // Drop iterator assertions because HTMLCollections / NodeList use a fine-grained invalidation scheme.
    it.dropAssertions();
    return it;
}

template <typename CollectionClass>
inline auto CollectionTraversal<CollectionTraversalType::ChildrenOnly>::last(const CollectionClass& collection, ContainerNode& rootNode) -> Iterator
{
    RefPtr lastElement = childrenOfType<Element>(rootNode).last();
    if (!lastElement)
        return childrenOfType<Element>(rootNode).begin();
    auto it = childrenOfType<Element>(rootNode).beginAt(*lastElement);
    while (it && !collection.elementMatches(*it))
        --it;
    // Drop iterator assertions because HTMLCollections / NodeList use a fine-grained invalidation scheme.
    it.dropAssertions();
    return it;
}

template <typename CollectionClass>
inline void CollectionTraversal<CollectionTraversalType::ChildrenOnly>::traverseForward(const CollectionClass& collection, Iterator& current, unsigned count, unsigned& traversedCount)
{
    ASSERT(collection.elementMatches(*current));
    for (traversedCount = 0; traversedCount < count; ++traversedCount) {
        do {
            ++current;
            if (!current)
                return;
        } while (!collection.elementMatches(*current));
    }
}

template <typename CollectionClass>
inline void CollectionTraversal<CollectionTraversalType::ChildrenOnly>::traverseBackward(const CollectionClass& collection, Iterator& current, unsigned count)
{
    ASSERT(collection.elementMatches(*current));
    for (; count; --count) {
        do {
            --current;
            if (!current)
                return;
        } while (!collection.elementMatches(*current));
    }
}

// CollectionTraversal::CustomForwardOnly

template <typename CollectionClass>
inline Element* CollectionTraversal<CollectionTraversalType::CustomForwardOnly>::begin(const CollectionClass& collection, ContainerNode&)
{
    return collection.customElementAfter(nullptr);
}

template <typename CollectionClass>
inline Element* CollectionTraversal<CollectionTraversalType::CustomForwardOnly>::last(const CollectionClass&, ContainerNode&)
{
    ASSERT_NOT_REACHED();
    return nullptr;
}

template <typename CollectionClass>
inline void CollectionTraversal<CollectionTraversalType::CustomForwardOnly>::traverseForward(const CollectionClass& collection, Element*& current, unsigned count, unsigned& traversedCount)
{
    RefPtr element = current;
    for (traversedCount = 0; traversedCount < count; ++traversedCount) {
        element = collection.customElementAfter(element);
        if (!element) {
            current = nullptr;
            return;
        }
    }
    current = element;
}

template <typename CollectionClass>
inline void CollectionTraversal<CollectionTraversalType::CustomForwardOnly>::traverseBackward(const CollectionClass&, Element*&, unsigned count)
{
    UNUSED_PARAM(count);
    ASSERT_NOT_REACHED();
}


}