C++ TreeScope类代码示例

void TreeScope::setParentTreeScope(TreeScope& newParentScope)
{
    // A document node cannot be re-parented.
    ASSERT(!rootNode().isDocumentNode());

    newParentScope.guardRef();
    if (m_parentTreeScope)
        m_parentTreeScope->guardDeref();
    m_parentTreeScope = &newParentScope;
    setDocument(newParentScope.document());
}

RelatedNodeRetargeter::RelatedNodeRetargeter(Node& relatedNode, Node& target)
    : m_relatedNode(relatedNode)
    , m_retargetedRelatedNode(&relatedNode)
{
    auto& targetTreeScope = target.treeScope();
    TreeScope* currentTreeScope = &m_relatedNode.treeScope();
    if (LIKELY(currentTreeScope == &targetTreeScope && target.inDocument() && m_relatedNode.inDocument()))
        return;

    if (&currentTreeScope->documentScope() != &targetTreeScope.documentScope()) {
        m_hasDifferentTreeRoot = true;
        m_retargetedRelatedNode = nullptr;
        return;
    }
    if (relatedNode.inDocument() != target.inDocument()) {
        m_hasDifferentTreeRoot = true;
        m_retargetedRelatedNode = moveOutOfAllShadowRoots(relatedNode);
        return;
    }

    collectTreeScopes();

    // FIXME: We should collect this while constructing the event path.
    Vector<TreeScope*, 8> targetTreeScopeAncestors;
    for (TreeScope* currentTreeScope = &targetTreeScope; currentTreeScope; currentTreeScope = currentTreeScope->parentTreeScope())
        targetTreeScopeAncestors.append(currentTreeScope);
    ASSERT_WITH_SECURITY_IMPLICATION(!targetTreeScopeAncestors.isEmpty());

    unsigned i = m_ancestorTreeScopes.size();
    unsigned j = targetTreeScopeAncestors.size();
    ASSERT_WITH_SECURITY_IMPLICATION(m_ancestorTreeScopes.last() == targetTreeScopeAncestors.last());
    while (m_ancestorTreeScopes[i - 1] == targetTreeScopeAncestors[j - 1]) {
        i--;
        j--;
        if (!i || !j)
            break;
    }

    bool lowestCommonAncestorIsDocumentScope = i + 1 == m_ancestorTreeScopes.size();
    if (lowestCommonAncestorIsDocumentScope && !relatedNode.inDocument() && !target.inDocument()) {
        Node& targetAncestorInDocumentScope = i ? *downcast<ShadowRoot>(m_ancestorTreeScopes[i - 1]->rootNode()).shadowHost() : target;
        Node& relatedNodeAncestorInDocumentScope = j ? *downcast<ShadowRoot>(targetTreeScopeAncestors[j - 1]->rootNode()).shadowHost() : relatedNode;
        if (targetAncestorInDocumentScope.rootNode() != relatedNodeAncestorInDocumentScope.rootNode()) {
            m_hasDifferentTreeRoot = true;
            m_retargetedRelatedNode = moveOutOfAllShadowRoots(relatedNode);
            return;
        }
    }

    m_lowestCommonAncestorIndex = i;
    m_retargetedRelatedNode = nodeInLowestCommonAncestor();
}

void HTMLLabelElement::updateLabel(TreeScope& scope, const AtomicString& oldForAttributeValue, const AtomicString& newForAttributeValue)
{
    if (!inDocument())
        return;

    if (oldForAttributeValue == newForAttributeValue)
        return;

    if (!oldForAttributeValue.isEmpty())
        scope.removeLabel(oldForAttributeValue, this);
    if (!newForAttributeValue.isEmpty())
        scope.addLabel(newForAttributeValue, this);
}

void DocumentOrderedMap::add(const AtomicStringImpl& key, Element& element, const TreeScope& treeScope)
{
    ASSERT_WITH_SECURITY_IMPLICATION(element.isInTreeScope());
    ASSERT_WITH_SECURITY_IMPLICATION(treeScope.rootNode()->containsIncludingShadowDOM(&element));
    if (!element.isInTreeScope() || &element.document() != treeScope.documentScope())
        return;
    Map::AddResult addResult = m_map.add(&key, MapEntry(&element));
    if (addResult.isNewEntry)
        return;

    MapEntry& entry = addResult.iterator->value;
    ASSERT_WITH_SECURITY_IMPLICATION(entry.count);
    entry.element = 0;
    entry.count++;
    entry.orderedList.clear();
}

void RelatedNodeRetargeter::moveToNewTreeScope(TreeScope* previousTreeScope, TreeScope& newTreeScope)
{
    if (m_hasDifferentTreeRoot)
        return;

    auto& currentRelatedNodeScope = m_retargetedRelatedNode->treeScope();
    if (previousTreeScope != &currentRelatedNodeScope) {
        // currentRelatedNode is still outside our shadow tree. New tree scope may contain currentRelatedNode
        // but there is no need to re-target it. Moving into a slot (thereby a deeper shadow tree) doesn't matter.
        return;
    }

    bool enteredSlot = newTreeScope.parentTreeScope() == previousTreeScope;
    if (enteredSlot) {
        if (m_lowestCommonAncestorIndex) {
            if (m_ancestorTreeScopes.isEmpty())
                collectTreeScopes();
            bool relatedNodeIsInSlot = m_ancestorTreeScopes[m_lowestCommonAncestorIndex - 1] == &newTreeScope;
            if (relatedNodeIsInSlot) {
                m_lowestCommonAncestorIndex--;
                m_retargetedRelatedNode = nodeInLowestCommonAncestor();
                ASSERT(&newTreeScope == &m_retargetedRelatedNode->treeScope());
            }
        } else
            ASSERT(m_retargetedRelatedNode == &m_relatedNode);
    } else {
        ASSERT(previousTreeScope->parentTreeScope() == &newTreeScope);
        m_lowestCommonAncestorIndex++;
        ASSERT_WITH_SECURITY_IMPLICATION(m_ancestorTreeScopes.isEmpty() || m_lowestCommonAncestorIndex < m_ancestorTreeScopes.size());
        m_retargetedRelatedNode = downcast<ShadowRoot>(currentRelatedNodeScope.rootNode()).host();
        ASSERT(&newTreeScope == &m_retargetedRelatedNode->treeScope());
    }
}

void RelatedNodeRetargeter::collectTreeScopes()
{
    ASSERT(m_ancestorTreeScopes.isEmpty());
    for (TreeScope* currentTreeScope = &m_relatedNode.treeScope(); currentTreeScope; currentTreeScope = currentTreeScope->parentTreeScope())
        m_ancestorTreeScopes.append(currentTreeScope);
    ASSERT_WITH_SECURITY_IMPLICATION(!m_ancestorTreeScopes.isEmpty());
}

void TreeScope::setParentTreeScope(TreeScope& newParentScope) {
  // A document node cannot be re-parented.
  DCHECK(!rootNode().isDocumentNode());

  m_parentTreeScope = &newParentScope;
  setDocument(newParentScope.document());
}

void DocumentOrderedMap::add(const AtomicStringImpl& key, Element& element, const TreeScope& treeScope)
{
    UNUSED_PARAM(treeScope);
    ASSERT_WITH_SECURITY_IMPLICATION(element.isInTreeScope());
    ASSERT_WITH_SECURITY_IMPLICATION(treeScope.rootNode().containsIncludingShadowDOM(&element));

    if (!element.isInTreeScope())
        return;
    Map::AddResult addResult = m_map.ensure(&key, [&element] {
        return MapEntry(&element);
    });
    MapEntry& entry = addResult.iterator->value;

#if !ASSERT_DISABLED || ENABLE(SECURITY_ASSERTIONS)
    ASSERT_WITH_SECURITY_IMPLICATION(!entry.registeredElements.contains(&element));
    entry.registeredElements.add(&element);
#endif

    if (addResult.isNewEntry)
        return;

    ASSERT_WITH_SECURITY_IMPLICATION(entry.count);
    entry.element = nullptr;
    entry.count++;
    entry.orderedList.clear();
}

static Position adjustPositionForStart(const Position& currentPosition, Node* endContainerNode)
{
    TreeScope* treeScope = endContainerNode->treeScope();

    ASSERT(currentPosition.containerNode()->treeScope() != treeScope);
    
    if (Node* ancestor = treeScope->ancestorInThisScope(currentPosition.containerNode())) {
        if (ancestor->contains(endContainerNode))
            return positionBeforeNode(ancestor);
        return positionAfterNode(ancestor);
    }

    if (Node* firstChild = treeScope->rootNode()->firstChild())
        return positionBeforeNode(firstChild);

    return Position();
}

TreeScopeEventContext::TreeScopeEventContext(TreeScope& treeScope)
    : m_treeScope(treeScope)
    , m_rootNode(treeScope.rootNode())
    , m_containingClosedShadowTree(nullptr)
    , m_preOrder(-1)
    , m_postOrder(-1)
{
}

AtomicString SVGURIReference::fragmentIdentifierFromIRIString(
    const String& urlString,
    const TreeScope& treeScope) {
  SVGURLReferenceResolver resolver(urlString, treeScope.document());
  if (!resolver.isLocal())
    return emptyAtom;
  return resolver.fragmentIdentifier();
}

void InsertionPoint::attach()
{
    TreeScope* scope = treeScope();
    if (scope->isShadowRoot()) {
        ShadowRoot* root = toShadowRoot(scope);
        if (doesSelectFromHostChildren()) {
            distributeHostChildren(root->tree());
            attachDistributedNode();
        } else if (!root->olderShadowRoot()->assignedTo()) {
            ASSERT(!root->olderShadowRoot()->attached());
            assignShadowRoot(root->olderShadowRoot());
            root->olderShadowRoot()->attach();
        }
    }

    HTMLElement::attach();
}

EventTarget* EventPath::findRelatedNode(TreeScope& scope, RelatedTargetMap& relatedTargetMap)
{
    WillBeHeapVector<RawPtrWillBeMember<TreeScope>, 32> parentTreeScopes;
    EventTarget* relatedNode = 0;
    for (TreeScope* current = &scope; current; current = current->olderShadowRootOrParentTreeScope()) {
        parentTreeScopes.append(current);
        RelatedTargetMap::const_iterator iter = relatedTargetMap.find(current);
        if (iter != relatedTargetMap.end() && iter->value) {
            relatedNode = iter->value;
            break;
        }
    }
    ASSERT(relatedNode);
    for (WillBeHeapVector<RawPtrWillBeMember<TreeScope>, 32>::iterator iter = parentTreeScopes.begin(); iter < parentTreeScopes.end(); ++iter)
        relatedTargetMap.add(*iter, relatedNode);
    return relatedNode;
}

void TreeScope::setParentTreeScope(TreeScope& newParentScope)
{
    // A document node cannot be re-parented.
    ASSERT(!m_rootNode.isDocumentNode());

    m_parentTreeScope = &newParentScope;
    setDocumentScope(newParentScope.documentScope());
}

Element* TreeScope::focusedElement()
{
    Document& document = m_rootNode.document();
    Element* element = document.focusedElement();

    if (!element && document.page())
        element = focusedFrameOwnerElement(document.page()->focusController().focusedFrame(), document.frame());
    if (!element)
        return nullptr;
    TreeScope* treeScope = &element->treeScope();
    while (treeScope != this && treeScope != &document) {
        element = downcast<ShadowRoot>(treeScope->rootNode()).host();
        treeScope = &element->treeScope();
    }
    if (this != treeScope)
        return nullptr;
    return element;
}