Node* FlatTreeTraversal::lastWithin(const Node& node)
{
assertPrecondition(node);
Node* descendant = traverseLastChild(node);
for (Node* child = descendant; child; child = lastChild(*child))
descendant = child;
assertPostcondition(descendant);
return descendant;
}
Node* previousInScope(const Node* node)
{
ASSERT(!isActiveInsertionPoint(node));
if (Node* current = traversePreviousSibling(node)) {
while (Node* child = traverseLastChild(current, DontCrossShadowRoot))
current = child;
return current;
}
return traverseParent(node, DontCrossShadowRoot);
}
void ComposedShadowTreeWalker::previous()
{
assertPrecondition();
if (Node* n = traversePreviousSibling(m_node)) {
while (Node* child = traverseLastChild(n))
n = child;
m_node = n;
} else
parent();
assertPostcondition();
}
// TODO(yosin) We should consider introducing template class to share code
// between DOM tree traversal and flat tree tarversal.
Node* FlatTreeTraversal::previousPostOrder(const Node& current, const Node* stayWithin)
{
assertPrecondition(current);
if (stayWithin)
assertPrecondition(*stayWithin);
if (Node* lastChild = traverseLastChild(current)) {
assertPostcondition(lastChild);
return lastChild;
}
if (current == stayWithin)
return nullptr;
if (Node* previousSibling = traversePreviousSibling(current)) {
assertPostcondition(previousSibling);
return previousSibling;
}
return previousAncestorSiblingPostOrder(current, stayWithin);
}
Node* previousSiblingSlow(const Node* node)
{
ASSERT(!node->isShadowRoot());
Node* previousSibling = 0;
if (node->isAfterPseudoElement()) {
ContainerNode* parent = traverseParent(node, CrossShadowRoot);
previousSibling = traverseLastChild(parent, CrossShadowRoot);
} else
previousSibling = traversePreviousSibling(node);
if (previousSibling || node->isBeforePseudoElement())
return previousSibling;
ContainerNode* parent = traverseParent(node, CrossShadowRoot);
if (parent && parent->isElementNode())
return toElement(parent)->beforePseudoElement();
return 0;
}
Node* lastChildInScope(const Node* node)
{
ASSERT(!isActiveInsertionPoint(node));
return traverseLastChild(node, DontCrossShadowRoot);
}
void ComposedShadowTreeWalker::lastChild()
{
assertPrecondition();
m_node = traverseLastChild(m_node);
assertPostcondition();
}