// TODO(hayato): This may return a wrong result for a node which is not in a
// document flat tree. See FlatTreeTraversalTest's redistribution test for details.
Node* FlatTreeTraversal::traverseSiblings(const Node& node, TraversalDirection direction)
{
if (node.isChildOfV1ShadowHost())
return traverseSiblingsForV1HostChild(node, direction);
if (shadowWhereNodeCanBeDistributed(node))
return traverseSiblingsForV0Distribution(node, direction);
if (Node* found = resolveDistributionStartingAt(direction == TraversalDirectionForward ? node.nextSibling() : node.previousSibling(), direction))
return found;
if (!node.isInV0ShadowTree())
return nullptr;
// For v0 older shadow tree
if (node.parentNode() && node.parentNode()->isShadowRoot()) {
ShadowRoot* parentShadowRoot = toShadowRoot(node.parentNode());
if (!parentShadowRoot->isYoungest()) {
HTMLShadowElement* assignedInsertionPoint = parentShadowRoot->shadowInsertionPointOfYoungerShadowRoot();
DCHECK(assignedInsertionPoint);
return traverseSiblings(*assignedInsertionPoint, direction);
}
}
return nullptr;
}
Node* ComposedShadowTreeWalker::traverseSiblingInCurrentTree(const Node* node, TraversalDirection direction)
{
ASSERT(node);
if (Node* found = traverseSiblings(direction == TraversalDirectionForward ? node->nextSibling() : node->previousSibling(), direction))
return found;
return escapeFallbackContentElement(node, direction);
}
Node* FlatTreeTraversal::traverseSiblingsForV1HostChild(const Node& node, TraversalDirection direction)
{
HTMLSlotElement* slot = finalDestinationSlotFor(node);
if (!slot)
return nullptr;
if (Node* siblingInDistributedNodes = (direction == TraversalDirectionForward ? slot->distributedNodeNextTo(node) : slot->distributedNodePreviousTo(node)))
return siblingInDistributedNodes;
return traverseSiblings(*slot, direction);
}
Node* ComposedTreeWalker::traverseSiblingInCurrentTree(const Node* node, TraversalDirection direction)
{
ASSERT(node);
if (Node* found = traverseSiblings(direction == TraversalDirectionForward ? node->nextSibling() : node->previousSibling(), direction))
return found;
if (Node* next = traverseBackToYoungerShadowRoot(node, direction))
return next;
return 0;
}
Node* FlatTreeTraversal::traverseSiblingsForV0Distribution(const Node& node, TraversalDirection direction)
{
const InsertionPoint* finalDestination = resolveReprojection(&node);
if (!finalDestination)
return nullptr;
if (Node* found = (direction == TraversalDirectionForward ? finalDestination->distributedNodeNextTo(&node) : finalDestination->distributedNodePreviousTo(&node)))
return found;
return traverseSiblings(*finalDestination, direction);
}
Node* ComposedShadowTreeWalker::traverseLightChildren(const Node* node, TraversalDirection direction)
{
ASSERT(node);
return traverseSiblings(direction == TraversalDirectionForward ? node->firstChild() : node->lastChild(), direction);
}
