ComposedTreeIterator.cpp [plain text]
#include "config.h"
#include "ComposedTreeIterator.h"
#include "HTMLSlotElement.h"
#include "TextStream.h"
namespace WebCore {
ComposedTreeIterator::Context::Context()
{
}
ComposedTreeIterator::Context::Context(ContainerNode& root, FirstChildTag)
: iterator(root, ElementAndTextDescendantIterator::FirstChild)
{
}
ComposedTreeIterator::Context::Context(ContainerNode& root, Node& node)
: iterator(root, &node)
{
}
ComposedTreeIterator::Context::Context(ContainerNode& root, Node& node, SlottedTag)
: iterator(root, &node)
, end(iterator)
{
end.traverseNextSibling();
}
ComposedTreeIterator::ComposedTreeIterator(ContainerNode& root, FirstChildTag)
{
ASSERT(!is<ShadowRoot>(root));
if (is<HTMLSlotElement>(root)) {
auto& slot = downcast<HTMLSlotElement>(root);
if (auto* assignedNodes = slot.assignedNodes()) {
initializeContextStack(root, *assignedNodes->at(0));
return;
}
}
if (auto* shadowRoot = root.shadowRoot()) {
ElementAndTextDescendantIterator firstChild(*shadowRoot, ElementAndTextDescendantIterator::FirstChild);
initializeContextStack(root, firstChild ? *firstChild : root);
return;
}
m_contextStack.uncheckedAppend(Context(root, FirstChild));
}
ComposedTreeIterator::ComposedTreeIterator(ContainerNode& root, Node& current)
{
ASSERT(!is<ShadowRoot>(root));
ASSERT(!is<ShadowRoot>(current));
bool mayNeedShadowStack = root.shadowRoot() || (¤t != &root && current.parentNode() != &root);
if (mayNeedShadowStack)
initializeContextStack(root, current);
else
m_contextStack.uncheckedAppend(Context(root, current));
}
void ComposedTreeIterator::initializeContextStack(ContainerNode& root, Node& current)
{
auto* node = ¤t;
auto* contextCurrent = node;
size_t currentSlotNodeIndex = notFound;
while (node != &root) {
auto* parent = node->parentNode();
if (!parent) {
*this = { };
return;
}
if (is<ShadowRoot>(*parent)) {
auto& shadowRoot = downcast<ShadowRoot>(*parent);
m_contextStack.append(Context(shadowRoot, *contextCurrent));
m_contextStack.last().slotNodeIndex = currentSlotNodeIndex;
node = shadowRoot.host();
contextCurrent = node;
currentSlotNodeIndex = notFound;
continue;
}
if (auto* shadowRoot = parent->shadowRoot()) {
m_contextStack.append(Context(*parent, *contextCurrent, Context::Slotted));
m_contextStack.last().slotNodeIndex = currentSlotNodeIndex;
auto* assignedSlot = shadowRoot->findAssignedSlot(*node);
if (assignedSlot) {
currentSlotNodeIndex = assignedSlot->assignedNodes()->find(node);
ASSERT(currentSlotNodeIndex != notFound);
node = assignedSlot;
contextCurrent = assignedSlot;
continue;
}
*this = { };
return;
}
node = parent;
}
m_contextStack.append(Context(root, *contextCurrent));
m_contextStack.last().slotNodeIndex = currentSlotNodeIndex;
m_contextStack.reverse();
}
void ComposedTreeIterator::dropAssertions()
{
for (auto& context : m_contextStack)
context.iterator.dropAssertions();
m_didDropAssertions = true;
}
void ComposedTreeIterator::traverseShadowRoot(ShadowRoot& shadowRoot)
{
Context shadowContext(shadowRoot, FirstChild);
if (!shadowContext.iterator) {
traverseNextSkippingChildren();
return;
}
if (m_didDropAssertions)
shadowContext.iterator.dropAssertions();
m_contextStack.append(WTFMove(shadowContext));
}
void ComposedTreeIterator::traverseNextInShadowTree()
{
ASSERT(m_contextStack.size() > 1);
if (is<HTMLSlotElement>(current())) {
auto& slot = downcast<HTMLSlotElement>(current());
if (auto* assignedNodes = slot.assignedNodes()) {
context().slotNodeIndex = 0;
auto* assignedNode = assignedNodes->at(0);
m_contextStack.append(Context(*assignedNode->parentElement(), *assignedNode, Context::Slotted));
return;
}
}
context().iterator.traverseNext();
if (context().iterator == context().end)
traverseNextLeavingContext();
}
void ComposedTreeIterator::traverseNextLeavingContext()
{
ASSERT(m_contextStack.size() > 1);
while (context().iterator == context().end && m_contextStack.size() > 1) {
m_contextStack.removeLast();
if (context().iterator == context().end)
return;
if (is<HTMLSlotElement>(current()) && advanceInSlot(1))
return;
context().iterator.traverseNextSkippingChildren();
}
}
bool ComposedTreeIterator::advanceInSlot(int direction)
{
ASSERT(context().slotNodeIndex != notFound);
auto& assignedNodes = *downcast<HTMLSlotElement>(current()).assignedNodes();
context().slotNodeIndex += direction;
if (context().slotNodeIndex >= assignedNodes.size())
return false;
auto* slotNode = assignedNodes.at(context().slotNodeIndex);
m_contextStack.append(Context(*slotNode->parentElement(), *slotNode, Context::Slotted));
return true;
}
void ComposedTreeIterator::traverseSiblingInSlot(int direction)
{
ASSERT(m_contextStack.size() > 1);
ASSERT(current().parentNode()->shadowRoot());
m_contextStack.removeLast();
if (!advanceInSlot(direction))
*this = { };
}
String composedTreeAsText(ContainerNode& root, ComposedTreeAsTextMode mode)
{
TextStream stream;
auto descendants = composedTreeDescendants(root);
for (auto it = descendants.begin(), end = descendants.end(); it != end; ++it) {
writeIndent(stream, it.depth());
if (is<Text>(*it)) {
stream << "#text";
if (mode == ComposedTreeAsTextMode::WithPointers)
stream << " " << &*it;
stream << "\n";
continue;
}
auto& element = downcast<Element>(*it);
stream << element.localName();
if (element.shadowRoot())
stream << " (shadow root)";
if (mode == ComposedTreeAsTextMode::WithPointers)
stream << " " << &*it;
stream << "\n";
}
return stream.release();
}
}