void RenderTreeUpdater::updateRenderTree(ContainerNode& root)
{
ASSERT(root.renderer());
ASSERT(m_parentStack.isEmpty());
m_parentStack.append(Parent(root));
auto descendants = composedTreeDescendants(root);
auto it = descendants.begin();
auto end = descendants.end();
// FIXME: https://bugs.webkit.org/show_bug.cgi?id=156172
it.dropAssertions();
while (it != end) {
popParentsToDepth(it.depth());
auto& node = *it;
if (auto* renderer = node.renderer())
renderTreePosition().invalidateNextSibling(*renderer);
if (is<Text>(node)) {
auto& text = downcast<Text>(node);
if (parent().styleChange == Style::Detach || m_styleUpdate->textUpdate(text) || m_invalidatedWhitespaceOnlyTextSiblings.contains(&text))
updateTextRenderer(text);
it.traverseNextSkippingChildren();
continue;
}
auto& element = downcast<Element>(node);
auto* elementUpdate = m_styleUpdate->elementUpdate(element);
if (!elementUpdate) {
it.traverseNextSkippingChildren();
continue;
}
updateElementRenderer(element, *elementUpdate);
bool mayHaveRenderedDescendants = element.renderer() || (element.hasDisplayContents() && shouldCreateRenderer(element, renderTreePosition().parent()));
if (!mayHaveRenderedDescendants) {
it.traverseNextSkippingChildren();
continue;
}
pushParent(element, elementUpdate ? elementUpdate->change : Style::NoChange);
it.traverseNext();
}
popParentsToDepth(0);
m_invalidatedWhitespaceOnlyTextSiblings.clear();
}
PassRefPtr<Node> Text::mergeNextSiblingNodesIfPossible()
{
RefPtr<Node> protect(this);
// Remove empty text nodes.
if (!length()) {
// Care must be taken to get the next node before removing the current node.
RefPtr<Node> nextNode(NodeTraversal::nextPostOrder(*this));
remove(IGNORE_EXCEPTION);
return nextNode.release();
}
// Merge text nodes.
while (Node* nextSibling = this->nextSibling()) {
if (nextSibling->nodeType() != TEXT_NODE)
break;
RefPtr<Text> nextText = toText(nextSibling);
// Remove empty text nodes.
if (!nextText->length()) {
nextText->remove(IGNORE_EXCEPTION);
continue;
}
// Both non-empty text nodes. Merge them.
unsigned offset = length();
String nextTextData = nextText->data();
String oldTextData = data();
setDataWithoutUpdate(data() + nextTextData);
updateTextRenderer(oldTextData.length(), 0);
// Empty nextText for layout update.
nextText->setDataWithoutUpdate(emptyString());
nextText->updateTextRenderer(0, nextTextData.length());
document().didMergeTextNodes(nextText.get(), offset);
// Restore nextText for mutation event.
nextText->setDataWithoutUpdate(nextTextData);
nextText->updateTextRenderer(0, 0);
document().incDOMTreeVersion();
didModifyData(oldTextData);
nextText->remove(IGNORE_EXCEPTION);
}
return NodeTraversal::nextPostOrder(*this);
}