void YGNode::cloneChildrenIfNeeded() {
// YGNodeRemoveChild in yoga.cpp has a forked variant of this algorithm
// optimized for deletions.
const uint32_t childCount = static_cast<uint32_t>(children_.size());
if (childCount == 0) {
// This is an empty set. Nothing to clone.
return;
}
const YGNodeRef firstChild = children_.front();
if (firstChild->getOwner() == this) {
// If the first child has this node as its owner, we assume that it is
// already unique. We can do this because if we have it has a child, that
// means that its owner was at some point cloned which made that subtree
// immutable. We also assume that all its sibling are cloned as well.
return;
}
const YGCloneNodeFunc cloneNodeCallback = config_->cloneNodeCallback;
for (uint32_t i = 0; i < childCount; ++i) {
const YGNodeRef oldChild = children_[i];
YGNodeRef newChild = nullptr;
if (cloneNodeCallback) {
newChild = cloneNodeCallback(oldChild, this, i);
}
if (newChild == nullptr) {
newChild = YGNodeClone(oldChild);
}
replaceChild(newChild, i);
newChild->setOwner(this);
}
}
