+set< RowItemOwner* > RowItemOwner::list_row_item_owners()
+{
+ set< RowItemOwner* > owners;
+ for (const auto &r : *this)
+ owners.insert(r->owner());
+ return owners;
+}
+
+template<class T>
+set< shared_ptr<T> > RowItemOwner::list_by_type()
+{
+ set< shared_ptr<T> > items;
+ for (const auto &r : *this) {
+ shared_ptr<T> p = dynamic_pointer_cast<T>(r);
+ if (p)
+ items.insert(p);
+ }
+
+ return items;
+}
+
+template set< shared_ptr<Trace> > RowItemOwner::list_by_type();
+
+pair<int, int> RowItemOwner::v_extents() const
+{
+ pair<int, int> extents(INT_MAX, INT_MIN);
+
+ for (const shared_ptr<RowItem> r : child_items()) {
+ assert(r);
+ if (!r->enabled())
+ continue;
+
+ const int child_offset = r->layout_v_offset();
+ const pair<int, int> child_extents = r->v_extents();
+ extents.first = min(child_extents.first + child_offset,
+ extents.first);
+ extents.second = max(child_extents.second + child_offset,
+ extents.second);
+ }
+
+ return extents;
+}
+
+void RowItemOwner::restack_items()
+{
+}
+