public override QModelIndex Parent(QModelIndex index)
{
if (!index.IsValid())
{
return(new QModelIndex());
}
TreeItem childItem = (TreeItem)index.InternalPointer();
TreeItem parentItem = childItem.Parent();
if (parentItem == rootItem)
{
return(new QModelIndex());
}
return(CreateIndex(parentItem.Row(), 0, parentItem));
}