private void UpdateNodesInternal(TreeNodeCollection nodes)
{
List<TreeItem> children = GetChildren().ToList();
Dictionary<TreeItem, bool> shouldShow = children.ToDictionary(x => x, x => true);
int i, j;
for (i = 0, j = 0; j < children.Count; )
{
TreeNode node = i < nodes.Count ? nodes[i] : null;
TreeItem item = node != null ? node.Tag as TreeItem : null;
if (children[j].Equals(item))
{
children[j].UpdateInternal(node);
i++; j++;
}
else if (node == null || (item != null && shouldShow.ContainsKey(item)))
{
nodes.Insert(i, children[j].CreateNode());
i++; j++;
}
else
{
nodes.RemoveAtWithSelectionBackup(i, nodes[i].TreeView, nodes[i].Parent);
}
}
for (int k = nodes.Count - 1; k >= i; k--)
nodes.RemoveAtWithSelectionBackup(k, nodes[k].TreeView, nodes[k].Parent);
}
