/// <summary>
/// Notification that all child nodes are being removed.
/// </summary>
/// <param name="tc">Reference to owning TreeControl.</param>
/// <param name="nc">Reference to NodeCollection instance.</param>
public virtual void NodeCollectionClearing(TreeControl tc, NodeCollection nc)
{
// Ensure all children of the node are deselected as they
// are no longer showing and so cannot be in the selected state
foreach (Node n in nc)
{
tc.DeselectNode(n, true);
}
// Ask control to move the focus to new calculated position
tc.NodeContentCleared(false);
}