/// <summary>
/// Method called when a children is removed.
/// </summary>
/// <param name="sender">Sender widget.</param>
/// <param name="e">List of removed children.</param>
protected override void OnItemRemoved(ObservableList <Widget> sender, ListChangedEventArgs <Widget> e)
{
base.OnItemRemoved(sender, e);
m_Header = null;
}
/// <summary>
/// Constructor.
/// </summary>
/// <param name="displayName">Display name of the foldout.</param>
/// <param name="children">List of attached children.</param>
/// <param name="columnLabels">Optional list of column names.</param>
public Foldout(string displayName, ObservableList <Widget> children, string[] columnLabels = null)
: base(displayName, children)
{
this.columnLabels = columnLabels;
}