/// <summary>
/// Shortcut method to inform the control that the structure has changed.
/// </summary>
private void MarkStructure()
{
if (owner != null)
{
owner.MarkStructuralChange();
}
}
/// <summary>
/// Sorts the items in the collection based on item weight.
/// </summary>
public void Sort()
{
items.Sort();
container.MarkStructuralChange();
}