/// <summary>
/// Gets all <code>IInputHandler</code> controls within <paramref name="control"/> ordered by thier TabIndex
/// </summary>
/// <param name="control">The control to search in</param>
/// <returns>A list of controls</returns>
private IEnumerable<Control> CalculateList(ContainerControl control)
{
foreach (var c in control.OrderBy(c => c.TabIndex))
{
if (c is IInputHandler)
yield return c;
if (c is ContainerControl)
foreach (var cc in CalculateList(c as ContainerControl).Where(cc => cc is IInputHandler))
yield return cc;
}
}
