TAdvOfficeCheckGroup

I need to find out in TAdvOfficeCheckGroup.CheckClick whether the event was triggered by clicking on Checkbox or otherwise. I don't know how to find out.

//  if not (frmprnDiscipline.ActiveControl = CheckGrp) then  //  Allways False
//  if not CheckGrp.CheckBox.Focused then - not exists
  if not CheckGrp.Focused then  //  Allways False
    Exit;
  for I := 0 to CheckGrp.Items.Count - 1 do
  begin
    Selected := TCheckBox(CheckGrp.Controls[I]).Focused;

OnCheckClick is triggered when a checkbox is toggled and the CheckBoxIndex parameter returns what checkbox was toggled.