TOPIC:

procedure TCheckComboBoxForm.MeasureHeight(out AHeight: Integer);
var
  i: Integer;
  h: Integer = 0;
begin
  AHeight := 0;
  for i := 0 to FCheckListbox.Items.Count-1 do
    if i < FDropDownCount then
    begin
      FCheckListbox.MeasureItem(i, h);

      if h=0 then h:=14;  //<<<<=== ct9999 =====

      inc(AHeight,h);
    end;
  inc(AHeight, 6);
end;