Question: How can I tell if a form is modal; that is, whether or not it was displayed with ShowModal?

Answer: Check the form's FormState property for the fsModal member, as shown in the following code:

procedure TForm1.FormShow(Sender: TObject);
var
  blnIsModal : Boolean;
begin
   // enable buttons according to form modality

   blnIsModal := fsModal in self.FormState;

   btnSave.Visible := not blnIsModal;
   btnClear.Visible := not blnIsModal;
   btnDelete.Visible := not blnIsModal;

   btnSelect.Visible := blnIsModal;
   btnCancel.Visible := blnIsModal;
end;

In this example, different buttons are displayed for different form states. This lets you design forms for different situations, which in turn reduces overall maintenance over time.

Important: FormState isn't set until after the form is created; thus, you should not use this from a form's OnCreate event. Use the OnShow event instead.