how to determine which event calls procedure in delphi

Question

I have a procedure named XYZ(sender:TObject) in delphi. There is one button on my form.

Button.onclick:= xyz;
Button.OnExit:= xyz;

Both the events calls the same procedure. I want to determine in procedure XYZ, which event calls this(onclick or onexit) and according to that proceed with coding. How to determine which event gets fired? thanks

Answer 1

You can't get hold of that information by fair means. The solution is to use two separate top-level event handlers which in turn can call another method passing a parameter identifying which event is being handled.

type
  TButtonEventType = (beOnClick, beOnExit);

procedure TMyForm.ButtonClick(Sender: TObject);
begin
  HandleButtenEvent(beOnClick);
end;

procedure TMyForm.ButtonExit(Sender: TObject);
begin
  HandleButtenEvent(beOnExit);
end;

procedure TMyForm.HandleButtonEvent(EventType: TButtonEventType);
begin
  //use EventType to decide how to handle this
end;