Sample project attached.
Thank you. I can see the problem (the issue is with tab change events actually within Cocoa-Widgetset. Not much you can do about it.).
If you comment out code of
- Procedure TForm1.TabSheet2Show(Sender: TObject);
- Procedure TForm1.PageControl1Change(Sender: TObject);
You'll see that
- Procedure TForm1.Button1Click(Sender: TObject);
would work.
Which is only a little relief
But I'd think this is fixable. Stay tuned.