Question

Any body please can please help me, how to center a JFrame on Mac. OS X?

I have tried:

this.setLocationRelativeto(null);

this.setLocationRelativeto(this);
this.setLocationRelativeto(getRootPane());

..and

    final Toolkit toolkit = Toolkit.getDefaultToolkit();
    final Dimension screenSize = toolkit.getScreenSize();
    final int x = (screenSize.width - this.getWidth()) / 2;
    final int y = (screenSize.height - this.getHeight()) / 2;
    this.setLocation(x, y);

None of the above worked, my frame is still at the bottom and hidden behind the Mac dock.

Answer 1

Location should be set after you packed your frame (wich calculates size of the frame).
And after that it should be made visible (it is hidden by default otherwize).

 pack();
 setLocationRelativeTo(null);
 setVisible(true);