setLayout(new GridBagLayout());
constraints.weightx = 1.0;
constraints.weighty = 1.0;
constraints.fill = GridBagConstraints.BOTH;
int x, y; // for clarity
addGB(new JButton("North"), x = 1, y = 0);
addGB(new JButton("West"), x = 0, y = 1);
addGB(new JButton("Center"), x = 1, y = 1);
addGB(new JButton("East"), x = 2, y = 1);
addGB(new JButton("South"), x = 1, y = 2);