Designing Graphical Interfaces - Beginning Java Programming: The Object-Oriented Approach - page 481

"1", "2", "3", "=", "+", "-", "*", "/"
);

JTextField resultBox = new JTextField("*** BATTERY EMPTY ***");
resultBox.setEditable(false); // Prevent user editing

frame.getContentPane().add(buttonPanel, BorderLayout.CENTER);
frame.getContentPane().add(resultBox, BorderLayout.NORTH);

frame.pack();
frame.setVisible(true);

}

private static void addButtons(Container contentPane, String... strings) {
for (String label : strings) {
contentPane.add(new JButton(label));
}
}

}

The result will now look like Figure 11-13.

figure 11-13

How It Works

This is how it works:
1.

This class is similar to the previous one, but now you have specified a GridLayout object as the
layout manager.

2.

In the second version, a new JPanel container is constructed, and its layout manager is set to be
a GridLayout . Then it is added to the center of the JFrame . A JTextField is then added in the
north position. Note the use of the setEditable method to prevent users from typing in characters
in the textbox.