Change the layout. Try adding the button to another JPanel
then add the panel the frame. BorderLayout
will stretch the button across the available width of the panel when the component is placed in the NORTH
or SOUTH
position
import java.awt.BorderLayout;
import java.awt.EventQueue;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class TestBorderLayout {
public static void main(String[] args) {
new TestBorderLayout();
}
public TestBorderLayout() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JButton fat = new JButton("Fat");
JButton skinny = new JButton("Skinny");
JPanel buttonPane = new JPanel();
buttonPane.add(skinny);
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(fat, BorderLayout.NORTH);
frame.add(buttonPane, BorderLayout.SOUTH);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}