Spring Layout compound spring problem, on container

Question

I don't understand why these labels are getting resized. This test case is concise and shows the problem clearly, just comment out the line indicated for what the correct behavior I desire is.
package gaillard;
import java.awt.Color;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JLabel;
import javax.swing.Spring;
import javax.swing.SpringLayout;
import javax.swing.SpringLayout.Constraints;
import javax.swing.border.LineBorder;
* @author gaillard
public class Test
     final SpringLayout layout = new SpringLayout();
     final JFrame frame = new JFrame("Test");
     final JPanel contentPane = new JPanel();
     final JLabel label1 = new JLabel("HI");
     final JLabel label2 = new JLabel("HI AGAIN");
     public Test()
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          frame.setContentPane(contentPane);
          contentPane.setLayout(layout);
          contentPane.add(label1);
          contentPane.add(label2);
          label1.setBorder(new LineBorder(Color.red));
          label2.setBorder(new LineBorder(Color.green));
          final Constraints label1Con = layout.getConstraints(label1);
          final Constraints label2Con = layout.getConstraints(label2);
          final Constraints contentPaneCon = layout.getConstraints(contentPane);
          Spring strut = Spring.constant(5);
          Spring columnOneWidth = Spring.max(label1Con.getWidth(),
                                  label2Con.getWidth());
          label1Con.setX(Spring.sum(columnOneWidth,
                            Spring.minus(label1Con.getWidth())));
          label2Con.setX(Spring.sum(columnOneWidth,
                            Spring.minus(label2Con.getWidth())));
          label2Con.setY(Spring.sum(label1Con.getHeight(), strut));
          //TRY COMMENTING THIS LINE OUT FOR THE DESIRED BEHAVIOR!!!!
          //TRY COMMENTING THIS LINE OUT FOR THE DESIRED BEHAVIOR!!!!
          contentPaneCon.setWidth(columnOneWidth);
          frame.pack();
          frame.setVisible(true);
     public static void main(String[] args)
          EventQueue.invokeLater(new Runnable()
               @Override
               public void run()
                    new Test();
}Edited by: gaillard on Jan 7, 2008 8:49 PM

Answer 1

is this a bug? Because there are some examples floating around on the web that do similiar such things expecting this code to work, yet when you run their code it doesn't match their screenshot, so perhaps a bug with java 6 or 5?