BorderLayout clobbers child layouts.

Question

Smells like a bug to me. If you place child panels with, say GridBagLayouts inside a panel which has a BorderLayout, the parental BorderLayout clobbers the child layouts. So if you have a panel in the CENTER and you want a button anchored to the upper left hand corner with GridBagConstraints.NORTHWEST, you'll find that your GridBag is completely ignored and your component is centered.
Check out the following code:
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.tree.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Enumeration;
public class Foo3 extends JPanel {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Joe's Foo3");
        frame.addWindowListener(new WindowAdapter() {
                public void windowClosing(WindowEvent e) {
                System.exit(0);
        // Here's your main panel with BorderLayout
        JPanel mainPanel = new JPanel();
        mainPanel.setLayout(new BorderLayout());
        // Here's your inner panel with a GridBag...you want the
        // "NorthWest" button to appear in the northwest corner
        // of the center panel.
        JPanel innerPanel = new JPanel(new GridBagLayout());
        innerPanel.setBackground(Color.black);
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridx = 0;
        gbc.gridy = 0;
        gbc.anchor = GridBagConstraints.NORTHWEST;
        gbc.fill = GridBagConstraints.BOTH;
        innerPanel.add(new JButton("NorthWest"), gbc);
        // Add a button to each of the layout areas
        mainPanel.add(new JButton("North"), BorderLayout.NORTH);
        mainPanel.add(new JButton("West"), BorderLayout.WEST);
        mainPanel.add(innerPanel, BorderLayout.CENTER);
        mainPanel.add(new JButton("East"), BorderLayout.EAST);
        mainPanel.add(new JButton("South"), BorderLayout.SOUTH);
        // Show
        frame.getContentPane().add("Center", mainPanel);
        frame.pack();
        frame.setSize(new Dimension(300, 300));
        frame.setVisible(true);

Answer 1

Hmmm... I tried a few things with your app and nothing worked so far. Looks like you might not be the first to encounter this, but I haven't found a resolution other than don't use GridBag. :)
http://forum.java.sun.com/thread.jsp?forum=5&thread=238875