How to make a JPanel containing buttons take up the width of the window?

Question

I'm creating a GUI and I have a button group that I want to be the width of the window. I have another JPanel on the same window that doesn't have a button group in it and it takes up the width of the window. I don't think I'm doing anything differently creating the two, but I need consistency.
The best way I can explain this is with code, so I created an example of what I am doing here:
import java.awt.*;
import javax.swing.*;
public class test extends JFrame {
     public test() {
          JPanel win = new JPanel();
          JPanel buttonsPanel = new JPanel();
          JPanel statusPanel = new JPanel();
          win.setLayout(new BoxLayout(win, BoxLayout.Y_AXIS));
          buttonsPanel.setLayout(new BoxLayout(buttonsPanel, BoxLayout.Y_AXIS));
          statusPanel.setLayout(new BoxLayout(statusPanel, BoxLayout.Y_AXIS));
//          createRadioButtonsPanel
          ButtonGroup buttons = new ButtonGroup();
          JRadioButton currentMap = new JRadioButton("option1", true);
          JRadioButton newMap = new JRadioButton("option2");
          JRadioButton noMap = new JRadioButton("option3");
          buttons.add(currentMap);
          buttons.add(newMap);
          buttons.add(noMap);
          buttonsPanel.add(currentMap);
          buttonsPanel.add(newMap);
          buttonsPanel.add(noMap);
          buttonsPanel.setBorder(
                    BorderFactory.createTitledBorder("Create: "));
//           createStatusPanel
          JLabel statusLabel = new JLabel("Loading...");
          statusLabel.setBorder(BorderFactory.createLoweredBevelBorder());
          statusLabel.setPreferredSize(new Dimension(400,20));
          statusLabel.setMinimumSize(new Dimension(400,20));
          statusLabel.setMaximumSize(new Dimension(400,20));
          statusPanel.add(statusLabel);
          JPanel statusButtons = new JPanel(new FlowLayout(FlowLayout.RIGHT));
          JButton pauseSearch = new JButton("Pause");
          JButton cancelSearch = new JButton("Cancel");
          statusButtons.add(pauseSearch);
          statusButtons.add(cancelSearch);
          statusPanel.add(statusButtons);
          statusPanel.setBorder(BorderFactory.createTitledBorder("Status: "));
          win.add(buttonsPanel);
          win.add(statusPanel);
          getContentPane().add(win);
          pack();
          setVisible(true);
     public static void main(String args[]) {
          test s = new test();
}When I compile and run this class I get this window:
http://img136.imageshack.us/img136/1538/exampleek5.png
You see how on the bottom, "Status" JPanel takes up the entire width of the window? When the window is resized, the border is also resized. I would love to have the top "Create" JPanel have the same behavior. How do I do this?
Thanks in advance!

Answer 1

It can get confusing when using the BoxLayout. The box layout takes into consideration the X alignment of the components as well as the minimum and maximum lengths.
So I suggest you read the Swing tutorial on [url http://java.sun.com/docs/books/tutorial/uiswing/layout/box.html]How to Use Box Layout for examples and explanations on how these values are used in the layout process.
It may be easier to use a BorderLayout for the high level layout manger, since it will resize a components width when added to the NORTH, CENTER or SOUTH.