JDialog sizing problems

Question

First of all, just let me say I have read everything there is available on layout managers and how pack() and validate() work.
My problem is simply that my JDialog appears far longer than its components, and I can't see why.
I've created screenshots of the desired appearance and the actual appearance:
http://www.komododave.co.uk/gallery/main.php?g2_itemId=167
The first 'undesired' screenshot shows what the JDialog looks like upon instantiation. The second shows what it looks like once you manually shrink it in the Y direction by more than about 10 pixels.
I don't understand how the maximum size can exceed the Dimension I set with 'dialog.setMaximumSize(...', since I'm using BoxLayout for the JDialog and that respects a given maximum size.
The constructor creating the JDialog is shown here:
          public AbstractSelectionDialog(Vector<String> argVector, String title,
                    String message) {
               Vector<String> vector = argVector;
               // create new modal JDialog
               final JDialog dialog = new JDialog(Silk.getFrame(), title, true);
               // set boxlayout for dialog frame
               dialog.getContentPane().setLayout(new BoxLayout(dialog.getContentPane(),
                         BoxLayout.Y_AXIS));
               // set default close operation
               dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
               // create ButtonGroup to enforce exclusive collection choice
               final ButtonGroup buttonGroup = new ButtonGroup();
               // initialise other components
               // use fake space for label rather than use another HorizontalGlue
               JLabel label = new JLabel("   " + message);
               // panel containing collection selection
               JPanel selectionPanel = new JPanel();
               // run initialiser methods
               JPanel buttonPanel = (JPanel) createButtons(buttonGroup, dialog);
               AbstractButton selection[] = createSelection(vector, buttonGroup,
                         selectionPanel);
               // scrollPane containing collection panel
               JScrollPane scrollPane = new JScrollPane(selectionPanel,
                         JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED,
                         JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
               // panel containing scroll pane
               JPanel scrollPanel = new JPanel();
               scrollPanel.setLayout(new BoxLayout(scrollPanel, BoxLayout.X_AXIS));
               selectionPanel.setLayout(new GridLayout(vector.size(), 1));
               // assemble component structure
               scrollPanel.add(Box.createHorizontalGlue());
               scrollPanel.add(scrollPane);
               scrollPanel.add(Box.createHorizontalGlue());
               dialog.add(label);
               dialog.add(scrollPanel);
               dialog.add(buttonPanel);
               // set all components to be left-justified
               label.setAlignmentX(0.0F);
               scrollPanel.setAlignmentX(0.0F);
               selectionPanel.setAlignmentX(0.0F);
               buttonPanel.setAlignmentX(0.0F);
               // set higher-level component sizes
               Silk.setSizeAttributes(label, 300, 30, true);
               selectionPanel.setMaximumSize(new Dimension(250, 400));
               scrollPane.setMinimumSize(new Dimension(250, 50));
               scrollPane.setMaximumSize(new Dimension(250, 400));
               dialog.setMinimumSize(new Dimension(300, 200));
               dialog.setMaximumSize(new Dimension(300, 500));
               dialog.pack();
               // set components to be opaque
               label.setOpaque(true);
               scrollPane.setOpaque(true);
               selectionPanel.setOpaque(true);
               // display dialog frame
               //dialog.setResizable(false);
               dialog.setVisible(true);
          }The 'createButtons' method it uses is here:
     public JPanel createButtons(ButtonGroup bg, JDialog jd) {
               final ButtonGroup buttonGroup = bg;
               final JDialog dialog = jd;
               // confirmation buttons
               JButton okBtn = new JButton();
               JButton cancelBtn = new JButton();
               JButton newBtn = new JButton();
               // panel containing OK and CANCEL buttons
               JPanel bothPanel = new JPanel();
               // panel containing NEW COLLECTION button
               JPanel newPanel = new JPanel();
               // panel to contain all other button panels
               JPanel confPanel = new JPanel();
               confPanel.setLayout(new BoxLayout(confPanel, BoxLayout.X_AXIS));
               newPanel.setLayout(new BoxLayout(newPanel, BoxLayout.X_AXIS));
               bothPanel.setLayout(new BoxLayout(bothPanel, BoxLayout.Y_AXIS));
               // definition of button Actions
               okBtn.setAction(new AbstractAction() {
                    public void actionPerformed(ActionEvent ae) {
                         Actions.addScript(buttonGroup.getSelection()
                                   .getActionCommand(), null);
                         dialog.dispose();
               cancelBtn.setAction(new AbstractAction() {
                    public void actionPerformed(ActionEvent ae) {
                         dialog.dispose();
               newBtn.setAction(new AbstractAction() {
                    public void actionPerformed(ActionEvent ae) {
                         dialog.dispose();
                         new Actions.NewCollectionAction().actionPerformed(ae);
                         new Actions.NewScriptAction().actionPerformed(ae);
               // override action-set button text
               okBtn.setText("Ok");
               cancelBtn.setText("Cancel");
               newBtn.setText("Add New Collection");
               // set button sizes
               Silk.setSizeAttributes(okBtn, 115, 30, true);
               Silk.setSizeAttributes(cancelBtn, 115, 30, true);
               Silk.setSizeAttributes(newBtn, 250, 35, true);
               // set opaque buttons
               confPanel.setOpaque(true);
               okBtn.setOpaque(true);
               cancelBtn.setOpaque(true);
               // assemble components
               confPanel.add(Box.createHorizontalGlue());
               confPanel.add(okBtn);
               confPanel.add(Box.createRigidArea(new Dimension(20, 0)));
               confPanel.add(cancelBtn);
               confPanel.add(Box.createHorizontalGlue());
               newPanel.add(Box.createHorizontalGlue());
               newPanel.add(newBtn);
               newPanel.add(Box.createHorizontalGlue());
               bothPanel.add(Box.createRigidArea(new Dimension(0, 10)));
               bothPanel.add(confPanel);
               bothPanel.add(Box.createRigidArea(new Dimension(0, 5)));
               bothPanel.add(newPanel);
               bothPanel.add(Box.createRigidArea(new Dimension(0, 10)));
               bothPanel.setMaximumSize(new Dimension(300, 100));
               return bothPanel;
          }And the createSelection() method it uses is defined here:
     public AbstractButton[] createSelection(Vector<String> argVector,
                    ButtonGroup buttonGroup, JPanel selectionPanel) {
               Vector<String> vector = argVector;
               JRadioButton selection[] = new JRadioButton[vector.size()];
               for (int i = 0; i < vector.size(); i++)
                    selection[i] = new JRadioButton(vector.get(i));
               AbstractButton current;
               for (byte i = 0; i < selection.length; i++) {
                    current = selection;
                    // set action command string to later identify button that's
                    // selected
                    current.setActionCommand(vector.get(i));
                    // fix button's size
                    Silk.setSizeAttributes(current, 250, 30, true);
                    // set button's colour
                    current.setBackground(Color.WHITE);
                    // add button to buttongroup
                    buttonGroup.add(current);
                    // add button to appropriate JPanel
                    selectionPanel.add(current);
               // ensure one button is selected to prevent pressing OK with no
               // selection
               selection[0].setSelected(true);
               return selection;
Please help if you can.
Thank you.
- Dave

Answer 1

Yeah sorry camickr, I need to get into the habit of posting SSCCEs.
Here it is in SSCCE form:
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.AbstractButton;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.ButtonGroup;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JRadioButton;
import javax.swing.JScrollPane;
import java.util.Vector;
public class Testing {
     // prevent instantiation
     private Testing() {
     public interface SelectionDialog {
          // produces a component containing all dialog buttons
          public Component createButtons(ButtonGroup bg, JDialog jd);
          // produces an array of the selection buttons to be used
          public abstract AbstractButton[] createSelection(
                    Vector<String> selectionVector, ButtonGroup buttonGroup,
                    JPanel selectionPanel);
     abstract static class AbstractSelectionDialog implements SelectionDialog {
          public AbstractSelectionDialog() {
               Vector<String> vector = new Vector<String>();
               String title = "Broken dialog box";
               String message = "Why is the maximum size exceedable, hmm?";
               /* for sscce */
               vector.add("choice 1");
               vector.add("choice 2");
               vector.add("choice 3");
               vector.add("choice 4");
               vector.add("choice 5");
               vector.add("choice 6");
               vector.add("choice 7");
               vector.add("choice 8");
               vector.add("choice 9");
               vector.add("choice 10");
               vector.add("choice 11");
               vector.add("choice 12");
               vector.add("choice 13");
               vector.add("choice 14");
               vector.add("choice 15");
               vector.add("choice 16");
               vector.add("choice 17");
               vector.add("choice 18");
               // create new modal JDialog
               final JDialog dialog = new JDialog(Silk.getFrame(), title, true);
               // set boxlayout for dialog frame
               dialog.getContentPane().setLayout(new BoxLayout(dialog.getContentPane(),
                         BoxLayout.Y_AXIS));
               // set default close operation
               dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
               // create ButtonGroup to enforce exclusive collection choice
               final ButtonGroup buttonGroup = new ButtonGroup();
               // initialise other components
               // use fake space for label rather than use another HorizontalGlue
               JLabel label = new JLabel("   " + message);
               // panel containing collection selection
               JPanel selectionPanel = new JPanel();
               // run initialiser methods
               JPanel buttonPanel = (JPanel) createButtons(buttonGroup, dialog);
               AbstractButton selection[] = createSelection(vector, buttonGroup,
                         selectionPanel);
               // scrollPane containing collection panel
               JScrollPane scrollPane = new JScrollPane(selectionPanel,
                         JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED,
                         JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
               // panel containing scroll pane
               JPanel scrollPanel = new JPanel();
               scrollPanel.setLayout(new BoxLayout(scrollPanel, BoxLayout.X_AXIS));
               selectionPanel.setLayout(new GridLayout(vector.size(), 1));
               // assemble component structure
               scrollPanel.add(Box.createHorizontalGlue());
               scrollPanel.add(scrollPane);
               scrollPanel.add(Box.createHorizontalGlue());
               dialog.add(label);
               dialog.add(scrollPanel);
               dialog.add(buttonPanel);
               // set all components to be left-justified
               label.setAlignmentX(0.0F);
               scrollPanel.setAlignmentX(0.0F);
               selectionPanel.setAlignmentX(0.0F);
               buttonPanel.setAlignmentX(0.0F);
               // set higher-level component sizes
               Silk.setSizeAttributes(label, 300, 30, true);
               selectionPanel.setMaximumSize(new Dimension(250, 400));
               scrollPane.setMinimumSize(new Dimension(250, 50));
               scrollPane.setMaximumSize(new Dimension(250, 400));
               dialog.setMinimumSize(new Dimension(300, 200));
               dialog.setMaximumSize(new Dimension(300, 500));
               dialog.pack();
               // set components to be opaque
               label.setOpaque(true);
               scrollPane.setOpaque(true);
               selectionPanel.setOpaque(true);
               // display dialog frame
               // dialog.setResizable(false);
               dialog.setVisible(true);
     protected static class ChooseCollectionDialog extends
               AbstractSelectionDialog implements SelectionDialog {
          public ChooseCollectionDialog() {
               super();
          public JPanel createButtons(ButtonGroup bg, JDialog jd) {
               final ButtonGroup buttonGroup = bg;
               final JDialog dialog = jd;
               // confirmation buttons
               JButton okBtn = new JButton();
               JButton cancelBtn = new JButton();
               JButton newBtn = new JButton();
               // panel containing OK and CANCEL buttons
               JPanel bothPanel = new JPanel();
               // panel containing NEW COLLECTION button
               JPanel newPanel = new JPanel();
               // panel to contain all other button panels
               JPanel confPanel = new JPanel();
               confPanel.setLayout(new BoxLayout(confPanel, BoxLayout.X_AXIS));
               newPanel.setLayout(new BoxLayout(newPanel, BoxLayout.X_AXIS));
               bothPanel.setLayout(new BoxLayout(bothPanel, BoxLayout.Y_AXIS));
               // definition of button Actions
               okBtn.setAction(new AbstractAction() {
                    public void actionPerformed(ActionEvent ae) {
                         dialog.dispose();
               cancelBtn.setAction(new AbstractAction() {
                    public void actionPerformed(ActionEvent ae) {
                         dialog.dispose();
               newBtn.setAction(new AbstractAction() {
                    public void actionPerformed(ActionEvent ae) {
               // override action-set button text
               okBtn.setText("Ok");
               cancelBtn.setText("Cancel");
               newBtn.setText("Add New Collection");
               // set button sizes
               Silk.setSizeAttributes(okBtn, 115, 30, true);
               Silk.setSizeAttributes(cancelBtn, 115, 30, true);
               Silk.setSizeAttributes(newBtn, 250, 30, true);
               // set opaque buttons
               confPanel.setOpaque(true);
               okBtn.setOpaque(true);
               cancelBtn.setOpaque(true);
               // assemble components
               confPanel.add(Box.createHorizontalGlue());
               confPanel.add(okBtn);
               confPanel.add(Box.createRigidArea(new Dimension(20, 0)));
               confPanel.add(cancelBtn);
               confPanel.add(Box.createHorizontalGlue());
               newPanel.add(Box.createHorizontalGlue());
               newPanel.add(newBtn);
               newPanel.add(Box.createHorizontalGlue());
               bothPanel.add(Box.createRigidArea(new Dimension(0, 10)));
               bothPanel.add(confPanel);
               bothPanel.add(Box.createRigidArea(new Dimension(0, 5)));
               bothPanel.add(newPanel);
               bothPanel.add(Box.createRigidArea(new Dimension(0, 10)));
               bothPanel.setMaximumSize(new Dimension(300, 100));
               return bothPanel;
          public AbstractButton[] createSelection(Vector<String> argVector,
                    ButtonGroup buttonGroup, JPanel selectionPanel) {
               Vector<String> vector = argVector;
               JRadioButton selection[] = new JRadioButton[vector.size()];
               for (int i = 0; i < vector.size(); i++)
                    selection[i] = new JRadioButton(vector.get(i));
               AbstractButton current;
               for (byte i = 0; i < selection.length; i++) {
                    current = selection;
                    // set action command string to later identify button that's
                    // selected
                    current.setActionCommand(vector.get(i));
                    // fix button's size
                    Silk.setSizeAttributes(current, 250, 30, true);
                    // set button's colour
                    current.setBackground(Color.WHITE);
                    // add button to buttongroup
                    buttonGroup.add(current);
                    // add button to appropriate JPanel
                    selectionPanel.add(current);
               // ensure one button is selected to prevent pressing OK with no
               // selection
               selection[0].setSelected(true);
               return selection;
     public static void main(String args[]) {
          javax.swing.SwingUtilities.invokeLater(new Runnable() {
               public void run() {
                    new ChooseCollectionDialog();
I considered that the GridLayout might be a problem, but surely the fact that it's ultimately contained in a BoxLayout (which [i]does respect maximum size) means the maximum size still shouldn't be exceedable?
Thanks.