Bringing JFileChooser on top of all windows

The API for showOpenDialog() refers to showDialog(), which says, “If the parent is null, then the dialog depends on no visible window, and it’s placed in a look-and-feel-dependent position such as the center of the screen.”

The example below positions the chooser in the center of the screen on my L&F. You might see how it compares to yours.

package gui;

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;
import javax.swing.JScrollPane;
import javax.swing.KeyStroke;

/**
 * @see http://stackoverflow.com/questions/8507521
 * @see http://stackoverflow.com/questions/5129294
 */
public class ImageApp extends JPanel {

    private static final int MASK =
        Toolkit.getDefaultToolkit().getMenuShortcutKeyMask();
    private JFileChooser chooser = new JFileChooser();
    private Action openAction = new ImageOpenAction("Open");
    private Action clearAction = new ClearAction("Clear");
    private JPopupMenu popup = new JPopupMenu();
    private BufferedImage image;

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                new ImageApp().create();
            }
        });
    }

    public void create() {
        JFrame f = new JFrame();
        f.setTitle("Title");
        f.add(new JScrollPane(this), BorderLayout.CENTER);
        JMenuBar menuBar = new JMenuBar();
        JMenu menu = new JMenu("File");
        menu.setMnemonic('F');
        menu.add(new JMenuItem(openAction));
        menu.add(new JMenuItem(clearAction));
        menuBar.add(menu);
        f.setJMenuBar(menuBar);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.pack();
        f.setSize(new Dimension(640, 480));
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public ImageApp() {
        this.setComponentPopupMenu(popup);
        popup.add("Popup Menu");
        popup.add(new JMenuItem(openAction));
        popup.add(new JMenuItem(clearAction));
    }

    @Override
    public Dimension getPreferredSize() {
        if (image == null) {
            return new Dimension();
        } else {
            return new Dimension(image.getWidth(), image.getHeight());
        }
    }

    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.drawImage(image, 0, 0, null);
    }

    private class ClearAction extends AbstractAction {

        public ClearAction(String name) {
            super(name);
            this.putValue(Action.MNEMONIC_KEY, KeyEvent.VK_C);
            this.putValue(Action.ACCELERATOR_KEY,
                KeyStroke.getKeyStroke(KeyEvent.VK_C, MASK));
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            image = null;
            revalidate();
            repaint();
        }
    }

    private class ImageOpenAction extends AbstractAction {

        public ImageOpenAction(String name) {
            super(name);
            this.putValue(Action.MNEMONIC_KEY, KeyEvent.VK_O);
            this.putValue(Action.ACCELERATOR_KEY,
                KeyStroke.getKeyStroke(KeyEvent.VK_O, MASK));
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            int returnVal = chooser.showOpenDialog(chooser);
            if (returnVal == JFileChooser.APPROVE_OPTION) {
                File f = chooser.getSelectedFile();
                try {
                    image = ImageIO.read(f);
                    revalidate();
                    repaint();
                } catch (IOException ex) {
                    ex.printStackTrace(System.err);
                }
            }
        }
    }
}