The Java method works on Windows but not on Macintosh?


I had a real weird method which is used to hide JInternalFrame's title bar. Now the dilemma is below method works on windows platform,

((javax.swing.plaf.basic.BasicInternalFrameUI) aXInternalFrame.getUI()).setNorthPane(null);

But not on Macintosh! Any experts have any idea which can explain internal process which makes this method not usable on Mac.

And is there any method which may work on both platform to hide titlebar of JInternalFrame?


On Mac OS X, an instance of defines the appearance of internal frames. You can minimize the disparity by setting the isPalette property and disabling the frame icons on Mac OS X specifically, as shown below.

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JInternalFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
import javax.swing.plaf.basic.BasicInternalFrameUI;

/** @see */
public class InternalFrame {

    private static final int DELTA = 40;
    private JDesktopPane desktop = new JDesktopPane();
    private int offset = DELTA;

    public InternalFrame() {
        JFrame f = new JFrame("Add Frame");
        f.setPreferredSize(new Dimension(400, 400));
        JPanel p = new JPanel();
        p.add(new JButton(new AbstractAction("Add") {

            public void actionPerformed(ActionEvent e) {
        f.add(p, BorderLayout.SOUTH);
        f.add(desktop, BorderLayout.CENTER);

    private void createInternalFrame() {
        JInternalFrame internalFrame = new JInternalFrame(
            "Internal Frame");//, true, true, true, true);
        internalFrame.setLocation(offset, offset);
        offset += DELTA;
        if (System.getProperty("").startsWith("Mac OS")) {
            internalFrame.putClientProperty("JInternalFrame.isPalette", true);
        } else {
            ((BasicInternalFrameUI) internalFrame.getUI()).setNorthPane(null);

    // take up some space
    private JTabbedPane createTabbedPane() {
        JTabbedPane jtp = new JTabbedPane();
        createTab(jtp, "One");
        createTab(jtp, "Two");
        return jtp;

    private void createTab(JTabbedPane jtp, String s) {
        jtp.add(s, new JLabel("TabbedPane " + s, JLabel.CENTER));

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

            public void run() {
                InternalFrame myInternalFrame = new InternalFrame();