JFrame maximizing - non deterministic behaviour

Question

Hi there,
I wonder why in the following code the componentResized Method gets a JFrame instance wthich's extended state is MAX_BOTH and the componentMoved Method NORMAL.
Does someone have an explanation or an work around for storing the last position of the JFrame (to store in preferences in order to load them again).
Here is a minimal example.
import javax.swing.JFrame;
* @author Karlheinz Toni
public class Test {
    public static void main(String[] args) {
        JFrame mainFrame = new JFrame();
        mainFrame.addComponentListener(new ComponentAdapter() {
             * (non-Javadoc)
             * @see java.awt.event.ComponentAdapter#componentMoved(java.awt.event.ComponentEvent)
            public void componentMoved(ComponentEvent e) {
                // TODO Auto-generated method stub
                super.componentMoved(e);
                printExtendedState(e.getComponent(), "moving");
             * (non-Javadoc)
             * @see java.awt.event.ComponentAdapter#componentResized(java.awt.event.ComponentEvent)
            public void componentResized(ComponentEvent e) {
                // TODO Auto-generated method stub
                super.componentResized(e);
                printExtendedState(e.getComponent(), "resizing");
            private void printExtendedState(Component component,
                    String whatDoIDo) {
                if (component instanceof JFrame) {
                    System.out.println("Extended state for " + whatDoIDo + ":"
                            + ((JFrame) component).getExtendedState());
        mainFrame.setVisible(true);
}I would be greatful to any help ;)
Sincerely
Charly

Answer 1

I was playing with exactly this kind of thing last night and discovered that the order you get the events isn't really guaranteed. I solved this by using a swing Timer to wait for 1 second of inactivity before querying the Frame and updating the user preferences. Here's the chopped down version of my code:
I register a GeometryTracker object as a ComponentListener and a WindowStateListener in the frame to be monitored.
This all seems to work quite well, but I'm still seeing differences between windows and OS-X for example. (on OS-X the maximized state doesn't seem to correlate with reality. If anyone knows of a trick I'd love to see it.
Thanks and I hope this helps!
Cheers,
Seve
import javax.swing.Timer;
public class GeometryTracker
    extends ComponentAdapter
    implements WindowStateListener
    private Frame       frame;
    private Preferences framePrefs;
    private int         frameState = 0;
    private Rectangle   frameBounds;
    private Timer       updateTimer;
    // TODO: problem with setting up the preferences once like this: changes to screen size aren't handled
    public GeometryTracker( Frame targetFrame ) {
        frame                  = targetFrame;
        framePrefs             = Preferences.userNodeForPackage( frame.getClass() );
        frameState             = frame.getExtendedState();
        frameBounds            = frame.getBounds();
        updateTimer            = new Timer( 1000, new AbstractAction() { public void actionPerformed( ActionEvent e ) { updatePrefs(); } } );
    private synchronized void updatePrefs() {
        frameState = frame.getExtendedState();
        // don't update the window size/location if it has been maximized
        if( ( frameState & Frame.MAXIMIZED_BOTH ) == 0 ) {
            frameBounds = frame.getBounds();
        framePrefs.putInt( "x",      frameBounds.x      );
        framePrefs.putInt( "y",      frameBounds.y      );
        framePrefs.putInt( "width",  frameBounds.width  );
        framePrefs.putInt( "height", frameBounds.height );
        framePrefs.putInt( "state",  frameState         );
        updateTimer.stop();
    public void setBounds( Rectangle defaultBounds ) {
        Rectangle r = new Rectangle();
        r.x         = framePrefs.getInt( "x",      defaultBounds.x      );
        r.y         = framePrefs.getInt( "y",      defaultBounds.y      );
        r.width     = framePrefs.getInt( "width",  defaultBounds.width  );
        r.height    = framePrefs.getInt( "height", defaultBounds.height );
        frameState  = framePrefs.getInt( "state",  Frame.NORMAL );
        frame.setBounds( r );
        if( ( frameState & Frame.MAXIMIZED_BOTH ) != 0 ) {
            frame.setExtendedState( frameState );
    public void componentMoved( ComponentEvent e ) {
        updateTimer.setDelay( 1000 );
        updateTimer.start();
    public void componentResized( ComponentEvent e ) {
        updateTimer.setDelay( 1000 );
        updateTimer.start();
    public void windowStateChanged( WindowEvent e ) {
        updateTimer.setDelay( 1000 );
        updateTimer.start();
    }