Name: vi73552 Date: 04/30/99


If the Windows look and feel is active and you close a JInternalFrame which is not currently selected, but has been, the JInternalFrame is sometimes immediately added back into the JDesktopPane, although it the frame does disappear. This is a serious issue both because of memory consumption issues, and because some of my code attempts to track open internal frames by watching them get added to the desktop.

The following code demostrates the problem:

  import java.util.*;
  import java.awt.*;
  import java.awt.event.*;
  import javax.swing.*;
  import javax.swing.event.*;
  import java.beans.*;

  public class Test {

    JFrame mainFrame = new JFrame("Testing");
    JDesktopPane desktop = new JDesktopPane() {
      protected void addImpl(Component comp, Object constraints, int index) {
        System.out.println(((JInternalFrame)comp).getTitle() +
                           " added to desktop at index " + index + ".");
        super.addImpl(comp, constraints, index);
      }
    };

    Test() throws Exception {
      mainFrame.getContentPane().add(desktop);
      mainFrame.setSize(350, 350);
      mainFrame.show();
      final JInternalFrame frame1 = makeFrame(1), frame2 = makeFrame(2);
      System.out.println("Adding frame 1.");
      desktop.add(frame1);
      System.out.println("Adding frame 2.");
      desktop.add(frame2);
      System.out.println("Selecting frame 1.");
      frame1.show();
      System.out.println("Selecting frame 2.");
      frame2.show();
      System.out.println("Closing frame 1.");
      frame1.setClosed(true);
    }

    JInternalFrame makeFrame(int frameNum) {
      final JInternalFrame frame =
          new JInternalFrame("Frame " + frameNum, true, true, true);
      frame.setSize(300, 40);
      frame.setLocation(10, 10 + frameNum * 50);
      frame.addInternalFrameListener(new InternalFrameListener() {
        public void internalFrameActivated(InternalFrameEvent e)
          { System.out.println(frame.getTitle() + " Activated."); }
        public void internalFrameClosed(InternalFrameEvent e)
          { System.out.println(frame.getTitle() + " Closed."); }
        public void internalFrameClosing(InternalFrameEvent e)
          { System.out.println(frame.getTitle() + " Closing."); }
        public void internalFrameDeactivated(InternalFrameEvent e)
          { System.out.println(frame.getTitle() + " Deactivated."); }
        public void internalFrameDeiconified(InternalFrameEvent e)
          { System.out.println(frame.getTitle() + " Deiconified."); }
        public void internalFrameIconified(InternalFrameEvent e)
          { System.out.println(frame.getTitle() + " Iconified."); }
        public void internalFrameOpened(InternalFrameEvent e)
          { System.out.println(frame.getTitle() + " Opened."); }
      });
      return frame;
    }

    static void main(String[] args) throws Exception {
      UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
      new Test();
      System.exit(0);
    }

  }

Here's an example of the program's output on my machine. Note that Frame 1 is added to desktop and activated immediately after it is closed:

  Adding frame 1.
  Frame 1 added to desktop at index -1.
  Adding frame 2.
  Frame 2 added to desktop at index -1.
  Selecting frame 1.
  Frame 1 Opened.
  Frame 1 Activated.
  Selecting frame 2.
  Frame 2 Opened.
  Frame 2 added to desktop at index 0.
  Frame 1 Deactivated.
  Frame 2 Activated.
  Closing frame 1.
  Frame 1 Closing.
  Frame 1 Closed.
  Frame 2 Deactivated.
  Frame 1 added to desktop at index 0.
  Frame 1 Activated.

If one goes to the Metal look and feel (by commenting out the 'setLookAndFeel' line) or the Motif look and feel, the problem goes away.

I also undeterministically sometimes get this error from the above code: "Exception occurred during event dispatching: java.lang.ArrayIndexOutOfBoundsException: No such child: 1". I suspect is a timing-related thread problem.
(Review ID: 57244)
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Name: skT88420 Date: 05/14/99


1. Create a Windows look and feel Swing app using internal frames.
Open and close an internal window. Use JProbe or some other tool
and you should see that WindowsDesktopManager is still hold a
reference to it. It isn't the Vector that holds the frames but
the initialFrame.





2. Here is the code in WindowsDestopManager that maybe the cause
...
    JInternalFrame initialFrame;
<snip>
    Vector childFrames = new Vector(1);

    public void closeFrame(JInternalFrame f) {
        activateNextFrame();
        childFrames.removeElement(f);
        super.closeFrame(f);
    }
...
    public void activateNextFrame(JInternalFrame f){
      initialFrame = f;
      switchFrame(true);
    }

As you can see initialFrame still holds the reference.

5.
C:\>java -version
java version "1.2"
HotSpot VM (1.0fcs, mixed mode, build E)
C:\>java -fullversion
java full version "JDK-1.2-V"
(Review ID: 63189)
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