GUI update and threads

From: Karsten Wutzke (kwutzke-blahblah_at_emporis.com)
Date: 03/31/04

  • Next message: A. Bolmarcich: "Re: GUI update and threads" 
    Date: Wed, 31 Mar 2004 00:03:34 +0200

    Hello all!

    I use Observer-Observable to update my GUI when desired (setChanged,
    notifyObservers). However, I sometimes get an exception irregularly:

    java.lang.ArrayIndexOutOfBoundsException: No such child: 4
            at java.awt.Container.getComponent(Container.java:237)
            at javax.swing.JComponent.rectangleIsObscured(JComponent.java:3705)
            at javax.swing.JComponent.paint(JComponent.java:806)
            at javax.swing.JComponent.paintWithOffscreenBuffer(JComponent.java:4795)
            at javax.swing.JComponent.paintDoubleBuffered(JComponent.java:4748)
            at javax.swing.JComponent._paintImmediately(JComponent.java:4692)
            at javax.swing.JComponent.paintImmediately(JComponent.java:4495)
            at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:410)
            at
    javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(SystemEventQueueUtilities.java:117)
            at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:178)
            at java.awt.EventQueue.dispatchEvent(EventQueue.java:454)
            at
    java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:201)
            at
    java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
            at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:145)
            at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:137)
            at java.awt.EventDispatchThread.run(EventDispatchThread.java:100)

    I have three threads running which call methods on objects that lead to
    an update of the GUI, so I assume it's a threading problem (due to the
    irregularities).

    I remember from some time ago, that there was a way to have the AWT
    thread handle the repaint (or was it the event dispatcher? or are they
    the same?).

    Does anyone know how I can post the GUI updates to the "Java GUI repaint
    thread"? I can't remember how it was done, I think it was a simple
    static method call on some class, but which one?

    Can anyone make some other suggestions as to what I could try?

    Thanks very much!
    Karsten

  • Next message: A. Bolmarcich: "Re: GUI update and threads"

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