20050715: IDV - Null pointer in workshop section 3.1.4

>From: "Doug Lindholm" <address@hidden>
>Organization: UCAR/Unidata
>Keywords: 200507152253.j6FMrf2h021755 IDV SoundingControl

Hi Doug-

>Institution: UCAR
>Package Version: 1.2
>Operating System: os.name:Linux; os.arch:i386; os.version:2.6.11-1.27_FC3smp;
>Hardware Information: java.vendor:Sun Microsystems Inc.; java.version:1.4.2_08
> ; java.home:/sparky/opt/j2sdk1.4.2_08/jre;
>Inquiry: When going through section 3.1.4 (Probing Gridded Data) in the latest
>  workshop 
>material using the nightly build, I get the following error when I try to crea
> te the 
>skew-t display.

Thanks for finding this.  It was a problem where the panel of boxes had
not been initialized and something was trying to update it.  I put a wrapper
around it to check for the null condition.

>An error has occurred:
>Error
>java.lang.NullPointerException
>
>******************
>Stack trace:
>java.lang.NullPointerException
>       at ucar.visad.display.AnimationWidget$2.propertyChange(AnimationWidget.
> java:619)
>       at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSu
> pport.java:252)
>       at ucar.visad.display.Displayable.firePropertyChange(Displayable.java:9
> 00)
>       at ucar.visad.display.Animation$AnimationControlListener.controlChanged
> (Animation.java:927)
>       at visad.Control.changeControl(Control.java:95)
>       at visad.java2d.AnimationControlJ2D.setCurrent(AnimationControlJ2D.java
> :162)
>       at visad.AnimationSetControl.setSet(AnimationSetControl.java:150)
>       at visad.java2d.AnimationSetControlJ2D.setSet(AnimationSetControlJ2D.ja
> va:50)
>       at visad.java2d.AnimationControlJ2D.setSet(AnimationControlJ2D.java:366
> )
>       at visad.ScalarMap.setRange(ScalarMap.java:726)
>       at visad.ScalarMap.setRange(ScalarMap.java:585)
>       at visad.DisplayRenderer.prepareAction(DisplayRenderer.java:852)
>       at visad.DisplayImpl.doAction(DisplayImpl.java:1646)
>       at visad.java2d.DisplayImplJ2D.doAction(DisplayImplJ2D.java:312)
>       at visad.ActionImpl.run(ActionImpl.java:353)
>       at visad.util.ThreadPool$ThreadMinnow.run(ThreadPool.java:95)

Don Murray
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