Re: [JAVA3D] problem with removeChild()

[David Turland]

children always count from 0, so if you remove 1 child from your 7, the
remaining occupy indices 0-5, and so on,

          int childNum = bg.numChildren();
                for( int j =0; j<childNum; j++) {
                  System.out.println(" test child number" + childNum + " " +
j );
               bg.removeChild(0);
               }


        would work,but

        while(bg.numChildren() >0)
        {
               bg.removeChild(0);
        }

        is probably neater



David Turland


> -----Original Message-----
> From: Liming CHEN [SMTP:[EMAIL PROTECTED]]
> Sent: 31 January 2001 13:15
> To:   [EMAIL PROTECTED]
> Subject:      [JAVA3D] problem with removeChild()
>
> Hi,
>
> I add seven children (Behaviour) to a BranchGroup. Then I try to remove
> all these
> children by the following codes
>
>  int childNum = bg.numChildren();
>         for( int j =0; j<childNum; j++) {
>           System.out.println(" test child number" + childNum + " " + j );
>        bg.removeChild(j);
>        }
> However, there is a error message as follows:
>
> test child number7 0
>  test child number7 1
>  test child number7 2
>  test child number7 3
>  test child number7 4
> Exception occurred during event dispatching:
> java.lang.ArrayIndexOutOfBoundsException: 4 >= 3
>  at java.util.Vector.elementAt(Vector.java:417)
>  at javax.media.j3d.GroupRetained.doRemoveChild(GroupRetained.java:312)
>  at javax.media.j3d.GroupRetained.removeChild(GroupRetained.java:303)
>  at javax.media.j3d.Group.removeChild(Group.java:201)
>  at HumanBehavior.setBehaviour(HumanBehavior.java:176)
>  at VirtualAgent.actionPerformed(VirtualAgent.java:301)
>  at java.awt.MenuItem.processActionEvent(MenuItem.java:531)
>  at java.awt.MenuItem.processEvent(MenuItem.java:495)
>
> the message show the index is invalid. However I think 4 is less than the
> numChildren (that is 7). It should be okay. I can not figure out the
> reason.
>
> Is it a bug or I make a mistake somewhere?
>
> thanks
>
> liming
>
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