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Re: JScrollBar problems

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  To: comp.lang.java.gui
>I am trying to force the scrolling to show the top of what I have just
>generated in a JTextArea.
>
> JTextArea  howTo =
>                new JTextArea(  ... );
>        howTo.setForeground( BLACK );
>        howTo.setMargin( new Insets( 5, 5, 5, 5 ) );
>        howToScroller =
>                new JScrollPane( howTo,
> JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
> JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED
>                         );
>....
>
>             howTo.setText( ...  );
>
>            // make sure top of generated code is visible.
>            final JScrollBar v = howToScroller.getVerticalScrollBar();
>            v.setValue( v.getMinimum() );
>
>Yet it ignores me. It acts as if I had said v.getMaximum() showing the
>END of the text instead of the beginning.

mystery solved.  This might be considered a bug in sun.

There is how I got it to work:

  // invoke later to give time for text to render.
            SwingUtilities.invokeLater( new Runnable() {
                public void run()
                    {
                    final JScrollBar v =
howToScroller.getVerticalScrollBar();
                    v.setValue( v.getMinimum() );
                    }
            } );
The key is, the setText had to RENDER before the setValue was
processed. 
-- 
Roedy Green Canadian Mind Products
The Java Glossary
http://mindprod.com

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JScrollBar problems "Roedy Green" <roedy.green@THRWHITE.remove-dii-this> - 2011-04-27 15:37 +0000
  Re: JScrollBar problems "Roedy Green" <roedy.green@THRWHITE.remove-dii-this> - 2011-04-27 15:37 +0000
    Re: JScrollBar problems "Sabine Dinis Blochberger" <sabine.dinis.blochberger@THRWHITE.remove-dii-this> - 2011-04-27 15:37 +0000
  Re: JScrollBar problems "Roedy Green" <roedy.green@THRWHITE.remove-dii-this> - 2011-04-27 15:37 +0000
    Re: JScrollBar problems "Knute Johnson" <knute.johnson@THRWHITE.remove-dii-this> - 2011-04-27 15:37 +0000
      Re: JScrollBar problems "Roedy Green" <roedy.green@THRWHITE.remove-dii-this> - 2011-04-27 15:37 +0000
        Re: JScrollBar problems "Daniel Pitts" <daniel.pitts@THRWHITE.remove-dii-this> - 2011-04-27 15:37 +0000

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