Scrolling a JEditorPane

Question

I have a JEditorPane inside a JScrollPane.
In this JEditorPane I show a Html file which is bigger than the JEditorPane, so the ScrollBars appears.
In my application, the keys (up,down,left, right) should be used for Scrolling, so we've used this code:
  peditor.addKeyListener( new KeyAdapter() {
         public void keyPressed( KeyEvent e ) {
            int icode = e.getKeyCode();
            if ( icode == KeyEvent.VK_UP ) {
               int igo = pscroll.getVerticalScrollBar().getUnitIncrement( 1 );
               int ival = pscroll.getVerticalScrollBar().getValue();
               int idest = ival - igo;
               if ( idest < pscroll.getVerticalScrollBar().getMinimum() ) {
                  idest = pscroll.getVerticalScrollBar().getMinimum();
               pscroll.getVerticalScrollBar().setValue( idest );
            else if ( icode == KeyEvent.VK_DOWN ) {
               int igo = pscroll.getVerticalScrollBar().getUnitIncrement( 1 );
               int ival = pscroll.getVerticalScrollBar().getValue();
               int idest = ival + igo;
               if ( idest > pscroll.getVerticalScrollBar().getMaximum() ) {
                  idest = pscroll.getVerticalScrollBar().getMaximum();
               pscroll.getVerticalScrollBar().setValue( idest );
      });in fact it worked, but I have 2 bugs:
1)When the keys are used after the mouse, the position changes to where the mouse had started.
2)When you keep the key pressed, the ScrollBars doesn't move in a standard way, they are fast in some points, and slow in some other.
What should I do ?
Can someone help me to solve these bugs ?
Thanks.
Wmiro.

Answer 1

Hello,
bbrittas solution works for me (jdk1.42), but the
problem is that it only looks where the cursor is and
not where the user scrolled to.
You have to check whether the vertical ScrollBar is at
maximum + model-extent else dont scroll to bottom.
regards,
TimHeres an ugly(flickering) but working start:public void actionPerformed(ActionEvent ae)
     final JScrollBar bar = scroll.getVerticalScrollBar();
     final int barPos = bar.getValue();
     boolean end = bar.getValue() == bar.getMaximum() - bar.getModel().getExtent() - 3;
     try
          doc.insertString(doc.getLength(), "Something", null);
          if (end)
               jep.setCaretPosition(doc.getLength());
          else
               SwingUtilities.invokeLater(new Runnable()
                    public void run(){
                         bar.setValue(barPos);
     catch (BadLocationException ble){}
}regards,
Tim