How to prevent scrolling if you have two Jpanels in a JScrollPane

Question

I have a JScrollPane with a JPanel for Linenumbers and one for a JTextArea,
each time you have a new line in the JTextarea the propertyListenerEvent call a Method that sets the LineNumbers in the JPanel for Linenumbers, but then you get an unwanted behaviour of the scrollbar: The Scrollbar scrolls down to the last Line. (e.g. if youre writing in the first Line - LineNumber update after pressing return, set's the view to the last Line e.g. 200 - the caret/cursor is on the second) I tried to set the Linenumber Panel not focusable, but it doesn't work. Does anyone got a hint for me?

Answer 1

Thanks for the answers.
@itchyscratchy: didn't get it working with that workarround. but thanks a lot :)
camickr: Since we can't see your code, we can't suggest what you might be doing wrong.I better kick my idea... thought it could be possible like: when
LnNums=false after setLineNum Call in jTPaneCaretUpdate!?
* LineNumberTest.java
* Created on 12. Dezember 2006, 23:40
public class LineNumberTest extends javax.swing.JFrame
    /** Creates new form LineNumberTest */
    public LineNumberTest()
        initComponents();
   // <editor-fold defaultstate="collapsed" desc=" Generated Code ">
    private void initComponents()
    jScrollPane1 = new javax.swing.JScrollPane();
        jPanel1 = new javax.swing.JPanel();
        jTxtArea1 = new javax.swing.JTextArea();
        jTLineNums = new javax.swing.JTextArea();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
       jPanel1.setLayout(new java.awt.BorderLayout());
        jTxtArea1.addCaretListener(new javax.swing.event.CaretListener() {
            public void caretUpdate(javax.swing.event.CaretEvent evt) 
                jTxtArea1CaretUpdate(evt);
        jPanel1.add(jTxtArea1, java.awt.BorderLayout.CENTER);
        jTLineNums.setBackground(javax.swing.UIManager.getDefaults().getColor("TextField.disabledBackground"));
        jTLineNums.setEditable(false);
        jPanel1.add(jTLineNums, java.awt.BorderLayout.WEST);
        jScrollPane1.setViewportView(jPanel1);
        getContentPane().add(jScrollPane1, java.awt.BorderLayout.CENTER);
        java.awt.Dimension screenSize = java.awt.Toolkit.getDefaultToolkit().getScreenSize();
        setBounds((screenSize.width-400)/2, (screenSize.height-300)/2, 400, 300);
    // </editor-fold>
    private void jTxtArea1CaretUpdate(javax.swing.event.CaretEvent evt)
        //Caret
        ci = jTxtArea1.getCaretPosition();
        String sc;
        sc = Integer.toString(ci);
        String s = "0";
        sli=jTxtArea1.getLineCount();
        s = Integer.toString(sli);
        if(LnNums) {
            setLineNums();
           //LnNums =false;
         private void setLineNums()
        jTLineNums.setText("");
        //jTLNums.setFont (new Font (fName, Font.PLAIN, fSize));
        for (int i = 1; i <= sli; i++) {
            jTLineNums.append(i+" \r\n");
        //setFoc ();
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new LineNumberTest().setVisible(true);
    public javax.swing.JPanel jPanel1;
    public javax.swing.JScrollPane jScrollPane1;
    public javax.swing.JTextArea jTLineNums;
    public javax.swing.JTextArea jTxtArea1;
    boolean LnNums = true;
    int iLnNums, iSymBar, iCodeBar, iInv, sli, ci;
}