Cursor loops infinitely in multiline JTextPane

Name: jbT81659 Date: 03/24/2000

Inserting multiline text in JTextPane causes the cursor to loop infintely.

To reproduce bug:
1- Compile and run attached example.
2- Though all JTextPanes in example are initialized with text, insert more text until you have
more than one line of bidi text.
3- Go to Home position and begin scrolling by pressing the right or left arrow key on the
keyboard so the cursor is moving constantly toward the END.
4- Note that after passing the first line or couple of lines, the cursor
goes back to beginning of line and starts scrolling over again.
5- Try the same procedure for all JTextPanes in example.
6- Note that all of the JTextPanes share this problem.
7- Insert LTR text only. Note that this problem is there.
8- Insert RTL text only. Note that this problem is there.

------Code------

/* Copyright (c) Sun Microsystems 1999

$Header: /home/sun/src/JDK1.2/jTextPane.java,v 1.16 1999/11/28 11:34:25 isam Exp $

*/

import java.awt.*;
import java.awt.font.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.text.*;

public class jTextPane extends JApplet
{
  public void init()
  {
    jTextPane1 jpane = new jTextPane1();
    getContentPane().add(jpane);
  }

  public static void main(String[] args)
  {
    JFrame frame = new JFrame("\u0645\u062b\u0627\u0644");
    frame.setContentPane(new jTextPane1());
    frame.pack();
    frame.setVisible(true);
        frame.addWindowListener( new WindowAdapter()
        {
             public void windowClosing( WindowEvent e)
             {
                 System.exit(0);
             }
        });

  }
}
class jTextPane1 extends JPanel
{
  public jTextPane1()
  {
    JLabel l;
    JPanel p;
    JTextField field;
    JTextArea area;
    JTextPane pane;
    JPanel panel = new JPanel(new FlowLayout(FlowLayout.LEFT));

    p = new JPanel(new FlowLayout(FlowLayout.LEFT, 0, 0));
    l = new JLabel("JTP1 implicit, left");
    pane = new JTextPane();
    pane.setFont(new Font("Lucida Sans Regular", Font.PLAIN, 9));
    l.setVerticalAlignment(SwingConstants.BOTTOM);
    l.setFont(new Font("Lucida Sans Regular", Font.PLAIN, 9));
    pane.setPreferredSize(new Dimension(320, 320));
    pane.setText("\u062a\u0641\u0627\u062d\u0020\u0623\u062d\u0645\u0631\u0020\u05d9\u05d5\u05dd\u0020\u05e0\u05e2\u05d9\u05dd");
    p.add(l);
    p.add(pane);
    p.setPreferredSize(new Dimension(450,450));
    panel.add(p);

    p = new JPanel(new FlowLayout(FlowLayout.LEFT, 0, 0));
    l = new JLabel("JTP2 explicit RTL, left");
    pane = new JTextPane();
    pane.setFont(new Font("Lucida Sans Regular", Font.PLAIN, 9));
    l.setVerticalAlignment(SwingConstants.BOTTOM);
    l.setFont(new Font("Lucida Sans Regular", Font.PLAIN, 9));
    pane.getDocument().putProperty(TextAttribute.RUN_DIRECTION,TextAttribute.RUN_DIRECTION_RTL);
    pane.setPreferredSize(new Dimension(320, 320));
    pane.setText("\u0053\u0074\u0061\u0072\u0074\u0020\u062a\u0641\u0627\u062d\u0020\u0623\u062d\u0645\u0631\u0020\u05d9\u05d5\u05dd\u0020\u05e0\u05e2\u05d9\u05dd");
    p.add(l);
    p.add(pane);
    p.setPreferredSize(new Dimension(500,500));
    panel.add(p);

    p = new JPanel(new FlowLayout(FlowLayout.LEFT, 0, 0));
    l = new JLabel("JTP3 explicit RTL, right");
    l.setVerticalAlignment(SwingConstants.BOTTOM);
    l.setFont(new Font("Lucida Sans Regular", Font.PLAIN, 9));
    pane = new JTextPane();
    pane.getDocument().putProperty(TextAttribute.RUN_DIRECTION,TextAttribute.RUN_DIRECTION_RTL);
    MutableAttributeSet rightStyle;
    rightStyle = new SimpleAttributeSet();
    StyleConstants.setAlignment(rightStyle,StyleConstants.ALIGN_RIGHT);
    StyledDocument doc = pane.getStyledDocument();
    SimpleAttributeSet a = new SimpleAttributeSet();
    //pane.setFont(new Font("Lucida Sans Regular", Font.PLAIN, 9));
    pane.setText("\u0053\u0074\u0061\u0072\u0074\u0020\u062a\u0641\u0627\u062d\u0020\u0623\u062d\u0645\u0631\u0020\u05d9\u05d5\u05dd\u0020\u05e0\u05e2\u05d9\u05dd");
    pane.setParagraphAttributes(rightStyle,true);
    p.setPreferredSize(new Dimension(500,500));
    p.add(l);
    p.add(pane);
    pane.setPreferredSize(new Dimension(320, 320));
    panel.add(p);

    p = new JPanel(new FlowLayout(FlowLayout.LEFT, 0, 0));
    l = new JLabel("JTP4 explicit LTR, left");
    l.setVerticalAlignment(SwingConstants.BOTTOM);
    l.setFont(new Font("Lucida Sans Regular", Font.PLAIN, 9));
    pane = new JTextPane();
    pane.setFont(new Font("Lucida Sans Regular", Font.PLAIN, 9));
    pane.getDocument().putProperty(TextAttribute.RUN_DIRECTION,TextAttribute.RUN_DIRECTION_LTR);
    pane.setPreferredSize(new Dimension(320, 320));
    pane.setText("\u062a\u0641\u0627\u062d\u0020\u0623\u062d\u0645\u0631\u0020\u05d9\u05d5\u05dd\u0020\u05e0\u05e2\u05d9\u05dd");
    p.add(l);
    p.add(pane);
    p.setPreferredSize(new Dimension(500,500));
    panel.add(p);
    
    panel.setPreferredSize(new Dimension(500,2000));

    JScrollPane scroll = new JScrollPane(panel);
    scroll.setPreferredSize(new Dimension(650,450));

    add(scroll);
  }
}


WorkAround:
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