Swing---JTextPane(a boring trouble---looking forward to answer)

Question

In the following program the JLabel inherited can'nt be seen when it inserted into the JTextPane, I wander why?
import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;
import java.awt.event.*;
public class AdvancedJTextPane extends JFrame
JTextPane jtp;
public AdvancedJTextPane(){
     jtp=new JTextPane();
     this.getContentPane().setLayout(new BorderLayout());
     JScrollPane js = new JScrollPane();
     js.getViewport().add(jtp);
     this.getContentPane().add(js);
     this.pack();
     this.setSize(350, 250);
     this.setVisible(true);
     jtp.insertComponent(new DrawLabel(""));
     this.addWindowListener(new WindowAdapter(){
public void windowClosing(WindowEvent e){
System.exit(0);
public static void main(String[] args) {
new AdvancedJTextPane();
class DrawLabel extends JLabel {
public DrawLabel(String label) {
super(label);
Dimension size = getPreferredSize();
size.width = size.height = Math.max(size.width,
size.height);
setPreferredSize(size);
protected void paintComponent(Graphics g) {
g.setColor(Color.lightGray);
g.drawOval(0, 0, getSize().width-3, getSize().height-3);
super.paintComponent(g);
protected void paintBorder(Graphics g) {
g.setColor(getForeground());
g.drawOval(0, 0, getSize().width-1, getSize().height-1);
}

Answer 1

Here's your culprit:
jtp.insertComponent(new DrawLabel(""));You need to use something other than an empty string (spaces will work):
jtp.insertComponent(new DrawLabel("     "));