Please help with a drawing on JPanel in a background.

Question

Hello everybody,
I have already post this question in the main java forum and was adviced to place the question here. Since then, I have refactored the code. I need your opinion and advice.
My task is to draw some objects on the JPanel or some other components and to place the names to the objects, for example squares, but later, from the thread. Because it can take some time, untill the names will be avaliable.
So, I refactored the code I post before http://forum.java.sun.com/thread.jspa?threadID=5192586&tstart=15
And now, it draws on layers and from thread on resize, with some imitating interval.
Is it a good approach I use, is there a better way, to draw on JPanel, after some objects were already painted.
Here is my sample, try to resize window:
package test;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.ComponentEvent;
import java.awt.event.ComponentListener;
import java.awt.geom.Rectangle2D;
import javax.swing.JFrame;
import javax.swing.JLayeredPane;
import javax.swing.JPanel;
public class Painter extends JFrame implements ComponentListener{
     private static final long serialVersionUID = 1L;
     private ThreadPainter threadPainter;
     JPanel panel = new JPanel() {
          private static final long serialVersionUID = 1L;
          @Override
          protected void paintComponent(Graphics g) {
               super.paintComponent(g);
               System.out.println("repaint");
               Graphics2D g2d = (Graphics2D) g;
               g2d.setColor(Color.gray);
               g2d.fillRect(0, 0, 800, 600);
               g2d.setColor(Color.white);
               for (int i = 0; i < 6; i++) {
                    Rectangle2D rec2d = new Rectangle2D.Double(10 + i * 100,
                              10 + i * 100, 10, 10);
                    g2d.fill(rec2d);
                    g2d.drawString("Square " + i, 10 + i * 100 + 20, 10 + i * 100);
               // start thread to paint some changes later
               if (threadPainter == null) {
                    threadPainter = new ThreadPainter();
                    threadPainter.start();
     JPanelTest panel1 = new JPanelTest();
     public class JPanelTest extends JPanel {
          private static final long serialVersionUID = 1L;
          private int times = 0;
          @Override
          protected void paintComponent(Graphics g) {
               super.paintComponent(g);
               Graphics2D g2d = (Graphics2D) g;
               g2d.setColor(Color.red);
               System.out.println("repaint panel test");
                    System.out.println("repaitn times");
                    g2d.drawString("Square " + times, 10 + times * 100 + 20, 10 + times * 100);
          public void repaintMethod(int times) {
               this.times = times;
               this.repaint(times * 100 + 20, times * 100, 300,300);
     public class ThreadPainter extends Thread {
          private boolean stop = false;
          @Override
          public void run() {
               while (!stop) {
                    int cnt = 0;
                    for (int i = 0; i < 6; i++) {
                         System.out.println("do task");
                         panel1.repaintMethod(i);
                         // load data, do calculations
                         try {
                              // emulate calcilation
                              Thread.sleep(1000);
                         } catch (InterruptedException e) {
                              e.printStackTrace();
                         if (stop) {
                              break;
                         cnt++;
                    if (cnt == 6) {
                         stopThread();
          public void stopThread() {
               this.stop = true;
     public Painter() {
          this.setLayout(new BorderLayout());
          JLayeredPane pane = new JLayeredPane();
          this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          this.setLocation(new Point(100, 100));
          this.setPreferredSize(new Dimension(800, 600));
          this.panel.setOpaque(false);
          this.panel1.setOpaque(false);
          pane.setOpaque(false);
          pane.add(panel, JLayeredPane.DEFAULT_LAYER);
          pane.add(panel1, new Integer(
                    JLayeredPane.DEFAULT_LAYER.intValue() + 1));
          this.add(pane, BorderLayout.CENTER);
          panel.setBounds(new Rectangle(0, 0, 800, 600));
          panel1.setBounds(new Rectangle(0, 0, 800, 600));
          this.addComponentListener(this);
     public static void main(String[] args) {
          Painter painter = new Painter();
          painter.pack();
          painter.setVisible(true);
     @Override
     public void componentHidden(ComponentEvent e) {
          // TODO Auto-generated method stub
     @Override
     public void componentMoved(ComponentEvent e) {
          // TODO Auto-generated method stub
     @Override
     public void componentResized(ComponentEvent e) {
          if (threadPainter != null) {
               threadPainter.stopThread();
               threadPainter = new ThreadPainter();
               threadPainter.start();
     @Override
     public void componentShown(ComponentEvent e) {
          // TODO Auto-generated method stub
}

Answer 1

Hello camickr,
thanks for your answers.
It sounds like you are trying to add a component and
descriptive text of this component to a panel. So the
question is why are you overriding paintComponent()
method on your main panel and why are you using a
Thread.JLabel is not a good way I think, because of the performance. Think about 1000 labels on the panel. And the text can have different style, so drawString method is better here.
Create a component that draws your "shape" and then
add that component to the main panel that uses a null
layout. That means you need to specify the bounds of
the component. Then you can add a JLabel containing
the releated text of the component. If you don't know
the text then it can always be updated with the
setText() method in the future. Also, the foreground
can be updated as well.If it would be lable, I could update Text as us say and JLabels would be perfect. In this case, JLabels are not what I need.
You said the names will not be available right away.
Well then you don't start a thread to schedule the
repainting of the names since you don't know exactly
when the name will be available. You wait until you
have the names and then simple use the setText()
method.I have decided this way.
Draw all objects on the panel in different layers, for different type of objects.
Get names and make some calculations, for example, optimal position of the text on the panel (in Thread) and after it repaint();
Repaint draw all objects, but now it have the names, which will be added too.
The requirement is: thousand of objects on the panel
Different type of ojbects should be drawn in different layers
Names should be added to the objects and maybe some other drawings (showing state). Name and drawing can be done later, but should be added dynamically, after all calculation are done.