How to wait until all components painted?

Question

Hi - I have searched for hours for an answer to this and have yet to find something so any help is much appreciated!
Ive posted some code below to simulate the problem im facing. This is a simple frame which has a couple of custom jPanels embedded within it.
When this is run, the first 3 lines i see are:         I want this comment to be the last thing output
        Now finished panel paint
        Now finished panel paintBut, as this output suggests, i want the "I want this comment to be the last thing output" line to be displayed after the two panels are completely painted on the screen (in real life i need to know my components are displayed before the program can move on to further processing). Of course, if you cause a repaint you see the "now finished panel paint" each time, but im not interested in this, im simply interested in how to overcome this when the frame is first created and shown.
Ive tried everything i can think of at the "// ***** What do i need to put here? ******" position but nothing seems to work... In short my question is how can i construct my frame and get it to ensure that all components are fully displayed before moving on?
Sorry if the answer to this is obvious to someone who knows these things, but its driving me mad.
Cheers
import javax.swing.*;
import java.awt.*;
public class Frame1 extends JFrame {
  public static void main(String[] args) {
    Frame1 frame1 = new Frame1();
    // ***** What do i need to put here? ******
    // to ensure that the System.err.. call below
    // is only executed once both panels paint methods
    // have finished?????
    System.err.println("I want this comment to be the last thing output");
    System.err.flush();
  public Frame1() {
    this.getContentPane().setLayout(new FlowLayout());
    MyPanel  p1 = new MyPanel(); p1.setBackground(Color.red);
    MyPanel  p2 = new MyPanel(); p2.setBackground(Color.green);
    this.getContentPane().add(p1, null);
    this.getContentPane().add(p2, null);
    this.pack();
    this.setVisible(true);
  class MyPanel extends JPanel {
    Dimension preferredSize = new Dimension(200,200);
    public Dimension getPreferredSize() { return preferredSize;  }
    public MyPanel () { }
    public synchronized void paintComponent(Graphics g) {
      super.paintComponent(g);  //paint background
      // do some irrelevant drawing to simulate a bit of work...
      for (int i=0; i<200; i+=20) {
        g.drawString("help please!",50,i);
      System.err.println("Now finished panel paint"); System.err.flush();
    } // end of MyPanel
  }

Answer 1

Thanks both for your replies.
When doing the "Runnable runnable = new Runnable(){public void run(){ frame1.paint(frame1.getGraphics());....." method i sometimes see
    Now finished panel paint
    Now finished panel paint
    I want this comment to be the last thing output       
    Now finished panel paint
    Now finished panel paintwhich is a pain.
As for making a new Runnable to do the system.err.println and then doing the SwingUtilities(invoke) on that runnable, that didnt work for me at all.
So... in the end, my solution was to have the paint method set a boolean when finished and the main program sleep while this is false
     // Dont want to sleep for say a few seconds as cant be sure
     //painting will be finished, must monitor state of painting ...
     //therefore use while loop
     while (!isOk) {  // isOk is true when both panel paint methods complete
         System.err.println("Waiting......");
         try{   Thread.sleep(300 /* wait some time */);  }
         catch(Exception e){}
       System.err.println("Thankfully this works");which is a kind of mixture of both your suggestions i guess!
Thanks for your help, much appreciated.