/* 
AddComp.java 

CS 585 example of Timer and dynamically adding and removing 
components to an application.

Uses the Window method pack() to determine preferred size and re-validate
layout.

Mike Barnes 9/19/03
*/

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class addComp extends JFrame {

   private static addComp app;
   private Container contentPane;
   private JLabel aLabel;
   private int count, minute;
   private Timer timer;

   public static void main(String args[]) {
      app = new addComp("? ? ?");
      app.setBounds(30, 30, 10, 10);
      app.show  ();
      // need to be able to close the window.
      app.addWindowListener( new WindowAdapter() {
         public void windowClosing(WindowEvent e)
            {System.exit(0);}   });
      }

   public addComp(String frameTitle) {
      super(frameTitle);
      count = 0;
      minute = 1000;  // milliseconds in a 5 seconds
      timer = new Timer(minute, new TimerListener());
      timer.start();
      contentPane = getContentPane();
      contentPane.setLayout(new FlowLayout(FlowLayout.CENTER, 20, 10));
      pack();
      }

 
  class TimerListener implements ActionListener {
    public void actionPerformed(ActionEvent event) {
      if (count < 20) {
          aLabel = new JLabel(Integer.toString(count));
          contentPane.add(aLabel);
          count++;
          // if there are five components remove the first component.
          if (count > 5)  contentPane.remove(0);
          app.pack();  // resizes and re-validates Windows
          }
        else 
          timer.stop();
      }
    }

}