public void keyPressed(KeyEvent e)
   {
      System.out.println(angle);
      if (e.getKeyCode() == KeyEvent.VK_UP)
         angle += 1f;
      if (e.getKeyCode() == KeyEvent.VK_DOWN)
         angle -= 1f;
      
      examineModelViewMatrix(canvas.getGL());
   }

package org.kramer.utils;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 * Internally uses nanoseconds due to Java 1.5's System.nanoTime() being more
 * accurate. The public interface is in milliseconds though for convenience.
 * 
 * TODO: add support for one-off events, look into threading 
 * 
 * @author Kramer
 *
 */
public class Timer
{
   private long lastLoopTime = System.nanoTime();
   private List<Event> events = new ArrayList<Event>();

   /**
    * Call this in the display() loop
    */
   public void update()
   {
//      long deltaMillis = (System.nanoTime() - lastLoopTime) / 1000000;
      
      Iterator<Event> it = events.iterator();
      while (it.hasNext())
      {
         Event event = it.next();
         if (event.nextExecution <= System.nanoTime())
         {
            event.nextExecution = System.nanoTime() + (event.frequency * 1000000);
            event.doEvent();
         }
      }
      lastLoopTime = System.nanoTime();
   }
   
   /**
    * @param frequency Frequency in milliseconds
    * @param event
    */
   public void scheduleEvent(long frequency, Event event)
   {
      event.frequency = frequency;
      event.nextExecution = System.nanoTime() + (frequency * 1000000);
      events.add(event);
   }
   

   /**
    *
    */
   public abstract class Event
   {
      long nextExecution;
      long frequency;
      
      public abstract void doEvent();
   }

}

      Timer timer = new Timer();
      timer.scheduleEvent(500, timer.new Event(){
         public void doEvent() {
            System.out.println("every 500 milliseconds");
         }
      });
      timer.scheduleEvent(100, timer.new Event(){
         public void doEvent() {
            System.out.println("every 100 milliseconds");
         }
      });