import java.util.Vector;

/*
 * The clock admin can control an arbitrary number of
 * RoundClocks. The admin sleeps for 1/4 second
 * between each update cycle.
 *
 * The ClockAdmin implements the Runnable interface, and can
 * therefore run in its own thread.
 */

public class ClockAdmin implements Runnable{

  // We use a vector to hold the clocks.
  Vector clocks = new Vector();

  /*
   * Adds a clock to the collection of clocks.
   */

  public void addClock(RoundClock clock){
    clocks.addElement(clock);
  }

  /*
   * This method should conatain an infinite loop. Within
   * the loop you should place the instructions to
   * update the clocks.
   */

  public void run(){
    while(true){
      for(int i=0 ; i < clocks.size() ; i++){
        RoundClock clock = (RoundClock) clocks.elementAt(i);
        clock.updateClock();
      }

      // The clock admin sleeps for 0.25 seconds. I.e. we redraw
      // approximately 4 times every second.

      try{
	Thread.sleep(250);
      }
      catch (InterruptedException e){}
    }
  }
}