package dk.itu.nulx30.eventSimulation;

import dk.itu.nulx30.util.BinaryHeapElement;

/**
 * Event is the common superclass of all events in the event based simulation. 
 * It contains the information about when an event is to occur. It uses the
 * priority field in BinaryHeapElement to indicate the time. This facilitates
 * that instances of <code>Event</code> can be put in a binary heap and that the
 * extractMin method, will extract the event that will occur first. It is not
 * possible to change the time when an event will occur.
 *
 * @author Jacob Wahl Winther
 * @author Mikkel Bundgaard
 * @author Troels C. Damgaard
 * @author Federico Decara
 */
public abstract class Event extends BinaryHeapElement {

  /**
   * Class constructor. Set the time when this event is about to occur.
   * Must be called from subclasses.
   *
   * @param eTime the time when this event should occur.
   */
  public Event( double eTime ) {
    setPriority( eTime );
  }

  /**
   * Returns the time when this event will occur,
   * @return time when event occurs
   */
  public double getTime() {
    return getPriority();
  }
  
  /**
   * The code that must be executed when event occurs.
   */
  public abstract void doEvent();
}