package de.unibayreuth.se.observer;

import java.util.*;

public abstract class Subject {
	private List<Observer> observers;

	public Subject() {
		observers = new ArrayList<Observer>();
	}

	void attach(Observer observer) {
		observers.add(observer);
	}

	void detach(Observer observer) {
		observers.remove(observer);
	}

	protected void fireUpdate() {
		System.out.println("Sending update to observers ...");
		for(Observer o : observers)
			o.update(this);
	}
}