001package csheets.ext.database.controller;
002
003import java.util.Observer;
004
005/**
006 * The subject class of observer
007 * @author João Carreira
008 */
009public interface Subject 
010{
011    public void addObserver(Observer o);
012    public void removerObserver(Observer o);
013    public void notifyObserver(String str);
014}