Presence.java

package hfdst3;

import java.util.*;

enum PresenceStatus {
    AANWEZIG,
    BEZET,
    AFWEZIG
}

// use Observer and Subject from Observer.java

class Persoon2 extends Subject implements Observer {
    protected String id;
    protected PresenceStatus status;
    public Persoon2(String id){
        this.id = id;
    }
    public String toString(){
        return id;
    }
    // inherited method
    public void update(Subject s, Object arg){
        System.out.println("" + id + " : Subject " + s + " -> " + arg);
    }
    // new method
    public void updateStatus(PresenceStatus status) {
        this.status = status;
        notify(status);
    }
}

class LogSysteem2 extends Subject implements Observer {
    protected String id;
    protected ArrayList<String> messages = new ArrayList<>();
    public LogSysteem2(String id){
        this.id = id;
    }
    public String toString() {
        return messages.toString();
    }
    // inherited method
    public void update(Subject s, Object arg){
        // System.out.println(id + ":"+ o);
        messages.add("" + s + " : PresenceStatus changed to " + arg);
    }
}



class TestPresence {
    public static void main(String[] args){
        Persoon2 an = new Persoon2("an");
        Persoon2 jan = new Persoon2("jan");
        Persoon2 bruno = new Persoon2("bruno");
        Persoon2 sofie = new Persoon2("sofie");
        LogSysteem2 l1 = new LogSysteem2("l1");
        LogSysteem2 l2 = new LogSysteem2("l2");
        an.addObserver(jan);
        an.addObserver(bruno);
        an.addObserver(l1);
        an.addObserver(l2);
        an.updateStatus(PresenceStatus.AFWEZIG);
        an.updateStatus(PresenceStatus.BEZET);
        System.out.println(l1);
    }
}