@Override
public void openChatEvent(User u) {
// Si la fenetre du user existe pas, la creer et l.ajouter au desk
if (!contactHash.containsKey(u.getUsername()) && u.getOnline()) {
CustomChatWindow cw = new CustomChatWindow(u, this);
contactHash.put(u.getUsername(), cw);
chatDesk.add((contactHash.get(u.getUsername())));
cw.setVisible(true);
} else if(u.getOnline()){
if (contactHash.get(u.getUsername()).isIcon()) {
try {
contactHash.get(u.getUsername()).setIcon(false);
} catch (PropertyVetoException e) {