public void collectionChanged(CollectionEvent<HomePieceOfFurniture> ev) {
HomePieceOfFurniture piece = (HomePieceOfFurniture)ev.getItem();
switch (ev.getType()) {
case ADD :
addObject(group, piece, true, false);
piece.addPropertyChangeListener(furnitureChangeListener);
break;
case DELETE :
deleteObject(piece);
piece.removePropertyChangeListener(furnitureChangeListener);
break;