void (ListSelectionEvent e) { final List<Locale> currentItems = myLocalesModel.getItems(); for (Locale l : projectExistLocalesList.getSelectedValuesList()) { if (!restrictedLocales.contains(l) && !currentItems.contains(l)) { myAddLocaleFromExistButton.setEnabled(true); return; } } myAddLocaleFromExistButton.setEnabled(false); }