MessageCell messageCell = new MessageCell();
messageList = new DefaultCellList<Message>(messageCell);
messageList.setTabIndex(-1);
messageList.addStyleName("message-list");
messageList.setEmptyListWidget(new HTML(emptyMessage.toSafeHtml()));
messageList.setKeyboardSelectionPolicy(HasKeyboardSelectionPolicy.KeyboardSelectionPolicy.ENABLED);
final SingleSelectionModel<Message> selectionModel = new SingleSelectionModel<Message>();
messageList.setSelectionModel(selectionModel);
selectionModel.addSelectionChangeHandler(new SelectionChangeEvent.Handler() {