fileMenu.addItem("New", new AlertCommand("'New' was clicked")).setIconStyleName("menu-item-file-new");
fileMenu.addItem("Open...", new AlertCommand("'Open...' was clicked")).setIconStyleName("menu-item-file-open");
fileMenu.addSeparator();
fileMenu.addItem("Save...", new AlertCommand("'Save...' was clicked")).setIconStyleName("menu-item-file-save");
fileMenu.addItem("Save As...", new AlertCommand("'Save As...' was clicked")).setIconStyleName("menu-item-file-save");
fileMenu.addSeparator();
fileMenu.addItem("Exit", new AlertCommand("'Exit' was clicked")).setIconStyleName("menu-item-file-exit");
menubar.addItem("File", fileMenu);
Menu editMenu = new Menu(true);
editMenu.addItem("Undo", new AlertCommand("'Undo' was clicked")).setIconStyleName("menu-item-edit-undo");