Time for action – adding menu options

Follow these steps to add the buttons that will form the main menu of the application:

1. Add the following method to MainLayout:

   public class MainLayout extends VerticalLayout {
   
     ...
   
     public void addMenuOption(String caption,
         final Component component) {
       Button button = new Button(caption);
       menuLayout.addComponent(button);
   
       button.addClickListener(new ClickListener() {
         public void buttonClick(ClickEvent event) {
           contentLayout.removeAllComponents();
           contentLayout.addComponent(component);
         }
       });
     }
   }

2. Comment out the line that set menuLayout to be full size:

   public MainLayout() {
   
     ...
   
     //menuLayout.setSizeFull(); you can delete this line ;)
   
     ...
   
   }

3. Change your LayoutFrameworkUI class to the following:

   public class LayoutFrameworkUI extends UI {
   
     protected void init(VaadinRequest request) {
       MainLayout layout = new MainLayout();
       layout.addMenuOption("Option 1", new Label("Component 1"));
       layout...