可滚动的vaadin视图以显示页面中的所有组件

如何使用布局组件在Vaadin中实现html网页（vaadin的新功能）

现在，无论我在UI组件中添加了什么组件，浏览器中都只会出现一些组件...

没有滚动选项可以查看我在层次结构下面添加的其他组件

public class LoginView extends CustomComponent implements View,
    Button.ClickListener {

    public static final String NAME = "login";

    private TextField user;

    private PasswordField password;

    private Button loginButton;
    NativeSelect select_role;

    private HorizontalLayout fieldsBottomPanel;

    private VerticalLayout fieldsLeftPanel;

    private GridLayout loginPanelGrid;

    private VerticalLayout filedsTopPanel;

    private VerticalLayout loginFormLayout;

    private Label top_header_panel;

    private VerticalLayout virtualKeyboard;

    private VerticalLayout fieldsRightPanel;

    private VerticalLayout footer;

    private VerticalLayout header;

    private Window page;



    public LoginView() {
        setSizeFull();  
        addTopPanelToLoginForm();
        addLeftPanelToLoginForm();
        addBottomPanelToLoginForm();
        addRightPanelToLoginForm();
        addLoginFormToPage();
        addFooterToPage();
        addHeaderToPage();

        VerticalLayout viewLayout = new VerticalLayout(header,loginFormLayout,footer);
        viewLayout.setComponentAlignment(loginFormLayout,
                Alignment.MIDDLE_CENTER);
        viewLayout.setStyleName(Reindeer.LAYOUT_WHITE);

        setCompositionRoot(viewLayout);
    }

    public void addHeaderToPage(){
        header = new VerticalLayout();
        header.setStyleName("header-login");
    }


    public void addFooterToPage(){
        footer = new VerticalLayout();
        footer.addStyleName("footer-login");
    }
}