In Click a applications menu is in the configuration file /WEB-INF/menu.xml.

This JavaScript drop down menu is rendered using the Velocity Macro writeMenu(), defined in macro.vm.

#writeMenu($rootMenu)

When the page body loads the JavaScript initMenu() function is called to initialize the menus dynamic behaviour. See the JavaScript include menu/menu.js

The example menu pages all extend MenuPage which defines a "rootMenu" control.

public class MenuPage extends BorderedPage {

     public Menu rootMenu = new Menu();
        
     public String headInclude = "menu/menu.js";
     public String bodyOnload = "initMenu();";

}