限制Vaadin中的窗口拖动运动

I have a Vaadin application which contains a header and a menu bar as well. The menu bar provides options where some of which opens up a new Window much similar to a desktop MIDI application. However the window can be moved above the menu and over the header. Does anyone know how it is possible to limit the view movement to within the content area. This content area is currently a VerticalLayout.I have a Vaadin application which contains a he