text: from rctk.widgets.control import Attribute
  from rctk.widgets.container import Container
  
  class Panel(Container):
      """ a simple container-control to add elements using 
          a layoutmanager.
      """
      name = "panel"
  
      scrolling = Attribute(False, Attribute.BOOLEAN)
  
      ## valid: top, bottom, left, right. Create-only attribute. XXX
      scrollto = Attribute("", Attribute.STRING)
  
      def scrollbottom(self):
          self.scrollto = "bottom"
  
      def scrolltop(self):
          self.scrollto = "top"
  
  