code: public static void setEnabled (Container comp, final boolean enabled)
      {
          applyToHierarchy(comp, new ComponentOp() {
              public void apply (Component comp) {
                  comp.setEnabled(enabled);
              }
          });
      }
docs: Enables (or disables) the specified component, <em>and all of its children.</em> A simple
  call to {@link Container#setEnabled} does not propagate the enabled state to the children of
  a component, which is senseless in our opinion, but was surely done for some arguably good
  reason.