code: private void applyLayout()
      {
          int n = container.getComponentCount();
          for (int i=0; i<n; i++)
          {
              Component component = container.getComponent(i);
              if (component instanceof FrameComponent)
              {
                  FrameComponent frameComponent = (FrameComponent)component;
                  JInternalFrame internalFrame = 
                      frameComponent.getInternalFrame();
                  Rectangle bounds = SwingUtilities.convertRectangle(
                      container, component.getBounds(), rootContainer);
                  //System.out.println(
                  //    "Set bounds of "+internalFrame.getTitle()+" to "+bounds);
                  internalFrame.setBounds(bounds);
              }
              else
              {
                  LayoutContainer childLayoutContainer = 
                      (LayoutContainer)component;
                  //System.out.println(
                  //    "Child with "+childLayoutContainer.getLayout());
                  childLayoutContainer.owner.applyLayout();
              }
          }
      }
docs: Apply the current layout to the internal frames