src/share/classes/sun/swing/JLightweightFrame.java

*** 104,114 ****
       * instance.
       */
      public JLightweightFrame() {
          super();
          copyBufferEnabled = "true".equals(AccessController.
!             doPrivileged(new GetPropertyAction("jlf.copyBufferEnabled", "true")));
  
          add(rootPane, BorderLayout.CENTER);
          setFocusTraversalPolicy(new LayoutFocusTraversalPolicy());
          if (getGraphicsConfiguration().isTranslucencyCapable()) {
              setBackground(new Color(0, 0, 0, 0));
--- 104,114 ----
       * instance.
       */
      public JLightweightFrame() {
          super();
          copyBufferEnabled = "true".equals(AccessController.
!             doPrivileged(new GetPropertyAction("swing.jlf.copyBufferEnabled", "true")));
  
          add(rootPane, BorderLayout.CENTER);
          setFocusTraversalPolicy(new LayoutFocusTraversalPolicy());
          if (getGraphicsConfiguration().isTranslucencyCapable()) {
              setBackground(new Color(0, 0, 0, 0));
*** 248,257 ****
--- 248,262 ----
                  return true;
              }
          };
          contentPane.setLayout(new BorderLayout());
          contentPane.add(component);
+         if ("true".equals(AccessController.
+             doPrivileged(new GetPropertyAction("swing.jlf.contentPaneTransparent", "false"))))
+         {
+             contentPane.setOpaque(false);
+         }
          setContentPane(contentPane);
  
          contentPane.addContainerListener(new ContainerListener() {
              @Override
              public void componentAdded(ContainerEvent e) {