public void mouseMoved(MouseEvent ev) {
      JRootPane root = getRootPane();

      if (root.getWindowDecorationStyle() == JRootPane.NONE) {
        return;
      }

      Window w = (Window) ev.getSource();

      Frame f = null;
      Dialog d = null;

      if (w instanceof Frame) {
        f = (Frame) w;
      } else if (w instanceof Dialog) {
        d = (Dialog) w;
      }

      // Update the cursor
      int cursor = getCursor(calculateCorner(w, ev.getX(), ev.getY()));

      if (cursor != 0
          && ((f != null && (f.isResizable() && (f.getExtendedState() & Frame.MAXIMIZED_BOTH) == 0))
              || (d != null && d.isResizable()))) {
        w.setCursor(Cursor.getPredefinedCursor(cursor));
      } else {
        w.setCursor(lastCursor);
      }
    }
 /**
  * Uninstalls any state that <code>installClientDecorations</code> has installed.
  *
  * <p>NOTE: This may be called if you haven't installed client decorations yet (ie before <code>
  * installClientDecorations</code> has been invoked).
  */
 private void uninstallClientDecorations(JRootPane root) {
   uninstallBorder(root);
   uninstallWindowListeners(root);
   setTitlePane(root, null);
   uninstallLayout(root);
   // We have to revalidate/repaint root if the style is JRootPane.NONE
   // only. When we needs to call revalidate/repaint with other styles
   // the installClientDecorations is always called after this method
   // imediatly and it will cause the revalidate/repaint at the proper
   // time.
   int style = root.getWindowDecorationStyle();
   if (style == JRootPane.NONE) {
     root.repaint();
     root.revalidate();
   }
   // Reset the cursor, as we may have changed it to a resize cursor
   if (window != null) {
     window.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
   }
   window = null;
 }
 public void mouseExited(MouseEvent ev) {
   Window w = (Window) ev.getSource();
   w.setCursor(lastCursor);
 }