private void mayShowContextPopupMenu(JComponent c) {
            if (c.getComponentPopupMenu() == null) {
                ContextActionSupport<?> cas = (ContextActionSupport<?>)
                        c.getClientProperty(PropertyKeys.CONTEXT_ACTION_SUPPORT);
                if (cas != null) {
                    cas.showContextPopupMenu(x, y);
                }
            }
        }