@Override
        public void addNotify() {
            super.addNotify();
            /* you have to notify if the canvas is visible to draw on it. */
            synchronized (lock) {
                hasNativePeer.set(true);
            }
            requestFocusInWindow();
        }
(non-Javadoc)
@see java.awt.Component#addNotify()
jme3-lwjgl3/src/main/java/com/jme3/system/lwjgl/LwjglCanvas.java