please include function rsyntaxTextArea_fixNumPad. sclass NumPadFixingInputMap extends InputMap { public void put(KeyStroke keyStroke, Object actionMapKey) { super.put(keyStroke, actionMapKey); Int code = rsyntaxTextArea_fixNumPad_map.get(keyStroke.getKeyCode()); if (code != null) put(KeyStroke.getKeyStroke(code, keyStroke.getModifiers()), actionMapKey); } }