LayoutManager () { return new BasicComboBoxUI.ComboBoxLayoutManager() { @Override public void layoutContainer(Container parent) { JComboBox<?> cb = (JComboBox<?>)parent; if (arrowButton != null) { if (cb.getComponentOrientation().isLeftToRight()) { arrowButton.setBounds(cb.getWidth() - ARROW_BUTTON_SIZE.width, 0, ARROW_BUTTON_SIZE.width, cb.getHeight()); } else { arrowButton.setBounds(0, 0, ARROW_BUTTON_SIZE.width, cb.getHeight()); } } layoutEditor(); } }; }