JComponent () { final JPanel result = new JPanel(new BorderLayout()); result.add(super.createSouthPanel(), BorderLayout.EAST); final JSlider slider = new JSlider(0, 100); slider.setValue(100); slider.addChangeListener(new ChangeListener() { @Override public void stateChanged(ChangeEvent e) { final int value = slider.getValue(); float alpha = value / 100f; final Window wnd = SwingUtilities.getWindowAncestor(slider); if (wnd != null) { final WindowManagerEx mgr = WindowManagerEx.getInstanceEx(); if (value == 100) { mgr.setAlphaModeEnabled(wnd, false); } else { mgr.setAlphaModeEnabled(wnd, true); mgr.setAlphaModeRatio(wnd, 1f - alpha); } } } }); result.add(slider, BorderLayout.WEST); return result; }