void (String prop, int value) { GrayFilter filter = getGrayFilter(); int brightness = filter.getBrightness(); int contrast = filter.getContrast(); int alpha = filter.getAlpha(); if ("brightness".equals(prop)) { brightness = value; } else if ("contrast".equals(prop)) { contrast = value; } else if ("alpha".equals(prop)) { alpha = value; } else { return; } String key = getGrayFilterKey(); UIManager.getDefaults().remove(key); UIManager.getDefaults().put(key, new GrayFilter(brightness, contrast, alpha)); }