static { /* ensure that the necessary native libraries are loaded */ NativeLibLoader.loadLibraries(); if (!GraphicsEnvironment.isHeadless()) { initIDs(); } final Toolkit tk = Toolkit.getDefaultToolkit(); if (tk instanceof SunToolkit) { cachedNumberOfButtons = ((SunToolkit) tk).getNumberOfButtons(); } else { // It's expected that some toolkits (Headless, // whatever besides SunToolkit) could also operate. cachedNumberOfButtons = 3; } }