public Win32GraphicsEnvironment() 
{

}

 public  void displayChanged() 
{
        // getNumScreens() will return the correct current number of screens
        GraphicsDevice newDevices[] = new GraphicsDevice[getNumScreens()];
        GraphicsDevice oldScreens[] = screens;
        // go through the list of current devices and determine if they
        // could be reused, or will have to be replaced
        if (oldScreens != null) {
            for (int i = 0; i <  oldScreens.length; i++) {
                if (!(screens[i] instanceof Win32GraphicsDevice)) {
                    // REMIND: can we ever have anything other than Win32GD?
                    assert (false) : oldScreens[i];
                    continue;
                }
                Win32GraphicsDevice gd = (Win32GraphicsDevice)oldScreens[i];
                // devices may be invalidated from the native code when the
                // display change happens (device add/removal also causes a
                // display change)
                if (!gd.isValid()) {
                    if (oldDevices == null) {
                        oldDevices =
                            new ArrayList< WeakReference< Win32GraphicsDevice > >();
                    }
                    oldDevices.add(new WeakReference< Win32GraphicsDevice >(gd));
                } else if (i <  newDevices.length) {
                    // reuse the device
                    newDevices[i] = gd;
                }
            }
            oldScreens = null;
        }
        // create the new devices (those that weren't reused)
        for (int i = 0; i <  newDevices.length; i++) {
            if (newDevices[i] == null) {
                newDevices[i] = makeScreenDevice(i);
            }
        }
        // install the new array of devices
        // Note: no synchronization here, it doesn't matter if a thread gets
        // a new or an old array this time around
        screens = newDevices;
        for (GraphicsDevice gd : screens) {
            if (gd instanceof DisplayChangedListener) {
                ((DisplayChangedListener)gd).displayChanged();
            }
        }
        // re-invalidate all old devices. It's needed because those in the list
        // may become "invalid" again - if the current default device is removed,
        // for example. Also, they need to be notified about display
        // changes as well.
        if (oldDevices != null) {
            int defScreen = getDefaultScreen();
            for (ListIterator< WeakReference< Win32GraphicsDevice > > it =
                    oldDevices.listIterator(); it.hasNext();)
            {
                Win32GraphicsDevice gd = it.next().get();
                if (gd != null) {
                    gd.invalidate(defScreen);
                    gd.displayChanged();
                } else {
                    // no more references to this device, remove it
                    it.remove();
                }
            }
        }
        // Reset the static GC for the (possibly new) default screen
        WToolkit.resetGC();
        // notify SunDisplayChanger list (e.g. VolatileSurfaceManagers and
        // CachingSurfaceManagers) about the display change event
        displayChanger.notifyListeners();
        // note: do not call super.displayChanged, we've already done everything
}

 protected native int getDefaultScreen()

 public GraphicsDevice getDefaultScreenDevice() 
{
        return getScreenDevices()[getDefaultScreen()];
}

 protected native int getNumScreens()

 public native int getXResolution()
Returns the number of pixels per logical inch along the screen width.
In a system with multiple display monitors, this value is the same for
all monitors.

 public native int getYResolution()
Returns the number of pixels per logical inch along the screen height.
In a system with multiple display monitors, this value is the same for
all monitors.

 public static  void initDisplayWrapper() 
{
        if (!displayInitialized) {
            displayInitialized = true;
            initDisplay();
        }
}

 public static boolean isDWMCompositionEnabled() 
{
        return isDWMCompositionEnabled;
}

Returns true if dwm composition is currently enabled, false otherwise.

 public boolean isDisplayLocal() 
{
        return true;
}

 public boolean isFlipStrategyPreferred(ComponentPeer peer) 
{
        GraphicsConfiguration gc;
        if (peer != null && (gc = peer.getGraphicsConfiguration()) != null) {
            GraphicsDevice gd = gc.getDevice();
            if (gd instanceof D3DGraphicsDevice) {
                return ((D3DGraphicsDevice)gd).isD3DEnabledOnDevice();
            }
        }
        return false;
}

 public static native boolean isVistaOS()
Used to find out if the OS is Windows Vista or later.

 protected GraphicsDevice makeScreenDevice(int screennum) 
{
        GraphicsDevice device = null;
        if (WindowsFlags.isD3DEnabled()) {
            device = D3DGraphicsDevice.createDevice(screennum);
        }
        if (device == null) {
            device = new Win32GraphicsDevice(screennum);
        }
        return device;
}