public static void main(String[] args) {
	final Display display = new Display();
	//Shell must be created with style SWT.NO_TRIM
	final Shell shell = new Shell(display, SWT.NO_TRIM | SWT.ON_TOP);
	shell.setBackground(display.getSystemColor(SWT.COLOR_RED));
	//define a region that looks like a key hole
	Region region = new Region();
	region.add(circle(67, 67, 67));
	region.subtract(circle(20, 67, 50));
	region.subtract(new int[]{67, 50, 55, 105, 79, 105});
	//define the shape of the shell using setRegion
	shell.setRegion(region);
	Rectangle size = region.getBounds();
	shell.setSize(size.width, size.height);
	//add ability to move shell around
	Listener l = new Listener() {
		Point origin;
		@Override
		public void handleEvent(Event e) {
			switch (e.type) {
				case SWT.MouseDown:
					origin = new Point(e.x, e.y);
					break;
				case SWT.MouseUp:
					origin = null;
					break;
				case SWT.MouseMove:
					if (origin != null) {
						Point p = display.map(shell, null, e.x, e.y);
						shell.setLocation(p.x - origin.x, p.y - origin.y);
					}
					break;
			}
		}
	};
	shell.addListener(SWT.MouseDown, l);
	shell.addListener(SWT.MouseUp, l);
	shell.addListener(SWT.MouseMove, l);
	//add ability to close shell
	Button b = new Button(shell, SWT.PUSH);
	b.setBackground(shell.getBackground());
	b.setText("close");
	b.pack();
	b.setLocation(10, 68);
	b.addListener(SWT.Selection, new Listener() {
		@Override
		public void handleEvent(Event e) {
			shell.close();
		}
	});
	shell.open();
	while (!shell.isDisposed()) {
		if (!display.readAndDispatch())
			display.sleep();
	}
	region.dispose();
	display.dispose();
}