static int forwardOneClick_windowSize = 11; // odd should look nice. Set to 1 for an invisible window

static int forwardOneClick_clickDelay = 0; // Delay in ms between closing window and forwarding click. 0 seems to work fine.

static int forwardOneClick_trackingSpeed = 10; // How often to move the window (ms)

// onClick: voidfunc(Point, int) - 2nd parameter is button (1 to 3)

// if you make it a func and return false, click is not forwarded

static void forwardOneClick(final O onClick) {

  awtIfNecessary {

    final new JWindow window;

    final int windowSize = forwardOneClick_windowSize;

    window.setSize(windowSize, windowSize);

    window.setVisible(true);

    window.setAlwaysOnTop(true);

    JPanel panel = singleColorPanel(Color.red);

    window.setContentPane(panel);

    revalidate(window);

    final new Robot robot;

    panel.addMouseListener(new MouseAdapter {

      public void mouseReleased(final MouseEvent e) {

        window.setVisible(false);

        final int b = e.getButton();

        final int mod =

          b == 1 ? InputEvent.BUTTON1_DOWN_MASK

          : b == 2 ? InputEvent.BUTTON2_DOWN_MASK

          : InputEvent.BUTTON3_DOWN_MASK;

        final Point point = getMouseLocation();

        swingLater(forwardOneClick_clickDelay, r {

          if (isFalse(callF(onClick, point, b))) ret;

          robot.mousePress(mod);

          robot.mouseRelease(mod);

        });

      }

    });

    swingEvery(window, forwardOneClick_trackingSpeed, r {

      Point p = getMouseLocation();

      window.setLocation(p.x-windowSize/2, p.y-windowSize/2);

    });

  }

}