// This works when the ctrl key is pressed/released when a Swing window
// is in focus or the mouse is inside a Swing window.
// If you press ctrl before the program starts and the mouse is never
// inside any of the windows, the key press will not be registered.

static AutoCloseable tempAddGlobalCtrlKeyListener(IVF1<Bool> onStatusChanged) {
  AWTEventListener l = new AWTEventListener {
    Bool status;
    
    public void eventDispatched(AWTEvent evt) {
      if (evt cast InputEvent) {
        Bool b = evt.isControlDown();
        if (!eq(b, status))
          pcallF_typed(onStatusChanged, status = b);
      }
    }
  };
  
  Toolkit.getDefaultToolkit().addAWTEventListener(l,
    AWTEvent.KEY_EVENT_MASK |
    AWTEvent.MOUSE_EVENT_MASK |
    AWTEvent.MOUSE_MOTION_EVENT_MASK);
  ret -> Toolkit.getDefaultToolkit().removeAWTEventListener(l);
}