// f : voidfunc(DoublePt) - point can be null, then mouse has exited
static void imageSurfaceOnMouseMoveOrDrag_double(final ImageSurface is, final O f) {
  swing {
    MouseAdapter ma = new MouseAdapter {
      public void mouseMoved(MouseEvent e) {
        pcallF(f, imageSurface_doublePtFromEvent(is, e));
      }
      
      public void mouseDragged(MouseEvent e) {
        pcallF(f, imageSurface_doublePtFromEvent(is, e));
      }
      
      public void mouseEntered(MouseEvent e) {
        pcallF(f, imageSurface_doublePtFromEvent(is, e));
      }
  
      public void mouseExited(MouseEvent e) {
        pcallF(f, (DoublePt) null);
      }
    };
    is.addMouseMotionListener(ma);
    is.addMouseListener(ma);
  }
}

Began life as a copy of #1019911