code: protected boolean duringDrag(SVGPoint startPoint, SVGPoint dragPoint, Event evt, boolean inside) {
      if (listener != null) {
        return listener.duringDrag(startPoint, dragPoint, evt, inside);
      }
      return true;
    }
docs: Method called during drags.
  
  @param startPoint Drag starting point
  @param dragPoint Drag end point
  @param evt The event object
  @param inside Inside the tracked element
  @return {@code true} to continue the drag