code: public static Coordinate getPosition(MouseEvent<?> event, int offsetX, int offsetY) {
  		return new Coordinate(event.getX() + offsetX, event.getY() + offsetY);
  	}
docs: Get the position of a mouse event.
  
  @param event
  The mouse event itself.
  @param offsetX
  An extra value to be added to the X axis.
  @param offsetY
  An extra value to be added to the Y axis.
  @return Returns a coordinate holding the event's X and Y ordinate, where the origin is the upper left corner of
  the DOM element catching the event. If used in a
  {@link org.geomajas.gwt.client.controller.GraphicsController}, these are screen coordinates.