public Dimension preferredLayoutSize(Container parent) { return null;
public Dimension preferredLayoutSize(Container parent) { JViewport vp = (JViewport)parent; Component view = vp.getView(); if (view instanceof Scrollable) { Scrollable sc = (Scrollable) view; Dimension d = sc.getPreferredScrollableViewportSize();  return d;
	public Dimension preferredLayoutSize(Container parent) {          return null;	}