if (index == -1) return null;
if (index == -1) return new Point (0, 0);
public Point getPreferredSize () {	checkWidget ();	int index = parent.indexOf (this);	if (index == -1) return null;	int hwnd = parent.handle;	REBARBANDINFO rbBand = new REBARBANDINFO ();	rbBand.cbSize = REBARBANDINFO.sizeof;	rbBand.fMask = OS.RBBIM_CHILDSIZE | OS.RBBIM_IDEALSIZE;	OS.SendMessage (hwnd, OS.RB_GETBANDINFO, index, rbBand);	return new Point (rbBand.cxIdeal, rbBand.cyMinChild);}