Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!hplabs!hpfcdc!hpfclp!diamant
From: diamant@hpfclp.SDE.HP.COM (John Diamant)
Newsgroups: comp.windows.x
Subject: Re: Re: XtReparentWidget (How about XtCopyWidget)
Message-ID: <9740088@hpfclp.SDE.HP.COM>
Date: 6 Apr 89 05:34:04 GMT
References: <9941@polyslo.CalPoly.EDU>
Organization: HP SESD, Fort Collins, CO
Lines: 32

> I was wondering if anybody already had some
> sort of general XtCopyWidget routine which could copy an arbitrary
> widget.  Any ideas on what this would involve.  Does the Toolkit contain
> enough information in itself about each widget?  This would be a simple
> solution to the reparent problem.

The Toolkit does contain enough information.  The size of a widget w can
be obtained as follows:

    XtClass(w)->core_class.widget_size;

With that, you can malloc up a suitable sized chunk of memory and do a raw
memory copy using bcopy to the new location.  Examples of this appear in
the Toolkit code already (in Resources.c).  So, a general XtCopyWidget
routine, would in fact, be very easy to write (about 4 lines of code).
In fact, here it is (untested):

Widget XtCopyWidget(w)
Widget w;
{
	int widgetSize = XtClass(w)->core_class.widget_size;
	Widget new = (Widget) XtMalloc(widgetSize);

	bcopy((char *) w, (char *) new, widgetSize);
	return new;
}


John Diamant
Software Engineering Systems Division
Hewlett-Packard Co.		ARPA Internet: diamant@hpfclp.sde.hp.com
Fort Collins, CO		UUCP:  {hplabs,hpfcla}!hpfclp!diamant