Path: utzoo!attcan!uunet!husc6!bloom-beacon!TUB.BITNET!net
From: net@TUB.BITNET (Oliver Laumann)
Newsgroups: comp.windows.x
Subject: Re: Bug in Athena scrollbar widget (float resource)
Message-ID: <8812191103.AA16776@tub.UUCP>
Date: 19 Dec 88 11:03:09 GMT
Sender: daemon@bloom-beacon.MIT.EDU
Organization: The Internet
Lines: 39

> > The srollbar widget has resources of the representation type XtRFloat
> > (e.g. `shown').  These resources are declared as `float'.
> >
> > This is wrong; it is impossible to set a resource of type `float'
> > using XtSetValues() (for instance, a float cannot be assigned to an
> > XtArgVal).  The type should be float* instead.
>
> In general there is no requirement that a resource be able to fit into an
> XtArgVal and the float is no exception.  If the resource is larger than a
> XtArgVal then you need to pass a pointer to the resource into XtSetValues.

I don't quite understand what this has to do with the specific problem
I mentioned.  If I am assumed to store a pointer to a float into an
XtArgVal, then the type for XtRFloat is `float*', not `float'.

However, the relevant scrollbar fields are declared like this:

   float top;
   float shown;

and referenced like

   ScrollbarWidget w = ...;
   w->scrollbar.top = 0.5;

Thus, something like

   float f = 0.5; Arg a[1];

   XtSetArg (a[0], XtNtop, &f);
   XtSetValues (widget, a, ONE);

would not work (I have just tried it).  If this is not a bug then I would
appreciate if you could show me how the `float' resources can be set
by means of XtSetValues.  Am I missing something?

Regards,
--
Oliver Laumann              net@TUB.BITNET              net@tub.UUCP