Re: Size requisition changes

[Owen Taylor <otaylor redhat com>]

Martin Baulig <martin@home-of-linux.org> writes:

> Hello,
> 
> my GTop change below seems to work fine, but some other question:
> 
> Is there any need to call gtk_widget_size_request () and then throw
> away the returned requisition ? The code in question is in
> gnome-pim/gncal/gncal-full-day.c around line 208 (after applying the
> requisition change):
> 
> 	gtk_widget_size_request (child->widget, &child_requisition); /* FIXME: is this needed? */
> 	gtk_widget_size_allocate (child->widget, &allocation);
> 
> The &child_requisition is not used at all.

When gtk_widget_size_request() is called on a widget, you 
must always call gtk_widget_size_request on your children, even
if you ignore their requisitions. You can, however, pass in NULL
as the second parameter to gtk_widget_size_request().
 
> >  If your code is affected by these changes (there are
> >  about 4 places in GNOME that will print out warnings),
> >  you should probably not change it immediately, but
> >  wait for the next release of GTK+, and then call
> >  AM_PATH_GTK () with a version of 1.1.16, since the
> >  necesarry changes will not be compatible with older 
> >  versions of GTK+.
> > 
> > I apologize for any inconvience this causes (it shouldn't
> > really be much - I'll do the GNOME changes myself),
> > but I think this change is necesary and the
> > right thing to do.
> 
> Just a short question (GTop is one of the places):
> 
> After applying the following patch to GTop:
> 
> ------------------------------------------------------------------------
> --- gtop-procview.c     1999/02/15 04:44:15     1.12
> +++ gtop-procview.c     1999/02/22 22:26:39
> @@ -332,10 +332,11 @@
>         requisition->height = GTK_CONTAINER (widget)->border_width * 2;
>  
>         if (bin->child && GTK_WIDGET_VISIBLE (bin->child)) {
> -               gtk_widget_size_request (bin->child, &bin->child->requisition);
> +               GtkRequisition child_requisition;
> +               gtk_widget_size_request (bin->child, &child_requisition);
>  
> -               requisition->width += bin->child->requisition.width;
> -               requisition->height += bin->child->requisition.height;
> +               requisition->width += child_requisition.width;
> +               requisition->height += child_requisition.height;
>         }
>  }
>  
> ------------------------------------------------------------------------
> 
> the warnings went away - does this gtk_widget_size_request () return
> the correct requisition in &child_requsition or do I need to call
> gtk_widget_get_child_requisition again or something else ?

The source code in gtk_widget_size_request looks like:

  /* ... emit the size request signal ... */

  if (requisition)
    gtk_widget_get_child_requisition (widget, requisition);

So, yes, the requisition from gtk_widget_size_request is
identical to that from gtk_widget_get_child_requisition().

Regards,
                                        Owen