Re: initial draw problem with gnomedruid/gtklist

[Tim Janik <timj gtk org>]

On 17 Feb 2000, Owen Taylor wrote:

> 
> NotZed <notzed@helixcode.com> writes:
> 
> > Hi guys,
> > 
> > The attached program below demonstrates a problem i'm
> > having with GnomeDruid, Havoc suggested I post here.
> > 
> > Basically the problem is that some things I have inside of
> > viewported'd scrolled windows dont seem to render, until
> > you resize the window, and then ones that continue to
> > render as i switch pages dont update their contents if the
> > contents change during the page setup.
> > 
> > Anywya, the program is below, and the behaviour is
> > self-explanatory.
> 
> OK, I tracked this one down and I'd say it is pretty clearly a GTK+
> bug, though it could be conceivably blamed on GnomeDruid.
> The problem is the following code in gtkcontainer.c:
> 
> =====
> void
> gtk_container_queue_resize (GtkContainer *container)
> {
>   GtkContainer *resize_container;
>   
>   g_return_if_fail (container != NULL);
>   g_return_if_fail (GTK_IS_CONTAINER (container));
> 
>   [...]
>   
>   resize_container = gtk_container_get_resize_container (container);
>   
>   if (resize_container)
>     {
>       if (GTK_WIDGET_VISIBLE (resize_container) &&
> 	  (GTK_WIDGET_TOPLEVEL (resize_container) || GTK_WIDGET_DRAWABLE (resize_container)))
> 	{
> 
>   [...]
> =====
> 
> In the test case, list items are added just before switching to a 
> new page of the druid.
> 
> When the items are added the above code is triggered, and the
> resize_container found is the GtkScrolledWindow.
> 
> The GtkScrolledWindow is not mapped, since it is in is not
> current, so the above code thinks it doesn't need to queue a 
> resize, since one will be queued when the window is mapped.

sorry owen, *why* is the scrolle dwindow not mapped? i got parsing
errors from your above sentence.

> But the scrolled window is visible, and all its parents are visible,
> and no resize is queued when it is mapped. For this reason the newly
> added list items never get size allocated.
> 
> I think the above conditional is just completely bogus. It could

i definitely don't, that code portion has been changed quite a couple
of times to figure the correct condition. basically no resizes should
be queued on not mapped containrs (constraint), with the exception that
we want to keep a flag for resize needs on toplevels. but you probably
already know that, and maybe i see your point after i understand your
above sentence.

> be:
> 
>  if (GTK_WIDGET_VISIBLE (resize_container))
> 
> Or, if you wanted to be more precise, you could define a function
> that checked if a widget and all its parents are visible and 
> replace the GTK_WIDGET_DRAWABLE() in the above with that. But I don't
> think the win in efficiency from doing so is very large.
> 
> Regards,
>                                         Owen
> 

---
ciaoTJ