Re: Window flickering (Was: Question on mini windows)

[Richard Frith-Macdonald]

On 11 Jan 2008, at 18:14, David Chisnall wrote:

> On 11 Jan 2008, at 17:40, Fred Kiefer wrote:
>
> > Andreas Schik wrote:
> > > On 2008-01-10 22:15:31 +0100 Sas(o Kiselkov <skiselkov@gmail.com>
> > > wrote:
> > >
> > > It used to work on gnustep-gui-0.11 without any problem. Also,  
> > > when I
> > >
> > >
> > > > I can confirm that. gui-0.12 worked for me as well.
> > >
> > > run an app in my X environment, it start spawning a window a large
> > > number of times over and over again (basically, it appears as a  
> > > small
> > > window flickering) for about two seconds. After that the app starts
> > > up normally. Any subsequent app launching (of either the same app or
> > > different ones) doesn't cause the flickering anymore. Any
> > > > This I have seen as well, but i occurs in -gui-0.12, too. I think
> > > > it is somehow related to Étoilé as I watched this flicker appear
> > > > the first time after installing Étoilé.
> >
> > No, it isn't Etoile. This is the test used by GNUstep to find out  
> > about
> > the window borders. The idea here is to check all combination of  
> > border
> > settings once and to store the resulting window borders for these.  
> > The
> > values get cached on the root window, that is why you see it only for
> > one GNUstep applications. This wont be needed in the future, when  
> > more
> > and more window manager will adopt the new _NET_REQUEST_FRAME_EXTENTS
> > protocol. The code for this is already in GNUstep, just try it  
> > once with
> > Gnome.
>
> I patched my version of GNUstep to draw the flickering windows off  
> the screen and suffered no ill effects.

Yes, the only problem with that is that, if the window is off-screen,  
the window manager is under no obligation to decorate it ... so  
whether or not it works is window-manager dependent.

That being said, as the common window-managers seem to decorate the  
window whether it's off-screen or not, perhaps the best thing to do  
would be to create the windows off-screen normally, and have an  
NSUserDefault value to tell the backend to do it on-screen so that  
people can try that if the off-screen method doesn't work with their  
window manager.