[PATCH weston] desktop-shell: do not black out with startup "none"

[Derek Foreman]

On 27/05/15 02:27 AM, Pekka Paalanen wrote:
> On Tue, 26 May 2015 23:59:41 -0700
> Bryce Harrington <bryce at osg.samsung.com> wrote:
> 
>> On Wed, May 27, 2015 at 09:48:50AM +0300, Pekka Paalanen wrote:
> 
>>> One thing worth to note: if Weston is using "none" background meaning
>>> that we get undefined (garbage) content, then removing a wl_surface may
>>> not really remove the surface's image from the screen, because there is
>>> nothing that would make Weston to scrub it (paint over it). Therefore
>>> no screenshooting test should ever rely on that scrubbing unless we
>>> know there is something that enforces the image to disappear.
>>
>> Is there a way weston can forcibly ensure this is always zeroed when
>> doing testing so there's no question, without burdening test writers
>> from needing to be aware of it?
> 
> One way would be to set up a solid color surface beneath everything.
> I'd hesitate to make it a test-only feature, so if it's added, it
> should be there also in production. We could make it nice and pink, so
> that it would reveal problems like badly rendered wallpapers.
>
> But I think it may need integration with the shell plugins, because the
> shells are in charge of the scenegraph. The other option being ad hoc
> hacking it in weston core...
> 
> Not sure what's best.

Is this a problem that really needs solving?

If a test is removing a surface then looking where the surface was, what
could it be expecting to see?

either something it put there (ok), or the shell (not ok because we
don't yet have a way to wait for shell launch in a test)

So maybe the real problem that could use solving is waiting for shell
launch.

Maybe it's useful to have the black surface be settable (a boot logo or
something) instead of black - but that's a different problem altogether.  :)