Re: Ugly flickering in some views

[Eric Wasylishen]

Hi Fred,

>> 
>> Ok, thanks for testing. I'm not sure what we should do; I asked Fred's 
>> opinion.
>> 
>> If we end up keeping copy-on-scroll on for the release you can put in this 
>> hack for the problematic scroll view:
>> 
>> [[aScrollView contentView] setCopiesOnScroll: NO];
>> 
>> Not ideal, but debugging flickering problems tends to be very difficult.
> 
> German's problem was before you applied r34614, how did that change affect 
> this problem? But that patch seems to have its own problems.
> 
> My main problem is when resizing a whole window, this flickers horribly, but 
> I am not sure whether GNUstep is causing this or my driver for the graphic 
> card. But it happens only with GNUstep windows.
> 
> 
> What are our options here?
> 
> - Find a proper solution within the next few days.
> 
> - Disable copy-on-scroll in all scroll views.
> 
> - Revert to the old cairo surface.
> 
> - Ignore the problem as it only happens for some views.
> 
> None of that (apart from the first one, which isn't that realistic) sounds 
> too attractive. Disabling copy-on-scroll will make scroll views horribly slow 
> and affect everybody, even people not using cairo. I think I hate the option 
> to revert the standard cairo surface the least. This should send us back to 
> the way GNUstep was about a year ago, but we can revert this step if we find 
> a proper fix for the open issues.
> 
> Fred
> 

I thought a bit about this. First, sorry for putting us in this situation!

The conclusion I came to is I should have strictly followed the code freeze. 
Only bugfixes that have a localized effect should be allowed in during the 
freeze… we should be shipping code that was tested over the last 8 months and 
not doing large last-minute changes like I did.

So my preference is to revert the two commits to gui I made since the freeze 
(r34606 and r34614). This is, in other words, the "Disable copy-on-scroll in 
all scroll views." option. I know scrolling will be slower than it should, but 
on the other hand it took almost 8 months to realize I had introduced a bug 
that was disabling it, and AFAIK no one complained to the mailing list.

If I find solution to the scrolling flickering (or the general window resize 
flickering) in the next few weeks after the release, we could always do a 
bugfix release.

btw, but is it KDE4 where you are having very bad flickering when resizing? 
Which video card do you have?

Eric