Bug 329991 - flicker in slidingpopups: setData(WindowClosedGrabRole) gets lost
Summary: flicker in slidingpopups: setData(WindowClosedGrabRole) gets lost
Alias: None
Product: kwin
Classification: Unclassified
Component: effects-various (show other bugs)
Version: git master
Platform: Compiled Sources Linux
: NOR normal (vote)
Target Milestone: ---
Assignee: KWin default assignee
Depends on:
Reported: 2014-01-15 11:45 UTC by Marco Martin
Modified: 2014-02-20 13:39 UTC (History)
1 user (show)

See Also:
Latest Commit:
Version Fixed In:


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Description Marco Martin 2014-01-15 11:45:09 UTC
closing a plasma popup that has sliding popups effect set flickers a bit. the reason is
the slidingpopup effect sets 
w->setData(WindowClosedGrabRole, QVariant::fromValue(static_cast<void*>(this)));
to make the other windowclosed effects *not* manage it

but in the fade effect, effect.isGrabbed(w, Effect.WindowClosedGrabRole) is false, so either the property gets lost along the way or fade gets executed before slidingpopup can set the data

Reproducible: Always
Comment 1 Thomas Lübking 2014-01-15 14:00:29 UTC
do you have caching enabled in the blur effect and does the issue disappear if you disable it?
Comment 2 Sebastian Kügler 2014-02-20 03:28:40 UTC
This patch moves the WindowClosedGrabRole call from windowClosed() to windowAdded(), fixes the bug for me.
Comment 3 Sebastian Kügler 2014-02-20 13:39:55 UTC
Git commit 0d9582627e055f80c380a8812aa81ba4b9379fc7 by Sebastian Kügler.
Committed on 20/02/2014 at 13:38.
Pushed by sebas into branch 'master'.

slidingpopups claim windowClosedGrabRole earlier

This seems like a more proper fix for the flickering issue in the
sliding popups effect. The problem is that slidingpopups grabs the
window in windowClosed, the fade effect checks it there, which makes
it racy.

In my tests, I've not seen this problem with the WindowAddedGrab, but
as far as I understand, the problem may well be present there as well.
(And my proposed trick doesn't work.) I've not seen this happening in my
debugging, however. The problem there is also less visible since the
transparency curves go into the same direction, and are more "in line
with each other".

So, fix: Move the setData(WindowClosedGrabRole, ...) call from
windowClosed into windowAdded, which makes sure it's set whenever the
window goes away.


M  +5    -1    kwin/effects/slidingpopups/slidingpopups.cpp