Bug 329991

Summary:	flicker in slidingpopups: setData(WindowClosedGrabRole) gets lost
Product:	[Plasma] kwin	Reporter:	Marco Martin <notmart>
Component:	effects-various	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	sebas
Priority:	NOR
Version:	git master
Target Milestone:	---
Platform:	Compiled Sources
OS:	Linux
Latest Commit:	http://commits.kde.org/kde-workspace/0d9582627e055f80c380a8812aa81ba4b9379fc7	Version Fixed In:
Sentry Crash Report:

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.
https://git.reviewboard.kde.org/r/115903/

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.

REVIEW:115903

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

http://commits.kde.org/kde-workspace/0d9582627e055f80c380a8812aa81ba4b9379fc7