Bug 423597

Summary:	No blur effect in the drop-down menus when using the "QtCurve Application style"
Product:	[Plasma] kwin	Reporter:	ParsaMousavi <sepamou>
Component:	effects-various	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	normal	CC:	kde
Priority:	NOR
Version First Reported In:	unspecified
Target Milestone:	---
Platform:	Neon
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	Custom QtCurve theme xprop output for dolphin

Description ParsaMousavi 2020-06-27 20:45:26 UTC

After a recent upgrade (i.e second half of the June 2020) of KDE Neon 5.19.80 I faced a problem.There's no blur in the background of the drop-down menus when using "QtCurve Application style".There's no problem with the default "Breeze" style however.

STEPS TO REPRODUCE :
1. Install QtCurve
2. Import this theme : https://pastebin.ubuntu.com/p/HJHP6trYmM/
 
Linux: KDE Neon Unstable with kernel v5.3.0
KDE Plasma Version: 5.19.80
KDE Frameworks Version: 5.72.0
Qt Version: 5.14.2

Comment 1 ParsaMousavi 2020-06-27 20:47:36 UTC

Created attachment 129727 [details]
Custom QtCurve theme

Comment 2 David Edmundson 2020-06-28 18:02:00 UTC

>There's no problem with the default "Breeze" style however.

So what indicates this is a kwin problem?

Please run xprop and click on the window that should be blurred.

Comment 3 ParsaMousavi 2020-06-29 10:45:58 UTC

Created attachment 129756 [details]
xprop output for dolphin

Comment 4 ParsaMousavi 2020-06-29 10:49:27 UTC

I was unable to get the properties of the drop-down menu via "xprop" because simply it's not a window and because of focus stealing problems I cannot even click that while the "xprop" is listening.Using "xprop -spy" doesn't show anything about the menu either.What I've got from xprop while clicking for example the Dolphin window is posted as an attachment.
And I thought it might be related to KWin because clients are using KWin's API to do the blur,but maybe I'm wrong and should file a report about QtCurve instead because for example the blur for the Dolphin's side-bar works,but it doesn't work for menus only.

Comment 5 ParsaMousavi 2020-06-29 11:40:13 UTC

I think the call "KWindowEffects::enableBlurBehind" is causing the background region to be blurred.And recently I was inspecting the recent commits of QtCurve and found nothing related to that.

Comment 6 David Edmundson 2020-06-29 13:12:21 UTC

menus are real windows

sleep 10 ; xprop can be a good solution to get the output



>but maybe I'm wrong and should file a report about QtCurve instead because for example the blur for the Dolphin's side-bar works,but it doesn't work for menus only.


We'll see from the xprop output, if it contains

_KDE_NET_WM_BLUR_BEHIND_REGION(CARDINAL) =  ....


and kwin isn't blurring kwin is at fault, if it's not set, then it's qtcurve

Comment 7 ParsaMousavi 2020-06-29 15:19:16 UTC

I've tried "sleep 5 ; xprop" before but got the error "Can't grab the mouse." as I mentioned "focus stealing problems" ."xprop -spy" solves that problem but still nothing printed concerning the menus when I right-click.
And the property "_KDE_NET_WM_BLUR_BEHIND_REGION" exist in the window properties,and as I said the dolphin sidebar is correctly blurred as expected,but only menus(and also tooltips,but put them aside for now) behave unexpectedly.However thanks for your help and patience.
Can I create another report this time with QtCurve as the product?

Comment 8 Christoph Feck 2020-07-13 12:13:27 UTC

The requested information cannot be provided, because xprop cannot grab the mouse while menus own the grab. Reopening for further investigation.

Comment 9 ParsaMousavi 2020-07-13 13:48:36 UTC

(In reply to Christoph Feck from comment #8)
> The requested information cannot be provided, because xprop cannot grab the
> mouse while menus own the grab. Reopening for further investigation.

That problem has been solved after a recent upgrade.Now menu backgrounds when using either QtCurve or Kvantum theme are blurred.