Bug 376095

Summary:	cant scroll down desktop effects list using wacom stylus
Product:	[Plasma] kwin	Reporter:	tomekp1981
Component:	general	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED UPSTREAM
Severity:	normal	CC:	clubmajo
Priority:	NOR
Version:	5.8.5
Target Milestone:	---
Platform:	Neon
OS:	Linux
Latest Commit:		Version Fixed In:
Attachments:	problem with hovering over menus with wacom pen problem with scrollbar and wacom pen

Description tomekp1981 2017-02-06 10:00:29 UTC

I can't scroll down desktop effects list using wacom pen stylus. Pen clicks are ignored over this scrollbar. When I hover over scrollbar, it highlights, but I can't grab it. It scrolls with a mouse without problems.
I can use other scroll bars with my tablet, but the one in desktop effects section causes problems.
I also experienced this on Fedora 25 and Debian Stretch and three different tablets - Wacom Bamboo Fun, Wacom Intuos Art and One by Wacom.

Comment 1 tomekp1981 2017-02-06 12:19:50 UTC

I've just noticed, that everything works fine in plasma 5.8.4 on Fedora 24. Don't know if thats useful information.

Comment 2 Martin Flöser 2017-02-06 18:44:10 UTC

Might it be that Fedora 25 uses libinput-xorg?

Comment 3 tomekp1981 2017-02-06 21:22:34 UTC

Created attachment 103870 [details]
problem with hovering over menus with wacom pen

Comment 4 tomekp1981 2017-02-06 21:26:49 UTC

(In reply to Martin Gräßlin from comment #2)
> Might it be that Fedora 25 uses libinput-xorg?

I don't know about Fedora 25 for sure - I replaced it with Debian Stretch yesterday. But I have libinput-1.5.3-1.fc24.x86_64 and xorg-x11-drv-libinput-0.19.0-2.fc24.x86_64 on Fedora 24, so my guess is that Fedora 25 uses libinput.
I've just discovered another problem - with tablet and menus this time. Hovering over menus with tablet seems to be ignored. A minute ago I sent a video showing exactly how it works.

Comment 5 clubmajo 2017-02-06 23:39:08 UTC

I have problems using wacom pens too. I updated my system recently and seems like hover events doesn't work. After some testing and I think that is a recent QT bug because I doesn't happen in QT 4 based apps. Seems already reported in https://bugreports.qt.io/browse/QTBUG-57485

Comment 6 Martin Flöser 2017-02-07 05:57:33 UTC

Setting to upstream as Qt has it already reported. We need to wait for Qt to fix it.

Comment 7 tomekp1981 2017-02-07 09:35:40 UTC

Created attachment 103877 [details]
problem with scrollbar and wacom pen

I need to ask one more question, because my knowledge is very limited and I'd like to understand it better. If Qt is the source of the problem, why other sliders in kde settings work fine? (see attached video, please) Does it mean that these sliders use different qt controls and only some are broken?

Comment 8 clubmajo 2017-02-07 14:03:48 UTC

(In reply to tomekp1981 from comment #7)
> I need to ask one more question, because my knowledge is very limited and
> I'd like to understand it better. If Qt is the source of the problem, why
> other sliders in kde settings work fine? (see attached video, please) Does
> it mean that these sliders use different qt controls and only some are
> broken?

QML has worse behaviours when hover events don't happen like unclickable buttons or unscrollable lists

Comment 9 Martin Flöser 2017-02-07 18:30:45 UTC

> Does it mean that these sliders use different qt controls and only some are broken?

Yes, the setup is different. This is an embedded window. So X11 events might just not be routed correctly. But as said: that's inside Qt.

Comment 10 tomekp1981 2017-02-08 07:47:15 UTC

I understand. Thanks for explanations.