Bug 428760

Summary:	Map/Remap touch input ONLY to related touchscreen panel
Product:	[Plasma] kwin	Reporter:	Aldoo <aldo-public>
Component:	input	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	julius.kuenzel, kantras, kde, matteo.bucci.1995, nate, pfyu817, piroisl33t
Priority:	NOR
Version:	5.23.5
Target Milestone:	---
Platform:	Manjaro
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	Image of the Production Use Case

Description Aldoo 2020-11-06 15:34:00 UTC

I have a laptop with a touchscreen.
When using it alone (without an external monitor), the touchscreen works as expected.
But when I plug an external monitor and do multi-monitor, then the touchscreen area is mapped to the whole visual area (not just limited to laptop integrated panel), which is awkward since the user expects that the pixel being interacted with is the one under the finger.

Please, make it so the touchscreen input is always mapped to the laptop panel, whatever happens !

For information I use X11 Plasma.

Also it seems that the command "xinput --map-to-output <touchpad_id> <screen_id>" works for fixing the touchscreen manually, so it would be enough if kded would run this command on every display change (maybe the user would have to declare what screen is the laptop panel and what pointing device is the touchscreen, if this cannot be automated?).

Comment 1 Matteo Bucci 2021-12-28 09:25:26 UTC

I'm experiencing the same exact issue.
plasmashell 5.23.4 on X11

Comment 2 Jerrod Frost 2022-01-04 19:41:19 UTC

I too have this issue and its bigger than kscreen alone as Wayland greatly alters the situation. This is occurring on more than just laptops and drawing tablets, but production machines as well.

Scenario:
I run a livestream broadcasting station for a small church of about 100 people and we livestream broadcast to Facebook and Youtube. I run a station of about 4 monitors. 2 are for OBS (1 streaming, 1 Preview which is split off and presented on TVs all around the church), 2 of these monitors are 12" touchscreen monitors set to 1366x768 and are used to control a BlackMagic TV Studio ATEM for camera switching and the other is used to control a Behringer-X32 Soundboard for Livestream Volume control across 32 channels. We've had other churches contacting us from all over asking how we're doing all this and we've invited them over to look, learn, and replicate. So this scenario will likely grow drastically over time.

These touch screens attempt to act as a touch interface for ALL 4 MONITORS. I have to lock them to their respective monitors with the command "xinput --map-to-output {xinput device ID} {xrandr ouput ID}" every time I boot up the computer. While this isn't ideal, it is a doable solution. The problem is, when using wayland/xwayland, this solution is gone. xinput list is masked and you are presented with "xwayland-pointer, xwayland-related-pointer, and xwayland-touch". You no longer have individual device IDs to link multiple or any touch screens to specific outputs. You're now stuck with every touchscreen attempting to control ALL 4 SCREENS unless you revert to X11.

There needs to be method to link inputs to specific outputs even under wayland.

Comment 3 Jerrod Frost 2022-01-04 20:43:10 UTC

Created attachment 145116 [details]
Image of the Production Use Case

Sorry for the messy view, we just finished building the sound-proof room and migrated the livestream station. We still need to perform some final touch ups and the custom desk/rack we're welding for the station is incomplete. This image should still show the use case and viability of locking specific inputs to specific outputs.

Comment 4 Julius Künzel 2022-01-06 21:50:56 UTC

I can confirm the issue too. 

Operating System: KDE neon 5.23
KDE Plasma Version: 5.23.4
KDE Frameworks Version: 5.89.0
Qt Version: 5.15.3
Kernel Version: 5.15.6-051506-generic (64-bit)
Graphics Platform: X11
Processors: 16 × AMD Ryzen 7 5800HS with Radeon Graphics
Memory: 15.1 GiB of RAM
Graphics Processor: NVIDIA GeForce GTX 1650 with Max-Q Design/PCIe/SSE2

Comment 5 David Edmundson 2022-03-15 17:01:09 UTC


*** This bug has been marked as a duplicate of bug 415683 ***