Bug 96481

Summary:	xf86-input-libinput provides for touchscreen axis labelling no "Abs MT Position X"
Product:	xorg	Reporter:	bernhardu <bernhardu>
Component:	Input/libinput	Assignee:	Peter Hutterer <peter.hutterer>
Status:	RESOLVED FIXED	QA Contact:	Xorg Project Team <xorg-team>
Severity:	minor
Priority:	medium	CC:	peter.hutterer
Version:	7.7 (2012.06)
Hardware:	x86-64 (AMD64)
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:

Description bernhardu 2016-06-10 12:20:35 UTC

Qt5 versions before 5.6.0 are relying on axes existing
labelled "Abs MT Position X" for touch screens. [48279] [3]

This is currently visible in Debian testing as touch screen
events have no effect on Qt5 based applications when using
the xf86-input-libinput driver.
Other toolkit based applications work as expected.

See Debian bug [826830].
(Got closed as Qt5 version 5.6.1 is already worked on.)

The libinput driver provides: "Abs X" and Y, "Rel Horiz Scroll" and Vert.

The evdev driver for the same device provides: "Abs MT Position X" and Y.

Currently I know no other software relying on the MT labelling.

[826830] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=826830
[48279]  https://bugreports.qt.io/browse/QTBUG-48279
[3]      http://code.qt.io/cgit/qt/qtbase.git/commit/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp?id=462f355e4fb16cc7a1838fa2dda0f763eee58c84

#define AXIS_LABEL_PROP_ABS_MT_POSITION_X  "Abs MT Position X"
#define ABS_MT_POSITION_X	0x35	/* Center X touch position */

Comment 1 Peter Hutterer 2016-06-12 23:37:30 UTC

https://patchwork.freedesktop.org/patch/92960/

Comment 2 Peter Hutterer 2016-06-14 02:16:14 UTC

commit ae4f0a8d72e396528e1108161a3bcc0132df43a2
Author: Peter Hutterer <peter.hutterer@who-t.net>
Date:   Fri Jun 10 08:27:30 2016 +1000

    Init touch x/y axis labels as MT axis labels

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