Touch issue with GTK+3 applications in Rootston

[Kareema0]

For at least some touch devices, touch input doesn't work as expected with GTK+3 applications when using Rootston.

The same applications are running as expected in Weston.

Observed behaviour (Rootston): For GTK+3 UI elements (tested with Gtk.Button), there are signals emitted to the wrong GTK UI object and some expected signals missing at all.

Test application: The issue has been tested with a small GTK+3 app written in Vala: buttonbox.vala. The app has 3 GTK buttons, each connected to the following signals: clicked, pressed, released, enter, leave.

Test case:
Tapping button 1, button 2, button 2, button1 in this order. Tested with Rootston and Weston with WAYLAND_DEBUG=client. Logs with the signals emitted in each case are attached.

Test configuration:

• Golden Delicious GTA04 board, TSC2007 touchscreen, kernel 4.19.12-letux+ armv7l, Debian Buster, GTK+ 3.24.2-3
• Raspberry Pi 3B+, ADS7846 touchscreen, kernel 4.14.86-v8-rpi aarch64, PureOS, GTK+ 3.24.2-3 (only short test without logs so far)

Notes:

• This problem doesn't seem to be present in all environments with touchscreens.
• Trying wlroots touch demo doesn't show any unexpected behaviour
• No problems with touch using X11 as well

Logs:
rootston-buttonbox-debug-log.txt
weston-buttonbox-debug-log.txt

Source code:
buttonbox.vala

[agx]

@Kareema0 if you already have a test application it might make sense to link it here (with build instruction) so it's easy to reproduce.

[Kareema0]

@agx Good idea - updated the issue with a link to the source code. Can be run with
vala --pkg=gtk+-3.0 buttonbox.vala

[dano6]

I can see similar issue with gnome documents, scrolling of the document works, but none of the buttons react to touch input. And I have still issue with this: swaywm/sway#2299 (comment)
Edit: @Kareema0 I can reproduce your issue with sway-master

[dos1]

Is it maybe fixed by 4f4d3cf?

[emersion]

Closing because this is a rootston bug. rootston has been removed from the wlroots tree.