Difficulties to map evdev to keyboard

[amoweb]

Hello,

I would like to map a button from my Wacom tablet to the keyboard Ctrl+Z.

sudo evtest /dev/input/event18 gives me this

Event: time 1764180784.035678, -------------- SYN_REPORT ------------
Event: time 1764180784.442358, type 1 (EV_KEY), code 256 (BTN_0), value 1
Event: time 1764180784.442358, type 3 (EV_ABS), code 40 (ABS_MISC), value 15
Event: time 1764180784.442358, -------------- SYN_REPORT ------------
Event: time 1764180785.432298, type 1 (EV_KEY), code 256 (BTN_0), value 0
Event: time 1764180785.432298, type 3 (EV_ABS), code 40 (ABS_MISC), value 0 

I found examples on github and created a capability file. I suppose I need to copy this to /usr/share/inputplumber/capability_maps. Then I restart inputplumber using systemctl. Sadly, this file doesn't seem to be loaded since there is no error even when I insert a syntax error.

# yaml-language-server: $schema=https://raw.githubusercontent.com/ShadowBlip/InputPlumber/main/rootfs/usr/share/inputplumber/schema/capability_map_v2.json
version: 1
kind: CapabilityMap
name: "Wacom Intuos Krita"
id: wacom
description: "Wacom Intuos Krita"

mapping:
  - name: Annuler
    source_event:
      evdev:
        event_type: EV_KEY
        event_code: BTN_0
        value_type: 1
    target_events:
      - keyboard: KeyLeftCtrl
      - keyboard: KeyZ

What can I do?

Thanks

[pastaq]

Capability maps don't let you translate into multiple events. They permit you to map multiple events to a single Capability. Capability is our internal event mechanism that describes an individual action. Capability maps also only load if attached to a device config. You also don't want to modify /usr files as changes will get lost during updates.

What you are looking for is a profile, where you can translate from the capability KeyButton0 to multiple capabilities. You'll also need to manually load it using the CLI or dbus. I'd recommend making a udev rule that will run whenever the virtual keyboard is present that will run a script to set the composite device profile to your profile.

To capture the keyboard data you'll need a device config. You'll want to set passthrough to true so the entire device isn't grabbed. It should use a default targets list that sets the keyboard device. Depending on if the axis events on the tablet portion are part of the same evdev or not you may also want a touchpad or mouse device as well. You can place new capability maps and device profiles in /etc/inputplumber/devices.d and capability_maps.d

So to summarize,

• add a device profile to /etc/inputplumber/devices.d that will get events from your tablet and pass them to the virtual keyboard/mouse
• add a profile that translates the KeyButton0 Capability to KeyButtonLeftCtrl and KeyButtonZ.
• load the profile using udev or some other script mechanism.