Custom keyboard layout in Wayland

Unfortunately, the configuration at the and of this post does not work for Wayland Qt applications, like konsole, kate. A colleage from KDE Brazil telegram channel pointed me to a working solution.

Update 28/12/2021: the configuration below works for X11/XWayland applications only.

Going forward with migrating to Wayland. There are several smalls things to fix in my setup, one of them is adding a custom layout to workaround the fact that my child broken the Up key of my laptop's keyboard. I had mapped F9 to Up using $HOME/.Xmodmap, which does not work in Wayland. I have figure out how to that in Wayland [1] [2] and maybe this can help other people.

Create this file to configure XDG_CONFIG_HOME variable:

# /etc/profile.d/xdg.sh
export XDG_CONFIG_HOME=$HOME/.config

Create the $HOME/.config/xkb/rules/evdev.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE xkbConfigRegistry SYSTEM "xkb.dtd">

<xkbConfigRegistry version="1.1">

  <layoutList>

    <layout>

      <configItem>

        <name>lvs</name> <!-- Change to any name you want -->

        <shortDescription>Layout LVS</shortDescription> <!-- Same here -->

        <description>Layout com F8, F9 e F10 remapeadas</description> <!-- Any description you want -->

        <countryList>

          <iso3166Id>US</iso3166Id> <!-- Add your country to this list -->

          <iso3166Id>BR</iso3166Id> <!-- My country: Brazil -->

        </countryList>

        <languageList>

          <iso639Id>eng</iso639Id> <!-- Layout language -->

          <iso639Id>por</iso639Id> <!-- Brazilian Portuguese -->

        </languageList>

      </configItem>

    </layout>

  </layoutList>

</xkbConfigRegistry>

Create a file $HOME/.config/xkb/symbols/lvs (the file name have to match the layout name in evdev.xml) with the actual changes you need. I just copied the file with the symbols I wanted to change to save time:

cp /usr/share/X11/xkb/symbols/srvr_ctrl $HOME/.config/xkb/symbols/lvs

Then I removed all lines that should not be changed. The final file is the following (the actual changes are in bold):

partial function_keys

xkb_symbols "fkey2vt" {

    key <FK08> {

        type="CTRL+ALT",

        symbols[Group1]= [ Prior, F8, F8, F8, XF86_Switch_VT_8 ]

    };

    key <FK09> {

        type="CTRL+ALT",

        symbols[Group1]= [ Up, Prior, F9, F9, XF86_Switch_VT_9 ]

    };

};

Comparing all this to the .Xmodmap it seems way more complicated :-( This is my .Xmodmap:

! 74 = F8 

keycode 74 = Prior                                            

! 75 = F9                                  
keycode 75 = Up Prior

You need to restart startplasma-wayland so the changes take affect. The best part is that it also works with X11, so I removed my .Xmodmap.

PS: the Up key does not work in konsole to show the previous command when running in wayland, even with an external keyboard with a physical Up key. That works in X11.