nixos/doc/manual: refine extraLayouts, add warnings an test commands

This commit is contained in:
Attila Lendvai 2021-04-20 12:50:08 +02:00
parent b0d0d6b2b3
commit 603707a137

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@ -204,18 +204,18 @@
XKB
</link>
keyboard layouts using the option
<option>
<link linkend="opt-services.xserver.extraLayouts">
services.xserver.extraLayouts
</link>
</option>.
<option><link linkend="opt-services.xserver.extraLayouts">
services.xserver.extraLayouts</link></option>.
</para>
<para>
As a first example, we are going to create a layout based on the basic US
layout, with an additional layer to type some greek symbols by pressing the
right-alt key.
</para>
<para>
To do this we are going to create a <literal>us-greek</literal> file
with a <literal>xkb_symbols</literal> section.
Create a file called <literal>us-greek</literal> with the following
content (under a directory called <literal>symbols</literal>; it's
an XKB peculiarity that will help with testing):
</para>
<programlisting>
xkb_symbols &quot;us-greek&quot;
@ -231,14 +231,13 @@ xkb_symbols &quot;us-greek&quot;
};
</programlisting>
<para>
To install the layout, the filepath, a description and the list of
languages must be given:
A minimal layout specification must include the following:
</para>
<programlisting>
<xref linkend="opt-services.xserver.extraLayouts"/>.us-greek = {
description = "US layout with alt-gr greek";
languages = [ "eng" ];
symbolsFile = /path/to/us-greek;
symbolsFile = /yourpath/symbols/us-greek;
}
</programlisting>
<note>
@ -248,9 +247,27 @@ xkb_symbols &quot;us-greek&quot;
</para>
</note>
<para>
The layout should now be installed and ready to use: try it by
running <literal>setxkbmap us-greek</literal> and type
<literal>&lt;alt&gt;+a</literal>. To change the default the usual
Applying this customization requires rebuilding several packages,
and a broken XKB file can lead to the X session crashing at login.
Therefore, you're strongly advised to <emphasis role="strong">test
your layout before applying it</emphasis>:
<screen>
<prompt>$ </prompt>nix-shell -p xorg.xkbcomp
<prompt>$ </prompt>setxkbmap -I/yourpath us-greek -print | xkbcomp -I/yourpath - $DISPLAY
</screen>
</para>
<para>
You can inspect the predefined XKB files for examples:
<screen>
<prompt>$ </prompt>echo "$(nix-build --no-out-link '&lt;nixpkgs&gt;' -A xorg.xkeyboardconfig)/etc/X11/xkb/"
</screen>
</para>
<para>
Once the configuration is applied, and you did a logout/login
cycle, the layout should be ready to use. You can try it by e.g.
running <literal>setxkbmap us-greek</literal> and then type
<literal>&lt;alt&gt;+a</literal> (it may not get applied in your
terminal straight away). To change the default, the usual
<option>
<link linkend="opt-services.xserver.layout">
services.xserver.layout