Initially i created this script to properly spawn i3wm in a Xephyr window on a i3wm host session. This boils down to setting the environment variable I3SOCK to a path that doesn't conflict with the current session.
xwmplayd2-2023-09-19_21.28.06.webm
While messing around with this I noticed that it
was possible to tile the Xephyr window, but it
would have the same initial resolution (equal to
initial windowsize), and when tiled, this
sometimes got messed up. It is possible to update
the resolution by simply executing xrandr in
the nested session. I searched and found xeventbind,
which can watch for changes in screen resolution and
execute a command when that happens, so I added that
to the script as well.
Another thing I noticed was that if i didn't
Ctrl-c terminate the xephyr process it was left
in a limbo state, making it confusing to start
new sessions on the same display. This happened
if i either killed the xephyr window or if i did
i3-msg exit. I solved it by starting xephyr
and xeventbind in the background from the
script and making the windowmanager command
blocking, and last in the script do a kill -P $$, which do kill all child processes of the
script.
I have tested the script with i3wm, and icewm
and some random other GUI programs, it
should "work" with other windowmanagers, but
they may or may not have similar IPC quirks as
i3.
Also, it is probably a good idea to use a separate config file for the nested wm. To avoid clashes with keybindings and other weirdness.
xwmplay -- i3 -c ~/.config/my-special-xephyr-config
The Xephyr window will have the instance
name: Xephyr, so it is possible to control it
with f.i. window rules (for_window in i3wm).
This is just a small simple bash script, but it
needs to be "built" before installation, and that
is done with GNU make . It is possible to customize
the shbang in the generated script, like this:
make SHBANG='#!/usr/bin/env bash'
There is some cool gawk code in the makefile, so
gawk is a build dependency.
$ make
# make install
Runtime dependencies is Xephyr . Optionally if
xrandr and xeventbind is installed auto update
of screenresolution is a thing.
There is also the xwmplay AUR package.
xwmplay [OPTIONS] -- COMMAND
-d, --display DISPLAY | set X display for COMMAND (defaults to 2)
-h, --help | print help and exit
--i3-socket PATH | path to socket, defaults to `mktemp`
-v, --version | print version info and exit
-w, --wallpaper-command COMMAND | command to set wallpaper
Copyright (c) 2023, budRich of budlabs
SPDX-License-Identifier: 0BSD