Two layers for the button, because one is not enough: while a session is
running PowerDevil holds logind's handle-power-key inhibitor and acts on
the button itself, so a logind drop-in alone would be overruled. logind
covers the machine before the session starts, after it ends, and if
PowerDevil is not running. Verified: after the drop-in is installed and
logind reloaded, it reports ignore for the power, suspend, hibernate and
lid keys, and the running session was not disturbed by the reload.
Holding the button still cuts the power. That is firmware, below any
operating system, and it is deliberately left alone as the only recovery
a person standing at a wedged machine has.
The maintenance terminal is Meta+Ctrl+Alt+Shift+K, declared in the
package rather than seeded into a teacher's configuration, where an
update could not reach it. KGlobalAccel read it and registered the
component; invoking it opened a working shell.
It needed a wrapper. The classroom's Kiosk policy sets shell_access=false
and Konsole honours it — measured: with the classroom configuration in
its cascade Konsole starts and says "Program to run not set." The
restriction is worth keeping everywhere else, so it is lifted for this
one process by leaving the classroom's configuration directory out of
its cascade. It grants no privilege: the classroom user has no sudo
rule, and that restriction was always a barrier in the interface rather
than a privilege boundary.
Konsole's own entry is shadowed and hidden from /usr/local/share, so
nothing is patched and Konsole's package stays maintainable. Nothing is
pinned to the panel; a task button appears only while a terminal is
open, and closing it returns the bar to three launchers.
Co-Authored-By: Claude Opus 5 <[email protected]>
Three marks were put on a real panel and judged at the size the bar
actually draws them. A bell sat inches from Plasma's own notification
bell and meant something entirely different. A handset with an outgoing
arrow read as a telephone feature. Breeze has people and it has
telephones and the two never meet, so this is drawn in Breeze's language
instead: an adult, a child, and one small speech bubble, on Breeze's
22-unit grid with its ColorScheme-Text class, so it recolours with the
session and needs no second file for the light theme.
Quick Launch carries it. The Icon widget copies the entry into the user's
home so an update could never change it; a task manager reads the entry
live but also shows every running window, which filled the auxiliary
corner with the lesson's tasks.
One defect found on the way, and it affected the Wonder Ink icon that is
already shipping: gdk-pixbuf recognises an SVG by sniffing the first
bytes, and a licence-length comment above the opening tag pushes it out
of that window. Every GTK program reported "couldn't recognize the image
file format" while Qt rendered the same file happily. The comments live
inside <svg> now.
Co-Authored-By: Claude Opus 5 <[email protected]>
The install list loses the dock, the window helper, the Chrome window
arbiter, the notification wrapper, the compositor and bar configs and the
GTK icon and stylesheet machinery, and gains a look and feel package, a
colour scheme, window rules, Kiosk restrictions and two supervised user
services. Dependencies follow: Plasma and SDDM in, sway, waybar, mako and
gtk-layer-shell out.
Co-Authored-By: Claude Opus 5 <[email protected]>
The whole appliance UI is now configuration for a desktop Debian already
ships: a Plasma 6.3 session with a colour scheme, a look and feel package
that builds the bar, window rules, and KDE's own Kiosk restrictions.
Two things were measured rather than assumed, and both changed a decision.
Plasma restarts a crashed panel three times a minute and then gives up,
which is the failure a classroom has already had. Four lines of systemd
drop-in make it unconditional; the panel then survived eight SIGKILLs a
second apart, back each time in 2.4s.
Plasma draws a minimised task and a background task identically, so the
five states the room needs cannot all be shown. Rather than write a task
manager, the classroom removes minimise: clicking a launcher always means
show me this.
Co-Authored-By: Claude Opus 5 <[email protected]>
The development host is a VM without /dev/kvm, so a candidate desktop
cannot be given a virtual machine here. It gets a systemd container
instead, with the session nested inside a headless sway so that grim can
photograph it and sway's IPC can aim a real pointer at it.
Plasma 6.3.6 comes up in it, software-rendered, at 1920x1080.
Co-Authored-By: Claude Opus 5 <[email protected]>
