Little Waders took the Plasma build and reported what a container
cannot. A disc player on a machine with no optical drive, a clock nobody
at the back of the room could read, a browser at half the size of the
panel around it, and Parent Call with no broker to call.
The broker is the same for every classroom, so it is a default now and
not something to fill in room by room. classroom-migrate brings an
existing room to the same place without touching its name, its username
or its password, and Parent Call distinguishes a broker it cannot reach
from one that was never set up: those send somebody to look at
completely different things.
The disc player's detection was right and ran too late — alongside the
session rather than before it, and the panel is built from the layout the
moment a session starts. It runs before the display manager now, and
again from udev when a drive is plugged in.
UI_SCALE had a ceiling of 1.5, which cannot express a 4K television; a
clock pinned at 15 points, which is the same size at every scale; and a
browser that was never told the number at all. All three are fixed and
the room doubles together at 200%.
This also brings 0.1.47's work into the repository, where it had only
ever existed in a build directory under /tmp: the hidden display dialog,
its authenticated writer, the polkit action, and the church's own
wallpaper. One piece of it is deliberately left out. The custom volume
display needed a shell package of our own, and with one selected
plasmashell builds no panel at all — measured twice, with that build's
own files, on a classroom that deletes its panel configuration at every
login by design.
The lab connected to the real church broker the moment the package
defaulted to it. Nothing was left behind, which was checked, but the
guard that should have stopped it had never worked: it used iptables,
which the lab image does not have, and probed with /dev/tcp under dash,
where that always fails. Both reported success.
Co-Authored-By: Claude Opus 5 <[email protected]>
A real room upgraded to 0.1.45 and came up as stock Debian Plasma with
the old Waybar across the top, mako still catching notifications, and a
lock screen on an account that has no password.
The cause was one line, and it was in the lab: the harness handed the
session under test XDG_CONFIG_DIRS by hand, so every result it had ever
produced was a result about a machine somebody had already configured.
On a machine SDDM starts the session through PAM, PAM does not read
/etc/environment.d, and Debian's own plasma-workspace env.sh then set the
variable from scratch — so the classroom's settings directory was not in
the cascade at all. No layout, no lock policy, no Kiosk restrictions.
The settings now arrive the way Plasma delivers them, through a file in
/etc/xdg/plasma-workspace/env. Around that: the look and feel is
immutable on its own key so a stale profile cannot answer for it; the
palette is composed into the package, because naming a colour scheme does
not produce one and the dark bar had been coming from a technician's
hand; the desktop reset converges another desktop's appearance state and
keeps the room's own; and classroom-migrate stops, deactivates and masks
the old shell, including the D-Bus activation that brought mako back
while the panel was down — found only by killing the panel on a migrated
machine.
device.conf loses COMPOSITOR and comes off the hyprland channel, which
would otherwise have handed the room the experiment back.
The lab stops flattering the package: it restarts the machine, lets SDDM
actually autologin, and asks a fresh install and a machine upgraded from
the Hyprland package the same sixty questions. Both answer identically,
twice, and the panel still comes back from eight SIGKILLs.
Co-Authored-By: Claude Opus 5 <[email protected]>
Records what was measured this pass and, as importantly, what was not.
KGlobalAccel will accept a bare Escape and its component carries both a
pressed and a released signal, so hold-and-cancel is expressible. What
could not be measured here is whether a global shortcut takes the key
away from applications, because key injection cannot reach the nested
session. The mechanism says it does — KWin matches shortcuts in an input
filter ahead of the focused surface — which would cost the classroom
every ordinary use of Escape. That is inference, and it is written down
as inference, with the thirty-second bench test that settles it.
The recommendation is to change the gesture rather than grab the key an
appliance uses most: hold-to-confirm on an on-screen control, which is
ordinary Qt inside our own surface, or a modifier chord like the one the
maintenance terminal just proved. Either keeps the deliberate ceremony
without an input daemon.
Co-Authored-By: Claude Opus 5 <[email protected]>
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 things in this window that a container cannot answer, and they are
now the top of the next-steps list: a real key pressed into Parent Call,
a television switched on after the computer, and a disc that plays.
Also brings the comments in the shared libraries up to date. The only
mention of sway left in the tree is the upgrade step that removes the
sway-era login shell from a room being upgraded.
Co-Authored-By: Claude Opus 5 <[email protected]>
Run against the lab as the package built it, not a session edited by
hand. The panel came back from eight SIGKILLs a second apart in about
2.2s each time, the compositor in 0.1s, the audio policy from three, and
neither Parent Call nor the browser dying disturbed the panel.
Co-Authored-By: Claude Opus 5 <[email protected]>
The DVD player was the only thing still speaking a compositor the room
no longer runs. It asked sway's tree whether VLC's window had really
gone fullscreen, because VLC reports playing while its window is still
the black startup one the loading cover exists to hide.
VLC's own status was measured as a replacement and is not one: it
reports fullscreen true in the same 250ms poll as playing, because the
flag is the option it was started with and not a report about its
window. So the cover is held for a floor and capped by the deadline that
was already there, and the compositor is not asked anything.
Focus-or-launch went the same way. The session already takes an
exclusive lock, so a second one cannot start, and bringing an existing
one to the front is the panel's job.
classroom-window, classroom_sway and classroom_chrome are gone with it —
the last of them was reachable from nothing at all.
DVD also moves out of the status row, where it sat beside the clock as
though a disc were a machine reading. It is an application: it is in the
row with Wonder Ink and the browser, and classroom-provision removes it
from the layout on a machine with no optical drive, which retires
DVD_ENABLED. A computer that moves between rooms takes its drive with
it; nobody remembers to edit a file when it does.
The panel is rebuilt from the package at every login now. Plasma keeps
whatever panel it first built, so an update could change the bar in the
package and never change it in a room — measured, with an icon that
outlived the file it came from. Editing the live panel configuration was
tried instead and destroyed the panel, because the shell owns that file.
Removing it before the shell starts is safe and makes the desktop
stateless.
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]>
Two findings, both from watching the bar refuse to change.
The Icon widget copies the desktop entry into the user's home and uses
the copy. A classroom that had already run kept the old icon and the old
command for ever: the package no longer contained a bell and the bar kept
showing one. The button is a task manager holding a single launcher now,
which resolves /usr/share/applications live — the place an OTA update
writes to — and costs nothing, because the classroom already runs one for
the applications.
NoDisplay=true then hid the entry from the very index that resolves
launchers, and the bar drew a blank page. There is no application menu in
this classroom for the entry to clutter, so it is indexable now.
Co-Authored-By: Claude Opus 5 <[email protected]>
The coordinator already existed on the control computer and its contract
is frozen, so this is the classroom half of a contract that was read from
its README and source rather than guessed: four fields out, the status
topic subscribed before anything is published, and every word the teacher
reads taken from the coordinator's own message field.
It is a separate process, not a Plasma applet. A broker library, a
network timeout and a text entry have no business inside the only way a
teacher has of getting anywhere; if this dies the bar is untouched.
The panel mark is Breeze's call-outgoing. The old one was a bell, sitting
two inches from Plasma's notification bell in the same bar and meaning
something entirely different.
Two things it will not do: claim a call was displayed, and let a teacher
type the room. The machine already knows which room it is.
Sixty tests cover the contract without a broker. The live path was proven
against the real coordinator running in the lab, on a loopback broker,
with ProPresenter mocked and the church's networks rejected from inside
the container first.
Co-Authored-By: Claude Opus 5 <[email protected]>
Removing gtk-layer-shell from the dependencies broke classroom-dvd on the
first run, and deleting the dock's stylesheet took the DVD control bar's
styling with it. Both go back: the template under a name that says what
still uses it, and the dependency with a line in the package description
explaining that it is there for the disc player and not for a dock.
A probe overlay confirms gtk-layer-shell works under KWin, so the loading
cover survives the move. The focus helper still speaks sway, which is
written down rather than papered over.
Co-Authored-By: Claude Opus 5 <[email protected]>
Building the package found two things reading the tree did not.
dpkg refused it outright: plasma-workspace already owns
/etc/xdg/plasmanotifyrc and friends, and two packages cannot own one
path. The room's settings move to a directory of their own with
/etc/environment.d putting it in front of /etc/xdg, which is KConfig's
own cascade rather than a file fight.
The postinst then failed on a chmod for a command that no longer
exists. It now walks what the package installed instead of naming
files, removes the login shell that used to start sway on tty1, and
enables SDDM and the audio service.
Verified by installing the built package on a fresh machine and
starting the session from it: restrictions in force, palette applied,
audio service enabled and running, panel supervision unconditional.
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 room that prompted this had a television on HDMI with working PCM
audio and nothing in the analog jack, and WirePlumber chose analog. A
teacher who corrected it by hand then had to restart the browser before
any sound came out.
The policy is a pure function so it can be tested against that room
rather than against a machine: an unavailable port is not a candidate,
an analog port merely existing is not evidence of a cable, and an
explicit AUDIO_OUTPUT overrides the lot. Twelve cases, the real room
among them.
The daemon follows PipeWire's own event stream rather than polling, and
moves streams that are already playing, which is the part that stops a
teacher having to close and reopen the browser.
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]>
