Printing through Elmer found two things. Black and white came out grey
while the preview stayed in colour: 0.2.6.2 only told the driver. And
right-clicking a picture in a lesson and choosing Print printed the whole
page around it, where some pictures cannot be opened on their own at all.
Black and white is now made before the preview. Ghostscript makes a grey
copy, the preview shows it, and CUPS is given that same file, still with
ColorModel=Grayscale so Elmer's PCL 6 driver prints with pxlmono. Measured
first: Ghostscript's own grey of the colour original and of the copy give
the same greys (Elmer's driver is Ghostscript); poppler's do not. It takes
up to 4.4 s for a lesson page of pictures, so it runs in the background
with a minute to finish, is made once and kept, and a failure is said so
and never printed in colour instead. Ghostscript is now a named dependency;
cups-filters already brought it.
Right-click asks the engine's hit test: on a picture or a canvas it offers
Print image and Print page, elsewhere only Print page. The picture comes
from the engine's own copy image — the only one of five ways measured that
worked for a signed-in picture, a hotlink-protected one, a one-time
address, blob:, data:, another site's, a canvas and WebP — and it fetches
nothing, so the teacher's sign-in is not needed again. It goes through the
clipboard, which is kept and put back; measured under KWin with another
program owning it. A picture that never arrives is said so; the page is
not printed in its place. It then gets the 0.2.6.2 picture layout.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
The kernel memory killer's "Memory Shortage Avoided" notice carried a
Configure button that ran kcmshell6 and opened KDE's whole Notifications
settings under the teacher's account. Reproduced in the lab.
Plasma draws that button without consulting the Kiosk policy, but
kcmshell6 and System Settings do: every settings module Debian 13's
Plasma 6.3 installs (90) is now refused in the classroom's immutable
kdeglobals, so the same click shows only "disabled by the system
administrator". The clock's Configure Digital Clock goes with
plasma/allow_configure_when_locked=false; Configure Audio Devices
disappears on its own; the disabled window's Help button opened KDE Help
Center, which the package now conflicts with (plasma-desktop only
recommends it).
The maintenance terminal runs outside the classroom's configuration and
still opens every module, verified. converged-check fails if any module
on a machine is ever left unrestricted: 126 passed in the lab.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
The validator asked fc-list whether Liberation Sans, Carlito and Caladea
were installed. fc-list belongs to the fontconfig package, which nothing
in this classroom pulls in, so the check could only ever fail — and it
did, twenty-odd minutes into a release run, for a reason that had
nothing to do with the fonts. They were all present the whole time.
Asserted by path now, which is what LibreOffice actually looks for.
Also depends on fonts-liberation rather than fonts-liberation2. The
latter is a transitional package in Trixie that exists only to depend on
the former, and a release should not name a package whose whole purpose
is to go away.
Co-Authored-By: Claude Opus 5 <[email protected]>
PRESENTATIONS_ENABLED, off by default, independent of everything else. A
teacher downloads a session in ordinary Chrome and it is on the
Presentations screen a few seconds later, ready for the television. No
file manager, no import button, no Impress.
WHY NOTHING LAUNCHES A DOCUMENT APPLICATION. The brief was to use
existing presentation software, so the existing software was tried
first, on Debian 13, before any of this was designed. `soffice --show`
does start a real fullscreen slideshow — and needs XDG_SESSION_TYPE plus
a VCL plugin or it dies with "Failed to open display", shows a splash,
opened a "Tip of the Day: 1/225" dialog over the slides, and leaves the
Impress editor when the show ends. `okular --presentation` opens THREE
windows: the presentation, the ordinary document window behind it, and
an information dialog. zathura is not a presenter. pdfpc is the closest
and is another dependency with a presenter-console model. Every one of
them leaves an application on screen that can open any file on the
machine, and none of them knows there is a library to go back to.
So LibreOffice converts once, headless, at import, with no window on any
screen; poppler renders the pages; the classroom shows the pictures.
Measured: 0.34s for a ten-slide PPTX, 0.03s for its ten thumbnails,
0.10s for one slide at 1920px. That is not a new renderer — it is the
same engine Impress would have used live — and it means Escape is ours,
presenting is instant, and a PDF exported from Google Slides skips the
conversion entirely and keeps the appearance Google gave it.
THE THREE THINGS KEPT APART. The library thumbnail, the starting slide
and the retention clock are independent, because the first slide of a
Bible study session is a generic opening shared by every session and the
one that names it is usually the second. Quick Look chooses the picture;
it does not change where the slideshow starts and it does not count as
having presented anything. mark_presented() is called when a slide is
actually drawn, not when Present is pressed: an intention is not a
presentation, and a viewer that failed to start must not buy another
thirty days.
IMPORTING. The teacher's download is copied, never moved, renamed or
deleted. A file with a .crdownload beside it is still arriving. Wonder
Ink's own folder is not looked at. Two downloads of the same name are
two presentations, the second titled (2) — found in the lab, where a PDF
and a PPTX of one session both came out with the same name because the
import being named was excluded from the taken-titles set BY TITLE, and
a set holds one copy of a repeated string.
Metadata is written saying "importing" before any work, so a reboot
mid-conversion leaves a directory the next startup sweeps and imports
again. A file that cannot be converted gets a card saying so, offering
only Remove, with the teacher's download untouched.
Retention: 180 days never presented, 30 days from the last presentation,
every presentation starting the thirty over. The cleanup never touches a
presentation being shown, never leaves the library directory, and never
looks at Downloads.
The dock order is unchanged: Presentations is appended after the disc
player, so Wonder Ink, the browser and the player keep the places
teachers have been reaching for. There is a test for exactly that.
classroom-wonderink now asks feature() rather than carrying its own copy
of the default, so the panel and the command cannot disagree.
Co-Authored-By: Claude Opus 5 <[email protected]>
Teachers prepare a lesson across several tabs — the lesson, its video,
the activity — and app mode is the one thing that cannot give them that.
Chrome cannot be asked for "tabs but no omnibox". App mode has no tabs; a
normal window has an address bar and no policy, flag or extension removes
it; tabbed web apps need a manifest on a site that is not ours and push
off-origin links out into a normal browser window, which is the whole of
what this design exists to prevent. So the tab strip is ours, and the
engine is Chromium either way.
QtWebEngine, from Debian, measured before it was chosen rather than
after. The usual and correct objection is codecs: on Debian 13 it reports
H.264, AAC, MP3, VP8 and VP9 all playable, MediaSource supports avc1,
mp4a and vp9, and a 720p H.264 file decoded and played to the end in the
lab. app.wonderink.org loads, and its sign-in is an ordinary email and
password form rather than a Google flow that would mind an embedded
browser. The user agent has the QtWebEngine token stripped so a site
gating on it sees the Chromium this actually is, and Widevine is handed
over from Chrome's own bundle when the machine has Chrome, which a
classroom always does.
[ Lesson ] [ Video ] [ Activity ]
The strip appears only above one tab, so an ordinary lesson looks exactly
like the application it replaces. A tab can only come from the lesson —
target=_blank, window.open, a middle click, a Ctrl+click — and there is
no address bar, no search and no button that makes a blank tab. No
allowlist of domains either, on purpose: a list would have to be right
about every video service a lesson might ever embed.
Three bugs the lab caught and this fixes. A lesson calling window.print()
did nothing at all, which is worse than no print button because a teacher
concludes the printer is broken; printRequested is now bound to the page
that asked. Leaving fullscreen left the window 200 pixels wide in the
corner — a window that has only ever been maximised has no ordinary
geometry to return to — so the fullscreen bit is cleared rather than
maximised being re-requested. And the Present view video failure written
up in docs/wonder-ink.md is acted on at last: that investigation named
the autoplay gesture chain as the likeliest cause and declined to fix it,
because in Chrome the only lever governed the ordinary browser as well.
Here it does not — this profile is Wonder Ink and nothing else — so a
lesson may start its own video and no other page in the room may.
Reproduced both ways in the lab with an unmuted video started by a script
with no gesture: NotAllowedError at Chrome's default, playing as shipped.
That is not proof Present view is fixed; the lab has no Wonder Ink
account, and candidates 2 and 3 in that document are still open.
Measured on a rebooted machine, from the package: tabs open from a link
and from window.open, switch, and close; closing one leaves the others;
closing the last closes Wonder Ink; H.264 video plays and fills the
display in fullscreen and comes back maximised with its tabs; the print
dialog offers the room's own Elmer queue; a download lands in ~/Downloads;
back and forward work from a right-click menu that is built rather than
filtered; pressing the panel button twice raises one window rather than
starting a second on the same profile; KWin reports the window as
ekklesia-wonderink, which is one panel button and not two.
Separate from the browser as before, in its own profile, with cookies
that live only as long as the window — what the Chrome policy did for
wonderink.org, and the reason closing Wonder Ink ends a teacher's
session. Chrome's old profile directory is left untouched beside it, and
the browser's own policy is not edited by any of this.
Wonder Ink is now optional per device, through WONDERINK_ENABLED in
device.conf, because one future device is a laptop that will not have it.
It rides the mechanism the disc player already uses: one marked line in
the packaged layout, edited by classroom-desktop-layout. False takes the
launcher off the panel and makes the command refuse to start; the
browser, Parent Call and the disc player are untouched and the panel
stays balanced. Absent means yes, so every existing room is unchanged.
One scale, still. Chrome has to be handed UI_SCALE because it was
measured not to follow the compositor; Qt does follow it — devicePixelRatio
2.0 at UI_SCALE=2.0, measured — so Wonder Ink is deliberately not told,
or the room would get it twice.
Co-Authored-By: Claude Opus 5 <[email protected]>
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]>
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]>
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]>
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 first piece of turning these machines into connected endpoints.
classroom-mqtt is one small service per room that subscribes, validates
what arrives, and hands the work to commands that already exist.
Nothing in the room depends on it. A broker that is down, a network that
is missing, a machine with no broker configured at all — each is a
service sitting quietly, not a classroom that fails. Nothing waits for
it at boot and the shipped default is off, so every existing classroom
upgrades into this release with messaging disabled until a broker
exists.
The room is the hostname, which is already how these machines are named.
Topics carry no product name because the broker is the church's and
these are just rooms: classroom/notify/all, classroom/notify/<room>, and
a retained classroom/status/<room> so anyone asking later can be told
which rooms are up without waiting for them to say so again.
Notifications are events and are never retained; status is state and is.
Stale messages cannot come back, which is the property that matters most
and has two halves. The session is clean, so a broker never hands over a
backlog from while the room was off. And retained notifications are
refused on arrival, because otherwise one would replay into every room
at every reboot forever. The honest limit is written down: MQTT only
flags a retained message when it is replayed to a new subscription, so a
retained publish delivered live is indistinguishable from an ordinary
one and is shown once — which is right, since it is live at that moment,
and the replay is the actual hazard.
Delivery reuses the session-aware sender rather than a second copy of
it. classroom-notify-test grew into the real thing, so it is now
classroom-notify with the sample sender a wrapper over it, and its 36
tests came along.
The broker password lives in device.conf, so that file stops being world
readable: 0640 root:classroom, which everything that reads it already
satisfies.
Transport logic is kept free of any broker library so it can be tested
without one — 40 checks on room identity, the topic contract and which
payloads become notifications. Separately verified against a real
mosquitto: connect, subscribe, retained status, per-room and all-room
delivery, urgency, duplicate and expired and malformed messages ignored,
the broker killed with the daemon surviving, reconnect, and a stale
retained notification left on the broker not reaching the screen when a
room boots.
Co-Authored-By: Claude Opus 5 <[email protected]>
Pressing DVD now enters DVD mode rather than opening VLC. VLC is still
the backend, because its dvdnav module is what decodes disc menus and
nothing else on Debian does that reliably, but nothing a person can see
or press belongs to it any more.
classroom-dvd-session owns the whole thing. It puts a full-screen black
layer-shell surface up the moment the button is pressed, starts VLC
behind it, and drops it once playback is actually on screen — so the
harsh cut from wallpaper to VLC's black window is gone, and no partial
VLC window or reserved dock strip is ever visible. A deadline drops the
surface regardless, because DVD mode must never leave a black screen
with nothing behind it.
The controls are a classroom bar on the overlay layer, the one layer
sway draws above a fullscreen window. It slides up when the pointer
reaches the bottom of the screen and hides again shortly after it
leaves. It is drawn from the dock's own stylesheet at the room's UI
scale, so it is the same surface, the same radius and the same white
icons. While hidden it only accepts the pointer in a thin strip along
the bottom edge, so a click on a disc menu goes to the disc.
The bar reaches VLC through an HTTP interface on loopback behind a
password generated per session, sending hotkey *actions* by name. That
is what makes the next part possible.
All 108 hotkeys VLC 3.0.23 defines are unset, then Space, Esc and the
arrow keys plus Enter are bound. Crop, aspect ratio, subtitles, audio
tracks and deinterlacing are no longer reachable by pressing a key at
random, and the arrow keys no longer change VLC's volume — the
television owns volume, and CEC will own it properly later.
Esc quits instead of leaving fullscreen. There is nothing to leave, and
leaving it was what stranded people on a black VLC window. Close, Eject
and Esc all ask VLC to quit and escalate to SIGTERM then SIGKILL if it
does not; when VLC exits by any route, including a crash, the session
ends and the classroom desktop comes back.
Verified against VLC 3.0.23 on Trixie: every argument accepted, every
control action accepted over the control interface, a wrong password
refused, and quit exiting cleanly. The surfaces were rendered under a
headless sway and screenshotted to check the bar against the dock.
Co-Authored-By: Claude Opus 5 <[email protected]>
A fresh classroom needed two things installed by hand on every box:
Google Chrome, which is not in Debian, and the DVD codecs, which Debian
cannot ship. Both now happen on their own.
ekklesia-classroom-provision.service runs after every boot and does the
work that needs the network and the apt lock, neither of which a package
postinst can have. Each step returns immediately if it is already done,
so a provisioned machine costs nothing and a machine that was offline
the first time gets another go at the next boot. Nothing there is
allowed to fail the boot: a classroom with no DVD codecs is still a
working classroom, and it says so in the log rather than silently.
The postinst enables the service but deliberately does not start it.
Every OTA update reboots the moment the install finishes, and an apt run
killed by that reboot would leave dpkg half-configured.
Chrome comes from Google's own repository rather than a one-off .deb, so
it keeps getting security updates. Google's package migrates whatever we
write into a deb822 file of its own, so the repository is looked for
across every source file instead of only the one we would write;
otherwise a machine that had Chrome removed would end up with two copies
of the same repository.
The DVD codec helper previously assumed deb822 sources and did nothing
on a machine using a classic /etc/apt/sources.list, which is what the
hardware actually runs. It now handles both formats, and only ever adds
a missing component to an existing Debian entry — so it cannot produce a
duplicate repository or a duplicate component however many times it
runs, and third-party repositories like Chrome's are never touched. It
also answers libdvd-pkg's debconf questions, so nothing blocks on a
prompt in a service with no terminal.
Tested against fixture APT trees for classic sources.list, deb822
.sources, contrib already enabled, repeated runs, third-party
repositories and the awkward real lines: bracketed options, indentation,
trailing comments and flat repositories.
Co-Authored-By: Claude Opus 5 <[email protected]>
DVD support stays optional per room: DVD_ENABLED decides whether the
button is built at all, and rooms without it poll nothing. Upgrades
append a commented DVD_ENABLED=false so the option is discoverable
without changing what those rooms already do.
The dock polls the drive with CDROM_DRIVE_STATUS, which is a status
query rather than a read, so it does not spin the disc up. A disc that
becomes ready announces itself once and brings the DVD logo up to full
strength; an empty or unplugged drive holds it back, the same gray
versus colour language the LIVE icon already uses. Nothing autoplays —
playback always needs a deliberate press.
Playback is VLC rather than mpv because mpv dropped DVD menu support,
and menus are the part that matters for a commercial disc. It goes
through classroom-window like everything else, so the player minimizes
and restores from the dock exactly as the browser does.
Pressing the button with no drive, no disc, or a disc still spinning up
gives a plain-language notification instead of failing silently.
Reading the drive needs group cdrom, which the postinst grants and the
OTA reboot activates. Commercial CSS discs additionally need libdvdcss,
which Debian cannot ship; classroom-dvd-css-setup bootstraps it from
contrib. That is deliberately not run from the postinst, which executes
while dpkg already holds the apt lock.
The optical helpers live in a shared module both the dock and
classroom-dvd import, and the dock imports it defensively: if it ever
goes missing the shell loses disc detection rather than failing to
start.
Co-Authored-By: Claude Opus 5 <[email protected]>
