The women's Bible study laptop is a fixed appliance: AC power, battery
out, lid shut, one television on HDMI. Its own panel should be off.
DISPLAY_MODE=external-only says so, and it is a setting rather than
something inferred from having a lid, because another laptop may want its
own screen or both. Nothing reads DEVICE_TYPE to decide it.
The built-in panel is identified by kscreen's output TYPE — 7 is Panel —
rather than by connector name. Matching "eDP-1" would be matching one
machine's spelling: eDP, LVDS and DSI are all internal, numbered
differently per driver and renamed between kernel versions. The names are
kept only as a fallback for a driver that reports no type, which some
virtual devices do.
One rule overrides the setting: never leave the machine with no screen. A
laptop asked for external-only whose television is off keeps its own
panel and says so in the journal. A machine nobody can see is one nobody
can fix standing in front of it, and it corrects itself the next time
this runs with the set on. Only the outputs that are not already right
are touched, so a television power cycle is not a stream of mode sets.
Applied at login from an autostart entry named to sort before the scale
one, so the scale lands on the displays this leaves enabled.
The lid itself needed no new code — logind ignores every lid event,
PowerDevil's lidAction is 0 in all three profiles with
triggerLidActionWhenExternalMonitorPresent=false, the profiles are
immutable and the classroom account cannot reach suspend through polkit.
That was all already true for towers. What was missing was a test saying
so, and there is one now, because it is the property the laptop depends
on and nothing would have noticed it regressing.
KNOWN LIMITATION, and it is written into docs/testing.md rather than left
to be discovered: the mode is applied at login, not continuously. If KWin
re-enables the internal panel when the television is power cycled, it
stays enabled until the next login. The lab has no lid and no HDMI
hotplug, so this cannot be settled here; the physical procedure says to
check it specifically, because the answer decides whether the follow-up
needs an event-driven applier like the audio policy's.
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]>
