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]>
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]>
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]>
UI_SCALE only ever reached the surfaces we draw ourselves. Chrome stayed
tiny — its tabs, omnibox and menus are Chrome's own pixels, and Ctrl+
only scales page content, which is no use to a volunteer reading a
toolbar from across the room.
UI_SCALE is a property of the television, not of one program, so it now
sets sway's output scale, which every client is measured against.
classroom-scale runs first in the session and applies it. The display
mode is untouched: the panel stays at 1920x1080 and only the logical
coordinate space shrinks, which is what makes everything in it larger.
Our own surfaces stop scaling themselves. They are measured in the same
logical pixels sway is already scaling, so applying UI_SCALE again would
double it. SHELL_SCALE is that decision in one named place, and setting
it back to ui_scale(config) would restore per-surface scaling without
touching a template.
Measured at 1920x1080 with Chrome 152. Chrome's tab strip 40 -> 49 ->
59px against 1.0, 1.25, 1.5; sway's title bar 25 -> 31 -> 38px; the
classroom dock 74 -> 92 -> 110px. Everything scales once, together, and
1.0 is identical to no scaling at all.
Two tradeoffs, both measured rather than assumed. GTK 3 has no
fractional scaling, so at 1.5 it renders at 2x and sway scales down —
very slightly softer, invisible at classroom distance. XWayland is
softer too: terminal text at 1.5 showed about 50% more intermediate-tone
pixels than at 1.0. VLC is the only XWayland application here, and in
DVD mode none of its interface is on screen, only video from a 720x480
disc that is being upscaled regardless. Chrome is a native Wayland
client and stays sharp, which is what matters for reading.
Co-Authored-By: Claude Opus 5 <[email protected]>
A 32" panel a few feet from the children and a 65" set across a hall
want the same design at different sizes. UI_SCALE in device.conf now
sets that, and nobody has to edit CSS or source to tune a room.
The stylesheet and the notification config become templates carrying
measurement tokens. classroom-dock resolves the stylesheet in memory at
startup; classroom-notifications resolves the notification config into
the session's runtime directory and execs mako on it, so the process is
still just mako and everything that looks for it by name still finds it.
Neither template is rewritten on disk, so an update cannot lose a room's
setting and a room cannot drift from the packaged design.
Dock height and the reserved strip, corner radii, padding, button size,
spacing, every icon, the clock and its inset, and the notification
geometry all follow the scale. Colours, translucency and the hairline
borders do not: those are the design, not the size.
At UI_SCALE=1.0 the rendered stylesheet is byte-identical to the one the
shell used before any of this existed, which is the property worth
keeping. Values outside 0.8 to 1.5 are clamped and anything that is not
a number falls back to 1.0, so a typo in device.conf cannot produce an
unusable classroom.
Device configuration moves into a shared module, since the dock and the
notification daemon now have to agree about what a setting means.
Co-Authored-By: Claude Opus 5 <[email protected]>
