Files
Classroom_Desktop/scripts/classroom-desktop-layout
T
ekklesiaandClaude Opus 5 d2d30d6b0c feat: take the last of sway out of the classroom
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]>
2026-09-10 13:00:50 -05:00

97 lines
2.8 KiB
Python
Executable File

#!/usr/bin/env python3
"""Match the classroom's panel to the machine it is on.
There is exactly one thing about the bar that depends on hardware: a room
with no optical drive should not be offered a disc player. This edits the
one marked line in the installed layout, and nothing else.
It writes the *layout*, not the running panel. Editing
plasma-org.kde.plasma.desktop-appletsrc underneath a live plasmashell was
tried and it destroyed the panel: the shell owns that file and rewrites
it, so an edit races with it. The layout is a file the package owns and
the shell only reads, and classroom-desktop-reset makes the shell read it
again at the next login.
DVD_ENABLED is gone. A drive is something the machine can be asked about,
and asking is more reliable than remembering to edit a file when a
computer moves between rooms.
"""
import glob
import os
import re
import sys
LAYOUT = (
"/usr/share/plasma/look-and-feel/org.ekklesia.classroom.desktop"
"/contents/layouts/org.kde.plasma.desktop-layout.js"
)
MARKER = "/* CLASSROOM-DVD-LAUNCHER */"
# The kernel names optical drives sr0, sr1, ... regardless of bus.
DRIVE_GLOB = "/dev/sr[0-9]*"
def has_optical_drive():
return bool(glob.glob(DRIVE_GLOB))
def rewrite(text, wanted):
"""Comment the DVD launcher in or out, idempotently."""
line = re.compile(
r"^(\s*)(//\s*)?(" + re.escape(MARKER) + r'\s*"applications:ekklesia-dvd\.desktop")',
re.M,
)
def swap(match):
indent, _, body = match.groups()
return f"{indent}{'' if wanted else '// '}{body}"
return line.sub(swap, text)
def main():
path = sys.argv[1] if len(sys.argv) > 1 else LAYOUT
try:
with open(path, "r", encoding="utf-8") as handle:
before = handle.read()
except OSError as error:
print(f"classroom-desktop-layout: {error}", file=sys.stderr)
return 0
if MARKER not in before:
print("classroom-desktop-layout: no DVD marker in the layout",
file=sys.stderr)
return 0
wanted = has_optical_drive()
after = rewrite(before, wanted)
if after == before:
print(f"classroom-desktop-layout: DVD launcher already "
f"{'present' if wanted else 'absent'}")
return 0
# Replace the file rather than edit in place, so a full disk or a
# crash leaves the old layout intact rather than half of a new one.
temporary = f"{path}.new"
try:
with open(temporary, "w", encoding="utf-8") as handle:
handle.write(after)
os.replace(temporary, path)
except OSError as error:
print(f"classroom-desktop-layout: {error}", file=sys.stderr)
return 1
print(f"classroom-desktop-layout: DVD launcher "
f"{'added' if wanted else 'removed'}")
return 0
if __name__ == "__main__":
sys.exit(main())