Three numbers, taken on the emulator through the app's own render report
and written into EXPLORER.md; the fixture tree the sandbox now builds is
what they were taken against.
The viewer's scan was on the main thread. Decision 8 said off it, and the
first version did it in a `remember` inside the composition, which is not
that -- 460ms of frozen screen on a 1 MiB file, long enough that the
accessibility tree cannot be read, which is exactly what "the app has
stopped" looks like from outside. It runs on Dispatchers.Default now, with
a spinner where the file will be. Reading a megabyte is otherwise fine:
the viewer is a row per line, and it opens and scrolls 28,660 of them.
Edit mode needed a cap, and not the one the plan expected. The cost that
matters is not the highlighting -- 40ms a keystroke at 128 kB, which is
survivable -- it is Compose laying out one enormous text in the field:
2,027ms per frame at 128 kB, with typed characters dropped, and no
response at all at 1 MiB. Switching highlighting off would have saved
nothing, since every arrangement of a single text field pays it. So
EDIT_LIMIT is 32 kB, the largest size actually measured as usable, and
above it the pencil is disabled with the reason in words beside it: a
disabled control teaches what the thing can do but cannot say why it is
off, and a reader who cannot edit a file they can plainly read would
otherwise conclude the app is broken.
`FileLines.of` is timed like everything else here, so the figure lands in
the render report rather than needing a harness to ask for it.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
irisandClaude Opus 5
2c12274285