The coordinate-space confusion (screen px 1080x2400 for input tap/
screencap, display px 900x2000 for reading PNGs, app-local px offset by
the 128px status bar, pt at density 2.625) cost real debugging time.
Wrote it down in doc/README.md as the permanent reference:
- the four spaces + conversions (display x1.2 = screen; screen Y-128 =
app-local; /2.625 = pt)
- the practical tap rule: read (x,y) off the PNG, x1.2, input tap --
screenshot px ARE screen px, no 128 offset for tap-what-you-see
- fixed geometry (status/nav bars, Gboard rows, editor region in pt),
with re-measure guidance
- tap-test pitfalls (first-tap-swallowed, first input text can fail,
wrong-place text = cursor/selection suspect not tap math, don't
memorize drifting content positions)
All keyboard row values re-measured from a fresh screenshot and verified
live: tapping the Q key at (62, 1712) and backspace at (990, 2020) both
landed first try (file content confirmed). This also exposed that the
old notes had mixed display-px row values with screen-px key values in
the same list -- exactly the confusion this section eliminates.
Also fixed the stale Phase 6 'letterboxed window' note in
development_plan.md (window is full-screen; only the 128px status-bar
offset is real; content positions drift; the OpenFileChan logcat line
was removed) and pointed emu.sh's tap help at the x1.2 rule.
Replaces the ad-hoc adb/nohup sequences used throughout verification with
one self-contained script: up/down/status, app start|stop|restart, shot,
log, tap, type, cmd (one-shot editor debug command), perf on|off|pull,
push/pull of Notes test files. Encodes the machine-local paths
(Notes/, PadPerf/ profiler + cmd file) in one auditable place.
Reliability findings baked in (each hit during testing):
- The AVD auto-saves a 'default_boot' instant-boot snapshot on clean
shutdown; a corrupted one makes the emulator segfault during restore
(device never comes online). up() detects it (process death / no adb
device within PAD_ONLINE_TIMEOUT) and falls back to a cold boot with
-no-snapshot-load; the next clean down() re-saves a good snapshot, so
this self-heals. down() is the only sanctioned stop (clean kill saves
the snapshot; SIGKILL corrupts it).
- The emulator process identity is ambiguous (launcher vs
qemu-system-*-headless), and crashpad/netsimd children carry the AVD
name in their command lines. Liveness and kill therefore use a tight
signature: comm matches qemu-system-* AND cmdline contains ' -avd
<AVD>' (never a broad pkill -f pattern — one matched and killed the
calling shell during testing).
- Before any launch, orphaned qemu instances are cleared (they hold the
AVD lock and make new launches fail silently); before starting a
replacement, the old one must be fully gone (lingering device/lock
causes false success).
- Timeouts: short online window for the snapshot attempt, full
BOOT_TIMEOUT for the fallback cold boot (~20 s).
Tested: idempotent up, 10 s snapshot-restore boot, forced fallback
(30 s end-to-end, verified correct instance), orphan cleanup, perf/cmd/
push/pull/shot/log on-device. doc/README.md now documents it.
