screentinker/android
ScreenTinker 83c9bc5aa6 Clear ProvisioningActivity's service callbacks (the white-flash relaunch loop)
Reported on #234 as a screen that flashes white "over and over", unkillable — "there
is nothing we can do on the tablet". It is a leaked listener.

ProvisioningActivity installs onRegistered/onUnpaired/onPaired on WebSocketService and
then finish()es. The service outlives it and nothing ever clears them: MainActivity
assigns neither of those three, so nothing overwrites them either. onPaired therefore
stays wired to a destroyed Activity for the life of the process — keeping it alive, and
still firing.

And it fires often. The server sends device:paired on EVERY register, not only the
first. So: register -> paired -> the stale callback starts MainActivity with
CLEAR_TASK -> new Activity binds and registers -> paired -> again. Measured on an
Android 12 tablet with a bare paired device and nothing assigned: 240 activity starts
in 180 seconds, about 1.3 a second, indefinitely.

Android 12 is where it becomes intolerable rather than merely wasteful: every launch
draws a splash screen there, so each iteration is a visible white flash. The same loop
on Android 9 has no splash and reads as an occasional glitch — which is why it was
originally dismissed as unreproducible after a clean reinstall. A clean reinstall
starts MainActivity directly and never runs ProvisioningActivity, so the callback is
never installed and the loop never begins. Pairing is what arms it.

onPaired is now one-shot — the hand-off to MainActivity is all it was ever for — and
all three are dropped in onDestroy too, which covers backing out before pairing
completes.

Same device, same pairing flow, 180s: 240 activity starts and 240 splash screens
before, 0 and 0 after, with registrations falling from 240 to 2.

⚠️ No other callback is ever nulled either (there are ~20). MainActivity's are
overwritten by the next MainActivity so they self-heal, but each one leaks the previous
Activity until then. Worth a sweep; this commit fixes only the three that never get
overwritten.
2026-07-29 18:01:34 -05:00
..
app Clear ProvisioningActivity's service callbacks (the white-flash relaunch loop) 2026-07-29 18:01:34 -05:00
gradle/wrapper Initial open source release 2026-04-08 12:14:53 -05:00
build.gradle.kts Initial open source release 2026-04-08 12:14:53 -05:00
gradle.properties Initial open source release 2026-04-08 12:14:53 -05:00
gradlew Initial open source release 2026-04-08 12:14:53 -05:00
gradlew.bat Initial open source release 2026-04-08 12:14:53 -05:00
settings.gradle.kts Initial open source release 2026-04-08 12:14:53 -05:00