App crash for Android 12

[keerthankrrao]

Experiencing app crash at Android 12, but it works fine for < Android OS v12. I've added the permissions for Android 12 too i.e, Bluetooth Connect and Bluetooth Scan.

2022-07-28 16:25:36.966 15165-15297/ E/AndroidRuntime: FATAL EXCEPTION: DefaultDispatcher-worker-1
com.juul.kable.BluetoothDisabledException: Bluetooth adapter state is Off (10), but On (12) was required.
at com.juul.kable.PeripheralKt.checkBluetoothAdapterState(Peripheral.kt:499)
at com.juul.kable.PeripheralKt.access$checkBluetoothAdapterState(Peripheral.kt:1)
at com.juul.kable.AndroidPeripheral.connect(Peripheral.kt:231)
at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
at kotlinx.coroutines.internal.LimitedDispatcher.run(LimitedDispatcher.kt:42)
at kotlinx.coroutines.scheduling.TaskImpl.run(Tasks.kt:95)
at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:570)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:749)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:677)
at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:664)
Suppressed: kotlinx.coroutines.DiagnosticCoroutineContextException: [StandaloneCoroutine{Cancelling}@e20bf2e, Dispatchers.IO]

[twyatt]

It appears that the phone's bluetooth is turned off.

This is checked via:

kable/core/src/androidMain/kotlin/Peripheral.kt

Lines 480 to 501 in fe8ee14

	/**
	* Explicitly check the adapter state before connecting in order to respect system settings.
	* Android doesn't actually turn bluetooth off when the setting is disabled, so without this
	* check we're able to reconnect the device illegally.
	*/
	private fun checkBluetoothAdapterState(
	expected: Int,
	) {
	fun nameFor(value: Int) = when (value) {
	STATE_OFF -> "Off"
	STATE_ON -> "On"
	STATE_TURNING_OFF -> "TurningOff"
	STATE_TURNING_ON -> "TurningOn"
	else -> "Unknown"
	}
	val actual = BluetoothAdapter.getDefaultAdapter().state
	if (expected != actual) {
	val actualName = nameFor(actual)
	val expectedName = nameFor(expected)
	throw BluetoothDisabledException("Bluetooth adapter state is $actualName ($actual), but $expectedName ($expected) was required.")
	}
	}

Does this happen on all devices you've tried, or is it specific to certain manufactures or models?
I vaguely remember a specific model would misreport this, and the only workaround was the catch this exception in that situation. 😢

[keerthankrrao]

Thank you the update. It got worked after adding the permissions for Android 12 and enabling the bluetooth adapter.

[twyatt]

#335 might help in the future for checking if bluetooth is ready to use.

[degill]

Sorry for hijacking this Issue @twyatt, but would it make sense to document BluetoothDisabledException as another possible exception on Peripheral.connect? Currently only ConnectionRejectedException and CancellationException are documented.

To make my intrusion worse: I went through the code and got the following questions, which I can turn into their own issues if thats a better place for them. They both are about documentation.

1. It looks liks Scanner.advertisements can throw BluetoothDisabledException and ScanFailedException, which I believe would crash my app if the CoroutineContext with which I collect advertisements does not use a SupervisorJob and if I don't use Flow.catch. Would it make sense to document these exceptions on that property?
2. (Nearly same as my initial question) If I am not mistaken then Peripheral.connect can throw ConnectionRejectedException, BluetoothDisabledException and ConnectionLostException. Should these be documented?

I can create a PR with such documentation if desired.

[twyatt]

I'm traveling at the moment, so I'll respond more thoroughly after I get back, but not a problem at all "hijacking" this issue. Love all the help in identifying documentation shortcomings. PRs very welcome.

[twyatt]

@degill so this doesn't get lost, created #614 to track.