FlutterBleLib Don't work in Android 4.4.4

The lib scan for nearby peripherals and never finds any. I've already tested with two different devices with this system version and the result was the same. Please, help me!

Feb 20 '20 12:02 edsonboldrini

Here is the debug console: Apparently, the device finds a peripheral, but throw a exception right after.

Feb 20 '20 16:02 edsonboldrini

Do you have ACCESS_FINE_LOCATION permission and location services on?

Feb 24 '20 10:02 mikolak

Unfortunately yes :(

Feb 24 '20 15:02 edsonboldrini

I build for release and then execute the example project using a device with android 4.4.4 and nothing happens.

Feb 25 '20 14:02 edsonboldrini

Please, don't forget me!!

Mar 01 '20 13:03 edsonboldrini

Don't worry, I'll investigate this. Got a device set aside on my desk, but I didn't have time last week and I probably won't this week as well.

Mar 01 '20 19:03 mikolak

Here is another log using the example project from inside the lib to improve your investigation:

✓ Built build/app/outputs/apk/debug/app-debug.apk.
I/flutter ( 5947): 2020-03-03T09:19:02.768341	D	DeviceListScreenState.didChangeDependencies:	 DeviceListScreenState didChangeDependencies
I/flutter ( 5947): 2020-03-03T09:19:02.826080	D	DeviceListScreenState._onResume:	 onResume
I/flutter ( 5947): 2020-03-03T09:19:02.864868	D	DevicesBloc.init:	 Init devices bloc
D/com.polidea.flutter_ble_lib.FlutterBleLibPlugin( 5947): on native side observed method: createClient
I/flutter ( 5947): 2020-03-03T09:19:02.978027	D	DevicesBloc.init:	  listen to _devicePickerController.stream
W/dalvikvm( 5947): VFY: unable to find class referenced in signature (Landroid/bluetooth/le/ScanSettings;)
W/dalvikvm( 5947): VFY: unable to find class referenced in signature (Landroid/bluetooth/le/ScanCallback;)
I/dalvikvm( 5947): Could not find method android.bluetooth.BluetoothAdapter.getBluetoothLeScanner, referenced from method com.polidea.rxandroidble.internal.util.RxBleAdapterWrapper.startLeScan
W/dalvikvm( 5947): VFY: unable to resolve virtual method 334: Landroid/bluetooth/BluetoothAdapter;.getBluetoothLeScanner ()Landroid/bluetooth/le/BluetoothLeScanner;
D/dalvikvm( 5947): VFY: replacing opcode 0x6e at 0x0002
W/dalvikvm( 5947): VFY: unable to find class referenced in signature (Landroid/bluetooth/le/ScanCallback;)
I/dalvikvm( 5947): Could not find method android.bluetooth.BluetoothAdapter.getBluetoothLeScanner, referenced from method com.polidea.rxandroidble.internal.util.RxBleAdapterWrapper.stopLeScan
W/dalvikvm( 5947): VFY: unable to resolve virtual method 334: Landroid/bluetooth/BluetoothAdapter;.getBluetoothLeScanner ()Landroid/bluetooth/le/BluetoothLeScanner;
D/dalvikvm( 5947): VFY: replacing opcode 0x6e at 0x0002
W/dalvikvm( 5947): VFY: unable to find class referenced in signature (Landroid/bluetooth/le/ScanResult;)
I/dalvikvm( 5947): Could not find method android.bluetooth.le.ScanResult.getScanRecord, referenced from method com.polidea.rxandroidble.internal.scan.InternalScanResultCreator.create
W/dalvikvm( 5947): VFY: unable to resolve virtual method 414: Landroid/bluetooth/le/ScanResult;.getScanRecord ()Landroid/bluetooth/le/ScanRecord;
D/dalvikvm( 5947): VFY: replacing opcode 0x6e at 0x0002
W/dalvikvm( 5947): VFY: unable to find class referenced in signature (Landroid/bluetooth/le/ScanResult;)
I/dalvikvm( 5947): Could not find method android.bluetooth.le.ScanResult.getScanRecord, referenced from method com.polidea.rxandroidble.internal.scan.InternalScanResultCreator.create
W/dalvikvm( 5947): VFY: unable to resolve virtual method 414: Landroid/bluetooth/le/ScanResult;.getScanRecord ()Landroid/bluetooth/le/ScanRecord;
D/dalvikvm( 5947): VFY: replacing opcode 0x6e at 0x0002
I/flutter ( 5947): 2020-03-03T09:19:03.086608	D	DeviceListScreenState.build:	 build DeviceListScreenState
I/dalvikvm( 5947): Could not find method android.content.Context.createDeviceProtectedStorageContext, referenced from method androidx.core.content.ContextCompat.createDeviceProtectedStorageContext
W/dalvikvm( 5947): VFY: unable to resolve virtual method 455: Landroid/content/Context;.createDeviceProtectedStorageContext ()Landroid/content/Context;
D/dalvikvm( 5947): VFY: replacing opcode 0x6e at 0x0006
I/dalvikvm( 5947): Could not find method android.content.Context.getCodeCacheDir, referenced from method androidx.core.content.ContextCompat.getCodeCacheDir
W/dalvikvm( 5947): VFY: unable to resolve virtual method 462: Landroid/content/Context;.getCodeCacheDir ()Ljava/io/File;
D/dalvikvm( 5947): VFY: replacing opcode 0x6e at 0x0006
I/dalvikvm( 5947): Could not find method android.content.Context.getColor, referenced from method androidx.core.content.ContextCompat.getColor
W/dalvikvm( 5947): VFY: unable to resolve virtual method 463: Landroid/content/Context;.getColor (I)I
D/dalvikvm( 5947): VFY: replacing opcode 0x6e at 0x0006
I/dalvikvm( 5947): Could not find method android.content.Context.getColorStateList, referenced from method androidx.core.content.ContextCompat.getColorStateList
W/dalvikvm( 5947): VFY: unable to resolve virtual method 464: Landroid/content/Context;.getColorStateList (I)Landroid/content/res/ColorStateList;
D/dalvikvm( 5947): VFY: replacing opcode 0x6e at 0x0006
I/dalvikvm( 5947): Could not find method android.content.Context.getDataDir, referenced from method androidx.core.content.ContextCompat.getDataDir
W/dalvikvm( 5947): VFY: unable to resolve virtual method 466: Landroid/content/Context;.getDataDir ()Ljava/io/File;
D/dalvikvm( 5947): VFY: replacing opcode 0x6e at 0x0006
I/dalvikvm( 5947): Could not find method android.content.Context.getDrawable, referenced from method androidx.core.content.ContextCompat.getDrawable
W/dalvikvm( 5947): VFY: unable to resolve virtual method 468: Landroid/content/Context;.getDrawable (I)Landroid/graphics/drawable/Drawable;
D/dalvikvm( 5947): VFY: replacing opcode 0x6e at 0x0006
I/dalvikvm( 5947): Could not find method android.content.Context.getMainExecutor, referenced from method androidx.core.content.ContextCompat.getMainExecutor
W/dalvikvm( 5947): VFY: unable to resolve virtual method 475: Landroid/content/Context;.getMainExecutor ()Ljava/util/concurrent/Executor;
D/dalvikvm( 5947): VFY: replacing opcode 0x6e at 0x0006
I/dalvikvm( 5947): Could not find method android.content.Context.getNoBackupFilesDir, referenced from method androidx.core.content.ContextCompat.getNoBackupFilesDir
W/dalvikvm( 5947): VFY: unable to resolve virtual method 477: Landroid/content/Context;.getNoBackupFilesDir ()Ljava/io/File;
D/dalvikvm( 5947): VFY: replacing opcode 0x6e at 0x0006
I/dalvikvm( 5947): Could not find method android.content.Context.getSystemService, referenced from method androidx.core.content.ContextCompat.getSystemService
W/dalvikvm( 5947): VFY: unable to resolve virtual method 484: Landroid/content/Context;.getSystemService (Ljava/lang/Class;)Ljava/lang/Object;
D/dalvikvm( 5947): VFY: replacing opcode 0x6e at 0x0006
I/dalvikvm( 5947): Could not find method android.content.Context.getSystemServiceName, referenced from method androidx.core.content.ContextCompat.getSystemServiceName
W/dalvikvm( 5947): VFY: unable to resolve virtual method 486: Landroid/content/Context;.getSystemServiceName (Ljava/lang/Class;)Ljava/lang/String;
D/dalvikvm( 5947): VFY: replacing opcode 0x6e at 0x0006
I/dalvikvm( 5947): Could not find method android.content.Context.isDeviceProtectedStorage, referenced from method androidx.core.content.ContextCompat.isDeviceProtectedStorage
W/dalvikvm( 5947): VFY: unable to resolve virtual method 489: Landroid/content/Context;.isDeviceProtectedStorage ()Z
D/dalvikvm( 5947): VFY: replacing opcode 0x6e at 0x0006
I/dalvikvm( 5947): Could not find method android.content.Context.startForegroundService, referenced from method androidx.core.content.ContextCompat.startForegroundService
W/dalvikvm( 5947): VFY: unable to resolve virtual method 502: Landroid/content/Context;.startForegroundService (Landroid/content/Intent;)Landroid/content/ComponentName;
D/dalvikvm( 5947): VFY: replacing opcode 0x6e at 0x0006
D/permissions_handler( 5947): No permissions found in manifest for: 2
I/flutter ( 5947): Location permission status: PermissionStatus.unknown
I/flutter ( 5947): Location service status: ServiceStatus.notApplicable
D/com.polidea.flutter_ble_lib.FlutterBleLibPlugin( 5947): on native side observed method: getState
I/flutter ( 5947): 2020-03-03T09:19:05.615905	D	DevicesBloc._startScan:	 Ble client created
D/com.polidea.flutter_ble_lib.FlutterBleLibPlugin( 5947): on native side observed method: startDeviceScan
D/BluetoothAdapter( 5947): startLeScan(): null
D/BluetoothAdapter( 5947): onClientRegistered() - status=0 clientIf=6
D/BluetoothAdapter( 5947): onScanResult() - Device=D1:F7:87:7D:9D:FE RSSI=-85
D/BluetoothAdapter( 5947): stopLeScan()
W/BluetoothAdapter( 5947): Unhandled exception: rx.exceptions.OnErrorFailedException: Error occurred when trying to propagate error to Observer.onError

Interesting note that there is a log indicating that I'm missing 2 permissions inside manifest:

D/permissions_handler( 5947): No permissions found in manifest for: 2

And here is my manifest:

<uses-permission android:name="android.permission.INTERNET" />

<!-- Permissions options for the `location` group -->
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />

<!-- io.flutter.app.FlutterApplication is an android.app.Application that
     calls FlutterMain.startInitialization(this); in its onCreate method.
     In most cases you can leave this as-is, but you if you want to provide
     additional functionality it is fine to subclass or reimplement
     FlutterApplication and put your custom class here. -->
<application
    android:name="io.flutter.app.FlutterApplication"
    android:label="flutter_ble_lib_example"
    android:icon="@mipmap/ic_launcher">
    <activity

Mar 03 '20 12:03 edsonboldrini

Ah, it seems you're missing two permissions in the manifest:

<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />

Mar 04 '20 09:03 mikolak

Still the same error:

D/permissions_handler(12029): No permissions found in manifest for: 2
I/flutter (12029): Location permission status: PermissionStatus.unknown
I/flutter (12029): Location service status: ServiceStatus.notApplicable

Manifest:

<uses-permission android:name="android.permission.INTERNET" />

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_LOCATION_EXTRA_COMMANDS" />

<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.BLUETOOTH_PRIVILEGED" />

Mar 04 '20 11:03 edsonboldrini

Android 4.4 doesn't support runtime permissions, which was not taken into consideration when making the example.

Can you try commenting out line 61 in example/lib/devices_list/devices_bloc.dart?

Mar 04 '20 11:03 mikolak

Android 4.4 doesn't support runtime permissions, which was not taken into consideration when making the example.

Can you try commenting out line 61 in example/lib/devices_list/devices_bloc.dart?

Already done, same error.

I/flutter (12487): 2020-03-04T08:28:11.928247	D	DeviceListScreenState.build:	 build DeviceListScreenState
D/com.polidea.flutter_ble_lib.FlutterBleLibPlugin(12487): on native side observed method: getState
I/flutter (12487): 2020-03-04T08:28:14.318689	D	DevicesBloc._startScan:	 Ble client created
D/com.polidea.flutter_ble_lib.FlutterBleLibPlugin(12487): on native side observed method: startDeviceScan
D/BluetoothAdapter(12487): startLeScan(): null
D/BluetoothAdapter(12487): onClientRegistered() - status=0 clientIf=5
D/BluetoothAdapter(12487): onScanResult() - Device=C5:24:35:92:22:AD RSSI=-81
D/BluetoothAdapter(12487): stopLeScan()
W/BluetoothAdapter(12487): Unhandled exception: rx.exceptions.OnErrorFailedException: Error occurred when trying to propagate error to Observer.onError

Mar 04 '20 11:03 edsonboldrini

Any updates??

Mar 16 '20 17:03 edsonboldrini

Hi! I hadn't had the time yet, sorry. I forgot to ask: what's the device you're testing on?

Mar 19 '20 07:03 mikolak

A Samsung grand duos prime and a Samsung tablet (I don't know its model exactly, maybe an old galaxy tab).

Mar 23 '20 22:03 edsonboldrini

Hi!

Good news: finally found time to confirm it.

Bad news: the issue seems to lie in the native dependency RxAndroidBLE or somewhere in integration.

I haven't yet pinpointed the issue there, since it seems like it should work out of the box, and yet it doesn't. I'll try to find the exact issue and get it patched for us, but I'm unable to give you any timeline.

Mar 26 '20 08:03 mikolak

Ok! Thanks for the help!

Mar 30 '20 14:03 edsonboldrini