Using able with a python-for-android service

[barrydisign]

We have created a Kivy application which spawns a service and we wish to run able within this. We tried running some existing working code but get

05-28 13:23:56.487  8004  8024 I python  :  jnius.jnius.JavaException: JVM exception occurred: Attempt to invoke virtual method 'android.content.pm.PackageManager android.content.Context.getPackageManager()' on a null object reference
05-28 13:23:56.487  8004  8024 I python  : Python for android ended.

Is this at all possible?
Many thanks

[b3b]

Unfortunately, currently it is not possible to run able as a service, I have not tried it yet.

[jejmule]

Hi,
I am facing the same issue.
@barrydisign did you find a work around? I need it in a service to get streamed data via ble.

It is how the service is defined in the main app.

self.mActivity = autoclass(u'org.kivy.android.PythonActivity').mActivity
argument = ''
service.start(self.mActivity, argument)

and the complete log :

File "/home/jejmule/ISSULab/.buildozer/android/app/service.py", line 71, in
File "/home/jejmule/ISSULab/.buildozer/android/app/service.py", line 23, in init
File "/home/jejmule/ISSULab/.buildozer/android/app/arduinoBLE.py", line 31, in init
File "/home/jejmule/ISSULab/.buildozer/android/platform/build-armeabi-v7a/build/python-installs/issulab/able/dispatcher.py", line 38, in init
File "/home/jejmule/ISSULab/.buildozer/android/platform/build-armeabi-v7a/build/python-installs/issulab/able/android/dispatcher.py", line 60, in _set_ble_interface
File "jnius/jnius_export_class.pxi", line 256, in jnius.jnius.JavaClass.init
File "jnius/jnius_export_class.pxi", line 343, in jnius.jnius.JavaClass.call_constructor
File "jnius/jnius_utils.pxi", line 91, in jnius.jnius.check_exception

jnius.jnius.JavaException: JVM exception occurred: Attempt to invoke virtual method 'android.content.pm.PackageManager android.content.Context.getPackageManager()' on a null object reference

[barrydisign]

Sorry no fix or work around. We just altered the switch off time on the tablet so as to never sleep and not require a background service.

[jejmule]

Thank you for comment didi you use the wakelock option in the buildozer.spec file to keep the app alive?

# (bool) Indicate whether the screen should stay on
# Don't forget to add the WAKE_LOCK permission if you set this to True
#android.wakelock = False

I look into the code and the issue is coming from the BLE class defined in BLE.java.
on line 19 : import org.kivy.android.PythonActivity;
then in the constructor on line 40 the context is obtain from it
mContext = (Context) PythonActivity.mActivity;

able crashes on line 43 when calling mContext.getPackageManager()
Since the context is obtain from the PythonActivity and not the PythonService as a consequence the context is a null object and we obtain the following error :
jnius.jnius.JavaException: JVM exception occurred: Attempt to invoke virtual method 'android.content.pm.PackageManager android.content.Context.getPackageManager()' on a null object reference

I will try to modify the BLE.java to work from service and not activity to check if my guess is correct....

[b3b]

The ability to be used from a service context is added in 1.0.8.
Also, require_bluetooth_enabled and require_runtime_permissions decorators
are added to prepare adapter and permissions before service is started.

Usage example: https://herethere.me/able/examples.html#android-services

Future work should be done to add scan filters #25.
Without filters, scan stops when a device screen goes off.