[Mobile-sig] support of the android platform

[Gabriel Pettier]

On Thu, Apr 28, 2016 at 11:09:52AM +0200, Xavier de Gaye wrote:
>On 04/28/2016 03:01 AM, Russell Keith-Magee wrote:
>> (Apologies for the personal repost - I forgot to reply-all on the first attempt)
>>
>> Hi Xavier,
>>
>> Great stuff!
>>
>> I’ve got a question about your experience integrating with the native Android platform APIs.
>>
>> Getting CPython compiled as a native binary library is a huge step, but my experience has been that bridging between binary libraries and the Java/Dalvik APIs is a painful process - JNI *exists*, but
>> it’s *really* slow, and has some pretty harsh limitations (like the kernel-imposed JNI reference count limit).
>>
>> For some applications, this won’t matter - for example, if you’re treating the android device as a low power server, something that is terminal only isn’t a problem. However, if you want to write a
>> native app, then you need to be able to create an Activity, with a View, put a Button on it, and a Layout, and so on. Have you done any exploration of the binding to these native APIs?
>
>
>A first-class citizen java application embeds python using JNI. The embedded
>python accesses the android API by importing and invoking methods of an
>android.py module.  The android.py module maps those API requests to json RPC
>calls that are sent to another java application so that they may be processed
>and their results returned.  This is the design of Scripting Layer for Android
>(SL4A) [1], a languishing project.
>
>IMHO you should define what 'slow' means, slow for a gaming application, for
>tracking the smartphone accelerometer or for a pyephem based application that
>brings the ephemeresis of stars and planets at your finger tip :)
>
>Xavier
>
>[1] https://github.com/damonkohler/sl4a

You may be interested in pyjnius[1], which, if not working around the 
JNI limitations (speed being one, but other JNI limitations for using 
the Android API is the inhability to extend java classes), makes using 
it with python a lot easier, by using Java introspection capabilities, 
it may not be the best answer if speed is the most important criteria, 
but i would advocate for reconsidering using Python on Android if that's 
the case.

[1] https://github.com/kivy/pyjnius