Reading GPS position

[MarcoPolacco]

Hi,

how can I read the current GPS postion from a BeeWare application (in Python, of course)? Any method is ok, either in pure Python or as a reference to Java libraries (if I understand correctly, it is possible with BeeWare?).

Thanks.

[MarcoPolacco]

Of course, I have found examples using android package (import android), but this package seems to be part of Kivy, will it work with BeeWare?

[freakboy3742]

There isn't a cross-platform Python API for this (yet - it is on our radar).

In the meantime, the approach you take is to call the platform native APIs. On Android, this means using Rubicon-java to access the native Java APIs; on iOS, it means using Rubicon-ObjC to access the Objective C APIs.

Unfortunately, I don't have a good HOWTO tutorial to point you at. The docs for Rubicon Java and Rubicon ObjC may be some help (although the ObjC docs are a lot more complete). Other than that, the Android and iOS backends of Toga have lots of examples of complex interactions with the underlying libraries; mining that code for examples is probably your best bet.

Kivy is an entirely different framework, with it's own packaging tools and API wrapper layers; at this time, Kivy's tools aren't compatible with BeeWare.

[MarcoPolacco]

Thank you for a fast response!

Of course, what I have forgotten to state clearly but can be concluded, I am interested in Android only.

The first question is that a permission to use GPS is required in the manifest file, how can I specify this?

Second, I can see that the beeware environment uses/generates some Java classes. Would it be possible to create a Java class with all the required implementation inside and then call the class from Python with rubicon? I can see from examples on the net that the process of reading the position is quite complex (various listeners etc), so my first idea would be to do it all in Java with a simple interface to start/stop locating and return the last available position with time marker. I suspect that some threads may be involved here on the Java side but still should be feasible.

[freakboy3742]

There are two approaches possible here.

The first is along the lines of what you've described: add a Java/Kotlin class with all the logic you need to the project definition that Briefcase generates, and then reference that class from the Python code. If you know Java/Kotlin, this may be a good option. The only real complication here will be that Briefcase won't do much to help you coordinate the "non-Python" parts of the code - you'll need to carefully manage how the non-Python code you write will be merged/managed with the Briefcase generated parts.

The other approach is to write it all in Python. You can use Rubicon to implement any Java interface; so as long as the requirement on the GPS APIs are "implement interface and register with manager class", then you can do it entirely in Python. However, if the GPS APIs involve subclassing an abstract class, this approach won't work; you'll need to do at least a hybrid (implement a proxy Java class that extends the abstract base and defines an interface for the pieces that are abstract; then implement the interface in Python).

[MarcoPolacco]

OK, I have found the manifest file with permissions, with the src directory. So, the first problem is not a problem.