Android: how to use local libraries

[KroMignon]

Hi all,

maybe a seely question, but I want to know if it is possible to use a locally available C++ library with Qt for Android?

I've got some huge libraries which are stored somewhere in the internal storage of my Android device (/sdcard/myLibs/).
I don't want to add those libraries in the APK, is it possible to define a kind of "extra libraries path"?

Thanks for any suggestion

Fabrice

[jsulm]

@KroMignon said in Android: how to use local libraries:

I don't want to add those libraries in the APK

Why not? If your app is linked against these libs your APK will not work without them.
Or do you load these libs dynamically at runtime?

[KroMignon]

@jsulm said in Android: how to use local libraries:

Why not?

Because I want to reduce APK size. Do I need to have all libs I use in the APK, is there no way to have "shared libraries" between APKs?

[jsulm]

@KroMignon The problem I see: APK will not work without these libs, so how are you going to distribute your apps? I'm not an expert but I'm quite sure this is not supported by Android because of security: apps can only execute what is part of APK and nothing else (sandbox).

[KroMignon]

@jsulm It is a fully custom application, for customize hardware. It not has to be distributed to "the world" or to any app store. My goal is to be able to reduce APK size for on-line updates

[jsulm]

@KroMignon OK, understand.
I'm not sure this is possible with not rooted devices because of sandboxing, but I'm not expert.

[Tom_H]

@KroMignon You should be able to do it the same way that Ministro does it. The libraries have to be in a readable location. I think Ministro puts the Qt libraries in /data/local/tmp/qt, but anywhere under /data should work. Then you would have to dynamically load them. I don't think /sdcard/myLibs would work.

[SGaist]

@Tom_H said in Android: how to use local libraries:

@KroMignon You should be able to do it the same way that Ministro does it. The libraries have to be in a readable location. I think Ministro puts the Qt libraries in /data/local/tmp/qt, but anywhere under /data should work. Then you would have to dynamically load them. I don't think /sdcard/myLibs would work.

The problem is that recent version of Android disabled the access to such shared folder so it can't be used anymore.

[KroMignon]

@Tom_H @SGaist , thanks a lot for your suggestions.
In fact, the hardware I am targeting is rooted. I could copy Qt files anywhere but I don't really know what is the right way to do it.
It is based on Android 7.0 (Nougat).

Perhaps is using/customizing Ministro the best way?

[jsulm]

@kromignon Since Android is based on Linux you could put the libs in /usr/lib and see whether it works.