Mixing Native with Java

[MarcD]

Hello all, I'm pretty new to Android development and would like to know if the following is even possible :

We have a project in-house entirely written in Java (using Java UI and such). What we are trying to achieve is to make the program's entry point a NativeActivity now to get a tight OpenGL rendering loop for our in-house rendering engine written in C++. Because a lot of work has been done in java, I'd like to know if it's possible to start Java Fragments from the NativeActivity.

Example : 

1) Application starts, only NativeActivity written in C++/OpenGL is visible.

2) User hits 'Favorites"

3) NativeActivity starts a Java-based Fragment that displays the user's favorites in a Java UI, which would not cover the whole screen so that what's behind (the OpenGL rendering) is still visible.

I'm currently building the whole C++ engine successfully using a CMakeLists.txt file.

If you have any insights, please let me know!

Thank.