I believe this will solve:
Install the Oracle virtualbox: https://www.virtualbox.org/
Download some android ISO: http://www.android-x86.org/download
Install this iso in virtualbox: https://www.segredosgeek.com/2013/06/tutorial-como-instalar-o-android-no-virtual-box.html
Authorize root: Here you will have to search because it will depend on the version you choose, although it is almost the same in all.
After root, you will download titaniumBackup, after installing click 'Backup/Restore' and choose your application, then connect your mobile phone on PC, and you will get the folder of the Titanium backup, copy it to your PC and you will see that inside it will be your APK.
Change the format to ZIP or RAR and unzip, then use Dex2jar to do the reversal.
Convert this . JAR generated to . ZIP, now you will need to convert . class to . JAVA, for this use the Java Decompiler -> JD-GUI tool.
Now you will have the complete source code, but to group everything, I can’t say if you can with Android Studio, but in netbeans you can install it with the JAVA version, and try to combine the . JAR, but also not sure if it will be complete, not working with android dev, the most I’ll know how to help is this.
even the activitys codes are required ?
– Dev
If you have the project, just copy the codes play in the world and have it saved as PDF. I didn’t quite understand what you asked. ... If what you want is to document the code, then I’ll tell you straight away, there is no magic way to document things, this is a manual process and done by people and teams.
– Guilherme Nascimento