Building AOSP Apps and customizing them

Question

Ok sort of a n00b question but recently I was interested in ROM development for my device, the herolte (Galaxy S7) and wanted to build it off of LineageOS (vanilla Android basically). I already have all the source code and builds working perfectly on my virtual machine and installation is smooth too! Unfortunately, there is this one thing that has been constantly bugging me, customization!

I wanted to customize the Dialer app for example but realized that when I try to open it in Android Studio it doesn't show all the files under the project structure only showing "R", "Manifest", "BuildConfig". No drawables folder or anything (although the source code / directory in my folder shows it). So I am assuming I am missing something but not sure what it is exactly, so any help would be appreciated. I do understand that the apps like Dialer or Contacts come heavily tied into the Android Framework it is using like how the Samsung Dialer is tied down with TouchWiz.

I essentially wanted to modify some parameters of the original apps and then have them built with LineageOS. Any help is appreciated, thank you!

Answer 1

The AOSP is built via a custom build system based on " make ". When you open the AOSP in Android studio you get a nice representation of project sources and some resources but you should always keep in mind that eventually the app's compilation will be made by the 'make' build system with its 'mk' files.

In the case of the 'Dialer' app, you can find a hint to where are the app's resources if you take a look at its Android.mk file. Note that resources are getting imported from:

> res_dirs := res \
>     $(incallui_dir)/res \
>     $(contacts_common_dir)/res \
>     $(contacts_common_dir)/icons/res \
>     $(phone_common_dir)/res

Digging deeper into those definitions will resolute in the following directory: /packages/apps/PhoneCommon/res/