Jad Mouchy (jadware.com) presented at www.androiddevla.com on creating a free and paid version of an app using Android Libraries.

1. Android:Library Projects Make free and paid versions with a single codebase

2. Objective What are shared libraries? When are they needed? What goes inside?

3. What is a shared library? Logical container for shared assets To create multiple app versions Hidden inside the final product Typically linked statically

4. Why compartmentalize code? Follows DRY / DIE principles Promotes better architecture Easy for collaborative environments

5. Creating a library project Just like creating a normal project

6. Create a regular project

7. Make it a library project Package Explorer, Properties "Android" properties group, Library Set checkbox for "is Library" Click Apply/OK You can also convert an existing application project into a library.

8. Add code and resources

9. Create the manifest file Must declare all shared components Same syntax as normal project

10. Using the library The library exists, now what?

11. Reference the library Package Explorer, Properties Select "Android,” Library Click Add to open Project Selection dialog Select from available library projects

12. Library ordering Can reference multiple libraries Must set relative priority To set, use Upand Down buttons

13. Declare imports in manifest Must declare all components that are imported Just like library’s manifest file <activity>, <service>, <receiver>, <provider>, <permission>, <uses-library>, etc. Use fully-qualified package names, like com.example.app.MainActivity instead of .MainActivity

14. Structuring the FREE/PAID app One way to do the popular freemium format

15. Make three projects Common (Library) Almost everything goes here Paid All functionality like a regular app DRM, if applicable Free Special manifest permissions for ads AdMob conditional inclusions Different layouts as needed Alternate settings

16. What to put where Shared Library Backgrounds and other shared resources Layouts for common screens Shared activities Helper functions 3rd-party libraries Settings Activity App Projects Title images depicting version Unique string resources Ads (if applicable) Settings XML

17. What to put where Shared Library “strings.xml” App Projects “strings.xml” Library’s resources will be replaced by those in app project => easy version testing

18. Duplicates are replaced Works like OOP overloading Acts on activities and resources Project priority matters! Current project gets highest priority (expected behavior)

19. Final STEPS Projects exist and are linked, testing and polish remain

20. Next steps Create unit tests Watch your dependencies Don’t make more libraries than necessary Usually you only need one

21. Next steps Consider DRM for the paid version Built into Google’s Android Market Supported by Amazon Appstore

22. Testing Method one: a distinct test project Set up a test project Test project instruments an application project that depends on the library Add tests to the project for library-specific features Method two: integrated testing Set up a standard project that depends on the library Put instrumentation into that project Self-contained project will contain both tests/instrumentations and the code to test

23. Final thoughts Libraries are not code packages; they contain code packages Overall goal is to reduce redundancies Not everything will go into a library

24. Working example: KeenDriver Locate alt. fuel stations CNG, LPG, HY, ELEC, LNG, E85, etc. Filter by fuel type and public/private 15,000 stations around USA, AU, DE

25. Working example: KeenDriver Free version has ads No ad on map, tricky placement Paid version has richer layout Paid version has more settings Paid version: less than 50 LOC

26. External links “Adventures with Android Library Projects” http://androidblogger.blogspot.com/2010/09/android-library-projects.html “Managing Projects from Eclipse with ADT” http://developer.android.com/guide/developing/projects/projects-eclipse.html “Testing from Eclipse with ADT” (O.T.) http://developer.android.com/guide/developing/testing/testing_eclipse.html

27. Questions? Jad Meouchy jad.meouchy@gmail.com