The document discusses various architectural concepts for Android applications including: 1) Android provides activities, services, and applications as basic life-cycle components but lacks guidance on how to use them together. 2) Communicating between components can be done through remote procedure calls, singletons, handlers, or service binding. 3) The speaker demonstrates a framework for managing application state and communication between components using message queues, services, and bindings. Sample code is provided on GitHub.

1. Architecture your Android Application Mark Brady

2. Structure 20 Minutes talk

3. 10 Minutes of Q&A

4. Source Code: http://github.com/zedray/Android-Framework-Prototype/

5. Market App Framework Prototype [BETA]

6. About Me Mark Brady

7. Android developer at Vodafone

8. Background in web design, back-end development and Java ME

9. Android Blog: http://blog.zedray.com/category/android/ “ Quick Dial / Call Log Widget”

10. Overview Component life-cycles Activity, Service, Application... Communicating between components RPC, Handlers, Binding... Managing different life-cycles Framework , Example code...

11. Component life-cycles Android provides various life-cycle components.

12. Lack of guidance on how to use them. Service Application Activity

13. Activity #1 Chain of Activities = 1x Task 1 2 3 4 Home Screen

14. Activity #2 Activities are destroyed, but persisted as Bundles 3 4 Bundle Bundle

15. Activity #3 Use the Bundle to reinstate an Activity on the Tasks back-stack. Bundle Bundle 2 3 4

16. Activity #4 On Screen onResume() - onPause()

17. Running onStart() - onStop()

18. Finishing onStop() and onDestroy() may not be called if a process is killed (i.e. due to low memory)

19. Activity #5 Do your “stop work” in onPause() Release those resources.

20. Do long running work in AsyncTask Separate non-UI thread will avoid ANR error.

21. Activity #6 Difficult to maintain execution state in an application made up of multiple activities.

22. Code from multiple activities can be running in the background. No good definition for when an application has finished .

23. Service #1 Execute in the background, regardless of which Activity is on screen. Time 1 2 3 4 3

24. Service #2 Pause or block threads to reduce power consumption (e.g. block on long poll networking). Long running services invite “Service Killer” applications. Time

25. Service #3 Trigger execution from UI, Broadcast Receivers and Alarms. Time UI Broadcast Receiver

26. Service #4 Consider using Notifications to show the user that work is being done in the background. Think about “User Goals” during your design.

27. Application Longest running component, used for maintaining global state. Old execution model, i.e. not very Android . Application 1 2 3 4 3

28. Sleep and low memory 1 2 3 2

29. Communicating between components Remote procedure calls (i.e. AIDL)

30. Singletons

31. Handlers

32. Service binding

33. Remote procedure calls (i.e. AIDL) Do not use, as by default all your components run in the same process.

34. If you think your application is an exception: “Drag me to Hell - Optimizations for AIDL” Ronan Schwarz, Tic Mobile, 5.30pm. (Android Interface Definition Language)