Android History, development, guidelines and best practices.

1. Parinda Rajapaksha

2. What is Android?
➔ Open source, Linux based OS
➔ Developed by Open Handset Alliance
➔ Since 2008
➔ Android market
○ Entertainment, communication, Social Media etc..

3. Android Versions

4. Why Android?
➔ Open source code
➔ Low barrier of entry
○ Can be developed in any platform
○ Only one time payment of $25
➔ Google Play store
➔ Businesses are investing for app development

5. Architecture

6. Building Blocks
➔ Activities
○ Single screen
○ Handle user interactions
➔ Services
○ Background processes
○ Local or remote

7. ➔ Broadcast Receivers
○ Communication between OS and app

8. ➔ Content Providers
○ Handle data
➔ Additional Components
○ Fragments, Views, Layouts, Intents, Resources,
Manifest

9. Activity Lifecycle

10. How Apps are built and run
1. Java compilation
Java byte codes

11. 2. Convert to Dalvik bytecodes
Dalvik byte codes

12. 3. Packaging
○ Using Android Asset Packaging Tool

13. 4. Signing

14. 5. Deployment
○ Using Android Debug Bridge

15. Dalvik vs ART
➔ Convert DEX bytecodes to machine code
➔ Dalvik - Just in time (JIT)
○ App opening slow
➔ ART - Ahead of time (AOT)
○ One time process
○ Fast app opening, Slow Installation
○ Takes more storage

16. Tools
➔ JDK
➔ IDE
○ Android Studio
○ Eclipse
➔ SDK
➔ AVD
➔ Build Tool (Gradle)

17. Project Structure
➔ Manifest.xml
➔ Java classes
➔ Resources
○ Layouts
○ Drawables
○ Assets
○ Animations
○ Menu
○ Colors, Strings, Styles

18. Let’s get our hands
dirty!!

19. SPEED
SplashActivity MainActivity PlayActivity PlayActivity

20. Android Design
Guidelines

21. Which languages should I use?
➔ Java
- Official language
➔ Kotlin
- Reduced boilerplate codes
➔ C / C++
- Use of Java NDK
- Game developments

22. ➔ C#
- Beginner friendly for C or C++
- Supports Unity and Xamarin
➔ Corona
- Cross platform language
➔ Phone Gap
- Powered by Apache cordova
- WebView packaged like an app
➔ XML for layout designing

23. Application concerns
1. Which platform are you targeting?
- Mobile
- Tab
- Android TV
- Wear
- Android Auto

24. 2. Know your audience
- Min SDK version?
Global Android version distribution as of August 2017

25. 3. Choose your building blocks wisely
- Basic UI components
- Android support libraries
- Using 3rd party libraries from Jcenter
○ Reputation
○ Efficiency
○ Reusability
○ Eg: GSON, Retrofit, Universal Image Loader

26. 4. Choosing a database
- Speed and ease of use
- SQLite
○ Built-in database
- Core data, ORM Lite, Realm
- Realm
○ NoSQL
○ Cross Platform support
○ Json support
○ Encryption support
○ Limitations?

27. Security concerns
➔ Requesting permissions
➔ How to avoid application being reverse engineered
- Proguard
- Keep valuable info in a server
○ API keys
○ Secret keys & tokens
○ Payment info

28. Usability concerns
➔ Application speed
- Don’t keep the users waiting
➔ Resource consumption
- Memory
- Power
- Data
➔ APK size

29. ➔ Handle app crashes
- ANR dialogs
➔ Test Test Test
- Various devices and OS versions
- Manual testing
- Automated
○ Firebase Test Lab
○ Espresso
○ Robotium

30. Prepare for release
➔ Review the app Manifest.xml
- Application
- uses-permission
➔ Review the build configuration
- versionCode & versionName
- minSdkVerision & targetSdkVersion
➔ Signing the app
- Manual or Google App Signing

31. ➔ Building a release APK
➔ Run Google Play Alpha Beta testing
- Eg: for In-app purchasing
➔ Publishing on Google Play
- Read user reviews
- Bug fixes
- New updates

32. 7 Design Principles to remember...
1. Pictures are faster than words
2. If it looks the same, it should act the same
3. Decide for me but let me have the final say
4. Keep it brief
5. Make important things fast
6. Get to know me
7. Only interrupt me if it's important

33. Android Development
Course Outline

34. 1. Understanding main building blocks
- Activities
- Activity life cycle
- Intents
- Contents
- Service providers
- Broadcast receivers

35. 2. Understanding the Android project structure
- Manifest.xml
- Java classes
- Resources
○ Layouts
○ Drawables
○ Assets
○ Animations
○ Menu
○ Colors
○ Strings
○ Styles

36. 3. Application fundamentals
- Creating Activities and Fragments to process user inputs
- Communicating with intents
- Working with Threads
○ RunOnUiThreads
○ Handlers and Runnables
○ AsyncTasks

37. - Handling Notifications
○ Using Broadcast Receivers and Services
- Understanding parameters of UI components
○ Layout hierarchy
○ Positioning
○ Handling multiple screen resolutions
- Language localizations

38. 4. User interface designing
- Basic UI components
○ TextView, Button, Spinner etc...
- ListViews and Adapters
- Time and Date components
- Image and media components
- Alert dialogs, popups and toasts

39. - Advanced UI features
○ Navigation drawer
○ Action bar
○ Tab views, Toolbars and pages
○ Card views and Recycle views
○ Floating action button
- Applying themes and animations
- Material Design

40. 5. Persisting application data
- Saving and Loading User Preferences
- Using SQLite database or
- 3rd party databases
○ Realm
○ Core Data
○ ORM Lite

41. 6. Network communication
- Consuming Web Services Using HTTP
- Consuming JSON Services

42. 7. Working with device specific features
- Using Maps, GPS and location based services
- Access to Bluetooth and Wifi
- Working with sensors
- Handling gestures
- Accessing Phone services (SMS, Call, MMS)
- Using network connectivity services (Cell networks, Wifi)
- Accessing Camera, Alarm and speakers

43. 8. Publishing Android Application
- Preparing for release
- App signing
- Publishing to Google Play

44. Thank You!