1. www.greenITcenter.org DUE 0903239 Hello World on the Android Platform

2. www.greenITcenter.org Getting the Tools Setup Need to Install…  Eclipse (the IDE)  Android SDK  Java JDK (not just the JRE) Quick Start Guide is Here: http://developer.android.com/sdk/index.html 2

3. www.greenITcenter.org Integration 3 Then you need to integrate Eclipse and The Android Developer Toolkit http://developer.android.com/sdk/eclipse- adt.html

4. www.greenITcenter.org Android SDK Versions You then need to download SDK versions of Android to run your program against The Android SDK Manager in Eclipse will do this You don’t need the latest version – it’s slow API 7 (Android 2.1) is good & compatible with most devices

5. www.greenITcenter.org The AVD An Android Virtual Device (a simulator) needs to be created. You will specify this in Eclipse  Includes the features that this virtual phone will have, such as touch screen, etc.

6. www.greenITcenter.org The Tutorial 6 http://developer.android.com/resources/tutorial s/hello-world.html

7. www.greenITcenter.org The Result 7 Android Virtual Device can be a little quirky and take time to load

8. www.greenITcenter.org DUE 0903239 Android Application Fundamentals

9. www.greenITcenter.org Getting the Tools Setup Assuming you have Eclipse And the SDK setup 9

10. www.greenITcenter.org Android Online Tutorial http://developer.android.com/guide/topics/fun damentals.html http://developer.android.com/guide/topics/fun damentals.html 10

11. www.greenITcenter.org App Fundamentals Apps are stored in an.apk file Components in a Program  Activities – most important part  Services  Broadcast Receivers  Content Providers  Intents – a message that is sent  Widgets  Notifications 11

12. www.greenITcenter.org Activities A GUI element An activity can contain views such as buttons or check boxes One Activity is designated (in the Manifest) as where to “start” the application These are the “forms” of the application – the presentation layer

13. www.greenITcenter.org Services Not part of the GUI A background process  Playing audio  Network communication  Can be spawned in another thread

14. www.greenITcenter.org Broadcast Receivers A “listener” that receives announcements  From the system – battery is low  Broadcast Receivers could notify the user of something, for example A broadcast receiver receives an “Intent” – a message, and respond to create an event- driven application

15. www.greenITcenter.org Content Providers A method of interprocess communication to make data from your app available to other apps Or, vice-versa Implemented through a ContentProvider and a ContentResolver (to get the data). Example: The Contacts list in the phone – your application could access this.

16. www.greenITcenter.org Intents The actual message that is sent  An Intent to a Broadcast Receiver might announce that a picture has been taken  You can send an Intent to another application as well.  Intents are commonly used to launch a second Activity (screen)

17. www.greenITcenter.org Widgets Visual components that can be added to the user’s home screen Special broadcast receivers

18. www.greenITcenter.org Notifications Signal a user without interrupting the current activity. Example – text message comes in. We can trigger those notifications programmatically

19. www.greenITcenter.org The Result Think about apps as a collection of these independent pieces, passing messages to one another.

20. www.greenITcenter.org DUE 0903239 Application and Activity Classes

21. www.greenITcenter.org The Application Class Your app will extend the Application class Your application object is a singleton (only one object may be instantiated) 21

22. www.greenITcenter.org Application Class public class MyApplication extends Application{ private static MyApplication singleton; @Override public final void onCreate() { super.onCreate(); // call the parent singleton = this; // any other of my code } @Override public final void onTerminate() { super.onTerminate(); // call the parent // now my code }

23. www.greenITcenter.org MyApplication class I can override…  onCreate( )  onTerminate( ) – no guarantee this gets called  onLowMemory( )  onConfigurationChanged( ) Need to call the superclass methods in each of your overridden methods Sometimes the system kills your app w/ no notice

24. www.greenITcenter.org Android Activity The basis for the application The program will start running here, and we can add user interface elements (such as Views) to the Activity This is done in xml files in the ‘res’ folder

25. www.greenITcenter.org Android Activities import android.app.Activity; import android.os.Bundle; public class MyActivity extends Activity{ // override the base class onCreate() }

26. www.greenITcenter.org Activities -> Views We need to add a view to our activity to create a GUI

27. www.greenITcenter.org Resources The /res folder contains xml files We can specify in xml  GUI elements (using xml is preferred to using code)  String constants to be used in the program  Other resources the program needs, such as sounds or images

28. www.greenITcenter.org DroidDraw DroidDraw can help with the screen layouts http://www.droiddraw.org/

29. www.greenITcenter.org Styles and Themes You can also create a style for all of the Activities in your app Similar to css for web pages http://developer.android.com/guide/topics/ui/t hemes.html http://developer.android.com/guide/topics/ui/t hemes.html