TheEdge 2010: The Android platform has matured rapidly during the last two years. We're going to bring you up to speed in the latest cutting edge Android development techniques including: New UI Patterns, supporting multiple screen resolutions, REST clients, Push applications and optimizing your applications.

1. Advanced Android Techniques By: GiladGaron

2. This presentation is based onTheEdge 2010 Android Application: Download it from the Market Download the source code: http://code.google.com/p/theedge2010/for all the examples in this presentation Before we begin! TheEdge 2010 Android App

3. UI Design Patterns I/O Access Optimizations Agenda

4. UI Design Patterns

5. Activity Layouts Intent A little reminder about: UI Design Patterns

6. Dashboard Action Bar Search Bar Quick Actions Flingable List Item “Applications are ahead of the framework” UI Design Patterns

7. Dashboard You know what they say about First Impressions... UI Design Patterns Dashboard

8. Introduce your application Reveal its functionality Update the user Just a layout, nothing fancy Dashboard UI Design Patterns

9. Dashboard Components UI Design Patterns Action Bar Updates Panel Functionality Panel

10. Implementation UI Design Patterns <?xmlversion="1.0"encoding="utf-8"?> <LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" android:background="@color/background"> <LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android" android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="45dip" android:background="@color/action_bar_background"> <!-- Action Bar Code --> </LinearLayout> <LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android" android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="1"> <!-- Functionality Panel --> </LinearLayout> <LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/now_playing" android:layout_width="fill_parent" android:layout_height="90dip" android:orientation="horizontal"> <!-- Update Panel --> </LinearLayout> </LinearLayout>

11. Action Bar UI Design Patterns Action Bar

12. Improved Title Bar Persistent across the application Includes common actions Navigation Control Action Bar UI Design Patterns

13. Implementation UI Design Patterns <LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android" android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="45dip" android:background="@color/action_bar_background"> <ImageButtonstyle="@style/action_bar_button" android:src="@drawable/home_btn_default" android:onClick="onHomeClick"/> <ImageViewstyle="@style/action_bar_separator"/> <TextViewstyle="@style/action_bar_text" android:text="Sessions"/> <ImageViewstyle="@style/action_bar_separator"/> <ImageButtonandroid:id="@+id/search_button" style="@style/action_bar_button" android:src="@drawable/search_button" android:onClick="onSearchClick"/> </LinearLayout>

14. Search Bar UI Design Patterns Search Bar

15. Implement search in your app Persistent across the application Can be used with the Action Bar Multiple search modes A clearer way to filter results Search Bar UI Design Patterns

16. Declare your application as searchable Declare an activity that handles the search Handle the search itself Implementation UI Design Patterns

17. Declare in /res/xml/searchable.xml Searchable Configuration UI Design Patterns <?xmlversion="1.0"encoding="utf-8"?> <searchablexmlns:android="http://schemas.android.com/apk/res/android" android:label="@string/app_name" android:hint="Hint" > </searchable>

18. Searchable Activity Declare as Searchable in the AndroidManifest.xml: UI Design Patterns <manifestxmlns:android="http://schemas.android.com/apk/res/android" package="com.alphacsp.theedge" android:versionCode="4" android:versionName="1.03" android:installLocation="preferExternal"> <applicationandroid:label="TheEdge 2010"android:icon="@drawable/ic_launcher"> <activityandroid:name=".ui.activities.SearchActivity"android:label="Search"android:theme="@style/Theme.TheEdge"> <intent-filter> <actionandroid:name="android.intent.action.SEARCH"/> </intent-filter> <meta-dataandroid:name="android.app.searchable"android:resource="@xml/searchable"/> </activity> <activityandroid:name=".ui.activities.AboutActivity"android:label="About“ android:theme="@style/Theme.TheEdge"/> <meta-dataandroid:name="android.app.default_searchable"android:value=".ui.activities.SearchActivity"/> </manifest>

19. Searchable Activity Handle the Query: UI Design Patterns publicclassSearchActivityextendsTabActivity { @Override publicvoidonCreate(BundlesavedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.search_activity); Intentintent = getIntent(); String query = intent.getStringExtra(SearchManager.QUERY); finalTabHost host = getTabHost(); IntentspeakersIntent = new Intent(SearchActivity.this, SpeakersActivity.class); speakersIntent.putExtra(SearchManager.QUERY, query); host.addTab(host.newTabSpec("Speakers").setIndicator(buildIndicator("Speakers")).setContent(speakersIntent)); IntentsessionsIntent = new Intent(SearchActivity.this, SessionsActivity.class); sessionsIntent.putExtra(SearchManager.QUERY, query); host.addTab(host.newTabSpec("Sessions").setIndicator(buildIndicator("Sessions")).setContent(sessionsIntent)); }

20. Quick Actions Quick context menu UI Design Patterns

21. Contextual actions driven popup menu Natural flow to the screen context Simple and effective Wow effect Quick Actions UI Design Patterns

22. Not in the SDK Custom Views Implementation taken from: Lorenz’s Bloghttp://www.londatiga.net/it/how-to-create-quickaction-dialog-in-android/ Implementation UI Design Patterns

23. Flingable List Item Flingable context menu UI Design Patterns

24. Contextual actions driven flinged menu Natural flow to the screen context Wow effect Flingable List Item UI Design Patterns

25. Major players: ViewFlipper Layout GestureDetector ListAdaptor ListActivity Implementation UI Design Patterns

26. Vertical scrollable view that allows multiple rows views (List Item) Uses ListAdapter to populate each List Item Recycles Views (So don’t cache them!) Supports different view types A few words about ListView UI Design Patterns

27. ListView should not hold N Views. Use ConvertView in getView method: ListView Recycler UI Design Patterns @Override publicViewgetView(int position, ViewconvertView, ViewGroup parent) { if (convertView == null) { convertView = inflater.inflate(R.layout.speakers_list, parent, false); } //Get your components from the view finalTextViewspeakerName = (TextView) convertView.findViewById(R.id.speaker_name); //Get your item Speakerspeaker = getItem(position); returnconvertView; }

28. ListView Recycler in action UI Design Patterns

29. ViewFlipper UI Design Patterns Allows transition between layouts Supports animations <ViewFlipperxmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/flipper" android:layout_width="fill_parent" android:layout_height="fill_parent"> <includeandroid:id="@+id/first"layout="@layout/sessions_list"/> <includeandroid:id="@+id/second"layout="@layout/sessions_list_flinged"/> </ViewFlipper>

30. GestureDetector UI Design Patterns Detects various gestures and events using the supplied MotionEvents GestureDetectorgestureDetector= newGestureDetector(newGestureDetector.SimpleOnGestureListener() { @Override publicbooleanonFling(MotionEvent e1, MotionEvent e2, floatvelocityX, floatvelocityY) { } @Override publicbooleanonDown(MotionEvent e) { } @Override publicbooleanonSingleTapUp(MotionEvent e) { } });

31. Implementation UI Design Patterns Read the Source Code…

32. I/O Access

33. File System Database Network Types of I/O: I/O Access

34. Reading is fast Writing is slow Disk space affects performance Make sure you support External Storage (Both in installation and in caches/data) Flash I/O I/O Access

35. Virtual Table that allows Full Text Search Produces results significantly faster than LIKE Comprehensive syntax SQLite FTS I/O Access

36. Creating FTS table Similar to creating a regular table: I/O Access publicclassDatabaseHelperextendsSQLiteOpenHelper { privatestaticfinalStringDATABASE_NAME = "TheEdge"; publicstaticfinalStringSPEAKERS_TABLE = "speakers"; @Language("SQLite") privatestaticfinalStringCREATE_SPEAKERS_TABLE = "CREATE VIRTUAL TABLE " + SPEAKERS_TABLE + " USING fts3 (speaker_name TEXT , bio TEXT, company TEXT, image_uri TEXT)"; publicDatabaseHelper(Contextcontext, String name, SQLiteDatabase.CursorFactory factory, int version) { super(context, name, factory, version); } @Override publicvoidonCreate(SQLiteDatabasesqLiteDatabase) { Log.i(this.getClass().getSimpleName(), "Creating DB"); sqLiteDatabase.execSQL(CREATE_SPEAKERS_TABLE); }

37. Using: Use the MATCH keyword: I/O Access publicList<Session> searchSessions(String query) { finalList<Session> sessionList = newArrayList<Session>(); finalSQLiteDatabasereadableDatabase = getReadableDatabase(); finalCursorcursor = readableDatabase.rawQuery("select * from " + SESSIONS_TABLE + " where " + SESSIONS_TABLE + " match '" + query + "'", null); if (cursor.moveToFirst()) { do { finalSessionsession = newSession(); session.setTopic(cursor.getString(cursor.getColumnIndex("topic"))); session.setPresenter(cursor.getString(cursor.getColumnIndex("presenter"))); session.setSessionAbstract(cursor.getString(cursor.getColumnIndex("abstract"))); sessionList.add(session); } while (cursor.moveToNext()); } if (!cursor.isClosed()) { cursor.close(); } returnsessionList; }

38. Use a Service Use Apache HTTPClient not URLConnection Don’t do it on the UI thread Parsing can be costly, design your data structure carefully Network I/O Access

39. When using network, remember the following: Availability:Always check connectivity with ConnectivityManager. Performance:Don’t run on the UI Thread, use AsyncTask or Service. Bandwidth:Use as little as you can. Battery drain:Only use the network when you have to. I/O Access

40. I/O Access Activity with separate thread for Network

41. Optimization

42. Allows you to execute a task without having to manage thread pools. Defined by three generic types: Parameters, Progress and Result. Has a lifecycle: onPreExecute – Called before running the task. doInBackground – Actual work onProgressUpdate – Callback to update the UI on task progress onPostExecute – Called after task has ended, receives the response object Very smart and easy. AsyncTask Optimization

43. In order to implment lazy loading, we’ll need to do the following: Load the ListView an you would normally do. Create a task to fetch the data, use AsyncTask or a Service. Change the data on the UI thread. Use notifyDataSetChanged() to let ListView to update itself. Lazy Loading your ListView Optimization

44. Example Optimization publicclassSpeakersActivityextendsListActivityimplementsServiceListener { privatevoidfetchImages() { for (Speakerspeaker : speakers) { SpeakerImageFetcherspeakerImageFetcher = newSpeakerImageFetcher(); speakerImageFetcher.execute(speaker); } } privateclassSpeakerImageFetcherextendsAsyncTask<Speaker, Void, Void> { @Override protectedVoiddoInBackground(Speaker... speakers) { finalSpeakerspeaker = speakers[0]; finalBitmapbitmap = dataAccessor.fetchImage(speaker.getImageUrl()); speaker.setSpeakerImage(bitmap); returnnull; } @Override protectedvoidonPostExecute(VoidaVoid) { speakersAdapter.notifyDataSetChanged(); } } }

45. Runs in the background Is not killed when the application ends Running a service is easy Getting callbacks is a bit awkward Declare it in your AndroidManifest.xml Services Optimization

46. Services oriented application: Optimization SQLite HttpClient Data Accessor Service Service Helper Activity

47. Service Example: Optimization publicclassNetworkServiceextendsIntentService { @Override protectedvoidonHandleIntent(Intent intent) { finalDataAccessordataAccessor = DataAccessor.getSingleton(this); finalResultReceiver receiver = intent.getParcelableExtra(STATUS_LISTENER); finalintrequestAction = intent.getIntExtra(REFRESH_ACTION, -1); boolean result = false; if (requestAction == REFRESH_SPEAKERS) { result = dataAccessor.syncAllSpeakers(); } elseif (requestAction == REFRESH_SESSIONS) { result = dataAccessor.syncAllSessions(); } elseif (requestAction == REFRESH_SCHEDULE) { result = dataAccessor.syncAllEvents(); } elseif (requestAction == REFRESH_ALL) { dataAccessor.syncAllSpeakers(); dataAccessor.syncAllSessions(); dataAccessor.syncAllEvents(); } if (result) { receiver.send(STATUS_REFRESHED, Bundle.EMPTY); } receiver.send(STATUS_NOT_REFRESHED, Bundle.EMPTY); } }

48. ResultReceiver: Implements Parcelable, so can be passed in the Intent object Good for “Here and now” results per intent Getting a Callback from a Service: Optimization

49. ResultReceiver Example Accepts the Activity as the Listener using a custom interface Optimization publicclassNetworkServiceHelperextendsResultReceiver { privatefinalServiceListenerlistener; publicNetworkServiceHelper(ServiceListener listener) { super(new Handler()); this.listener = listener; } @Override protectedvoidonReceiveResult(intresultCode, BundleresultData) { if (listener != null) { listener.onReceiveResult(resultCode, resultData); } } }

50. Optimization Using the service: publicclassScheduleActivityextendsActivityimplementsServiceListener { privateNetworkServiceHelpernetworkServiceHelper; @Override publicvoidonCreate(BundlesavedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.schedule_activity); dataAccessor = DataAccessor.getSingleton(this); initCalendar(); networkServiceHelper = newNetworkServiceHelper(this); finalIntentserviceIntent = new Intent(Intent.ACTION_SYNC, null, this, NetworkService.class); serviceIntent.putExtra(NetworkService.STATUS_LISTENER, networkServiceHelper); serviceIntent.putExtra(NetworkService.REFRESH_ACTION, NetworkService.REFRESH_SCHEDULE); startService(serviceIntent); } @Override publicvoidonReceiveResult(intresultCode, BundleresultData) { if (resultCode == NetworkService.STATUS_REFRESHED) { calendarLayout.removeAllViews(); initCalendar(); } } }

51. Reference

52. Reference http://developer.android.com/guide/index.html http://www.londatiga.net/it/how-to-create-quickaction-dialog-in-android/ http://code.google.com/p/theedge2010/ http://android-developers.blogspot.com/?hl=en http://www.google.com/events/io/2010/sessions.html#Android http://www.sqlite.org/fts3.html http://www.sqlite.org/cvstrac/wiki/wiki?p=FtsUsage

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