Intro to Android

Hey, Robot!  A casual introduc5on to Android  development in Java  Ron DuPlain  ron.duplain@gmail.com  @rduplain  h@p://go.nrao.edu/android/talk  Android @ Richmond JUG ‐ July 15, 2009 

Discussion Goals  •  provide an Android overview  •  highlight the (free) Android Java SDK  •  introduce Android applica5on fundamentals  •  walk through real examples   * I am not aﬃliated with Google or any part of the Android project.  Android @ Richmond JUG ‐ July 15, 2009 

Android Overview  Android @ Richmond JUG ‐ July 15, 2009 

one‐page  •  “Android is a soYware stack for mobile devices  that includes an opera5ng system, middleware  and key applica5ons.” developer.android.com  •  development led by Google  •  developed by the Open Handset Alliance  •  carried ﬁrst by T‐Mobile (G1)  •  open source (Apache License)  •  supported by hardware vendors  •  ported by hardware enthusiasts  •  applica5ons on an Android device are “equal”  Android @ Richmond JUG ‐ July 15, 2009 

Architecture  h@p://developer.android.com/guide/basics/what‐is‐android.html  Android @ Richmond JUG ‐ July 15, 2009 

Android Devices  •  HTC/T‐Mobile G1  •  HTC Magic  •  “At Least 18 Android Phones Coming This Year”  •  h@p://www.businessweek.com/the_thread/ techbeat/archives/2009/05/ at_least_18_and.html  •  Ported to other devices  •  h@p://groups.google.com/group/android‐por5ng  Android @ Richmond JUG ‐ July 15, 2009 

Android Development  •  Android Java SDK, with Eclipse IDE support  •  Android C/C++ Na5ve Development Kit  –  addon to SDK, support for na5ve code  •  Android Scrip5ng Environment  –  Python, Lua, BeanShell now  –  expect Ruby and JavaScript later  •  PhoneGap (HTML & JavaScript)   Android @ Richmond JUG ‐ July 15, 2009 

Android Developers  •  sign up for $25  •  publish applica5ons to the Android Market  •  Market: free or paid  •  paid apps: 70% to developer, ~30% to carriers  •  developers can purchased unlocked phones  •  alterna5vely, get .apk zip bundles to users  Android @ Richmond JUG ‐ July 15, 2009 

Android Java SDK  Android @ Richmond JUG ‐ July 15, 2009 

SDK Overview  •  full‐featured emulator  •  Android Development Tools (ADT) plugin  for Eclipse IDE  •  suite of tools (mostly command‐line)  –  debugging, packaging, & installing applica5ons   –  querying devices  •  target emulator or device  Android @ Richmond JUG ‐ July 15, 2009 

SDK Overview  •  full‐featured emulator (no device needed)  •  Android Development Tools (ADT) plugin  for Eclipse IDE  •  suite of tools (mostly command‐line)  –  debugging, packaging, & installing applica5ons   –  querying devices  •  target emulator or device  Android @ Richmond JUG ‐ July 15, 2009 

SDK Installa5on  •  h@p://developer.android.com/sdk  •  Windows, Mac, GNU/Linux, x86 plaqorms only  •  grab zip for your plaqorm, unpack  •  add SDK tools to $PATH / %PATH%  •  conﬁgure IDE  –  Eclipse IDE oﬃcially supported  –  Android Development Tools (ADT) plugin  for Eclipse IDE  Android @ Richmond JUG ‐ July 15, 2009 

Not using Eclipse?  •  h@p://developer.android.com/guide/ developing/other‐ide.html  •  walks through tools usage to enable your IDE  to  –  maintain projects  –  integrate with emulator and debugger  Android @ Richmond JUG ‐ July 15, 2009 

Eclipse Integra5on  Android @ Richmond JUG ‐ July 15, 2009 

Emulator  Android @ Richmond JUG ‐ July 15, 2009 

Grab Screenshots  •  emulator or device  Android @ Richmond JUG ‐ July 15, 2009 

Applica5on Fundamentals  Android @ Richmond JUG ‐ July 15, 2009 

Applica5on Components  •  Ac?vity – foreground, with UI  •  Service – background, no UI  •  BroadcastReceiver – for speciﬁed Intents  •  ContentProvider – support func5onality  Android @ Richmond JUG ‐ July 15, 2009 

Ac5vity Lifecycle  Android @ Richmond JUG ‐ July 15, 2009 

Service Lifecycle  Android @ Richmond JUG ‐ July 15, 2009 

Resources, Layout, UI  •  store strings, colors, constants, drawables, etc in  project/res/  •  Android auto‐generates R.java, access resources  •  build UI layouts in Java, or…  •  declare UI elements in XML, manipulate in Java  •  build/assign listeners to UI elements (in Java)  Android @ Richmond JUG ‐ July 15, 2009 

Manifest  •  deﬁne applica5on components, request  permissions in AndroidManifest.xml  •  (examples coming)  Android @ Richmond JUG ‐ July 15, 2009 

Intents  •  call out to an ac5vity, a service, or receivers  •  can call within, or to other applica5ons  •  bundle “extras” – key/value pairs  •  “back stack”  Android @ Richmond JUG ‐ July 15, 2009 

Ammuni5on  •  Intents  •  ContentProviders  •  sqlite3  •  drawables/layouts (borrow from free projects)  Android @ Richmond JUG ‐ July 15, 2009 

Status/No5ﬁca5on Bar  Android @ Richmond JUG ‐ July 15, 2009 

Notable Features  •  can run in background as service  •  intents  •  broadcast intent ‐> applica5on  •  status/no5ﬁca5on bar   Android @ Richmond JUG ‐ July 15, 2009 

Android Examples  from open source applica5ons  Android @ Richmond JUG ‐ July 15, 2009 

Outline of Examples  •  BroadcastReceiver & AndroidManifest.xml  –  SMSPopup’s SMSReceiver  –  h@p://code.google.com/p/android‐smspopup/   •  Service  –  OI Countdown’s AlarmService  –  h@p://code.google.com/p/openintents/  •  Ac5vity, layout, and R.java  –  OI Countdown’s CountdownEditorAc5vity  * I am not aﬃliated with these projects. See websites for authors.  Android @ Richmond JUG ‐ July 15, 2009 

BroadcastReceiver  import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; public class SMSReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { Log.v("SMSReceiver: onReceive()"); intent.setClass(context, SMSReceiverService.class); intent.putExtra("result", getResultCode()); SMSReceiverService.beginStartingService(context, intent); } } Android @ Richmond JUG ‐ July 15, 2009 

AndroidManifest.xml  <receiver android:name=".SMSReceiver"> <intent-filter> <action android:name="android.provider.Telephony.SMS_RECEIVED”/> </intent-filter> <intent-filter> <action android:name="android.provider.Telephony.WAP_PUSH_RECEIVED”/> <data android:mimeType="application/vnd.wap.mms-message" /> </intent-filter> </receiver> Android @ Richmond JUG ‐ July 15, 2009 

Result  Android @ Richmond JUG ‐ July 15, 2009 

Service  public class AlarmService extends Service { private static final String TAG = LogConstants.TAG; private static final boolean debug = LogConstants.debug; Thread mThread; long mEndTime; @Override public void onCreate() { // Start up the thread running the service. Note that we create a // separate thread because the service normally runs in the process's // main thread, which we don't want to block. mThread = new Thread(null, mTask, "AlarmService"); mThread.start(); } ... } Android @ Richmond JUG ‐ July 15, 2009 

Ac5vity, when loaded  Android @ Richmond JUG ‐ July 15, 2009 

Layout  res/layout/countdown_editor.xml: <ScrollView xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" > <LinearLayout android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="wrap_content" > <EditText android:id="@+id/title" android:layout_height="wrap_content" android:layout_width="fill_parent" android:layout_marginTop="10dip" android:layout_marginBottom="10dip" android:hint="@string/hint_title" /> ... </LinearLayout> </ScrollView> Android @ Richmond JUG ‐ July 15, 2009 

Strings  res/values/strings.xml:  <?xml version="1.0" encoding="utf-8"?> <resources> ... <string name="hint_title">e.g. pizza</string> ... </resources> Android @ Richmond JUG ‐ July 15, 2009 

R.java  public final class R { ... public static final class id { ... public static final int countdown=0x7f08000a; ... public static final int title=0x7f080008; ... } ... } •  Just know that it’s auto‐generated.  Android @ Richmond JUG ‐ July 15, 2009 

Ac5vity  public class CountdownEditorActivity extends Activity { ... private TextView mCountdownView; ... protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); ... mCountdownView = (TextView) findViewById(R.id.countdown); ... } ... private void updateCountdown() { ... mCountdownView.setVisibility(View.VISIBLE); mCountdownView.setText("" + CountdownUtils.getDurationString(delta)); mCountdownView.setTextAppearance(this, android.R.style.TextAppearance_Large); mCountdownView.setTextSize(64); ... } ... } Android @ Richmond JUG ‐ July 15, 2009 

Conclusions  Android @ Richmond JUG ‐ July 15, 2009 

Key Takeaways  •  app integra5on through intents  •  apps can run in mul5ple ways:  –  in the foreground, with a UI (Ac?vity)  –  in the background, without a UI (Service)  –  triggered by intent, either direct or broadcast  (Ac?vity or BroadcastReceiver)  •  third‐party apps can replace core apps  (“equal”)  •  .apk zip bundles, for direct install or market  Android @ Richmond JUG ‐ July 15, 2009 

Android Developer Challenge  •  h@p://code.google.com/android/adc/  •  open submission August 1‐31, 2009  •  win up to $250,000 USD  •  winners announced ~November 2009  Android @ Richmond JUG ‐ July 15, 2009 

Get Started  Start here:  •  h@p://developer.android.com/ ‐ overview  •  h@p://source.android.com/ ‐ source code  Look for examples in Android source.  See also:  •  h@p://code.google.com/p/openintents/ ‐ large  collec5on of samples and free applica5ons  •  h@p://code.google.com/p/bites‐android/ ‐ cookbook  •  h@p://code.google.com/p/trolly/ ‐ shopping list  •  h@p://www.swiYp.org/ ‐ FTP server for the device  •  h@p://code.google.com/p/android‐smspopup/ ‐ SMS  •  (Thanks to @ben_caldwell and @callahad for 5ps.)  Android @ Richmond JUG ‐ July 15, 2009 

Intro to Android

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Intro to Android — Presentation Transcript

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