The document provides an overview of the Android infrastructure and key concepts: (1) It describes the layers of an Android application including the presentation layer, application logic layer, and domain layer. (2) It explains important Android concepts such as the Android runtime environment, Dalvik virtual machine, application lifecycle and activities, and use of contexts. (3) It discusses alternatives for common tasks like dependency injection with RoboGuice and Dagger, handling resources and views with ButterKnife and AndroidAnnotations, and accessing data with SQLite and ORMLite. (4) It also briefly covers testing approaches on the DVM and JVM using AndroidTestCase, Robotium, and Robolectric

1. Overview of Android
Infrastructure
Alexey Buzdin

2. @AlexeyBuzdin
alex.buzdin@gmail.com
LArchaon

3. Everyone needs an app....

4. We need an app too!

5. simple CRUD app

7. Requirement:
Support as many android
devices as you can
(including tablets)

8. 4.1–4.2
4.0
2.1
3.0 2.2
2.3
Google data, March 2013

10. Ain't that good for a developer

14. Is there is someone who
could help us?

15. nope

16. Ease our pain

17. maybe

20. Layers
Presentation
Application logic
Domain

21. Presentation
Application logic
Domain

22. But Whers the problem?

23. Missing in Android 2.2
●
ActionBar
●
Support for tablets
●
Decent ListView support for server communication

24. Solution?

25. Compatability libraries
Android Support library
ActionBarSherlock
etc

26. Support Library
http://developer.android.com/tools/extras/support-
library.html
Fragments
Async Stuff
Experimental stuff

27. Fragments

28. Example

29. ActionBar

30. ActionBarSherlock
http://actionbarsherlock.com/

31. Refreshing list

32. Pull to Refresh
https://github.com/chrisbanes/Andro
id-PullToRefresh

33. Presentation
Application logic
Domain

34. Android Runtime
On Android you develop in Java
... but Android does not run Java Bytecode !

35. DalvikVM
Dalvik Virtual Machine
– Custom VM optimized for mobile devices
– Register-based JVM
– More efficient and compact
– Use memory efficiently
– Dalvik Executable Code (.dex)
● 30% fewer instructions
● 35% fewer code units
● 35% more bytes
– Trace JIT compiler (since 2.2)

36. Android Runtime
Android Java = Java language + Dalvik + Apache Harmony
Android Java API = Java SE – AWT/Swing + Android API
Sun-Java = Java language + JVM + JDK
36

37. App lifecycle

38. Activity
public class MyActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}

40. Activity
public class MyActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}

41. Resources

42. Activity
public class MyActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}

43. Context
●
Context of current state of the
application/object

44. Context
●
Context of current state of the
application/object
●
Context is a handle to the system it
provides services like
– resolving resources
– obtaining access to databases and
preferences

45. Important
any resource taken from context will
leave as long as Context does

46. Context problem
public class MyActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
String appName = getString(R.string.appName);
}
}

47. Passing Context
public class MyStringProvider {
Context context;
public MyStringProvider(Context context) {
this.context = context;
}
public String getString(){
return context.getString(R.string.app_name);
}
}

48. Passing Context

49. Context problem
public class MyActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
String appName = getString(R.string.appName);
}
}
Presentation
Application logic
Domain

50. Injection libraries
Dependency Injection
●
RoboGuice
●
Dagger

51. RoboGuice
●
Based on Google Guice
●
Lightweight
●
Multifunctional (has resource injection)

52. RoboGuice
public class MyActivity extends RoboActivity {
@Inject MyStringProvider stringProvider;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
((TextView) findViewById(R.id.textView))
.setText(stringProvider.getString());
}
}

53. RoboGuice
public class MyStringProvider {
Context context;
@Inject
public MyStringProvider(Context context) {
this.context = context;
}
public String getString(){
return context.getString(R.string.app_name);
}
}

54. Notable fact

55. Optimezed context injection
public class MyActivity extends RoboActivity {
int i;
@Inject MyStringProvider stringProvider;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
i = 1;
((TextView) findViewById(R.id.textView))
.setText(stringProvider.getString());
}
}

56. RoboGuice
public class MyStringProvider {
Context context;
@Inject
public MyStringProvider(Context context) {
this.context = context;
}
public String getString(){
return context.getString(R.string.app_name) + ((MyActivity)context).i;
}
}

57. Dagger
public class DaggerActivity extends DaggerBaseActivity {
@Inject DaggerStringProvider stringProvider;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
((TextView) findViewById(R.id.textView))
.setText(stringProvider.getString());
}
}

58. Dagger
public class DaggerBaseActivity extends Activity {
@Inject
Bus bus;
@Override protected void onCreate(Bundle state) {
super.onCreate(state);
DaggerApplication.inject(this);
}
@Override protected void onResume() {
super.onResume();
bus.register(this);
}
@Override protected void onPause() {
super.onPause();
bus.unregister(this);
}
}

59. Dagger
public class DaggerApplication extends Application {
private static ObjectGraph objectGraph;
@Override public void onCreate() {
super.onCreate();
objectGraph = ObjectGraph.create(new DaggerModule(this));
}
public static <T> void inject(T instance) {
if(objectGraph != null) objectGraph.inject(instance);
}
}

60. @Module(
entryPoints = { DaggerApplication.class, DaggerActivity.class}
)
public class DaggerModule {
private final Context appContext;
public DaggerModule(Context appContext) {
this.appContext = appContext.getApplicationContext();
}
@Provides @Singleton Bus provideBus() {
return new Bus();
}
@Provides Context provideContext() {
return appContext;
}
}

61. Summary
Dagger
●
More customizable
●
Easy communicates with other libraries
●
Requires more code
RoboGuice
●
Simpler
●
Out of Box functionality

62. Problem with views

65. Other “Injection” libraries
Resource and View “Injection”
●
RoboGuice
●
ButterKnife
●
AndroidAnnotations

66. RoboGuice Views Injection
public class RoboGuiceActivity extends RoboActivity {
@Inject RoboGuiceStringProvider stringProvider;
@InjectView(R.id.textView) TextView textView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
textView.setText(stringProvider.getString());
}
}

67. Butterknife
public class DaggerActivity extends DaggerBaseActivity {
@Inject DaggerStringProvider stringProvider;
@InjectView(R.id.textView) TextView textView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Views.inject(this);
textView.setText(stringProvider.getString());
}
}

68. AndroidAnnotations
@EActivity(R.layout.translate) // Sets content view to R.layout.translate
public class TranslateActivity extends Activity {
@ViewById // Injects R.id.textInput
EditText textInput;
@ViewById(R.id.myTextView) // Injects R.id.myTextView
TextView result;
@AnimationRes // Injects android.R.anim.fade_in
Animation fadeIn;
@Click // When R.id.doTranslate button is clicked
void doTranslate() {
translateInBackground(textInput.getText().toString());
}
@Background // Executed in a background thread
void translateInBackground(String textToTranslate) {
String translatedText = callGoogleTranslate(textToTranslate);
showResult(translatedText);
}
@UiThread // Executed in the ui thread
void showResult(String translatedText) {
result.setText(translatedText);
result.startAnimation(fadeIn);
}
}

69. Presentation
Application logic
Domain

70. Data Source
Android has built in SQLite

71. Data Source
... but lacks ORM
Alternatives:
– GreenDAO
– ORMLite

72. ORMLite
@DatabaseTable(tableName = "accounts")
public class Account {
@DatabaseField(id = true) private String name;
@DatabaseField(canBeNull = false) private String password;
Account() {
// all persisted classes must define a no-arg constructor with at least package
visibility
}
}

73. ORMLite
// you get the SQLiteOpenHelper from your Android Activity
ConnectionSource connectionSource = new AndroidConnectionSource(sqliteOpenHelper);
// instantiate the DAO to handle Account with String id
Dao<Account,String> accountDao = BaseDaoImpl.createDao(connectionSource, Account.class);
TableUtils.createTable(connectionSource, Account.class);
String name = "Jim Smith";
Account account = new Account(name, "_secret");
accountDao.create(account)
Account account2 = accountDao.queryForId(name);
connectionSource.close();

74. Testing

75. Testing
●
DVM or JVM
●
Automation or Unit Tests

76. DVM
●
Requires a separate Test Project
●
android.test or Robotium

77. Android.test
public class SimpleActivityTestStandard extends
ActivityUnitTestCase<SimpleActivity> {
public SimpleActivityTestStandard() {
super(SimpleActivity.class);
}
public void setUp() throws Exception {
startActivity(new
Intent(getInstrumentation().getTargetContext(),
SimpleActivity.class), null, null);
}
public void testLayout() {
SimpleActivity activity = getActivity();
assertNotNull(activity.findViewById(R.id.button1));
Button view = (Button) activity
.findViewById(com.example.test.target.R.id.button1);
assertEquals("My Button 1", view.getText());
}
}

78.
Robotium
public void testPreferenceIsSaved() throws Exception {
Solo solo = new Solo(getInstrumentation(), getActivity());
solo.sendKey(Solo.MENU);
solo.clickOnText("More");
solo.clickOnText("Preferences");
solo.clickOnText("Edit File Extensions");
assertTrue(solo.searchText("rtf"));
solo.clickOnText("txt");
solo.clearEditText(2);
solo.enterText(2, "robotium");
solo.clickOnButton("Save");
solo.goBack();
solo.clickOnText("Edit File Extensions");
assertTrue(solo.searchText("application/robotium")
solo.finishOpenedActivities();
);

79. JVM
public class RoboGuiceActivityTest {
@Test
public void shouldHaveISet() throws Exception {
RoboGuiceActivity activity = new RoboGuiceActivity();
assertThat(activity.getI(), equalTo(1));
}
}

80. JVM
public class RoboGuiceActivityTest {
@Test
public void shouldHaveISet() throws Exception {
RoboGuiceActivity activity = new RoboGuiceActivity();
assertThat(activity.getI(), equalTo(1));
}
}

82. We have Mockito!
lets mock something
in our Activity ...

83. Activity source code

84. Robolectric to the rescue
Allows you to run
you android code
on JVM

85. Robolectric
@RunWith(RobolectricRoboTestRunner.class)
public class RoboGuiceActivityTest {
@Test
public void shouldHaveISet() throws Exception {
RoboGuiceActivity activity = new RoboGuiceActivity();
activity.onCreate(null);
assertThat(activity.getI(), equalTo(1));
}
}

86. Robolectric + Mockito

87. Testing
●
DVM or JVM
●
Automation or Unit Tests
●
Robotium or Robolectric
●
Or both

88. Conclusion

89. More libraries?

90. More libraries

91. Solution?

92. Android Bootstrap
●
Fragments,Fragment Pager
●
android-maven-plugin, Dagger
●
ActionBarSherlock
●
ViewPagerIndicator
●
http-request, GSON
●
Robotium
http://www.androidbootstrap.com/

93. or customs scripts

94. Build Systems
● Gradle
● Maven
https://github.com/LArchaon/android
_mvn_template/

95. Questions?