Overview of Android Infrastructure

Overview of Android Infrastructure

Alexey Buzdin

@AlexeyBuzdin

alex.buzdin@gmail.com

LArchaon

Everyone needs an app....

We need an app too!

simple CRUD app

Requirement:

Support as many android devices as you can

(including tablets)

4.04.1–4.2

3.0

2.3

2.22.1

Google data, March 2013

Ain't that good for a developer

Is there is someone who could help us?

nope

Ease our pain

maybe

Layers

Presentation

Application logic

Domain

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Application logic

Domain

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Application logic

Domain

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Application logic

Domain

But Whers the problem?

Missing in Android 2.2

● ActionBar● Support for tablets● Decent ListView support for server communication

Solution?

Compatability libraries

Android Support library

ActionBarSherlock

etc

Support Libraryhttp://developer.android.com/tools/extras/support-library.html

Fragments

Async Stuff

Experimental stuff

Fragments

Example

ActionBar

ActionBarSherlock

http://actionbarsherlock.com/

Refreshing list

Pull to Refresh

https://github.com/chrisbanes/Android-PullToRefresh

Presentation

Application logic

Domain

Presentation

Application logic

Domain

Android Runtime

On Android you develop in Java

... but Android does not run Java Bytecode !

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

App lifecycle

Activity

public class MyActivity extends Activity {

@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); }

}

Activity

public class MyActivity extends Activity {

@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); }

}

Resources

Activity

public class MyActivity extends Activity {

@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); }

}

Context● Context of current state of the

application/object

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

Important

any resource taken from context will leave as long as Context does

Context problempublic class MyActivity extends Activity {

@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); String appName = getString(R.string.appName); }

}

Passing Contextpublic class MyStringProvider {

Context context;

public MyStringProvider(Context context) { this.context = context; }

public String getString(){ return context.getString(R.string.app_name); }

}

Passing Context

Context problempublic 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

Presentation

Application logic

Domain

Injection libraries

Dependency Injection● RoboGuice● Dagger

RoboGuice

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

RoboGuicepublic 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()); }

}

RoboGuicepublic class MyStringProvider {

Context context;

@Inject public MyStringProvider(Context context) { this.context = context; }

public String getString(){ return context.getString(R.string.app_name); }}

Notable fact

Optimezed context injectionpublic 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()); }

}

RoboGuicepublic 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; }}

Daggerpublic 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());

}

}

Daggerpublic 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); }}

Daggerpublic 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); }}

@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; }

}

SummaryDagger

● More customizable● Easy communicates with other libraries● Requires more code

RoboGuice● Simpler● Out of Box functionality

Problem with views

Other “Injection” libraries

Resource and View “Injection”● RoboGuice● ButterKnife● AndroidAnnotations

RoboGuice Views Injectionpublic 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()); }

}

Butterknifepublic 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()); }

}

AndroidAnnotations@EActivity(R.layout.translate) // Sets content view to R.layout.translatepublic 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); } }

Presentation

Application logic

Domain

Presentation

Application logic

Domain

Data Source

Android has built in SQLite

Data Source

... but lacks ORM

Alternatives:– GreenDAO– ORMLite

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

}

}

// 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();

ORMLite

Testing

Testing

● DVM or JVM● Automation or Unit Tests

DVM

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

Android.testpublic 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()); }}

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();

);               

JVMpublic class RoboGuiceActivityTest {

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

JVMpublic class RoboGuiceActivityTest {

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

We have Mockito! lets mock something

in our Activity ...

Activity source code

Robolectric to the rescue

Allows you to run

you android code

on JVM

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)); }}

Robolectric + Mockito

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

Conclusion

More libraries?

More libraries

Solution?

Android Bootstrap● Fragments,Fragment Pager● android-maven-plugin, Dagger● ActionBarSherlock ● ViewPagerIndicator● http-request, GSON ● Robotium

http://www.androidbootstrap.com/

or customs scripts

Build Systems● Gradle● Maven

https://github.com/LArchaon/android_mvn_template/

Questions?