ReneeVandervelde

fun setOnClickListener(listener: (view: View) -> Unit) {
   // ...
}

ReneeVandervelde

class Foo {
  public void main() {
    // Anonymous Implementation:
    myView.setOnClickListener(new OnClickListener() {
      @Override
      void onClick(View v) {
        logger.debug("View Clicked!");
      }
    });

ReneeVandervelde

public interface OnClickListener {
    void onClick(View v);
}

ReneeVandervelde

// Fails:
// If onNext is a method Reference
// and onError is an object

import io.reactivex.Observable
import io.reactivex.functions.Consumer

class MyErrorHandler : Consumer<Throwable> {
    override fun accept(t: Throwable?) { TODO() }
}

ReneeVandervelde

public class MyActivity : Activity {
  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.my_layout)
  }
  
  fun useViews() {
    my_view.text = "Hello World"
    arrayOf(first, second).forEach { it.text = "Hello!" }
  }

ReneeVandervelde

apply plugin: 'kotlin-android-extensions'

ReneeVandervelde

public class MyActivity : Activity {
  private val myView: TextView by bindView(R.id.my_view)
  private val views: List<TextView> by bindViews(R.id.first, R.id.second)
  
  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.my_layout)
  }
  
  fun useViews() {

ReneeVandervelde

public class MyActivity extends Activity {
  
  @BindView(R.id.my_view) TextView myView;
  @BindViews({R.id.first, R.id.second}) TextView[] views;
  
  @Override
  protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.my_layout);
    

ReneeVandervelde

public class MyActivity extends Activity {
  private View myView;
  
  @Override
  protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.my_layout);
    
    // If you only want to look up once:
    myView = findViewById(R.id.my_view);

ReneeVandervelde

Completable data = Completable.mergeArrayDelayError(
    widgetRepository.observeWidgets()
                    .take(1)
                    .ignoreElements()
                    .subscribeOn(Schedulers.io())
                    .observeOn(AndroidSchedulers.mainThread())
    fooRepository.observeFoo()
                 .take(1)
                 .ignoreElements()
                 .subscribeOn(Schedulers.io())