rxjava usage in android

rxjava_sample.java

package com.mdaisuke.sample;

import android.app.Activity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import butterknife.ButterKnife;
import butterknife.InjectView;
import rx.Observable;
import rx.functions.Action1;
import rx.functions.Func2;
import rx.subjects.BehaviorSubject;
import rx.subjects.PublishSubject;

public class MainActivity extends Activity {

    @InjectView(R.id.email)
    EditText emailEdit;
    @InjectView(R.id.password)
    EditText passwordEdit;

    @InjectView(R.id.push_me_button)
    Button pushMe;
    @InjectView(R.id.push_me_text)
    TextView pushMeText;

    private int counter = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        ButterKnife.inject(this);

        //edit text filling sample
        final BehaviorSubject<String> email = BehaviorSubject.create(emailEdit.getText().toString());
        emailEdit.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence charSequence, int i, int i2, int i3) {}
            @Override
            public void onTextChanged(CharSequence charSequence, int i, int i2, int i3) {}
            @Override
            public void afterTextChanged(Editable editable) {
                email.onNext(editable.toString());
            }
        });
        final BehaviorSubject<String> password = BehaviorSubject.create(passwordEdit.getText().toString());
        passwordEdit.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence charSequence, int i, int i2, int i3) {}
            @Override
            public void onTextChanged(CharSequence charSequence, int i, int i2, int i3) {}
            @Override
            public void afterTextChanged(Editable editable) {
                password.onNext(editable.toString());
            }
        });
        Observable.combineLatest(email, password, new Func2<String, String, Boolean>() {
            @Override
            public Boolean call(String s, String s2) {
                return (s != null && !s.equals("") && s2 != null && !s2.equals(""));
            }
        }).subscribe(new Action1<Boolean>() {
            @Override
            public void call(Boolean aBoolean) {
                pushMe.setEnabled(aBoolean);
            }
        });

        //click event sample
        final PublishSubject<Object> push = PublishSubject.create();
        pushMe.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                push.onNext(new Object());
            }
        });
        push.subscribe(new Action1<Object>() {
            @Override
            public void call(Object o) {
                counter += 1;
                pushMeText.setText(Integer.toString(counter)+" times pushed");
            }
        });
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

}