Android Open Source - Android-RxJava Concurrency With Schedulers Demo Fragment

• Back to Example/learn  ↑

From Project

Back to project page Android-RxJava.

License

The source code is released under:

Apache License

Java Source Code

package com.morihacky.android.rxjava;
//from  w w w . j a v  a2 s . c om
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.ProgressBar;
import butterknife.ButterKnife;
import butterknife.InjectView;
import butterknife.OnClick;
import com.morihacky.android.rxjava.app.R;
import java.util.ArrayList;
import java.util.List;
import rx.Observable;
import rx.Observer;
import rx.Subscriber;
import rx.Subscription;
import rx.android.observables.AndroidObservable;
import rx.android.schedulers.AndroidSchedulers;
import rx.schedulers.Schedulers;
import timber.log.Timber;

public class ConcurrencyWithSchedulersDemoFragment
    extends Fragment {

  @InjectView(R.id.progress_operation_running) ProgressBar _progress;
  @InjectView(R.id.list_threading_log) ListView _logsList;

  private LogAdapter _adapter;
  private List<String> _logs;
  private Subscription _subscription;

  @Override
  public void onDestroy() {
    super.onDestroy();
    if (_subscription != null) {
      _subscription.unsubscribe();
    }
  }

  @Override
  public void onActivityCreated(@Nullable Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    _setupLogger();
  }

  @Override
  public View onCreateView(LayoutInflater inflater,
                           @Nullable ViewGroup container,
                           @Nullable Bundle savedInstanceState) {
    View layout = inflater.inflate(R.layout.fragment_concurrency_schedulers, container, false);
    ButterKnife.inject(this, layout);
    return layout;
  }

  @OnClick(R.id.btn_start_operation)
  public void startLongOperation() {

    _progress.setVisibility(View.VISIBLE);
    _log("Button Clicked");

    _subscription = AndroidObservable.bindFragment(this, _getObservable())      // Observable
        .subscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(_getObserver());                             // Observer
  }

  private Observable<Boolean> _getObservable() {
    return Observable.create(new Observable.OnSubscribe<Boolean>() {

      @Override
      public void call(Subscriber<? super Boolean> observer) {

        _log("Within Observable");

        _doSomeLongOperation_thatBlocksCurrentThread();
        observer.onNext(true);
        observer.onCompleted();
      }
    });
  }

  /**
   * Observer that handles the result List<Integer> from Observable
   * through the 3 important actions:
   *
   * 1. onCompleted
   * 2. onError
   * 3. onNext
   */
  private Observer<Boolean> _getObserver() {
    return new Observer<Boolean>() {

      @Override
      public void onCompleted() {
        _log("On complete");
        _progress.setVisibility(View.INVISIBLE);
      }

      @Override
      public void onError(Throwable e) {
        Timber.e(e, "Error in RxJava Demo concurrency");
        _log(String.format("Boo Error %s", e.getMessage()));
        _progress.setVisibility(View.INVISIBLE);
      }

      @Override
      public void onNext(Boolean aBoolean) {
        _log(String.format("onNext with return value \"%b\"", aBoolean));
      }
    };
  }

  // -----------------------------------------------------------------------------------
  // Method that help wiring up the example (irrelevant to RxJava)

  private void _doSomeLongOperation_thatBlocksCurrentThread() {
    _log("performing long operation");

    try {
      Thread.sleep(3000);
    } catch (InterruptedException e) {
      Timber.d("Operation was interrupted");
    }
  }

  private void _log(String logMsg) {

    if (_isCurrentlyOnMainThread()) {
      _logs.add(0, logMsg + " (main thread) ");
      _adapter.clear();
      _adapter.addAll(_logs);
    } else {
      _logs.add(0, logMsg + " (NOT main thread) ");

      // You can only do below stuff on main thread.
      new Handler(Looper.getMainLooper()).post(new Runnable() {

        @Override
        public void run() {
          _adapter.clear();
          _adapter.addAll(_logs);
        }
      });
    }
  }

  private void _setupLogger() {
    _logs = new ArrayList<String>();
    _adapter = new LogAdapter(getActivity(), new ArrayList<String>());
    _logsList.setAdapter(_adapter);
  }

  private boolean _isCurrentlyOnMainThread() {
    return Looper.myLooper() == Looper.getMainLooper();
  }

  private class LogAdapter
      extends ArrayAdapter<String> {

    public LogAdapter(Context context, List<String> logs) {
      super(context, R.layout.item_log, R.id.item_log, logs);
    }
  }
}

Java Source Code List

• Back to Example/learn  ↑