migrating to RxJava2.x

Author: Piotr Wittchen

README.md

@@ -1,9 +1,14 @@
 # ReactiveSensors 
-[![Android Arsenal](https://img.shields.io/badge/Android%20Arsenal-ReactiveSensors-brightgreen.svg?style=flat)](http://android-arsenal.com/details/1/2451) [![Build Status](https://travis-ci.org/pwittchen/ReactiveSensors.svg?branch=master)](https://travis-ci.org/pwittchen/ReactiveSensors) ![Maven Central](https://img.shields.io/maven-central/v/com.github.pwittchen/reactivesensors.svg?style=flat)
+[![Android Arsenal](https://img.shields.io/badge/Android%20Arsenal-ReactiveSensors-brightgreen.svg?style=flat)](http://android-arsenal.com/details/1/2451)
 
-Android library monitoring hardware sensors with RxJava Observables.
+Android library monitoring hardware sensors with RxJava.
 
-Library is compatible with RxJava 1.+ and RxAndroid 1.+ and uses them under the hood.
+| Current Branch | Branch  | Artifact Id | Build Status  | Coverage | Maven Central |
+|:--------------:|:-------:|:-----------:|:-------------:|:--------:|:-------------:|
+| | [`RxJava1.x`](https://github.com/pwittchen/ReactiveSensors/tree/RxJava1.x) | `reactivesensors` | [![Build Status for RxJava1.x](https://travis-ci.org/pwittchen/ReactiveSensors.svg?branch=RxJava1.x)](https://travis-ci.org/pwittchen/ReactiveSensors) | [![codecov](https://codecov.io/gh/pwittchen/ReactiveSensors/branch/RxJava1.x/graph/badge.svg)](https://codecov.io/gh/pwittchen/ReactiveSensors/branch/RxJava1.x) | ![Maven Central](https://img.shields.io/maven-central/v/com.github.pwittchen/reactivesensors.svg?style=flat) |
+| :ballot_box_with_check: | [`RxJava2.x`](https://github.com/pwittchen/ReactiveSensors/tree/RxJava2.x) | `reactivesensors-rx2` | [![Build Status for RxJava2.x](https://travis-ci.org/pwittchen/ReactiveSensors.svg?branch=RxJava2.x)](https://travis-ci.org/pwittchen/ReactiveSensors) | [![codecov](https://codecov.io/gh/pwittchen/ReactiveSensors/branch/RxJava2.x/graph/badge.svg)](https://codecov.io/gh/pwittchen/ReactiveSensors/branch/RxJava2.x) | ![Maven Central](https://img.shields.io/maven-central/v/com.github.pwittchen/reactivesensors-rx2.svg?style=flat) |
+
+This is **RxJava2.x** branch. To see documentation for RxJava1.x, switch to [RxJava1.x](https://github.com/pwittchen/ReactiveSensors/tree/RxJava1.x) branch.
 
 min sdk version = 9
 
@@ -17,7 +22,7 @@ Contents
 - [Good practices](#good-practices)
   - [Checking whether sensor exists](#checking-whether-sensor-exists)
   - [Letting it crash](#letting-it-crash)
-  - [Subscribing and unsubscribing observables](#subscribing-and-unsubscribing-observables)
+  - [Subscribing and disposing flowables](#subscribing-and-disposing-flowables)
   - [Filtering stream](#filtering-stream)
   - [Other practices](#other-practices)
 - [Download](#download)
@@ -32,14 +37,14 @@ Usage
 
 Code sample below demonstrates how to observe Gyroscope sensor. 
 
-Please note that we are filtering events occuring when sensor readings change with `ReactiveSensorFilter.filterSensorChanged()` method. There's also event describing change of sensor's accuracy, which can be filtered with `ReactiveSensorFilter.filterAccuracyChanged()` method. When we don't apply any filter, we will be notified both about sensor readings and accuracy changes.
+Please note that we are filtering events occurring when sensor readings change with `ReactiveSensorFilter.filterSensorChanged()` method. There's also event describing change of sensor's accuracy, which can be filtered with `ReactiveSensorFilter.filterAccuracyChanged()` method. When we don't apply any filter, we will be notified both about sensor readings and accuracy changes.
 
 ```java
 new ReactiveSensors(context).observeSensor(Sensor.TYPE_GYROSCOPE)
     .subscribeOn(Schedulers.computation())
     .filter(ReactiveSensorFilter.filterSensorChanged())
     .observeOn(AndroidSchedulers.mainThread())
-    .subscribe(new Action1<ReactiveSensorEvent>() {
+    .subscribe(new Consumer<ReactiveSensorEvent>() {
       @Override public void call(ReactiveSensorEvent reactiveSensorEvent) {
         SensorEvent event = reactiveSensorEvent.getSensorEvent();
 
@@ -59,16 +64,16 @@ We can observe any hardware sensor in the same way. You can check [list of all s
 
 ### Setting sampling period
 
-Default sampling period for observable below is set to `SensorManager.SENSOR_DELAY_NORMAL`.
+Default sampling period for flowable below is set to `SensorManager.SENSOR_DELAY_NORMAL`.
 
 ```java
-Observable<ReactiveSensorEvent> observeSensor(int sensorType)
+Flowable<ReactiveSensorEvent> observeSensor(int sensorType)
  ```
 
-We can configure sampling period according to our needs with the following observable:
+We can configure sampling period according to our needs with the following flowable:
 
 ```java
-Observable<ReactiveSensorEvent> observeSensor(int sensorType, 
+Flowable<ReactiveSensorEvent> observeSensor(int sensorType,
                                               final int samplingPeriodInUs)
  ```
 
@@ -80,13 +85,20 @@ We can use predefined values available in `SensorManager` class from Android SDK
 
 We can also define our own integer value in microseconds, but it's recommended to use predefined values.
 
+We can customize RxJava 2 Backpressure Strategy for our flowable with method:
+
+```java
+Flowable<ReactiveSensorEvent> observeSensor(int sensorType, final int samplingPeriodInUs,
+      final Handler handler, final BackpressureStrategy strategy)
+```
+
+Default Backpressure Strategy is `BUFFER`.
+
 Example
 -------
 
 Exemplary application, which gets readings of various sensors is located in `app` directory of this repository. You can easily change `SENSOR_TYPE` variable to read values from a different sensor in a given samples.
 
-If you are interested in library usage with Kotlin, check sample in `app-kotlin` directory.
-
 Good practices
 --------------
 
@@ -113,28 +125,22 @@ new ReactiveSensors(context).observeSensor(Sensor.TYPE_GYROSCOPE)
     .subscribeOn(Schedulers.computation())
     .filter(ReactiveSensorFilter.filterSensorChanged())
     .observeOn(AndroidSchedulers.mainThread())
-    .subscribe(new Subscriber<ReactiveSensorEvent>() {
-          @Override public void onCompleted() {
-            // subscription completed
-          }
-
-          @Override public void onError(Throwable throwable) {
-            if (throwable instanceof SensorNotFoundException) {
-              // device does not have given sensor - show error message
-            } else {
-              // handle other types of errors
-            }
-          }
-
-          @Override public void onNext(ReactiveSensorEvent event) {
-            // handle event
-          }
-        });
+    .subscribe(new Consumer<ReactiveSensorEvent>() {
+      @Override public void accept(ReactiveSensorEvent reactiveSensorEvent) throws Exception {
+        // handle reactiveSensorEvent
+      }
+    }, new Consumer<Throwable>() {
+      @Override public void accept(Throwable throwable) throws Exception {
+        if (throwable instanceof SensorNotFoundException) {
+          textViewForMessage.setText("Sorry, your device doesn't have required sensor.");
+        }
+      }
+    });
 ```
 
-### Subscribing and unsubscribing observables
+### Subscribing and disposing flowables
 
-When we are using subscriptions in Activity, we should subscribe them in `onResume()` method and unsubscribe them in `onPause()` method.
+When we are using Disposables in Activity, we should subscribe them in `onResume()` method and dispose them in `onPause()` method.
 
 ### Filtering stream
 
@@ -156,16 +162,16 @@ You can depend on the library through Maven:
 ```xml
 <dependency>
     <groupId>com.github.pwittchen</groupId>
-    <artifactId>reactivesensors</artifactId>
-    <version>0.1.2</version>
+    <artifactId>reactivesensors-rx2</artifactId>
+    <version>...</version>
 </dependency>
 ```
 
 or through Gradle:
 
 ```groovy
 dependencies {
-  compile 'com.github.pwittchen:reactivesensors:0.1.2'
+  compile 'com.github.pwittchen:reactivesensors-rx2:...'
 }
 ```
 

app-kotlin/src/main/kotlin/com/github/pwittchen/reactivesensors/kotlinapp/SensorActivity.kt

@@ -4,10 +4,10 @@ import android.os.Bundle
 import android.support.v7.app.AppCompatActivity
 import android.widget.TextView
 import com.github.pwittchen.reactivesensors.library.ReactiveSensors
-import rx.Subscription
+import io.reactivex.disposables.Disposable
 
 abstract class SensorActivity : AppCompatActivity() {
-  private var subscription: Subscription? = null
+  private var subscription: Disposable? = null
   private var sensorHelper: SensorHelper? = null
   protected var sensorType: Int = 0
   protected var sensorName: String = ""
@@ -32,6 +32,6 @@ abstract class SensorActivity : AppCompatActivity() {
       return
     }
 
-    sensorHelper!!.safelyUnsubscribe(subscription)
+    sensorHelper!!.safelyDispose(subscription)
   }
 }

app-kotlin/src/main/kotlin/com/github/pwittchen/reactivesensors/kotlinapp/SensorHelper.kt

@@ -5,20 +5,36 @@ import com.github.pwittchen.reactivesensors.library.ReactiveSensorEvent
 import com.github.pwittchen.reactivesensors.library.ReactiveSensorFilter
 import com.github.pwittchen.reactivesensors.library.ReactiveSensors
 import com.github.pwittchen.reactivesensors.library.SensorNotFoundException
-import rx.Subscriber
-import rx.Subscription
-import rx.android.schedulers.AndroidSchedulers
-import rx.schedulers.Schedulers
+import io.reactivex.android.schedulers.AndroidSchedulers
+import io.reactivex.disposables.Disposable
+import io.reactivex.functions.Consumer
+import io.reactivex.schedulers.Schedulers
+import org.reactivestreams.Subscriber
 
 class SensorHelper(private val reactiveSensors: ReactiveSensors, private val sensorType: Int,
     private val sensorName: String, private val textView: TextView) {
 
-  fun createSubscription(): Subscription {
+  fun createSubscription(): Disposable {
     return reactiveSensors.observeSensor(sensorType)
         .subscribeOn(Schedulers.computation())
         .filter(ReactiveSensorFilter.filterSensorChanged())
         .observeOn(AndroidSchedulers.mainThread())
-        .subscribe(object : Subscriber<ReactiveSensorEvent>() {
+        .subscribe({ reactiveSensorEvent ->
+          run {
+            if (reactiveSensorEvent != null) {
+              val event = reactiveSensorEvent.sensorEvent
+              val x = event.values[0]
+              val y = event.values[1]
+              val z = event.values[2]
+              val message = "%s readings:\n x = %f\n y = %f\n z = %f"
+              textView.text = message.format(sensorName, x, y, z)
+            }
+          }
+        })
+
+    /*
+
+    (object : Subscriber<ReactiveSensorEvent>() {
           override fun onCompleted() {
           }
 
@@ -38,16 +54,19 @@ class SensorHelper(private val reactiveSensors: ReactiveSensors, private val sen
               textView.text = message.format(sensorName, x, y, z)
             }
           }
-        })
+        }
+
+     */
+
   }
 
-  fun safelyUnsubscribe(subscription: Subscription?) {
+  fun safelyDispose(subscription: Disposable?) {
     if (!reactiveSensors.hasSensor(sensorType)) {
       return
     }
 
-    if (subscription != null && !subscription.isUnsubscribed) {
-      subscription.unsubscribe()
+    if (subscription != null && !subscription.isDisposed) {
+      subscription.dispose()
     }
   }
 }

app/src/main/java/com/github/pwittchen/reactivesensors/app/SensorActivity.java

@@ -5,15 +5,15 @@
 import android.widget.TextView;
 import com.github.pwittchen.reactivesensors.R;
 import com.github.pwittchen.reactivesensors.library.ReactiveSensors;
-import rx.Subscription;
+import io.reactivex.disposables.Disposable;
 
 public abstract class SensorActivity extends AppCompatActivity {
   protected int sensorType;
   protected String sensorName;
 
   private TextView tvSensor;
   private ReactiveSensors reactiveSensors;
-  private Subscription subscription;
+  private Disposable subscription;
   private SensorHelper sensorHelper;
 
   @Override protected void onCreate(Bundle savedInstanceState) {
@@ -31,6 +31,6 @@ public abstract class SensorActivity extends AppCompatActivity {
 
   @Override protected void onPause() {
     super.onPause();
-    sensorHelper.safelyUnsubscribe(subscription);
+    sensorHelper.safelyDispose(subscription);
   }
 }

app/src/main/java/com/github/pwittchen/reactivesensors/app/SensorHelper.java

@@ -6,63 +6,58 @@
 import com.github.pwittchen.reactivesensors.library.ReactiveSensorFilter;
 import com.github.pwittchen.reactivesensors.library.ReactiveSensors;
 import com.github.pwittchen.reactivesensors.library.SensorNotFoundException;
-import rx.Subscriber;
-import rx.Subscription;
-import rx.android.schedulers.AndroidSchedulers;
-import rx.functions.Action1;
-import rx.schedulers.Schedulers;
+import io.reactivex.android.schedulers.AndroidSchedulers;
+import io.reactivex.disposables.Disposable;
+import io.reactivex.functions.Consumer;
+import io.reactivex.schedulers.Schedulers;
+import java.util.Locale;
 
-public class SensorHelper {
+class SensorHelper {
   private ReactiveSensors reactiveSensors;
   private int sensorType;
   private String sensorName;
   private TextView textViewForMessage;
 
-  public SensorHelper(ReactiveSensors sensors, int type, String name, TextView textViewForMessage) {
+  SensorHelper(ReactiveSensors sensors, int type, String name, TextView textViewForMessage) {
     this.reactiveSensors = sensors;
     this.sensorType = type;
     this.sensorName = name;
     this.textViewForMessage = textViewForMessage;
   }
 
-  public Subscription createSubscription() {
-    Subscription subscription = reactiveSensors.observeSensor(sensorType)
+  Disposable createSubscription() {
+    return reactiveSensors.observeSensor(sensorType)
         .subscribeOn(Schedulers.computation())
-        .filter(ReactiveSensorFilter.filterSensorChanged())
         .observeOn(AndroidSchedulers.mainThread())
-        .subscribe(new Subscriber<ReactiveSensorEvent>() {
-          @Override public void onCompleted() {
-          }
-
-          @Override public void onError(Throwable throwable) {
-            if (throwable instanceof SensorNotFoundException) {
-              textViewForMessage.setText("Sorry, your device doesn't have required sensor.");
-            }
-          }
-
-          @Override public void onNext(ReactiveSensorEvent reactiveSensorEvent) {
+        .filter(ReactiveSensorFilter.filterSensorChanged())
+        .subscribe(new Consumer<ReactiveSensorEvent>() {
+          @Override public void accept(ReactiveSensorEvent reactiveSensorEvent) throws Exception {
             SensorEvent event = reactiveSensorEvent.getSensorEvent();
 
             float x = event.values[0];
             float y = event.values[1];
             float z = event.values[2];
 
             String format = "%s readings:\n x = %f\n y = %f\n z = %f";
-            String message = String.format(format, sensorName, x, y, z);
+            String message = String.format(Locale.getDefault(), format, sensorName, x, y, z);
             textViewForMessage.setText(message);
           }
+        }, new Consumer<Throwable>() {
+          @Override public void accept(Throwable throwable) throws Exception {
+            if (throwable instanceof SensorNotFoundException) {
+              textViewForMessage.setText("Sorry, your device doesn't have required sensor.");
+            }
+          }
         });
-
-    return subscription;
   }
 
-  public void safelyUnsubscribe(Subscription subscription) {
+  void safelyDispose(Disposable disposable) {
     if (!reactiveSensors.hasSensor(sensorType)) {
       return;
     }
 
-    if (subscription != null && !subscription.isUnsubscribed()) {
-      subscription.unsubscribe();
+    if (disposable != null && !disposable.isDisposed()) {
+      disposable.dispose();
     }
   }
 }

build.gradle

@@ -8,8 +8,8 @@ ext {
   kotlinVersion = '1.1.51'
 }
 
-ext.deps = [rxjava            : 'io.reactivex:rxjava:1.3.3',
-            rxandroid         : 'io.reactivex:rxandroid:1.2.1',
+ext.deps = [rxjava2           : 'io.reactivex.rxjava2:rxjava:2.1.6',
+            rxandroid2        : 'io.reactivex.rxjava2:rxandroid:2.0.1',
             supportannotations: 'com.android.support:support-annotations:25.3.0',
             appcompatv7       : 'com.android.support:appcompat-v7:27.0.0',
             testingsupportlib : 'com.android.support.test:testing-support-lib:0.1',

library/build.gradle

@@ -28,8 +28,8 @@ android {
 }
 
 dependencies {
-  api deps.rxjava
-  api deps.rxandroid
+  api deps.rxjava2
+  api deps.rxandroid2
 
   androidTestImplementation deps.testingsupportlib
   androidTestImplementation(deps.truth) {