Add sample for fragments and connectable observables

Author: mttkay

rxjava-contrib/rxjava-android-samples/samples/src/main/AndroidManifest.xml

@@ -11,6 +11,15 @@
         <activity
             android:name=".RetainedFragmentActivity">
 
+            <intent-filter>
+                <category android:name="android.intent.category.LAUNCHER"/>
+                <category android:name="android.intent.category.DEFAULT"/>
+                <action android:name="android.intent.action.MAIN"/>
+            </intent-filter>
+        </activity>
+        <activity
+            android:name=".ListeningFragmentActivity">
+
             <intent-filter>
                 <category android:name="android.intent.category.LAUNCHER"/>
                 <category android:name="android.intent.category.DEFAULT"/>

rxjava-contrib/rxjava-android-samples/samples/src/main/java/com/netflix/rxjava/android/samples/ListeningFragmentActivity.java

@@ -0,0 +1,96 @@
+package com.netflix.rxjava.android.samples;
+
+import android.app.Activity;
+import android.app.Fragment;
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.TextView;
+import android.widget.Toast;
+
+import rx.Subscriber;
+import rx.Subscription;
+import rx.observables.ConnectableObservable;
+import rx.subscriptions.Subscriptions;
+
+import static rx.android.schedulers.AndroidSchedulers.mainThread;
+
+/**
+ * Problem:
+ * You have a background sequence which keeps emitting items (either a limited or unlimited number)
+ * and your UI component should be able to "listen in" to the sequence, i.e. it's okay to miss
+ * in-flight items when going e.g. through a screen rotation or being otherwise detached from the
+ * screen for a limited period of time. (Another example is a "page out" in a fragment ViewPager.)
+ * <p/>
+ * This is useful if you need behavior that mimics event buses. Think of a publishing
+ * Observable as a channel or queue on an event bus.
+ * <p/>
+ * Solution:
+ * Combine {@link android.app.Fragment#setRetainInstance(boolean)} with
+ * {@link rx.android.schedulers.AndroidSchedulers#mainThread()} and {@link rx.Observable#publish()}
+ */
+public class ListeningFragmentActivity extends Activity {
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.listening_fragment_activity);
+    }
+
+    @SuppressWarnings("ConstantConditions")
+    public static class ListeningFragment extends Fragment {
+
+        private ConnectableObservable<String> strings;
+        private Subscription subscription = Subscriptions.empty();
+
+        public ListeningFragment() {
+            setRetainInstance(true);
+        }
+
+        @Override
+        public void onCreate(Bundle savedInstanceState) {
+            super.onCreate(savedInstanceState);
+
+            strings = SampleObservables.numberStrings(1, 50, 250).observeOn(mainThread()).publish();
+            strings.connect(); // trigger the sequence
+        }
+
+        @Override
+        public void onDestroyView() {
+            subscription.unsubscribe(); // stop listening
+            super.onDestroyView();
+        }
+
+        @Override
+        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
+            return inflater.inflate(R.layout.retained_fragment, container, false);
+        }
+
+        @Override
+        public void onViewCreated(final View view, Bundle savedInstanceState) {
+            super.onViewCreated(view, savedInstanceState);
+
+            final TextView textView = (TextView) view.findViewById(android.R.id.text1);
+
+            // re-connect to sequence
+            subscription = strings.subscribe(new Subscriber<String>() {
+
+                @Override
+                public void onCompleted() {
+                    Toast.makeText(getActivity(), "Done!", Toast.LENGTH_SHORT).show();
+                }
+
+                @Override
+                public void onError(Throwable throwable) {
+
+                }
+
+                @Override
+                public void onNext(String s) {
+                    textView.setText(s);
+                }
+            });
+        }
+    }
+}

rxjava-contrib/rxjava-android-samples/samples/src/main/res/layout/listening_fragment_activity.xml

@@ -0,0 +1,14 @@
+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context="com.netflix.rxjava.android.samples.ListeningFragmentActivity">
+
+    <fragment
+        android:tag="retained_fragment"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:name="com.netflix.rxjava.android.samples.ListeningFragmentActivity$ListeningFragment"
+        tools:layout="@layout/retained_fragment" />
+
+</RelativeLayout>