fix: buffer implementation for accumulation

Kaushik Gopal · Kaushik Gopal · commit 7a3e0e0586b6 · 2014-08-06T08:58:48.000-07:00
diff --git a/app/src/main/java/com/morihacky/android/rxjava/BufferDemoFragment.java b/app/src/main/java/com/morihacky/android/rxjava/BufferDemoFragment.java
@@ -10,6 +10,7 @@
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ArrayAdapter;
+import android.widget.Button;
 import android.widget.ListView;
 
 import com.morihacky.android.rxjava.app.R;
@@ -20,59 +21,70 @@
 
 import butterknife.ButterKnife;
 import butterknife.InjectView;
-import butterknife.OnClick;
 import rx.Observable;
 import rx.Observer;
 import rx.Subscriber;
+import rx.Subscription;
 import rx.android.schedulers.AndroidSchedulers;
 import rx.schedulers.Schedulers;
 import timber.log.Timber;
 
+/**
+ * credit to @tomrozb for this implementation:
+ * http://stackoverflow.com/questions/24922610/incorrect-understanding-of-buffer-in-rxjava
+ *
+ * An alternate mechanism of achieving the same result would be to use a {@link rx.subjects.PublishSubject}
+ * as demonstrated in the case of {@link com.morihacky.android.rxjava.SubjectDebounceSearchEmitterFragment}
+ */
 public class BufferDemoFragment
     extends Fragment {
 
     @InjectView(R.id.list_threading_log) ListView _logsList;
+    @InjectView(R.id.btn_start_operation) Button _tapBtn;
 
     private LogAdapter _adapter;
     private List<String> _logs;
     private int _tapCount = 0;
 
-    private Observable<List<Integer>> _bufferedObservable;
-    private Observer<List<Integer>> _observer;
+    private Subscription _subscription;
 
     @Override
-    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
-        super.onActivityCreated(savedInstanceState);
-        _setupLogger();
-
-        _bufferedObservable = _getBufferedObservable();
-        _observer = _getObserver();
+    public void onResume() {
+        super.onResume();
+        _subscription = _getBufferedObservable().subscribe(_getObserver());
     }
 
-
-    @OnClick(R.id.btn_start_operation)
-    public void onButtonTapped() {
-        Timber.d("--------- GOT A TAP");
-        _tapCount += 1;
-        _log("GOT A TAP");
-        _bufferedObservable.subscribeOn(Schedulers.io())
-                         .observeOn(AndroidSchedulers.mainThread())
-                         .subscribe(_observer);
+    @Override
+    public void onPause() {
+        super.onPause();
+        _subscription.unsubscribe();
     }
 
     // -----------------------------------------------------------------------------------
     // Main Rx entities
 
     private Observable<List<Integer>> _getBufferedObservable() {
+
         return Observable.create(new Observable.OnSubscribe<Integer>() {
 
 
             @Override
             public void call(Subscriber<? super Integer> subscriber) {
-                subscriber.onNext(1);
-            }
+                _tapBtn.setOnClickListener(new View.OnClickListener() {
 
-        }).buffer(2, TimeUnit.SECONDS);
+
+                    @Override
+                    public void onClick(View v) {
+                        Timber.d("--------- GOT A TAP");
+                        _tapCount += 1;
+                        _log("GOT A TAP");
+                    }
+                });
+            }
+        })
+                         .buffer(2, TimeUnit.SECONDS)
+                         .subscribeOn(Schedulers.io())
+                         .observeOn(AndroidSchedulers.mainThread());
     }
 
     private Observer<List<Integer>> _getObserver() {
@@ -81,8 +93,10 @@ private Observer<List<Integer>> _getObserver() {
 
             @Override
             public void onCompleted() {
-                _log(String.format("%d taps", _tapCount));
-                _tapCount = 0;
+                if (_tapCount > 0) {
+                    _log(String.format("%d taps", _tapCount));
+                    _tapCount = 0;
+                }
             }
 
             @Override
@@ -94,22 +108,27 @@ public void onError(Throwable e) {
             @Override
             public void onNext(List<Integer> integers) {
                 Timber.d("--------- onNext");
-
                 if (integers.size() > 0) {
                     for (int i : integers) {
                         _tapCount += i;
                     }
-                    onCompleted();
                 } else {
                     Timber.d("--------- No taps received ");
                 }
+                onCompleted();
             }
         };
     }
 
     // -----------------------------------------------------------------------------------
     // Method that help wiring up the example (irrelevant to RxJava)
 
+    @Override
+    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
+        super.onActivityCreated(savedInstanceState);
+        _setupLogger();
+    }
+
     @Override
     public View onCreateView(LayoutInflater inflater,
                              @Nullable ViewGroup container,
