Add OSA to Firestore

Change-Id: Ib0b685558bf4b7c19c1a12fc2b2dd2863cf3fcc6

Author: samtstern

common/src/main/java/com/firebase/ui/common/BaseChangeEventListener.java

@@ -1,7 +1,7 @@
 package com.firebase.ui.common;
 
 /**
- * TODO(samstern): Document
+ * Event listener for changes in an {@link BaseObservableSnapshotArray}.
  */
 public interface BaseChangeEventListener<S, E> {
 

common/src/main/java/com/firebase/ui/common/BaseObservableSnapshotArray.java

@@ -76,7 +76,9 @@ protected void onDestroy() {
     }
 
     /**
-     * Attach a listener to this array.
+     * Attach a {@link BaseChangeEventListener} to this array. The listener will receive one {@link
+     * ChangeEventType#ADDED} event for each item that already exists in the array at
+     * the time of attachment, and then receive all future child events.
      */
     @CallSuper
     public L addChangeEventListener(@NonNull L listener) {

database/src/androidTest/java/com/firebase/ui/database/TestUtils.java

@@ -35,9 +35,11 @@ private static FirebaseApp initializeApp(Context context) {
                 .build(), APP_NAME);
     }
 
-    public static ChangeEventListener runAndWaitUntil(ObservableSnapshotArray array,
-                                                      Runnable task,
-                                                      Callable<Boolean> done) throws InterruptedException {
+    public static ChangeEventListener runAndWaitUntil(
+            ObservableSnapshotArray<?> array,
+            Runnable task,
+            Callable<Boolean> done) throws InterruptedException {
+
         final Semaphore semaphore = new Semaphore(0);
         ChangeEventListener listener = array.addChangeEventListener(new ChangeEventListener() {
             @Override

database/src/main/java/com/firebase/ui/database/CachingObservableSnapshotArray.java

@@ -4,6 +4,8 @@
 
 import com.google.firebase.database.DataSnapshot;
 
+import java.util.List;
+
 /**
  * An extension of {@link ObservableSnapshotArray} that caches the result of {@link #getObject(int)}
  * so that repeated calls for the same key are not expensive (unless the underlying snapshot has
@@ -35,6 +37,8 @@ public T getObject(int index) {
         return mCache.parseSnapshot(get(index));
     }
 
+    protected abstract List<DataSnapshot> getSnapshots();
+
     @Override
     protected void onDestroy() {
         super.onDestroy();

database/src/main/java/com/firebase/ui/database/ObservableSnapshotArray.java

@@ -1,10 +1,8 @@
 package com.firebase.ui.database;
 
-import android.support.annotation.CallSuper;
 import android.support.annotation.NonNull;
 
 import com.firebase.ui.common.BaseObservableSnapshotArray;
-import com.firebase.ui.common.ChangeEventType;
 import com.google.firebase.database.DataSnapshot;
 import com.google.firebase.database.DatabaseError;
 
@@ -46,19 +44,6 @@ public ObservableSnapshotArray(@NonNull SnapshotParser<E> parser) {
         super(parser);
     }
 
-    /**
-     * Attach a {@link ChangeEventListener} to this array. The listener will receive one {@link
-     * ChangeEventType#ADDED} event for each item that already exists in the array at
-     * the time of attachment, and then receive all future child events.
-     */
-    @CallSuper
-    public ChangeEventListener addChangeEventListener(@NonNull ChangeEventListener listener) {
-        return super.addChangeEventListener(listener);
-    }
-
-    // TODO(samstern): Can I remove this?
-    protected abstract List<DataSnapshot> getSnapshots();
-
     protected void notifyListenersOnCancelled(DatabaseError error) {
         for (ChangeEventListener listener : getListeners()) {
             listener.onError(error);

firestore/src/main/java/com/firebase/ui/firestore/FirestoreArray.java

@@ -2,7 +2,6 @@
 
 import android.util.Log;
 
-import com.firebase.ui.common.BaseObservableSnapshotArray;
 import com.firebase.ui.common.ChangeEventType;
 import com.google.firebase.firestore.DocumentChange;
 import com.google.firebase.firestore.DocumentSnapshot;
@@ -19,8 +18,7 @@
 /**
  * Exposes a Firestore query as an observable list of objects.
  */
-public class FirestoreArray<T>
-        extends BaseObservableSnapshotArray<DocumentSnapshot, ChangeEventListener, T>
+public class FirestoreArray<T> extends ObservableSnapshotArray<T>
         implements EventListener<QuerySnapshot>  {
 
     private static final String TAG = "FirestoreArray";
@@ -161,11 +159,4 @@ private void stopListening() {
 
         mSnapshots.clear();
     }
-
-    // TODO: There should be a way to move this into the base class
-    private void notifyOnError(FirebaseFirestoreException e) {
-        for (ChangeEventListener listener : getListeners()) {
-            listener.onError(e);
-        }
-    }
 }

firestore/src/main/java/com/firebase/ui/firestore/FirestoreRecyclerAdapter.java

@@ -2,7 +2,6 @@
 
 import android.support.v7.widget.RecyclerView;
 
-import com.firebase.ui.common.BaseObservableSnapshotArray;
 import com.firebase.ui.common.ChangeEventType;
 import com.google.firebase.firestore.DocumentSnapshot;
 import com.google.firebase.firestore.FirebaseFirestoreException;
@@ -17,7 +16,7 @@
 public abstract class FirestoreRecyclerAdapter<T, VH extends RecyclerView.ViewHolder>
         extends RecyclerView.Adapter<VH> implements ChangeEventListener {
 
-    private BaseObservableSnapshotArray<DocumentSnapshot, ChangeEventListener, T> mArray;
+    private ObservableSnapshotArray<T> mArray;
 
     public FirestoreRecyclerAdapter(Query query, Class<T> modelClass) {
         mArray = new FirestoreArray<>(query, modelClass);

firestore/src/main/java/com/firebase/ui/firestore/ObservableSnapshotArray.java

@@ -0,0 +1,33 @@
+package com.firebase.ui.firestore;
+
+import android.support.annotation.NonNull;
+
+import com.firebase.ui.common.BaseObservableSnapshotArray;
+import com.firebase.ui.common.BaseSnapshotParser;
+import com.google.firebase.firestore.DocumentSnapshot;
+import com.google.firebase.firestore.FirebaseFirestoreException;
+
+/**
+ * Subclass of {@link BaseObservableSnapshotArray} for Firestore data.
+ */
+public abstract class ObservableSnapshotArray<E>
+        extends BaseObservableSnapshotArray<DocumentSnapshot, ChangeEventListener, E> {
+
+    public ObservableSnapshotArray() {
+        super();
+    }
+
+    /**
+     * See {@link BaseObservableSnapshotArray#BaseObservableSnapshotArray(BaseSnapshotParser)}
+     */
+    public ObservableSnapshotArray(@NonNull SnapshotParser<E> parser) {
+        super(parser);
+    }
+
+    // TODO: There should be a way to move this into the base class
+    protected void notifyOnError(FirebaseFirestoreException e) {
+        for (ChangeEventListener listener : getListeners()) {
+            listener.onError(e);
+        }
+    }
+}