Fix FirebaseArrayOfObjects$FirebaseArrayOfObjectsOptimized.java being incomprehensible and bugs related to adapters not listening for changes if FirebaseArray.java already had listeners by adding a new method to check if an object is listening for changes.

Signed-off-by: Alex Saveau <[email protected]>

Author: SUPERCILEX

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

@@ -145,6 +145,15 @@ public boolean isListening() {
         }
     }
 
+    /**
+     * @return true if the provided {@link ChangeEventListener} is listening for changes
+     */
+    public boolean isListening(ChangeEventListener listener) {
+        synchronized (mListeners) {
+            return mListeners.contains(listener);
+        }
+    }
+
     @Override
     public void onChildAdded(DataSnapshot snapshot, String previousChildKey) {
         int index = 0;

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

@@ -174,8 +174,6 @@ public String toString() {
     protected static class FirebaseArrayOfObjectsOptimized<E> extends FirebaseArrayOfObjects<E>
             implements ChangeEventListener, SubscriptionEventListener {
         protected List<E> mObjects = new ArrayList<>();
-        protected boolean mIsListening = true;
-        protected boolean mAddedListener = false;
 
         public FirebaseArrayOfObjectsOptimized(FirebaseArray snapshots, Class<E> modelClass) {
             super(snapshots, modelClass);
@@ -211,20 +209,14 @@ public void onSubscriptionRemoved() {
             FirebaseArray snapshots = (FirebaseArray) mSnapshots;
             if (!snapshots.isListening()) {
                 snapshots.removeChangeEventListener(this);
-                mIsListening = false;
-                mAddedListener = false;
             }
         }
 
         @Override
         public void onSubscriptionAdded() {
-            if (mAddedListener) {
-                mIsListening = true;
-                mAddedListener = false;
-            } else if (!mIsListening) {
-                ((FirebaseArray) mSnapshots).addChangeEventListener(this);
-                mIsListening = true;
-                mAddedListener = true;
+            FirebaseArray snapshots = (FirebaseArray) mSnapshots;
+            if (!snapshots.isListening(this)) {
+                snapshots.addChangeEventListener(this);
             }
         }
 

database/src/main/java/com/firebase/ui/database/adapter/FirebaseListAdapter.java

@@ -70,7 +70,7 @@ public FirebaseListAdapter(Activity activity,
 
     @Override
     public void startListening() {
-        if (!mSnapshots.isListening()) {
+        if (!mSnapshots.isListening(this)) {
             mSnapshots.addChangeEventListener(this);
         }
     }

database/src/main/java/com/firebase/ui/database/adapter/FirebaseRecyclerAdapter.java

@@ -75,7 +75,7 @@ public FirebaseRecyclerAdapter(Class<T> modelClass,
 
     @Override
     public void startListening() {
-        if (!mSnapshots.isListening()) {
+        if (!mSnapshots.isListening(this)) {
             mSnapshots.addChangeEventListener(this);
         }
     }