public CommentAdapter()

in database/app/src/main/java/com/google/firebase/quickstart/database/java/PostDetailFragment.java [161:245]
54 lines of code
3 McCabe index (conditional complexity)

        public CommentAdapter(final Context context, DatabaseReference ref) {
            mContext = context;
            mDatabaseReference = ref;

            // Create child event listener
            ChildEventListener childEventListener = new ChildEventListener() {
                @Override
                public void onChildAdded(DataSnapshot dataSnapshot, String previousChildName) {
                    Log.d(TAG, "onChildAdded:" + dataSnapshot.getKey());

                    // A new comment has been added, add it to the displayed list
                    Comment comment = dataSnapshot.getValue(Comment.class);

                    // Update RecyclerView
                    mCommentIds.add(dataSnapshot.getKey());
                    mComments.add(comment);
                    notifyItemInserted(mComments.size() - 1);
                }

                @Override
                public void onChildChanged(DataSnapshot dataSnapshot, String previousChildName) {
                    Log.d(TAG, "onChildChanged:" + dataSnapshot.getKey());

                    // A comment has changed, use the key to determine if we are displaying this
                    // comment and if so displayed the changed comment.
                    Comment newComment = dataSnapshot.getValue(Comment.class);
                    String commentKey = dataSnapshot.getKey();

                    int commentIndex = mCommentIds.indexOf(commentKey);
                    if (commentIndex > -1) {
                        // Replace with the new data
                        mComments.set(commentIndex, newComment);

                        // Update the RecyclerView
                        notifyItemChanged(commentIndex);
                    } else {
                        Log.w(TAG, "onChildChanged:unknown_child:" + commentKey);
                    }
                }

                @Override
                public void onChildRemoved(DataSnapshot dataSnapshot) {
                    Log.d(TAG, "onChildRemoved:" + dataSnapshot.getKey());

                    // A comment has changed, use the key to determine if we are displaying this
                    // comment and if so remove it.
                    String commentKey = dataSnapshot.getKey();

                    int commentIndex = mCommentIds.indexOf(commentKey);
                    if (commentIndex > -1) {
                        // Remove data from the list
                        mCommentIds.remove(commentIndex);
                        mComments.remove(commentIndex);

                        // Update the RecyclerView
                        notifyItemRemoved(commentIndex);
                    } else {
                        Log.w(TAG, "onChildRemoved:unknown_child:" + commentKey);
                    }
                }

                @Override
                public void onChildMoved(DataSnapshot dataSnapshot, String previousChildName) {
                    Log.d(TAG, "onChildMoved:" + dataSnapshot.getKey());

                    // A comment has changed position, use the key to determine if we are
                    // displaying this comment and if so move it.
                    Comment movedComment = dataSnapshot.getValue(Comment.class);
                    String commentKey = dataSnapshot.getKey();

                    // ...
                }

                @Override
                public void onCancelled(DatabaseError databaseError) {
                    Log.w(TAG, "postComments:onCancelled", databaseError.toException());
                    Toast.makeText(mContext, "Failed to load comments.",
                            Toast.LENGTH_SHORT).show();
                }
            };
            ref.addChildEventListener(childEventListener);

            // Store reference to listener so it can be removed on app stop
            mChildEventListener = childEventListener;
        }