Recycler View not working with ImageView but work with ImageView+TextView

Question

Today i am struggling with one of the craziest problems and its making me crazy. In my RecyclerView item xml, if i have only the imageView then nothing shows up and the list is blank but if i add TextView below that ImageView then everything work, both ImageView and TextView. What is happening , please help.

item_row.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/saved_post_imageview"/>

    <!--<TextView-->
        <!--android:layout_width="wrap_content"-->
        <!--android:layout_height="wrap_content"-->
        <!--android:id="@+id/text"/>-->

</RelativeLayout>

ProfileActivity.java

public class ProfileActivity extends AppCompatActivity {

FirebaseAuth mFirebaseAuth;
TextView usernameTxt;
ImageView displayPicImg;
RecyclerView recyclerView;
FirebaseDatabase mFirebaseDatabase;
DatabaseReference mUsersReference;
ArrayList<String> mPostList;
SavedPostsAdapter savedPostsAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_profile_activity);

    usernameTxt = findViewById(R.id.username);
    displayPicImg = findViewById(R.id.display_pic);
    recyclerView = findViewById(R.id.saved_posts);
    mFirebaseDatabase = FirebaseDatabase.getInstance();
    mUsersReference = mFirebaseDatabase.getReference().child("users");
    mPostList = new ArrayList<>();
    mFirebaseAuth = FirebaseAuth.getInstance();
    String username = mFirebaseAuth.getCurrentUser().getDisplayName();
    getSavedPosts(username);
    savedPostsAdapter = new SavedPostsAdapter(mPostList,ProfileActivity.this);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    recyclerView.setHasFixedSize(false);
    recyclerView.setAdapter(savedPostsAdapter);
    Uri displayPicURL = mFirebaseAuth.getCurrentUser().getPhotoUrl();
    usernameTxt.setText(username);
    setTitle(username);
    Glide.with(ProfileActivity.this).load(displayPicURL).apply(new RequestOptions().circleCrop()).apply(new RequestOptions().placeholder(R.drawable.defaultuser)).into(displayPicImg);
}

private void getSavedPosts(String username){
    Query query = mUsersReference.orderByChild("username").equalTo(username.toLowerCase());
    query.addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
            Log.d(MainActivity.TAG,""+dataSnapshot.getChildrenCount());
            for(DataSnapshot data: dataSnapshot.getChildren()){
                ArrayList<String> postList = (ArrayList<String>) data.child("post").getValue();
                Log.d(MainActivity.TAG,"post "+dataSnapshot.getChildrenCount());
                for(String imageUrl: postList){
                    Log.d(MainActivity.TAG,"Image url = "+imageUrl);
                    mPostList.add(imageUrl);
                    savedPostsAdapter.notifyDataSetChanged();
                }
            }
        }

        @Override
        public void onCancelled(@NonNull DatabaseError databaseError) {

        }
    });
}

}

Adapter

public class SavedPostsAdapter extends RecyclerView.Adapter<SavedPostsAdapter.ViewHolder> {

ArrayList<String> savedPostList;
Context context;

public SavedPostsAdapter(ArrayList<String> savedPostList, Context context) {
    this.savedPostList = savedPostList;
    this.context = context;
}

@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
    View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item_row,viewGroup,false);
    ViewHolder vh = new ViewHolder(view);
    return vh;
}

@Override
public void onBindViewHolder(@NonNull ViewHolder viewHolder, int i) {
//        viewHolder.text.setText("fsdfdas");
        Glide.with(context).load("https://firebasestorage.googleapis.com/v0/b/memespace-58171.appspot.com/o/images%2Fimage%3A197200?alt=media&token=8501146f-201d-4fca-a9e3-63cb49fc47de").into(viewHolder.savedPostImageView);
}

@Override
public int getItemCount() {
    Log.d(MainActivity.TAG,"count = "+savedPostList.size());
    return savedPostList.size();
}

public class ViewHolder extends RecyclerView.ViewHolder {

    ImageView savedPostImageView;
//        TextView text;
    public ViewHolder(@NonNull View itemView) {
        super(itemView);
        savedPostImageView = itemView.findViewById(R.id.imageview);
//            text = itemView.findViewById(R.id.text);

    }
}
}

Answer 1

Try to add ViewGroup in item_row.xml

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="50dp" // or wrap_content >
        <ImageView/>
</LinearLayout>

Answer 2

Provide default height and width value for your ImageView ex:

<ImageView
 android:layout_width="20dp"
 android:layout_height="20dp"
 android:id="@+id/imageview"
/>

Or provide default static image for your ImageView

I believe that your code is actually working, it's just that the size wasn't set by the RecyclerView properly.

RecyclerView recycles the views that were already created, since your ImageView doesn't have dimensions it cached that as the size of each row, which results in your Glide loading image on those small or invisible rows.

Plus, you can take advantage of Glide 's sizing feature also to fit it in the desired container like below:

Glide
    .with(context)
    .load(path)
    .apply(new RequestOptions().override(100, 100))
    .into(imageView);