How to hide Progressbar when data is retrived from frirebase into recycloeview

Question

I want to show a Progressbar when my data is being retrived from firebasedatabase into recyclerview, and hide it when its done. I searched online but no soln. works

here is my mainActivity

public class MemesSchool extends AppCompatActivity {

  RecyclerView recyclerView;
  MemeAdapter memeAdapter;
  ProgressBar progressBar;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    progressBar = (ProgressBar) findViewById(R.id.pbmeme);

    setContentView(R.layout.activity_memes_school);
    getWindow().setStatusBarColor(getResources().getColor(R.color.buttonclr));
    getSupportActionBar().setBackgroundDrawable(new ColorDrawable(getResources().getColor(R.color.buttonclr)));
    getSupportActionBar().setTitle("School Memes");

    recyclerView = findViewById(R.id.rvm);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    FirebaseRecyclerOptions < mememodel > options =
      new FirebaseRecyclerOptions.Builder < mememodel > ()
      .setQuery(FirebaseDatabase.getInstance().getReference().child("Memedata"), mememodel.class)
      .build();

    memeAdapter = new MemeAdapter(options);
    recyclerView.setAdapter(memeAdapter);

  }

  @Override
  protected void onStart() {
    super.onStart();
    memeAdapter.startListening();
  }

  @Override
  protected void onStop() {
    super.onStop();
    memeAdapter.stopListening();
  }
}

here is my MainActivity.XML

<?xml version="1.0" encoding="utf-8"?>
   <androidx.constraintlayout.widget.ConstraintLayout 
      xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MemesSchool">

<androidx.recyclerview.widget.RecyclerView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_constraintBottom_toBottomOf="parent"
    android:id="@+id/rvm"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.5"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

<ProgressBar
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:foregroundGravity="center"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    android:id="@+id/pbmeme"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />
   </androidx.constraintlayout.widget.ConstraintLayout>

my Adapterclass

public class MemeAdapter extends FirebaseRecyclerAdapter < mememodel, MemeAdapter.myViewHolder > {

  public MemeAdapter(@NonNull FirebaseRecyclerOptions < mememodel > options) {
    super(options);
  }

  @Override
  protected void onBindViewHolder(@NonNull myViewHolder holder, int position, @NonNull mememodel model) {

    holder.username.setText(model.getNameuser());
    holder.subuser.setText(model.getSubname());
    holder.title.setText(model.getTitle());
    Glide.with(holder.imgmeme.getContext()).load(model.getImagesurl())
      .placeholder(R.drawable.logoinhanced)
      .error(R.drawable.logoinhanced).into(holder.imgmeme);

  }

  @NonNull
  @Override
  public myViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    View view =
      LayoutInflater.from(parent.getContext()).inflate(R.layout.memes_item, parent, false);

    return new myViewHolder(view);
  }

  @Override
  public void onDataChanged() {

  }

  @Override
  public void onError(@NonNull DatabaseError error) {
    super.onError(error);

  }

  class myViewHolder extends RecyclerView.ViewHolder {

    ImageView imgmeme;
    TextView username, subuser, title;

    public myViewHolder(@NonNull View itemView) {
      super(itemView);

      imgmeme = itemView.findViewById(R.id.meme);
      username = itemView.findViewById(R.id.nameuser);
      subuser = itemView.findViewById(R.id.subname);
      title = itemView.findViewById(R.id.titlememe);
    }
  }
}

There Is an Mothod called ONDATACHANGE() when should be in adapter class and i dont know how to control my adapter class from there ;

what should happen :- a Progressbar should be visible when i open the Activity and it should hide when the data is loaded in the RecyclerView !

Answer 1

One way to hide the progress bar when the data is loaded is to pass it to your adapter in its constructor, and then hide it in onDataChanged:

public class MemeAdapter extends FirebaseRecyclerAdapter < mememodel, MemeAdapter.myViewHolder > {
  View progressBar;

  public MemeAdapter(@NonNull FirebaseRecyclerOptions <mememodel> options, View progressBar) {
    super(options);
    this.progressBar = progressBar;
  }

  ...

  @Override
  public void onDataChanged() {
    progressBar.setVisibility(View.GONE)
  }