Recyclerview animation not working in activity - android-studio

Question

i have an activity that contains 2 fragments
StepsFragment contains a Recyclerview but the Recyclerview's animation is not working
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="wrap_content"
android:layout_height="400dp"
android:background="#B3D1DB"
tools:context=".StepsFragment">
<TextView
android:id="#+id/inputEntred"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView"
android:visibility="invisible" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/RV"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipToPadding="false"
android:layoutAnimation="#anim/layou_animation_fall_down"
android:paddingTop="10dp"
android:paddingBottom="30dp" />
</RelativeLayout>
layou-animation-fall-down
<layoutAnimation xmlns:android="http://schemas.android.com/apk/res/android"
android:animation="#anim/fall_down"
android:animationOrder="normal"
android:delay="15%">
fall-down
<set xmlns:android="http://schemas.android.com/apk/res/android" android:duration="6000">
<translate
android:fromYDelta="-20%"
android:interpolator="#android:anim/accelerate_decelerate_interpolator"
android:toYDelta="0"
android:duration="1000" />
<alpha
android:fromAlpha="0"
android:interpolator="#android:anim/accelerate_decelerate_interpolator"
android:toAlpha="3"
android:duration="1000"
/>
<scale
android:fromXScale="105%"
android:fromYScale="105%"
android:interpolator="#android:anim/accelerate_decelerate_interpolator"
android:pivotX="50%"
android:pivotY="50%"
android:toXScale="100%"
android:toYScale="100%" android:duration="1000"
/>
</set>
activity layout
<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=".Sorting_activity">
<RelativeLayout
android:id="#+id/triLayout"
android:layout_width="0dp"
android:layout_height="300dp"
app:layout_constraintBottom_toTopOf="#+id/stepsLayout"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0">
</RelativeLayout>
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:id="#+id/stepsLayout"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/triLayout"></androidx.coordinatorlayout.widget.CoordinatorLayout>
StepsFragment
public class StepsFragment extends Fragment {
private OnFragmentInteractionListener mListener;
private static TextView inputEntred ;
private static RecyclerView RV ;
private Handler mhandler = new Handler();
public StepsFragment() {
// Required empty public constructor
}
public void setTextView(String textentered){
inputEntred.setText(textentered);
String[] numberList = inputEntred.getText().toString().split(",");
final Integer[] numbers = new Integer[numberList.length];
SelectionSort m1 = new SelectionSort();
ArrayList<String> mystepsList = m1.steps(numbers);// returns the steps numbers
final StepListAdapter adapter = new StepListAdapter() ;
RV.setAdapter(adapter);
LinearLayoutManager llm = new LinearLayoutManager(getActivity());
RV.setLayoutManager(llm);
adapter.setList(mystepsList);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view =inflater.inflate(R.layout.fragment_steps, container, false);
inputEntred =view.findViewById(R.id.inputEntred);
RV =view.findViewById(R.id.RV);
return view;
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnFragmentInteractionListener) {
// mListener = (OnFragmentInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnFragmentInteractionListener");
}
}
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
}}

Answer 1

Could you try this? I have to remove unnecessary duration in the XML. Thanks
<set xmlns:android="http://schemas.android.com/apk/res/android"
android:duration="250">
<translate
android:fromYDelta="-20%"
android:toYDelta="0"
android:interpolator="#android:anim/decelerate_interpolator"
/>
<alpha
android:fromAlpha="0"
android:toAlpha="1"
android:interpolator="#android:anim/decelerate_interpolator"
/>
<scale
android:fromXScale="105%"
android:fromYScale="105%"
android:toXScale="100%"
android:toYScale="100%"
android:pivotX="50%"
android:pivotY="50%"
android:interpolator="#android:anim/decelerate_interpolator"
/>
</set>