After updating the version of the libraries in build.gradle RecyclerView on api lvl 24+ displays the data through time, but on api lvl <24 everything works stably. What could be the problem? Thank you in advance.
Method to get data
private void setUpDB() { myRef.child(getIntent().getStringExtra(FActivity.TITLE)).addValueEventListener(new ValueEventListener() { @Override public void onDataChange(DataSnapshot dataSnapshot) { iterable = dataSnapshot.getChildren().iterator(); for (int i = 0; i < dataSnapshot.getChildrenCount(); i++) { DataSnapshot dataFormula = iterable.next(); Formula formula = new Formula(dataFormula.getKey(), String.valueOf(dataFormula .getValue())); listFormulas.add(formula); } } @Override public void onCancelled(DatabaseError databaseError) { Log.w(TAG, "Failed to read value.", databaseError.toException()); } }); } Full class for better understanding
public class CorrectListActivity extends AppCompatActivity { String TAG = "CorrectListActivity"; RecyclerView recyclerView; ArrayList<Formula> listFormulas; private Iterator<DataSnapshot> iterable; private DatabaseReference myRef; private Realm mRealm; private Realm mRealmForDel; private SharedPreferences preferences; @Override protected void onCreate(Bundle savedInstanceState) { preferences = PreferenceManager.getDefaultSharedPreferences(this); if (preferences.getBoolean("cb_pref_dark_style", false)) { setTheme(R.style.darkTheme); } else { setTheme(R.style.AppTheme); } super.onCreate(savedInstanceState); setContentView(R.layout.activity_correct_list); final FirebaseDatabase database = FirebaseDatabase.getInstance(); myRef = database.getReference(); myRef.keepSynced(true); mRealm = Realm.getInstance(PhysicsApp.getConfigForFavorites()); mRealmForDel = Realm.getInstance(PhysicsApp.getConfigForDelFormulas()); listFormulas = new ArrayList<>(); recyclerView = findViewById(R.id.correctList_recyclerView); setUpDB(); recyclerView.setLayoutManager(new LinearLayoutManager(this)); recyclerView.setHasFixedSize(true); CorrectListAdapter adapter = new CorrectListAdapter(listFormulas, this); adapter.setCorrectListCallback(new CorrectListCallback() { @Override public void liked(int position) { Formula item = listFormulas.get(position); mRealm.beginTransaction(); Favorite favorite = mRealm.createObject(Favorite.class); favorite.setSection(getIntent().getStringExtra(FActivity.TITLE)); favorite.setName(item.getTitle()); favorite.setFormula(item.getFormula()); mRealm.commitTransaction(); } @Override public void unLiked(int position) { Formula item = listFormulas.get(position); mRealm.beginTransaction(); RealmResults<Favorite> favorites = mRealm.where(Favorite.class) .equalTo("name", item.getTitle()).findAll(); for (int i = favorites.size() - 1; i >= 0; i--) { if (favorites.get(i) != null) { favorites.get(i).deleteFromRealm(); } } mRealm.commitTransaction(); } @Override public boolean getLikedState(int position) { Favorite favorite = mRealm.where(Favorite.class) .equalTo("name", listFormulas.get(position).getTitle()) .findFirst(); return favorite != null; } @Override public void crossToggle(int position, boolean isDelete) { Formula item = listFormulas.get(position); if(isDelete){ mRealmForDel.beginTransaction(); DelFormula delFormula = mRealmForDel.createObject(DelFormula.class); delFormula.setParent(getIntent().getStringExtra(FActivity.TITLE)); delFormula.setName(item.getTitle()); mRealmForDel.commitTransaction(); }else { mRealmForDel.beginTransaction(); RealmResults<DelFormula> delFormulas = mRealmForDel.where(DelFormula.class) .equalTo("name", item.getTitle()).findAll(); for (int i = delFormulas.size() - 1; i >= 0; i--) { if (delFormulas.get(i) != null) { delFormulas.get(i).deleteFromRealm(); } } mRealmForDel.commitTransaction(); } } @Override public boolean getCrossState(int position) { DelFormula delFormula = mRealmForDel.where(DelFormula.class) .equalTo("name", listFormulas.get(position).getTitle()) .findFirst(); return delFormula != null; } }); recyclerView.setAdapter(adapter); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.menu_correct_list, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.itemHelp: Intent intent = new Intent(this, HelpActivity.class); intent.putExtra(FActivity.TITLE,getIntent().getStringExtra(FActivity.TITLE)); startActivity(intent); break; } return super.onOptionsItemSelected(item); } private void setUpDB() { myRef.child(getIntent().getStringExtra(FActivity.TITLE)).addValueEventListener(new ValueEventListener() { @Override public void onDataChange(DataSnapshot dataSnapshot) { iterable = dataSnapshot.getChildren().iterator(); for (int i = 0; i < dataSnapshot.getChildrenCount(); i++) { DataSnapshot dataFormula = iterable.next(); Formula formula = new Formula(dataFormula.getKey(), String.valueOf(dataFormula .getValue())); listFormulas.add(formula); } } @Override public void onCancelled(DatabaseError databaseError) { Log.w(TAG, "Failed to read value.", databaseError.toException()); } }); } Adapter
public class CorrectListAdapter extends RecyclerView.Adapter<CorrectListAdapter.Holder> { private ArrayList<Formula> listData; private LayoutInflater inflater; private CorrectListCallback callback; private boolean isDelete; public CorrectListAdapter(ArrayList<Formula> listData, Context context) { this.listData = listData; this.inflater = LayoutInflater.from(context); } public void setCorrectListCallback(CorrectListCallback callback ){ this.callback = callback; } public boolean getLikedState(int position){ return callback.getLikedState(position); } public boolean getCrossState(int position){ return callback.getCrossState(position); } private void checkState(CrossView crossView, int position, Context context){ if(!getCrossState(position)){ crossView.cross(0); isDelete = false; }else { crossView.plus(0); crossView.setColor(ContextCompat.getColor(context, R.color.colorCorrect)); isDelete = true; } } @Override public Holder onCreateViewHolder(ViewGroup parent, int viewType) { View view = inflater.inflate(R.layout.correct_list_item, parent, false); return new Holder(view); } @Override public void onBindViewHolder(final Holder holder, final int position) { Formula item = listData.get(position); holder.title.setText(item.getTitle()); holder.starButton.setLiked(getLikedState(holder.getAdapterPosition())); holder.starButton.setOnLikeListener(new OnLikeListener() { @Override public void liked(LikeButton likeButton) { callback.liked(holder.getAdapterPosition()); } @Override public void unLiked(LikeButton likeButton) { callback.unLiked(holder.getAdapterPosition()); } }); checkState(holder.crossButton, position, holder.context); holder.crossButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { checkState(holder.crossButton, position, holder.context); holder.crossButton.toggle(); isDelete = !isDelete; if (isDelete){ holder.crossButton.setColor(ContextCompat.getColor(holder.context, R.color.colorCorrect)); }else { holder.crossButton.setColor(ContextCompat.getColor(holder.context, R.color.colorDelCross)); } callback.crossToggle(holder.getAdapterPosition(), isDelete); } }); if (item.getFormula().split("[=]")[0].contains("/")) { holder.doubleFractionView.setVisibility(View.VISIBLE); holder.fractionView.setVisibility(View.GONE); holder.stoFractionView.setVisibility(View.GONE); holder.doubleFractionView.setDoubleFraction(item.getFormula()); } else if (item.getFormula().split("[=]")[1].contains("â—¤") || item.getFormula().split("[=]")[1].contains("â—˘") || item.getFormula().split("[=]")[1].contains("â—‡")) { holder.stoFractionView.setVisibility(View.VISIBLE); holder.doubleFractionView.setVisibility(View.GONE); holder.fractionView.setVisibility(View.GONE); holder.stoFractionView.setSTOFraction(item.getFormula()); } else { holder.fractionView.setVisibility(View.VISIBLE); holder.doubleFractionView.setVisibility(View.GONE); holder.stoFractionView.setVisibility(View.GONE); holder.fractionView.setFraction(item.getFormula()); } } @Override public int getItemCount() { return listData.size(); } class Holder extends RecyclerView.ViewHolder { private TextView title; private FractionView fractionView; private DoubleFractionView doubleFractionView; private STOFractionView stoFractionView; private LikeButton starButton; private CrossView crossButton; private Context context; Holder(View itemView) { super(itemView); title = itemView.findViewById(R.id.correctItem_title); fractionView = itemView.findViewById(R.id.correctItem_formula); doubleFractionView = itemView.findViewById(R.id.correctItem_doubleFormula); stoFractionView = itemView.findViewById(R.id.correctItem_STOFormula); starButton = itemView.findViewById(R.id.correctItem_star_button); crossButton = itemView.findViewById(R.id.sample_cross_view); context = itemView.getContext(); } } 