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get context after returning from adapter to fragment

I am using contextual action bar in my fragment("UnitsFragment.java") to delete and edit items of recyclerview. But when I come back from recyclerview adapter class("UnitsRv.java"). The context seems to be null. I tried returning context from adapter and it worked for function "prepareSelection". However for "onActionItemClicked" under ActionMode.callback, I need to get context so that I can use alertdialog for editing the items.
The "requireContext()" throws this error: Fragment UnitsFragment{e3a36c8 (b4957397-055a-4b1c-8af2-fee89a3e9b35)} not attached to a context.
Here are my codes.
UnitsFragment.java
public class UnitsFragment extends Fragment {
private static final String TAG = "UnitsFragment";
private RecyclerView recyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager layoutManager;
ArrayList<UnitsList> unitsLists = new ArrayList<>();
Activity mcontext = getActivity();
Context dcontext;
ActionMode actionMode;
public static ArrayList<UnitsList> selectionList = new ArrayList<>();
public static boolean isInActionMode = false;
List<String> list = DatabaseClient.getInstance(getContext())
.getUserDatabase()
.getUnitDao().findUnitNameList();
public UnitsFragment() {
}
private ActionMode.Callback actionModeCallback = new ActionMode.Callback() {
#Override
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
mode.getMenuInflater().inflate(R.menu.menu_item_action, menu);
return true;
}
#Override
public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
return false;
}
#Override
public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_item_edit:
if (selectionList.size() == 1) {
final EditText editText = new EditText(requireContext());
new AlertDialog.Builder(requireContext())
.setTitle("Rename unit name").setView(editText)
.setPositiveButton("Rename", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
UnitsList unitsList = selectionList.get(0);
unitsList.setUnit_name(editText.getText().toString().trim());
isInActionMode = false;
((UnitsRv) mAdapter).changeDataItem(getCheckedLastPosition(), unitsList);
actionMode.finish();
selectionList.clear();
}
})
.create()
.show();
Toast.makeText(getContext(), "Edit", Toast.LENGTH_SHORT).show();
mode.finish();
return true;
}
case R.id.menu_item_delete:
isInActionMode = false;
((UnitsRv) mAdapter).removeData(selectionList);
Toast.makeText(getContext(), "Delete", Toast.LENGTH_SHORT).show();
actionMode.finish();
selectionList.clear();
return true;
default:
return false;
}
}
#Override
public void onDestroyActionMode(ActionMode mode) {
actionMode = null;
}
};
private int getCheckedLastPosition() {
ArrayList<UnitsList> dataSet = UnitsRv.getDataSet();
for (int i = 0; i < dataSet.size(); i++) {
if (dataSet.get(i).equals(selectionList.get(0))) {
return i;
}
}
return 0;
}
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
}
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_units, container, false);
setHasOptionsMenu(true);
dcontext = rootView.getContext();
Log.d(TAG, "onCreateView1: " + dcontext);
recyclerView = rootView.findViewById(R.id.rv_units);
recyclerView.setHasFixedSize(true);
recyclerView.addItemDecoration(new DividerItemDecoration(getContext(),
DividerItemDecoration.HORIZONTAL));
recyclerView.addItemDecoration(new DividerItemDecoration(getContext(),
DividerItemDecoration.VERTICAL));
layoutManager = new GridLayoutManager(getContext(), 2);
recyclerView.setLayoutManager(layoutManager);
for (String string : list) {
unitsLists.add(new UnitsList(string));
}
Log.d(TAG, "onCreateView: " + getContext());
mAdapter = new UnitsRv(mcontext,unitsLists);
recyclerView.setAdapter(mAdapter);
return rootView;
}
#Override
public void onCreateOptionsMenu(#NonNull Menu menu, #NonNull MenuInflater inflater) {
inflater.inflate(R.menu.add, menu);
super.onCreateOptionsMenu(menu, inflater);
}
#Override
public boolean onOptionsItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_item_new:
final View customLayout = getLayoutInflater().inflate(R.layout.add_unit_dialog, null);
final EditText edt_unit_name = customLayout.findViewById(R.id.edt_new_unit_name);
final AlertDialog dialog = new AlertDialog.Builder(getContext())
.setView(customLayout)
.setTitle("Unit name")
.setPositiveButton(android.R.string.ok, null) //Set to null. We override the onclick
.setNegativeButton(android.R.string.cancel, null)
.create();
dialog.setOnShowListener(new DialogInterface.OnShowListener() {
#Override
public void onShow(DialogInterface dialogInterface) {
Button ok_btn = dialog.getButton(AlertDialog.BUTTON_POSITIVE);
Button cancel_btn = dialog.getButton(AlertDialog.BUTTON_NEGATIVE);
ok_btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String unit_name = edt_unit_name.getText().toString().trim();
if (!TextUtils.isEmpty(unit_name)) {
String old_unit_name = DatabaseClient.getInstance(getContext())
.getUserDatabase()
.getUnitDao()
.findByUnitName(unit_name);
if (old_unit_name == null) {
DatabaseClient.getInstance(getContext())
.getUserDatabase()
.getUnitDao()
.insertUnits(new UnitsList(unit_name));
unitsLists.add(new UnitsList(unit_name));
dialog.dismiss();
} else {
edt_unit_name.setError("Unit already exists");
}
} else {
edt_unit_name.setError("Can't be empty");
}
}
});
cancel_btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
dialog.dismiss();
}
});
}
});
dialog.show();
return true;
}
return super.onOptionsItemSelected(item);
}
public void prepareSelection(Context context,int position) {
if(actionMode == null) {
isInActionMode = true;
for (String string : list) {
unitsLists.add(new UnitsList(string));
}
mAdapter = new UnitsRv(context, unitsLists);
Log.d(TAG, "prepareSelection: " + mAdapter);
Log.d(TAG, "prepareSelection1: " + dcontext);
mcontext = (Activity)context;
actionMode = mcontext.startActionMode(actionModeCallback);
mAdapter.notifyDataSetChanged();
if (!selectionList.contains(unitsLists.get(position))) {
selectionList.add(unitsLists.get(position));
}
updateViewCounter();
}
}
private void updateViewCounter() {
int counter = selectionList.size();
if (counter == 1) {
actionMode.setTitle(counter + "item selected");
} else {
actionMode.setTitle(counter + "items selected");
}
}
}
This is my Adapter class.
UnitsRv.java
public class UnitsRv extends RecyclerView.Adapter<UnitsRv.ViewHolder> {
private static final String TAG = "UnitsRv";
private static ArrayList<UnitsList> munitsLists = new ArrayList<>();
UnitsFragment unitsFragment = new UnitsFragment();
Context mcontext;
public UnitsRv(Context context,ArrayList<UnitsList> unitsLists) {
mcontext = context;
munitsLists = unitsLists;
}
class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener, View.OnLongClickListener {
TextView unit_name;
public ViewHolder(View v) {
super(v);
unit_name = v.findViewById(R.id.unit_name);
v.setOnLongClickListener(this);
}
#Override
public void onClick(View view) {
if (UnitsFragment.isInActionMode){
unitsFragment.prepareSelection(mcontext,getAdapterPosition());
notifyItemChanged(getAdapterPosition());
}
}
#Override
public boolean onLongClick(View view) {
Log.d(TAG, "onLongClick: " + getAdapterPosition());
unitsFragment.prepareSelection(view.getContext(),getAdapterPosition());
return true;
}
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.units_item, parent, false);
return new ViewHolder(itemView);
}
#Override
public void onBindViewHolder(#NonNull final ViewHolder holder, final int position) {
holder.unit_name.setText(munitsLists.get(position).getUnit_name());
if (UnitsFragment.isInActionMode){
if (UnitsFragment.selectionList.contains(munitsLists.get(position))){
holder.itemView.setBackgroundResource(R.color.colorSelected);
}
}
}
#Override
public int getItemCount() {
return munitsLists.size();
}
public static ArrayList<UnitsList> getDataSet() {
return munitsLists;
}
public void changeDataItem(int position, UnitsList unitsList) {
munitsLists.set(position, unitsList);
notifyDataSetChanged();
}
public void removeData(ArrayList<UnitsList> list) {
for (UnitsList unitsList : list) {
munitsLists.remove(unitsList);
}
notifyDataSetChanged();
}
}

First, you should not create instance of your UnitsFragment inside your adapter.
You can use EventBus to communicate between Activities, Fragments, Adapters, etc.
Or You can do your task using interface. like below.
Create an interface like this
public interface AdapterCallback {
void prepareSelection(Context context,int position);
}
In your UnitsFragment implement the above interface. like the following
public class UnitsFragment extends Fragment implements AdapterCallback{
// your other codes
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_units, container, false);
setHasOptionsMenu(true);
// .... your other codes
Log.d(TAG, "onCreateView: " + getContext());
// modify below line like this
mAdapter = new UnitsRv(mcontext, unitsLists, this); // here you have to pass an extra parameter that will implement your callback method from adapter.
recyclerView.setAdapter(mAdapter);
return rootView;
}
// ... you other codes
#Override
public void prepareSelection(Context context,int position) {
if(actionMode == null) {
isInActionMode = true;
for (String string : list) {
unitsLists.add(new UnitsList(string));
}
mAdapter = new UnitsRv(context, unitsLists,this); // add this as parameter.
Log.d(TAG, "prepareSelection: " + mAdapter);
Log.d(TAG, "prepareSelection1: " + dcontext);
mcontext = (Activity)context;
actionMode = mcontext.startActionMode(actionModeCallback);
mAdapter.notifyDataSetChanged();
if (!selectionList.contains(unitsLists.get(position))) {
selectionList.add(unitsLists.get(position));
}
updateViewCounter();
}
}
// other codes
}
Now, inside your Adapter you need to add an extra argument in constructor of UnitsRv and call your interface method from adapter ussing mAdapterCallback.
public class UnitsRv extends RecyclerView.Adapter<UnitsRv.ViewHolder> {
private static final String TAG = "UnitsRv";
private static ArrayList<UnitsList> munitsLists = new ArrayList<>();
UnitsFragment unitsFragment = new UnitsFragment(); // remove this line
private AdapterCallback mAdapterCallback; // add this line
Context mcontext;
public UnitsRv(Context context,ArrayList<UnitsList> unitsLists, AdapterCallback callback) {
mcontext = context;
munitsLists = unitsLists;
this.mAdapterCallback = callback; // add this line
}
class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener, View.OnLongClickListener {
TextView unit_name;
public ViewHolder(View v) {
super(v);
unit_name = v.findViewById(R.id.unit_name);
v.setOnLongClickListener(this);
}
#Override
public void onClick(View view) {
if (UnitsFragment.isInActionMode){
mAdapterCallback.prepareSelection(mcontext,getAdapterPosition()); // modify this line
notifyItemChanged(getAdapterPosition());
}
}
#Override
public boolean onLongClick(View view) {
Log.d(TAG, "onLongClick: " + getAdapterPosition());
mAdapterCallback.prepareSelection(view.getContext(),getAdapterPosition()); // modify this line
return true;
}
}
// your other codes....
}

You should check for your fragment is attached or not with isAdded()
place if(!isAdded()) return in your onActionItemClicked. and replace requireContext() with getContext() because requireContext() always throws IllegalStateException if fragment is not attached.

override onAttach method to save context in your fragment.
#Override
public void onAttach(Context context) {
super.onAttach(context);
this.context= context;
}
Hope this helps.

How to implement getItemViewType() for multiple layout in RecyclerView in a Movie Database app

I am creating a movie app using TMDB api, Retrofit, Gson and Glide. I have two recyclerView and two layout to inflate. But I am unable to inflate 2 layout in recyclerView adapter.
I have already implemented popular and upcoming movie list in 2 different recyclerView. But they are showing using 1 single layout. I want to inflate popular movies in one layout and upcoming movies in another layout. I can't set the condition for getItemViewType() method. How can I check for popular and upcoming movies list in getItemViewType() method and implement it on onCreateViewHolder() method of recyclerView.
MovieAdapter class:
public class MovieAdapter extends RecyclerView.Adapter<MovieAdapter.MovieViewHolder> {
private Context context;
private ArrayList<Movie> movieArrayList;
public MovieAdapter(Context context, ArrayList<Movie> movieArrayList) {
this.context = context;
this.movieArrayList = movieArrayList;
}
#NonNull
#Override
public MovieViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.movie_list_item, parent, false);
return new MovieViewHolder(view);
}
#Override
public int getItemViewType(int position) {
return super.getItemViewType(position);
}
#Override
// Set values to the list item components
public void onBindViewHolder(#NonNull MovieViewHolder holder, int position) {
holder.movieTitle.setText(movieArrayList.get(position).getOriginalTitle());
holder.rating.setText(String.valueOf(movieArrayList.get(position).getVoteAverage()));
String imagePath = "https://image.tmdb.org/t/p/w500" + movieArrayList.get(position).getPosterPath();
Glide.with(context)
.load(imagePath)
.placeholder(R.drawable.loading)
.into(holder.movieImage);
}
#Override
public int getItemCount() {
return movieArrayList == null ? 0 : movieArrayList.size();
}
public class MovieViewHolder extends RecyclerView.ViewHolder {
TextView movieTitle, rating;
ImageView movieImage;
public MovieViewHolder(#NonNull View itemView) {
super(itemView);
movieImage = itemView.findViewById(R.id.ivMovieImage);
movieTitle = itemView.findViewById(R.id.tvTitle);
rating = itemView.findViewById(R.id.tvRating);
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
int position = getAdapterPosition();
if (position != RecyclerView.NO_POSITION) {
Movie selectedMovie = movieArrayList.get(position);
Intent intent = new Intent(context, MovieActivity.class);
intent.putExtra("movie", selectedMovie);
context.startActivity(intent);
}
}
});
}
}
}
MainActivity class:
public class MainActivity extends AppCompatActivity {
private ArrayList<Movie> popularMovie, topRatedMovie;
private RecyclerView recyclerViewPopular, recyclerViewUpcoming;
private MovieAdapter movieAdapter, upcomingAdapter;
private SwipeRefreshLayout swipeRefreshLayout;
private static ViewPager mPager;
private static int currentPage = 0;
private static int NUM_PAGES = 0;
String[] urls = new String[] {
"https://image.tmdb.org/t/p/w500/udDclJoHjfjb8Ekgsd4FDteOkCU.jpg",
"https://image.tmdb.org/t/p/w500//2bXbqYdUdNVa8VIWXVfclP2ICtT.jpg",
"https://image.tmdb.org/t/p/w500//zfE0R94v1E8cuKAerbskfD3VfUt.jpg",
"https://image.tmdb.org/t/p/w500//lcq8dVxeeOqHvvgcte707K0KVx5.jpg",
"https://image.tmdb.org/t/p/w500//w9kR8qbmQ01HwnvK4alvnQ2ca0L.jpg"
};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initSlider();
getPopularMovies();
getUpcomingMovies();
swipeRefreshLayout = findViewById(R.id.swipe_layout);
swipeRefreshLayout.setColorSchemeResources(R.color.colorPrimaryDark);
swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
getPopularMovies();
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
swipeRefreshLayout.setRefreshing(false);
}
}, 4000);
}
});
}
public void getPopularMovies() {
MovieDataService movieDataService = RetrofitInstance.getService();
Call<MovieDBResponse> callPopular = movieDataService.getPopularMovies(this.getString(R.string.apiKey));
callPopular.enqueue(new Callback<MovieDBResponse>() {
#Override
public void onResponse(Call<MovieDBResponse> call, Response<MovieDBResponse> response) {
MovieDBResponse movieDBResponse = response.body();
if(movieDBResponse!=null && movieDBResponse.getMovies()!=null) {
popularMovie = (ArrayList<Movie>) movieDBResponse.getMovies();
showOnRecyclerView();
}
}
#Override
public void onFailure(Call<MovieDBResponse> call, Throwable t) { }
});
}
public void getUpcomingMovies() {
MovieDataService movieDataService = RetrofitInstance.getService();
Call<MovieDBResponse> callUpcoming = movieDataService.getUpcomingMovies(this.getString(R.string.apiKey));
callUpcoming.enqueue(new Callback<MovieDBResponse>() {
#Override
public void onResponse(Call<MovieDBResponse> call, Response<MovieDBResponse> response) {
MovieDBResponse movieDBResponse = response.body();
if(movieDBResponse!=null && movieDBResponse.getMovies()!=null) {
topRatedMovie = (ArrayList<Movie>) movieDBResponse.getMovies();
showOnRecyclerView();
}
}
#Override
public void onFailure(Call<MovieDBResponse> call, Throwable t) { }
});
}
private void showOnRecyclerView() {
recyclerViewPopular = findViewById(R.id.rvMovies);
recyclerViewUpcoming = findViewById(R.id.rvTopMovies);
RecyclerView.LayoutManager popularLayoutManager = new LinearLayoutManager(this);
RecyclerView.LayoutManager upcomingLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
recyclerViewUpcoming.setLayoutManager(upcomingLayoutManager);
recyclerViewPopular.setLayoutManager(popularLayoutManager);
movieAdapter = new MovieAdapter(this, popularMovie);
upcomingAdapter = new MovieAdapter(this, topRatedMovie);
if (this.getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) {
recyclerViewPopular.setLayoutManager(new GridLayoutManager(this, 2));
}else {
recyclerViewPopular.setLayoutManager(new GridLayoutManager(this, 4));
}
recyclerViewPopular.setItemAnimator(new DefaultItemAnimator());
recyclerViewUpcoming.setItemAnimator(new DefaultItemAnimator());
recyclerViewPopular.setAdapter(movieAdapter);
recyclerViewUpcoming.setAdapter(upcomingAdapter);
movieAdapter.notifyDataSetChanged();
upcomingAdapter.notifyDataSetChanged();
}
}
I want to inflate 2 different layout "movie_list_item.xml" and "upcoming_movie_list_item.xml" in onCreateViewHolder() method.

With in your adapter class(MovieAdapter) create a new constructor and add extra params of Int or enum whatever simple for you i am just giving you simple example:-
public class MovieAdapter extends RecyclerView.Adapter<MovieAdapter.MovieViewHolder> {
private Context context;
private ArrayList<Movie> movieArrayList;
private int viewType;
public MovieAdapter(Context context, ArrayList < Movie > movieArrayList, int viewType) {
this.context = context;
this.movieArrayList = movieArrayList;
this.viewType=viewType;
}
#NonNull
#Override
public MovieViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view;
if (viewType == 1) {
//Popular movie layout
view = LayoutInflater.from(parent.getContext()).inflate(R.layout.movie_list_item, parent, false);
} else {
//upcoming movie layout
view = LayoutInflater.from(parent.getContext()).inflate(R.layout.movie_list_item, parent, false);
}
return new MovieViewHolder(view);
}
#Override
public int getItemViewType(int position) {
if (viewType == 1)
return 1; //Popular Movie Layout
else
return 2; //Upcoming Movie Layout
// return super.getItemViewType(position);
}
#Override
// Set values to the list item components
public void onBindViewHolder(#NonNull MovieViewHolder holder, int position) {
holder.movieTitle.setText(movieArrayList.get(position).getOriginalTitle());
holder.rating.setText(String.valueOf(movieArrayList.get(position).getVoteAverage()));
String imagePath = "https://image.tmdb.org/t/p/w500" + movieArrayList.get(position).getPosterPath();
Glide.with(context)
.load(imagePath)
.placeholder(R.drawable.loading)
.into(holder.movieImage);
}
#Override
public int getItemCount() {
return movieArrayList == null ? 0 : movieArrayList.size();
}
public class MovieViewHolder extends RecyclerView.ViewHolder {
TextView movieTitle, rating;
ImageView movieImage;
public MovieViewHolder(#NonNull View itemView) {
super(itemView);
movieImage = itemView.findViewById(R.id.ivMovieImage);
movieTitle = itemView.findViewById(R.id.tvTitle);
rating = itemView.findViewById(R.id.tvRating);
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
int position = getAdapterPosition();
if (position != RecyclerView.NO_POSITION) {
Movie selectedMovie = movieArrayList.get(position);
Intent intent = new Intent(context, MovieActivity.class);
intent.putExtra("movie", selectedMovie);
context.startActivity(intent);
}
}
});
}
}
and within your activity change on this method only
private void showOnRecyclerView() {
recyclerViewPopular = findViewById(R.id.rvMovies);
recyclerViewUpcoming = findViewById(R.id.rvTopMovies);
RecyclerView.LayoutManager popularLayoutManager = new LinearLayoutManager(this);
RecyclerView.LayoutManager upcomingLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
recyclerViewUpcoming.setLayoutManager(upcomingLayoutManager);
recyclerViewPopular.setLayoutManager(popularLayoutManager);
movieAdapter = new MovieAdapter(this, popularMovie,1);
upcomingAdapter = new MovieAdapter(this, topRatedMovie,2);
if (this.getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) {
recyclerViewPopular.setLayoutManager(new GridLayoutManager(this, 2));
} else {
recyclerViewPopular.setLayoutManager(new GridLayoutManager(this, 4));
}
recyclerViewPopular.setItemAnimator(new DefaultItemAnimator());
recyclerViewUpcoming.setItemAnimator(new DefaultItemAnimator());
recyclerViewPopular.setAdapter(movieAdapter);
recyclerViewUpcoming.setAdapter(upcomingAdapter);
movieAdapter.notifyDataSetChanged();
upcomingAdapter.notifyDataSetChanged();
}

Create layout for movie_empty_item
public class MovieAdapter extends RecyclerView.Adapter<MovieAdapter.MovieViewHolder> {
private Context context;
private ArrayList<Movie> movieArrayList;
//add this two line
private static final int EMPTY_VIEW_TYPE = 0;
private static final int NORMAL_VIEW_TYPE = 1;
public MovieAdapter(Context context, ArrayList<Movie> movieArrayList) {
this.context = context;
this.movieArrayList = movieArrayList;
}
#NonNull
#Override
public MovieViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
//return viewholder replace like this
if(viewType == NORMAL_VIEW_TYPE) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.movie_list_item, parent, false);
return new MovieViewHolder(view);
}else {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.movie_empty_item, parent, false);
return new EmptyViewHolder(view);
};
}
//getItemViewType return replace like this
#Override
public int getItemViewType(int position) {
return movieArrayList.size()>0?NORMAL_VIEW_TYPE:EMPTY_VIEW_TYPE;
}
#Override
// Set values to the list item components
public void onBindViewHolder(#NonNull MovieViewHolder holder, int position) {
holder.movieTitle.setText(movieArrayList.get(position).getOriginalTitle());
holder.rating.setText(String.valueOf(movieArrayList.get(position).getVoteAverage()));
String imagePath = "https://image.tmdb.org/t/p/w500" + movieArrayList.get(position).getPosterPath();
Glide.with(context)
.load(imagePath)
.placeholder(R.drawable.loading)
.into(holder.movieImage);
}
#Override
public int getItemCount() {
return movieArrayList.size() ? movieArrayList.size():1 ;
}
public class MovieViewHolder extends RecyclerView.ViewHolder {
TextView movieTitle, rating;
ImageView movieImage;
public MovieViewHolder(#NonNull View itemView) {
super(itemView);
movieImage = itemView.findViewById(R.id.ivMovieImage);
movieTitle = itemView.findViewById(R.id.tvTitle);
rating = itemView.findViewById(R.id.tvRating);
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
int position = getAdapterPosition();
if (position != RecyclerView.NO_POSITION) {
Movie selectedMovie = movieArrayList.get(position);
Intent intent = new Intent(context, MovieActivity.class);
intent.putExtra("movie", selectedMovie);
context.startActivity(intent);
}
}
});
}
}
public class EmptyViewHolder extends RecyclerView.ViewHolder {
public EmptyViewHolder(#NonNull View itemView) {
super(itemView);
}
}
}

attempting to use incompatible return type

Can someone help me with this error that I keep getting? The program that I'm trying to implement admob banner ad between items in recyclerview. every thing is ok but still this one error that blocked me from go on.
public class RecipeAdapter extends RecyclerView.Adapter<RecipeAdapter.ViewHolder> {
public static final String TAG = RecipeAdapter.class.getSimpleName();
public static final HashMap<String, Integer> LABEL_COLORS = new HashMap<String, Integer>() {{
put("Low-Carb", R.color.colorLowCarb);
put("Low-Fat", R.color.colorLowFat);
put("Low-Sodium", R.color.colorLowSodium);
put("Medium-Carb", R.color.colorMediumCarb);
put("Vegetarian", R.color.colorVegetarian);
put("Balanced", R.color.colorBalanced);
}};
private Context mContext;
private LayoutInflater mInflater;
private ArrayList<Recipe> mDataSource;
private static final int DEFAULT_VIEW_TYPE = 1;
private static final int NATIVE_AD_VIEW_TYPE = 2;
public RecipeAdapter(Context context, ArrayList<Recipe> items) {
mContext = context;
mDataSource = items;
mInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE); }
#Override public int getItemViewType(int position) {
// Change the position of the ad displayed here. Current is after 5
if ((position + 1) % 6 == 0) {
return NATIVE_AD_VIEW_TYPE;
}
return DEFAULT_VIEW_TYPE; }
#NonNull
#Override public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view;
LayoutInflater layoutInflater = LayoutInflater.from(mContext);
switch (viewType) {
default:
view = layoutInflater
.inflate(R.layout.list_item_native_ad, parent, false);
return new ViewHolder(view);
case NATIVE_AD_VIEW_TYPE:
view = layoutInflater.inflate(R.layout.list_item_native_ad, parent, false);
return new ViewHolderAdMob(view);
}
}
#Override public void onBindViewHolder(#NonNull ViewHolder holder, int position) {
// Get relevant subviews of row view
TextView titleTextView = holder.titleTextView;
TextView subtitleTextView = holder.subtitleTextView;
TextView detailTextView = holder.detailTextView;
ImageView thumbnailImageView = holder.thumbnailImageView;
//Get corresponding recipe for row final Recipe recipe = (Recipe) getItem(position);
// Update row view's textviews to display recipe information
titleTextView.setText(recipe.title);
subtitleTextView.setText(recipe.description);
detailTextView.setText(recipe.label);
// Use Picasso to load the image. Temporarily have a placeholder in case it's slow to load
Picasso.with(mContext).load(recipe.imageUrl).placeholder(R.mipmap
.ic_launcher).into(thumbnailImageView);
holder.parentView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent detailIntent = new Intent(mContext, RecipeDetailActivity.class);
detailIntent.putExtra("title", recipe.title);
detailIntent.putExtra("url", recipe.instructionUrl);
mContext.startActivity(detailIntent);
}
});
// Style text views
Typeface titleTypeFace = Typeface.createFromAsset(mContext.getAssets(),
"fonts/JosefinSans-Bold.ttf");
titleTextView.setTypeface(titleTypeFace);
Typeface subtitleTypeFace = Typeface.createFromAsset(mContext.getAssets(),
"fonts/JosefinSans-SemiBoldItalic.ttf");
subtitleTextView.setTypeface(subtitleTypeFace);
Typeface detailTypeFace = Typeface.createFromAsset(mContext.getAssets(),
"fonts/Quicksand-Bold.otf");
detailTextView.setTypeface(detailTypeFace);
detailTextView.setTextColor(android.support.v4.content.ContextCompat.getColor(mContext, LABEL_COLORS
.get(recipe.label)));
}
#Override public int getItemCount() {
return mDataSource.size(); }
#Override public long getItemId(int position) {
return position; }
public Object getItem(int position) {
return mDataSource.get(position); }
public class ViewHolder extends RecyclerView.ViewHolder {
private TextView titleTextView;
private TextView subtitleTextView;
private TextView detailTextView;
private ImageView thumbnailImageView; private View parentView;
public ViewHolder(#NonNull View view){
super(view);
// create a new "Holder" with subviews
this.parentView = view;
this.thumbnailImageView = (ImageView) view.findViewById(R.id.recipe_list_thumbnail);
this.titleTextView = (TextView) view.findViewById(R.id.recipe_list_title);
this.subtitleTextView = (TextView) view.findViewById(R.id.recipe_list_subtitle);
this.detailTextView = (TextView) view.findViewById(R.id.recipe_list_detail);
// hang onto this holder for future recyclage
view.setTag(this);
}
}
public class ViewHolderAdMob extends RecyclerView.ViewHolder {
private final AdView mNativeAd;
public ViewHolderAdMob(View itemView) {
super(itemView);
mNativeAd = itemView.findViewById(R.id.nativeAd);
mNativeAd.setAdListener(new AdListener() {
#Override
public void onAdLoaded() {
super.onAdLoaded();
// if (mItemClickListener != null) {
Log.i("AndroidBash", "onAdLoaded");
// }
}
#Override
public void onAdClosed() {
super.onAdClosed();
// if (mItemClickListener != null) {
Log.i("AndroidBash", "onAdClosed");
// }
}
#Override
public void onAdFailedToLoad(int errorCode) {
super.onAdFailedToLoad(errorCode);
// if (mItemClickListener != null) {
Log.i("AndroidBash", "onAdFailedToLoad");
// }
}
#Override
public void onAdLeftApplication() {
super.onAdLeftApplication();
// if (mItemClickListener != null) {
Log.i("AndroidBash", "onAdLeftApplication");
// }
}
#Override
public void onAdOpened() {
super.onAdOpened();
// if (mItemClickListener != null) {
Log.i("AndroidBash", "onAdOpened");
// }
}
});
AdRequest adRequest = new AdRequest.Builder()
.addTestDevice("") // Remove this before publishing app
.build();
mNativeAd.loadAd(adRequest);
}
}
}

The return type needs to be whatever ViewHolder type you declared for your adapter class.
For example, from the Android RecyclerView example page:
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
// ^^^^^^^^^^^^^^^^^^^^^^
// It should return this type ^
public static class MyViewHolder extends RecyclerView.ViewHolder {
// your adapter
}
#Override
public MyAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent,int viewType) {
// Note: returns MyAdapter.MyViewHolder, not RecyclerView.ViewHolder
}
}
In your case, you have
public class RecipeAdapter extends RecyclerView.Adapter<RecipeAdapter.ViewHolder>
which means your onCreateViewHolder has to return RecipeAdapter.ViewHolder not RecyclerView.ViewHolder.
There is a separate issue too, which is that you have two ViewHolder types in the same adapter. To do this, you would need to change the ViewHolder type that your RecyclerView is based on to the generic type (RecyclerView.ViewHolder).
Please review this question, it has good answers for how to do this.

SetExpandAdapter in RecycleViewAdapter

I have RecycleView List with an ExpandableLinearLayout ( i use a third party library). In my ExpandableLinearLayout I have a ListView, with an custom ArrayAdapter.
I set my Adapter in the RecycleViewAdapter and submit one ArrayList that contains 4 ArrayLists and the position from the onBindViewHolder() method , too fill the different sections in the RecycleView.
I pass the data in the correct section but i get only the first element of each ArrayList. I Log some stuff and the problem is the position from the getView method in my ArrayAdapter is always 0..
I search and played around a bit but i didnt found a solution.. I hope somebody can help..
Sorry for my bad grammar
This is my RecycleView :
public class EmergencyPassAdapter extends RecyclerView.Adapter<EmergencyPassAdapter.EmergencyPassViewHolder> {
private static final String LOG_TAG = EmergencyPassAdapter.class.getName();
private Context context;
private ArrayList<CellInformation> cellInformations;
private SparseBooleanArray expandState = new SparseBooleanArray();
EmergencyPassExpandAdapter emergencyPassExpandAdapter;
public EmergencyPassAdapter(Context context, ArrayList<CellInformation> cellInformations) {
this.context = context;
this.cellInformations = cellInformations;
for (int i = 0; i < cellInformations.size(); i++) {
expandState.append(i, false);
}
}
#Override
public EmergencyPassViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.cell_emergency_pass, parent, false);
return new EmergencyPassViewHolder(view);
}
#Override
public void onBindViewHolder(final EmergencyPassViewHolder holder, final int position) {
CellInformation cellInformation = cellInformations.get(position);
holder.imageViewIcon.setImageDrawable(cellInformation.getIcon());
holder.textViewTitle.setText(cellInformation.getTitel());
emergencyPassExpandAdapter = new EmergencyPassExpandAdapter(context, EmergencyPassExpandDetailFactory.getExpandCellInformation(context), position);
holder.listView.setAdapter(emergencyPassExpandAdapter);
if (cellInformation.getTitel().equals(context.getResources().getString(R.string.emergency_informations_health_insurance_emergency_contacts))) {
holder.expandableLinearLayout.setExpanded(expandState.get(position));
holder.expandableLinearLayout.setListener(new ExpandableLayoutListenerAdapter() {
#Override
public void onPreOpen() {
expandState.put(position, true);
holder.imageViewArrow.setRotation(180);
}
#Override
public void onPreClose() {
expandState.put(position, false);
holder.imageViewArrow.setRotation(360);
}
});
} else if (cellInformation.getTitel().equals(context.getResources().getString(R.string.emergency_informations_health_insurance_legal_guardian))) {
holder.expandableLinearLayout.setExpanded(expandState.get(position));
holder.expandableLinearLayout.setListener(new ExpandableLayoutListenerAdapter() {
#Override
public void onPreOpen() {
expandState.put(position, true);
holder.imageViewArrow.setRotation(180);
}
#Override
public void onPreClose() {
expandState.put(position, false);
holder.imageViewArrow.setRotation(360);
}
});
} else {
holder.expandableLinearLayout.setExpanded(expandState.get(position));
holder.expandableLinearLayout.setListener(new ExpandableLayoutListenerAdapter() {
#Override
public void onPreOpen() {
expandState.put(position, true);
holder.imageViewArrow.setRotation(180);
}
#Override
public void onPreClose() {
expandState.put(position, false);
holder.imageViewArrow.setRotation(360);
}
});
}
holder.relativeLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (!holder.expandableLinearLayout.isExpanded()) {
Log.i(LOG_TAG, "expand");
holder.expandableLinearLayout.expand();
} else {
Log.i(LOG_TAG, "collapse");
holder.expandableLinearLayout.collapse();
}
}
});
}
#Override
public int getItemCount() {
return cellInformations.size();
}
public static class EmergencyPassViewHolder extends RecyclerView.ViewHolder {
TextView textViewTitle, textViewExpandText;
ImageView imageViewIcon, imageViewArrow;
ExpandableLinearLayout expandableLinearLayout;
RelativeLayout relativeLayout;
ListView listView;
public EmergencyPassViewHolder(View itemView) {
super(itemView);
textViewTitle = (TextView) itemView.findViewById(R.id.cell_emergency_pass_title_tv);
textViewExpandText = (TextView) itemView.findViewById(R.id.cell_emergency_pass_expand_detail_tv);
imageViewIcon = (ImageView) itemView.findViewById(R.id.cell_emergency_pass_icon_iv);
imageViewArrow = (ImageView) itemView.findViewById(R.id.cell_emergency_pass_arrow_icon_iv);
expandableLinearLayout = (ExpandableLinearLayout) itemView.findViewById(R.id.cell_emergency_pass_arrow_expandable_list);
relativeLayout = (RelativeLayout) itemView.findViewById(R.id.cell_emergency_pass_root_rl);
listView = (ListView) itemView.findViewById(R.id.cell_emergency_pass_expand_lv);
}
}
}
My ArrayAdapter
public class EmergencyPassExpandAdapter extends ArrayAdapter<CellExpandInformation>{
private static final String LOG_TAG = EmergencyPassExpandAdapter.class.getName();
private ArrayList<CellExpandInformation> values;
private int checkPosition;
private Context context;
public EmergencyPassExpandAdapter(Context context, ArrayList<CellExpandInformation> values, int checkPosition) {
super(context, -1, values);
this.context = context;
this.values = values;
this.checkPosition = checkPosition;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
Log.i(LOG_TAG,"View");
Log.i(LOG_TAG,"Position: " + position);
EmergencyPassExpandViewHolder viewHolder;
CellExpandInformation cellExpandInformation = values.get(position);
if (convertView == null) {
LayoutInflater inflater = ((Activity) context).getLayoutInflater();
convertView = inflater.inflate(R.layout.cell_emergency_pass_expand, parent, false);
viewHolder = new EmergencyPassExpandViewHolder();
viewHolder.textViewExpandTitle = (TextView) convertView.findViewById(R.id.cell_emergency_pass_expand_detail_tv);
convertView.setTag(viewHolder);
} else {
viewHolder = (EmergencyPassExpandViewHolder) convertView.getTag();
}
Log.i(LOG_TAG,"CheckPosition: " + checkPosition);
if (values != null) {
if (checkPosition == 0) {
viewHolder.textViewExpandTitle.setText(cellExpandInformation.getMedications().get(position).getMedicationName());
Log.i(LOG_TAG, "Medications: " + cellExpandInformation.getMedications().get(position).getMedicationName());
} else if (checkPosition == 1) {
viewHolder.textViewExpandTitle.setText(cellExpandInformation.getAllergies().get(position).getAllgergiesName());
} else if (checkPosition == 2) {
viewHolder.textViewExpandTitle.setText(cellExpandInformation.getDiseases().get(position).getDiseasesName());
} else if (checkPosition == 3) {
viewHolder.textViewExpandTitle.setText(cellExpandInformation.getLegalGuradian().get(position).getGuradianName());
} else if (checkPosition == 4) {
viewHolder.textViewExpandTitle.setText(cellExpandInformation.getEmergencyContact().get(position).getEmergencyContactName());
}
}
for(int i = 0; i < cellExpandInformation.getMedications().size(); i++){
Log.i(LOG_TAG,"Medis: " + cellExpandInformation.getMedications().get(i).getMedicationName());
}
return convertView;
}
static class EmergencyPassExpandViewHolder {
TextView textViewExpandTitle;
ImageView imageViewPhone, imageViewEmail, imageViewAdd;
}
}

Force close app on recyclerview Scroll

When I scroll on Recyclerview in my app it closes.
Here is a screenshot:
The main page of app- when i scroll the reyclerview of main page my app was force close:
This is my adapter:
public class RecyclerViewDataAdapter extends RecyclerView.Adapter<RecyclerViewDataAdapter.ItemRowHolder> {
private ArrayList<SectionDataModel> dataList;
private Context mContext;
private ImageView bg;
private boolean isLang;
public RecyclerViewDataAdapter(Context context, ArrayList<SectionDataModel> dataList) {
this.dataList = dataList;
this.mContext = context;
}
#Override
public ItemRowHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.list_item, null);
ItemRowHolder mh = new ItemRowHolder(v);
return mh;
}
#Override
public void onBindViewHolder(final ItemRowHolder itemRowHolder, int i) {
final String sectionName = dataList.get(i).getHeaderTitle();
final String sectionSub = dataList.get(i).getHeaderSubTitle();
final int sectionhesder = dataList.get(i).getHeader();
final int bgd = dataList.get(i).getPhoto();
final int bgg = dataList.get(i).getBg();
ArrayList singleSectionItems = dataList.get(i).getAllItemsInSection();
itemRowHolder.itemSubTitle.setText(sectionSub);
itemRowHolder.itemTitle.setText(sectionName);
itemRowHolder.bg.setImageResource(bgd);
itemRowHolder.bg.setBackgroundResource(bgg);
if (isLang = Locale.getDefault().getLanguage().equals("fa")) {
itemRowHolder.bg.setScaleType(ImageView.ScaleType.FIT_START);
} else {
itemRowHolder.bg.setScaleType(ImageView.ScaleType.FIT_END);
}
SectionListDataAdapter itemListDataAdapter = new SectionListDataAdapter(mContext, singleSectionItems);
itemRowHolder.recycler_view_list.setHasFixedSize(true);
itemRowHolder.recycler_view_list.setLayoutManager(new LinearLayoutManager(mContext, LinearLayoutManager.HORIZONTAL, false));
itemRowHolder.recycler_view_list.setAdapter(itemListDataAdapter);
itemRowHolder.recycler_view_list.setNestedScrollingEnabled(false);
/* itemRowHolder.recycler_view_list.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
int action = event.getAction();
switch (action) {
case MotionEvent.ACTION_DOWN:
// Disallow ScrollView to intercept touch events.
v.getParent().requestDisallowInterceptTouchEvent(true);
break;
case MotionEvent.ACTION_UP:
//Allow ScrollView to intercept touch events once again.
v.getParent().requestDisallowInterceptTouchEvent(false);
break;
}
// Handle RecyclerView touch events.
v.onTouchEvent(event);
return true;
}
});*/
itemRowHolder.btnMore.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(mContext, TopicActivity.class);
intent.putExtra("topicn",sectionName.toString());
intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
mContext.startActivity(intent);
}
});
/* Glide.with(mContext)
.load(feedItem.getImageURL())
.diskCacheStrategy(DiskCacheStrategy.ALL)
.centerCrop()
.error(R.drawable.bg)
.into(feedListRowHolder.thumbView);*/
}
#Override
public int getItemCount() {
return (null != dataList ? dataList.size() : 0);
}
public class ItemRowHolder extends RecyclerView.ViewHolder {
protected RelativeLayout itemHeader;
protected TextView itemTitle;
protected TextView itemSubTitle;
protected RecyclerView recycler_view_list;
protected Button btnMore;
public ImageView bg;
public ItemRowHolder(View view) {
super(view);
this.itemTitle = (TextView) view.findViewById(R.id.itemTitle);
this.itemSubTitle = (TextView) view.findViewById(R.id.itemsub);
this.itemHeader = (RelativeLayout) view.findViewById(R.id.header);
this.recycler_view_list = (RecyclerView) view.findViewById(R.id.recycler_view_list);
this.btnMore= (Button) view.findViewById(R.id.btnMore);
this.bg= (ImageView) view.findViewById(R.id.bg);
}}}