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Reload fragment from Adapter class

I have BottomNavigationView where i display fragments and i have adapter named FavoriteRecViewAdapter related on FavoritFragment.java, i need to reload FavoritFragment if one of favorites was deleted
I have BottomNavigationView where i display fragments and i have adapter named FavoriteRecViewAdapter related on FavoritFragment.java, i need to reload FavoritFragment if one of favorites was deleted
sorry for spam stackoverflow forced me ;)
FavoritFragment.java :
public class FavoriFragment extends Fragment {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
private List<Favorite> favorites;
private RecyclerView favoriteRecView;
private FloatingActionButton fabAddFavorite;
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
public FavoriFragment() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment FavoriFragment.
*/
// TODO: Rename and change types and number of parameters
public static FavoriFragment newInstance(String param1, String param2) {
FavoriFragment fragment = new FavoriFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View rootView = inflater.inflate(R.layout.fragment_favori, container, false);
favoriteRecView = (RecyclerView) rootView.findViewById(R.id.favoriteRecView);
fabAddFavorite = rootView.findViewById(R.id.fabAddFavorite);
favorites = new ArrayList<>();
Retrofit retrofit = RetrofitClientInstance.getRetrofitInstance(getContext());
final FavoriteAPI favoriteAPI = retrofit.create(FavoriteAPI.class);
Call<List<Favorite>> call = favoriteAPI.getFavorites();
call.enqueue(new Callback<List<Favorite>>() {
#Override
public void onResponse(Call<List<Favorite>> call, Response<List<Favorite>> response) {
if(response.code() != 200) {
Toast.makeText(getContext(), "Something wrong", Toast.LENGTH_SHORT).show();
} else {
List<Favorite> favoriteList = response.body();
for(Favorite favorite : favoriteList) {
favorites.add(favorite);
}
initData(favorites);
}
}
#Override
public void onFailure(Call<List<Favorite>> call, Throwable t) {
}
});
fabAddFavorite.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(getContext(), AddFavoriActivity.class);
getContext().startActivity(intent);
}
});
return rootView;
}
private void initData(List<Favorite> favorites) {
FavoriteRecViewAdapter favoriteRecViewAdapter = new FavoriteRecViewAdapter(favorites, getContext());
favoriteRecView.setAdapter(favoriteRecViewAdapter);
favoriteRecView.setLayoutManager(new LinearLayoutManager(getContext()));
}
}
FavoriteRecViewAdapter.java :
public class FavoriteRecViewAdapter extends RecyclerView.Adapter<FavoriteRecViewAdapter.viewHolder>{
private List<Favorite> favorites;
private Context mContext;
public FavoriteRecViewAdapter(List<Favorite> favorites, Context mContext) {
this.favorites = favorites;
this.mContext = mContext;
}
public FavoriteRecViewAdapter(List<Favorite> favorites) {
this.favorites = favorites;
}
#NonNull
#Override
public viewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.favorites_list_item, parent, false);
return new viewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull viewHolder holder, int position) {
holder.favoriteLibelle.setText(favorites.get(position).getCarte().getLibelle());
holder.favoriteNumero.setText(String.valueOf(favorites.get(position).getCarte().getNumero()));
holder.favoriteComments.setText(favorites.get(position).getComments());
holder.favoriteDate.setText(favorites.get(position).getDate());
holder.deleteFavoriteBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String msg = "are your sure ! you want to delete " +
favorites.get(holder.getAdapterPosition()).getCarte().getLibelle() +
" from favorites";
new MaterialAlertDialogBuilder(mContext)
.setTitle("Delete favorite")
.setMessage(msg)
.setNegativeButton("cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
}
})
.setPositiveButton("Yes delete it", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
Retrofit retrofit = RetrofitClientInstance.getRetrofitInstance(mContext);
final FavoriteAPI favoriteAPI = retrofit.create(FavoriteAPI.class);
Call<String> call = favoriteAPI.deleteFavorite(
favorites.get(holder.getAdapterPosition()).getId()
);
call.enqueue(new Callback<String>() {
#Override
public void onResponse(Call<String> call, Response<String> response) {
if(response.code() == 204) {
showSnackBarSuccess("Favorite was delete successfully");
} else{
showSnackBarError("Some thing wrong please try again !");
}
}
#Override
public void onFailure(Call<String> call, Throwable t) {
}
});
}
})
.show();
}
});
}
#Override
public int getItemCount() {
return favorites.size();
}
public class viewHolder extends RecyclerView.ViewHolder{
private TextView favoriteLibelle;
private TextView favoriteNumero;
private TextView favoriteComments;
private TextView favoriteDate;
private Button deleteFavoriteBtn;
public viewHolder(#NonNull View itemView) {
super(itemView);
favoriteLibelle = itemView.findViewById(R.id.favoriteLibelle);
favoriteNumero = itemView.findViewById(R.id.favoriteNumero);
favoriteComments = itemView.findViewById(R.id.favoriteComments);
favoriteDate = itemView.findViewById(R.id.favoriteDate);
deleteFavoriteBtn = itemView.findViewById(R.id.deleteFavoriteBtn);
}
}
private void showSnackBarError(String msg) {
Snackbar.make(((Activity) mContext).findViewById(android.R.id.content), msg, Snackbar.LENGTH_SHORT)
.setTextColor(ContextCompat.getColor(mContext,R.color.white))
.setBackgroundTint(ContextCompat.getColor(mContext,R.color.danger))
.show();
}
private void showSnackBarSuccess(String msg) {
Snackbar.make(((Activity) mContext).findViewById(android.R.id.content), msg, Snackbar.LENGTH_SHORT)
.show();
}
}
Thanks for any help ;)

java - How to match the details of a Dialog from RecyclerViewAdapter to another Fragment upon clicking the button

I'm new to android coding, I've tried all the possible solution here and on YouTube but still struggling. I just want how to match the data from a dialog of a fragment to another fragment upon pressing the button. we're working on a simple project. :)
Here is what we want to do.Kindly watch this link:
https://imgur.com/tGdWcfq
We want to change the name that will match the dialog upon clicking the "set parameters' button
here's what we found online the difference is we have a dialog button
https://www.youtube.com/watch?v=ZXoGG2XTjzU
https://www.youtube.com/watch?v=69C1ljfDvl0
Here are the codes
RecyclerViewAdapter.java
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.MyViewHolder> {
Context mContext;
List<specieList> mData;
Dialog myDialog;
public RecyclerViewAdapter(Context mContext, List<specieList> mData) {
this.mContext = mContext;
this.mData = mData;
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v;
Button b;
v = LayoutInflater.from(mContext).inflate(R.layout.row,parent,false);
final MyViewHolder vHolder = new MyViewHolder(v);
myDialog = new Dialog(mContext);
myDialog.setContentView(R.layout.fishpop);
myDialog.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
b = myDialog.findViewById(R.id.toasted);
b.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
TextView toastfish = (TextView) myDialog.findViewById(R.id.dialog_fish_id);
Toast.makeText(mContext,"Parameters are now set for " + toastfish.getText().toString(), Toast.LENGTH_SHORT).show();
// here upon clicking this button click we want to match the details in this dialog to another tab. Kindly watch the link above :)
}
});
vHolder.fish_choices.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
TextView dialog_fish = (TextView) myDialog.findViewById(R.id.dialog_fish_id);
TextView dialog_sciname = (TextView) myDialog.findViewById(R.id.dialog_sciname_id);
ImageView dialog_image = (ImageView) myDialog.findViewById(R.id.dialog_image_id);
dialog_fish.setText(mData.get(vHolder.getAdapterPosition()).getFish());
dialog_sciname.setText(mData.get(vHolder.getAdapterPosition()).getSciname());
dialog_image.setImageResource(mData.get(vHolder.getAdapterPosition()).getImage());
myDialog.show();
}
});
return vHolder;
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
holder.tv_fish.setText(mData.get(position).getFish());
holder.tv_sciname.setText(mData.get(position).getSciname());
holder.img.setImageResource(mData.get(position).getImage());
}
#Override
public int getItemCount() {
return mData.size();
}
public static class MyViewHolder extends RecyclerView.ViewHolder {
private LinearLayout fish_choices;
private TextView tv_fish;
private TextView tv_sciname;
private ImageView img;
public MyViewHolder(View itemView) {
super(itemView);
fish_choices = (LinearLayout) itemView.findViewById(R.id.choices);
tv_fish = (TextView) itemView.findViewById(R.id.textView1);
tv_sciname = (TextView) itemView.findViewById(R.id.textView2);
img = (ImageView) itemView.findViewById(R.id.image);
}
}
}
Code for overview tab(This tab we want to match the content)
public class overview extends Fragment {
View v2;
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
public overview() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment overview.
*/
// TODO: Rename and change types and number of parameters
public static overview newInstance(String param1, String param2) {
overview fragment = new overview();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
v2 = inflater.inflate(R.layout.fragment_overview, container, false);
Calendar calendar = Calendar.getInstance();
SimpleDateFormat time = new SimpleDateFormat("HH:mm:ss");
String currentDate = DateFormat.getDateInstance(DateFormat.FULL).format(calendar.getTime());
String currentTime = time.format(calendar.getTime());
TextView textViewDate =(TextView) v2.findViewById(R.id.date_id);
textViewDate.setText(currentDate);
TextView textViewTime =(TextView) v2.findViewById(R.id.time_id);
textViewTime.setText(currentTime);
return v2;
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
#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");
}
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
}
}
Code for Specie tab (this tab we want to refer)
public class specie extends Fragment {
View v;
private RecyclerView myrecyclerview;
private List<specieList> lstspecie;
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
public specie() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment specie.
*/
// TODO: Rename and change types and number of parameters
public static specie newInstance(String param1, String param2) {
specie fragment = new specie();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
lstspecie = new ArrayList<>();
lstspecie.add(new specieList("Nile Tilapia", "Oreochromis niloticus", R.drawable.tilapia));
lstspecie.add(new specieList("Ayungin (Silver Perch)", "Bidyanus bidyanus", R.drawable.ayungin));
lstspecie.add(new specieList("Sugpo (Tiger Prawn)", "Penaeus monodon", R.drawable.hipon));
lstspecie.add(new specieList("Hito (Catfish)", "Siluriformes", R.drawable.hito));
lstspecie.add(new specieList("Giant Gourami", "Osphronemus goramy", R.drawable.giant));
lstspecie.add(new specieList("Bangus (Milkfish)", "Chanos chanos", R.drawable.bangus));
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
v = inflater.inflate(R.layout.fragment_specie, container, false);
myrecyclerview = (RecyclerView)v.findViewById(R.id.specie_recycleview);
RecyclerViewAdapter recyclerAdapter = new RecyclerViewAdapter(getContext(), lstspecie);
myrecyclerview.setLayoutManager(new LinearLayoutManager(getActivity()));
myrecyclerview.setAdapter(recyclerAdapter);
return v;
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
#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");
}
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
}
}
Thank you!

Using object oriented Approach
You can write a function in your activity and you can call a fragment's method from it, as you have your Fragment's reference in your Activity when you initialized it like
In Your Activity
class yourActivity ... {
// your other methods
public void callFragmentMethod(String params) {
// here call your fragment's method
fragment.method(params);
}
}
In your Fragment now
class yourFragment ... {
// your other methods
public void method(String params) {
// here call your fragment's method
here do whatever you want to do it with params
}
}
Now you can call your Activity's method either from another fragment or from Adapter, whatever you want
From Fragment you can call like
((yourActivity)getActivity()).callFragmentMethod(params);
From Adapter
((yourActivity)context).callFragmentMethod(params);

Call below method on your button click..
public void replaceFragment(Fragment fragment) {
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction =
fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.frameContainer, fragment);
fragmentTransaction.addToBackStack(fragment.toString());
fragmentTransaction.commit();
}
pass frameContainer in constructor of your Adapter like..
new RecyclerViewAdapter(context, list, R.id.frameContainer);

Cannot Save RecyclerView Position in Fragment

I have read several threads on approaches to save the position of a RecyclerView. I have implemented the below, however it does not appear to be saving the position on either screen rotation or back navigation, it simply loads back to the top of the RecyclerView:
public class FeedFragment extends Fragment {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
private static final String POLL_QUESTION = "POLL_QUESTION";
private static final String POLL_IMAGE_URL = "POLL_IMAGE_URL";
private static final String FILTER_ACTION = "UPDATE_WIDGET";
private static final String POLL_ID = "POLL_ID";
private static final String RECYCLERVIEW_STATE = "Recyclerview_State";
private Parcelable mRecyclerViewState;
private static Bundle mRecyclerViewBundle;
private MyReceiver myReceiver;
#BindView(R.id.list)
RecyclerView mRecyclerview;
private SharedPreferences mPrefs;
private SharedPreferences.Editor editor;
private DatabaseReference mBaseRef;
private DatabaseReference mPollsRef;
private LinearLayoutManager mLayoutManager;
private FirebaseRecyclerAdapter<Poll, PollHolder> mFireAdapter;
private OnFragmentInteractionListener mListener;
public FeedFragment() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment FeedFragment.
*/
// TODO: Rename and change types and number of parameters
public static FeedFragment newInstance(String param1, String param2) {
FeedFragment fragment = new FeedFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View v = inflater.inflate(R.layout.fragment_poll_feed, container, false);
ButterKnife.bind(this, v);
mPrefs = getActivity().getSharedPreferences("MyPrefs", Context.MODE_PRIVATE);
editor = mPrefs.edit();
if (savedInstanceState != null) {
mRecyclerViewState = savedInstanceState.getParcelable(RECYCLERVIEW_STATE);
}
mRecyclerview.getItemAnimator().setChangeDuration(0);
mLayoutManager = new LinearLayoutManager(getContext());
mLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
mLayoutManager.setReverseLayout(true);
mLayoutManager.setStackFromEnd(true);
mRecyclerview.setSaveEnabled(true);
mRecyclerview.setLayoutManager(mLayoutManager);
setReceiver();
return v;
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
#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");
}
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
// #Override
// public void onSaveInstanceState(#NonNull Bundle outState) {
// super.onSaveInstanceState(outState);
// mRecyclerViewState = mLayoutManager.onSaveInstanceState();
// outState.putParcelable(RECYCLERVIEW_STATE, mRecyclerViewState);
// }
//
//
// #Override
// public void onViewStateRestored(#Nullable Bundle savedInstanceState) {
// super.onViewStateRestored(savedInstanceState);
// if (savedInstanceState != null){
// mRecyclerViewState = savedInstanceState.getParcelable(RECYCLERVIEW_STATE);
// }
// }
#Override
public void onSaveInstanceState(#NonNull Bundle outState) {
super.onSaveInstanceState(outState);
mRecyclerViewState = mLayoutManager.onSaveInstanceState();
outState.putParcelable(RECYCLERVIEW_STATE, mRecyclerViewState);
}
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
if (savedInstanceState != null){
mRecyclerViewState = savedInstanceState.getParcelable(RECYCLERVIEW_STATE);
}
}
#Override
public void onResume() {
super.onResume();
if (mRecyclerViewState != null){
mLayoutManager.onRestoreInstanceState(mRecyclerViewState);
}
}
#Override
public void onStart() {
super.onStart();
Query query = FirebaseDatabase.getInstance()
.getReference()
.child("Polls");
FirebaseRecyclerOptions<Poll> options = new FirebaseRecyclerOptions.Builder<Poll>()
.setQuery(query, Poll.class)
.build();
mFireAdapter = new FirebaseRecyclerAdapter<Poll, PollHolder>(options) {
#Override
protected void onBindViewHolder(#NonNull final PollHolder holder, int position, #NonNull Poll model) {
holder.mPollQuestion.setText(model.getQuestion());
String voteCount = String.valueOf(model.getVote_count());
//Update shared prefs with latest question
editor.putString(POLL_QUESTION, model.getQuestion());
editor.putString(POLL_IMAGE_URL, model.getImage_URL());
editor.apply();
//TODO: Investigate formatting of vote count for thousands
holder.mVoteCount.setText(voteCount);
Picasso.get()
.load(model.getImage_URL())
.fit()
.into(holder.mPollImage);
//TODO: Cannot understand how to utilize IntentService to update widget
//TODO: Followed this tutorial: https://www.journaldev.com/20735/android-intentservice-broadcastreceiver
Intent intent = new Intent(getContext(), MyService.class);
intent.putExtra(POLL_QUESTION, model.getQuestion());
intent.putExtra(POLL_IMAGE_URL, model.getImage_URL());
getActivity().startService(intent);
holder.mView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String pollID = mFireAdapter.getRef(holder.getAdapterPosition()).getKey();
if (getActivity().findViewById(R.id.two_pane_constraint_layout) != null & getActivity().getApplication().getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
FragmentManager fm = getActivity().getSupportFragmentManager();
PollFragment pollFragment = PollFragment.newInstance(pollID);
fm.beginTransaction()
.replace(R.id.poll_fragment, pollFragment)
.commit();
} else {
Intent i = new Intent(getActivity().getApplicationContext(), PollHostActivity.class);
i.putExtra(POLL_ID, pollID);
startActivity(i);
}
}
});
}
#Override
public PollHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.latest_item, parent, false);
return new PollHolder(v);
}
};
mRecyclerview.setAdapter(mFireAdapter);
scrollToPosition();
mFireAdapter.startListening();
}
public static class PollHolder extends RecyclerView.ViewHolder {
TextView mPollQuestion;
TextView mVoteCount;
ImageView mPollImage;
View mView;
String mTag;
public PollHolder(View itemView) {
super(itemView);
mPollQuestion = itemView.findViewById(R.id.latest_item_question);
mPollImage = itemView.findViewById(R.id.pollThumbNailImage);
mVoteCount = itemView.findViewById(R.id.latest_item_poll_count);
this.mView = itemView;
}
public void setTag(String tag) {
this.mTag = tag;
}
public View getViewByTag(String tag) {
return mView;
}
}
private void setReceiver() {
myReceiver = new MyReceiver();
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction(FILTER_ACTION);
// LocalBroadcastManager.getInstance(this).registerReceiver(myReceiver, intentFilter);
}
private void scrollToPosition() {
mFireAdapter.registerAdapterDataObserver(new RecyclerView.AdapterDataObserver() {
#Override
public void onItemRangeInserted(int positionStart, int itemCount) {
super.onItemRangeInserted(positionStart, itemCount);
int pollCount = mFireAdapter.getItemCount();
int lastVisiblePosition = mLayoutManager.findLastCompletelyVisibleItemPosition();
// If the recycler view is initially being loaded or the user is at the bottom of the list, scroll
// to the bottom of the list to show the newly added message.
if (lastVisiblePosition == -1 ||
(positionStart >= (pollCount - 1) && lastVisiblePosition == (positionStart - 1))) {
mRecyclerview.scrollToPosition(positionStart);
}
}
});
}
private class MyReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
String poll_Question = intent.getStringExtra("broadcastMessage");
//TODO: Update Widget - used answer from https://stackoverflow.com/questions/3455123/programmatically-update-widget-from-activity-service-receiver
int[] ids = AppWidgetManager.getInstance(getContext()).getAppWidgetIds(new ComponentName(getContext(), PollWidgetProvider.class));
PollWidgetProvider pollWidgetProvider = new PollWidgetProvider();
pollWidgetProvider.onUpdate(getContext(), AppWidgetManager.getInstance(getContext()), ids);
}
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
}
}
EDIT:
I am trying to save within a Fragment, that is attached to a host Activity. I have some RecyclerView functionality coded to on.Start(), which may be overriding the methods below.
I also feel I need to make a call to onPause() somewhere since the RecyclerView is located inside a Fragment.
Full code available:https://github.com/troy21688/LiveVotingUdacity

RecyclerView in Fragment - No Adapter Attached, Skipping Layout

I have an odd situation, I have an Activity hosting a TabLayout/Viewpager that populates data based on changes to a Firebase Database. Unfortunately, the RecyclerView is not being populated, and I am receiving the error below in my logcat. I believe the fragment is being loaded even when it is not on screen, which is causing an error in the population of the RecyclerView. It is also weird as the RecyclerView does populate when I rotate the screen:
12-13 21:31:40.013 12490-12490/com.troychuinard.fanpolls E/RecyclerView: No adapter attached; skipping layout
Here is the ViewPager Adapter I have in my host Activity:
public class SectionPagerAdapter extends FragmentPagerAdapter {
public SectionPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return new TrendingFragment();
case 1:
return new FollowingFragment();
case 2:
return new LiveFragment();
default:
return new TrendingFragment();
}
}
#Override
public int getCount() {
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
switch (position) {
case 0:
return getResources().getString(R.string.trending_text);
case 1:
return getResources().getString(R.string.following_text);
case 2:
return getResources().getString(R.string.new_text);
default:
return getResources().getString(R.string.trending_text);
}
}
}
Here is the complete fragment where I initialize the RecyclerView inside onCreateView() function in my LiveFragment, which is tab 3 in the TabLayout:
public class LiveFragment extends Fragment {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
private RecyclerView mRecyclerview;
private DatabaseReference mBaseRef;
private DatabaseReference mPollsRef;
private LinearLayoutManager mLayoutManager;
private FirebaseRecyclerAdapter <Poll, PollHolder> mFireAdapter;
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
public LiveFragment() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment LiveFragment.
*/
// TODO: Rename and change types and number of parameters
public static LiveFragment newInstance(String param1, String param2) {
LiveFragment fragment = new LiveFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mBaseRef = FirebaseDatabase.getInstance().getReference();
mPollsRef = mBaseRef.child("Polls");
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
final View v = inflater.inflate(R.layout.fragment_new, container, false);
Log.v("TAG", "ON CREATE CALLED FROM NEW");
mLayoutManager = new LinearLayoutManager(getActivity());
mLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
mRecyclerview = (RecyclerView)v.findViewById(R.id.new_RecyclerView);
if (mRecyclerview != null){
mRecyclerview.setHasFixedSize(true);
}
if (mRecyclerview == null){
Log.v("TAG", "RECYCLERVIEW NULL");
} else if (mLayoutManager == null){
Log.v("TAG", "LAYOUTMANAGER NULL");
} else if (mFireAdapter == null) {
Log.v("TAG", "mFIREADAPTER NULL");
}
return v;
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
#Override
public void onStart() {
super.onStart();
}
#Override
public void onStop() {
super.onStop();
if (mFireAdapter != null){
mFireAdapter.cleanup();
}
}
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mRecyclerview.setLayoutManager(mLayoutManager);
mFireAdapter = new FirebaseRecyclerAdapter<Poll, PollHolder>(Poll.class, R.layout.latest_item, PollHolder.class, mPollsRef) {
#Override
protected void populateViewHolder(PollHolder viewHolder, Poll model, int position) {
viewHolder.mPollQuestion.setText(model.getQuestion());
Picasso.with(getActivity().getApplicationContext())
.load(model.getImage_URL())
.fit()
.into(viewHolder.mPollImage);
Log.v("QUESTION", model.getQuestion());
Log.v("IMAGE", model.getImage_URL());
}
};
mRecyclerview.setAdapter(mFireAdapter);
mPollsRef.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot x : dataSnapshot.getChildren()){
mFireAdapter.notifyItemInserted(0);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
#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");
}
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public static class PollHolder extends RecyclerView.ViewHolder {
TextView mPollQuestion;
ImageView mPollImage;
public PollHolder(View itemView) {
super(itemView);
mPollQuestion = (TextView) itemView.findViewById(R.id.latest_item_question);
mPollImage = (ImageView) itemView.findViewById(R.id.pollThumbNailImage);
}
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
}
}

Move your Adapter from onCreateView to onActivityCreated method after you have read data from firebase.
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
//read Poll data from firebase mPollsRef for example
//.... database reference to firebase
//Query mPollsRef = databaseReference.child("pools").limitToFirst(200);
mRecyclerview.setLayoutManager(mLayoutManager);
mFireAdapter = new FirebaseRecyclerAdapter<Poll, PollHolder>(Poll.class, R.layout.latest_item, PollHolder.class, mPollsRef) {
#Override
protected void populateViewHolder(PollHolder viewHolder, Poll model, int position) {
viewHolder.mPollQuestion.setText(model.getQuestion());
Picasso.with(getActivity().getApplicationContext())
.load(model.getImage_URL())
.fit()
.into(viewHolder.mPollImage);
Log.v("QUESTION", model.getQuestion());
Log.v("IMAGE", model.getImage_URL());
}
};
mRecyclerview.setAdapter(mFireAdapter);
}
My code for initialize Pager at HostActivity.java
private FragmentPagerAdapter mPagerAdapter;
private ViewPager mViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_absence);
// Create the adapter that will return a fragment for each section
mPagerAdapter = new FragmentPagerAdapter(getSupportFragmentManager()) {
private final Fragment[] mFragments = new Fragment[] {
new MyAbsenceFragment(),
new MyAttendanceFragment(),
new AbsTypesFragment(),
new LiveFragment(),
};
private final String[] mFragmentNames = new String[] {
"Absences",
"Attendances",
"AbsTypes",
"Live"
};
#Override
public Fragment getItem(int position) {
return mFragments[position];
}
#Override
public int getCount() {
return mFragments.length;
}
#Override
public CharSequence getPageTitle(int position) {
return mFragmentNames[position];
}
};
// Set up the ViewPager with the sections adapter.
mViewPager = (ViewPager) findViewById(R.id.container);
mViewPager.setAdapter(mPagerAdapter);

Shared Preferences non Activity assign to variable gets nullpointerexception [duplicate]

This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 6 years ago.
I have a non activity class where I want to access my sharedpreferences I saved in a fragment. I can use these prefs in other fragments / activities, so they are working. When I try to assign the prefvalues to variables in my non_Activity class I always get a nullpointerexception no matter what I changed (I´ve read through mulitple topics here on stack on nothing worked).
public class VorgangDataSource {
Context mcontext;
float lbcount;
float rbcount;
float bcount;
SharedPreferences sharedPreferences;
SharedPreferences sharedPreferences1;
SharedPreferences sharedPreferences2;
private static final String LOG_TAG = VorgangDataSource.class.getSimpleName();
public SQLiteDatabase database;
private VorgangDbHelper dbHelper;
private String[] columns = {
VorgangDbHelper.COLUMN_ID,
VorgangDbHelper.COLUMN_START,
VorgangDbHelper.COLUMN_STOP,
VorgangDbHelper.COLUMN_LEFTB,
VorgangDbHelper.COLUMN_RIGHTB,
VorgangDbHelper.COLUMN_BOTTLE
};
public VorgangDataSource(Context context) {
Log.d(LOG_TAG, "DataSource erzeugt dbHelper!");
dbHelper = VorgangDbHelper.getInstance();
this.mcontext = context;
this.sharedPreferences = mcontext.getSharedPreferences("FILELB",Context.MODE_PRIVATE);
this.sharedPreferences1 = mcontext.getSharedPreferences("FILERB",Context.MODE_PRIVATE);
this.sharedPreferences2 = mcontext.getSharedPreferences("FILEBO",Context.MODE_PRIVATE);
this.lbcount = sharedPreferences.getFloat("KEYLB",0);
this.rbcount = sharedPreferences1.getFloat("KEYRB",0);
this.bcount = sharedPreferences2.getFloat("KEYBO",0);
}
public void open() {
Log.d(LOG_TAG, "Eine Referenz auf die Datenbank wird jetzt angefragt.");
database = dbHelper.getWritableDatabase();
Log.d(LOG_TAG, "Datenbank-Referenz erhalten. Pfad zur Datenbank: " + database.getPath());
}
public void close() {
dbHelper.close();
Log.d(LOG_TAG, "Datenbank mit Hilfe des DbHelpers geschlossen.");
}
public VorgangDataSource open(boolean readOnly) throws SQLException {
dbHelper = VorgangDbHelper.getInstance();
if(readOnly)
database = dbHelper.getReadableDatabase();
else
database = dbHelper.getWritableDatabase();
return this;
}
}
Error Log:
06-15 08:28:47.816 12806-12806/com.example... E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example PID: 12806
java.lang.NullPointerException
at com.example...VorgangDataSource.<init>(VorgangDataSource.java:169)
at com.example...frag_anzeigen.<init>(frag_anzeigen.java:53)
at com.example...MainActivity.onNavigationItemSelected(MainActivity.java:117)
at android.support.design.widget.NavigationView$1.onMenuItemSelected(NavigationView.java:151)
at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:811)
at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:152)
at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:958)
at android.support.design.internal.NavigationMenuPresenter$1.onClick(NavigationMenuPresenter.java:318)
at android.view.View.performClick(View.java:4748)
at android.view.View$PerformClick.run(View.java:19535)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:146)
at android.app.ActivityThread.main(ActivityThread.java:5679)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1291)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1107)
at dalvik.system.NativeStart.main(Native Method)
fragment-class
public class frag_anzeigen extends Fragment {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
private static final String TAG = frag_anlegen.class.getSimpleName();
private static final String FILENAME = TAG + ".kdf";
private List valueList = new ArrayList <String>();
final VorgangDataSource dataSource = new VorgangDataSource(getActivity());
ArrayAdapter<vorgangsdaten> VorgangArrayAdapter;
List<vorgangsdaten> vorgangsdatenList;
public frag_anzeigen() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment frag_anzeigen.
*/
// TODO: Rename and change types and number of parameters
public static frag_anzeigen newInstance(String param1, String param2) {
frag_anzeigen fragment = new frag_anzeigen();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View anzeigen = inflater.inflate(R.layout.frag_anzeigen,container,false);
anzeigen.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
if(event.getAction()==MotionEvent.ACTION_DOWN)
{
close();
}
return true;
}
});
Log.d(TAG,"Die Datenquelle wird geöffnet!");
dataSource.open();
vorgangsdatenList = dataSource.getAllVorgangsDaten();
VorgangArrayAdapter = new ArrayAdapter< >(getActivity(),R.layout.mylistlayout,vorgangsdatenList);
final ListView lv = (ListView)anzeigen.findViewById(R.id.listView);
lv.setAdapter(VorgangArrayAdapter);
//lv.setItemsCanFocus(false);
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, final int position, final long id) {
String s_id = String.valueOf(id);
Log.d(s_id,"id_in_onitem");
String p_id = String.valueOf(position);
Log.d(p_id,"position_on_item");
final AlertDialog delete = new AlertDialog.Builder(getActivity()).create();
delete.setTitle(getResources().getString(R.string.advice));
delete.setMessage(getResources().getString(R.string.delete2dialog));
delete.setIcon(R.drawable.warning);
delete.setButton(DialogInterface.BUTTON_POSITIVE, getResources().getString(R.string.ok), new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
vorgangsdatenList.remove(position);
dataSource.deleteRow(id);
VorgangArrayAdapter.notifyDataSetChanged();
Toast.makeText(getActivity(), getResources().getString(R.string.eventdeleted), Toast.LENGTH_SHORT).show();
}
});
delete.setButton(DialogInterface.BUTTON_NEGATIVE, getResources().getString(R.string.cancel), new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
delete.closeOptionsMenu();
}
});
delete.show();
}
});
return anzeigen;
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
#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");
}
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p/>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
}
#Override
public void onDestroyView() {
super.onDestroyView();
}
public void close (){
FragmentManager fm = getFragmentManager();
FragmentTransaction transaction = fm.beginTransaction();
transaction.setCustomAnimations(R.anim.slide_in_up,R.anim.slide_out_up);
transaction.remove(this);
transaction.commit();
}
}

The problem is in this line
final VorgangDataSource dataSource = new VorgangDataSource(getActivity());
Here getActivity() returns null because if onAttach isn't called yet of the respective fragment. So remove that line from there and write in onAttach method or onCreate method of fragment class.
Hope this will help you.