Android RecyclerView display issue in adapter - java

This is my code.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_all_user);
// getting id
UserList=findViewById(R.id.ChatUserRecycle);
toolbar=findViewById(R.id.mainPageBar);
databaseReference=FirebaseDatabase.getInstance().getReference().child("Student");
setSupportActionBar(toolbar);
getSupportActionBar().setTitle("Users"); //setting action bar title
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
UserList.setHasFixedSize(true);
UserList.setLayoutManager(new LinearLayoutManager(this));
}
#Override
protected void onStart() {
super.onStart();
FirebaseRecyclerOptions<ChatUsers> options=
new FirebaseRecyclerOptions.Builder<ChatUsers>()
.setQuery(databaseReference,ChatUsers.class)
.setLifecycleOwner(this)
.build();
firebaseRecyclerAdapter=new FirebaseRecyclerAdapter<ChatUsers,UsersViewHolder>(options) {
#NonNull
#Override
public UsersViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
return new UsersViewHolder(LayoutInflater.from(parent.getContext())
.inflate(R.layout.user_layout, parent, false));
}
#Override
protected void onBindViewHolder(#NonNull UsersViewHolder holder, int position, #NonNull ChatUsers model) {
holder.setName(model.getName());
}
};
UserList.setAdapter(firebaseRecyclerAdapter);
}
public static class UsersViewHolder extends RecyclerView.ViewHolder{
View mview;
public UsersViewHolder(#NonNull View itemView) {
super(itemView);
mview=itemView;
}
public void setName(String name){
Toast.makeText(itemView.getContext(),"2",Toast.LENGTH_SHORT).show();
TextView name1=(TextView)mview.findViewById(R.id.SingleUsername);
name1.setText(name);
}
}
}
When I run my code nothing show just empty layout without recycleview and layout which want to I inflate. And after few seconds app.
FirebaseRecyclerAdapter<image_details, BlogViewHolder> adapter = new FirebaseRecyclerAdapter<image_details, BlogViewHolder>(
image_details.class,
R.layout.individual_row,
myRef) {
#Override
protected void onBindViewHolder(BlogViewHolder holder, int position, image_details model) {
holder.setDate(model.getDate());
holder.setUrl(model.getUrl());
}
#Override
public BlogViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
return null;
}
};
First I use this method but it also not works.

When I run my code nothing show just empty layout
This is because you're not creating a view for your holder at all. To solve this, please add the following lines of code:
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.individual_row, parent, false);
return new BlogViewHolder(view);
Inside your onCreateViewHolder() method and remove return null;.

Related

Im getting error in startListening() stopListening()

This is the code in which I'm getting errors in startListening() and stopListening():
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_app_cart,container,false);
recyclerView = view.findViewById(R.id.recylervieww);
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
cartmodelList = new ArrayList<>();
cartadapt = new cartAdapter(getActivity(),cartmodelList);
recyclerView.setAdapter(cartadapt);
FirebaseRecyclerOptions<Cartmodel> options =
new FirebaseRecyclerOptions.Builder<Cartmodel>()
.setQuery(FirebaseDatabase.getInstance().getReference().child("Cart List"), Cartmodel.class)
.build();
cartadapt = new cartAdapter(options);
recyclerView.setAdapter(cartadapt);
return view;
}
#Override
public void onStart() {
super.onStart();
cartadapt.startListening();
}
#Override
public void onStop() {
super.onStop();
cartadapt.stopListening();
}
}
This is the code for cartAdapter:
public class cartAdapter extends RecyclerView.Adapter<cartAdapter.ViewHolder> {
Context context;
List<Cartmodel> cartmodelList;
public cartAdapter(Context context, List<Cartmodel> cartmodelList) {
this.context = context;
this.cartmodelList = cartmodelList;
}
public cartAdapter(FirebaseRecyclerOptions<Cartmodel> options) {
}
#NonNull
#Override
public cartAdapter.ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
return new ViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.cart_singlero,parent,false));
}
#Override
public void onBindViewHolder(#NonNull cartAdapter.ViewHolder holder, int position) {
holder.productName.setText(cartmodelList.get(position).getProductName());
holder.quantity.setText(cartmodelList.get(position).getQuantity());
holder.totalPrice.setText(cartmodelList.get(position).getTotalPrice());
Glide.with(holder.itemView.getContext()).load(Cartmodel.productImage()).into(holder.productImage);
}
#Override
public int getItemCount() {
return cartmodelList.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
TextView date,productName,productPrice,quantity,totalPrice;
ImageView productImage;
public ViewHolder(#NonNull View itemView) {
super(itemView);
productName = itemView.findViewById(R.id.pnametext);
quantity = itemView.findViewById(R.id.quantity);
totalPrice = itemView.findViewById(R.id.totalprice);
productImage = itemView.findViewById(R.id.img2);
}
}
}
I'm getting these errors:
Cannot resolve method 'startListening' in 'cartAdapter'
Cannot resolve method 'stopListening' in 'cartAdapter'
I'm using both classes in another activity but in those, I'm not getting any errors.
I'm getting error in startListening() and stopListening()
Because those methods are not present inside RecyclerView.Adapter class. Your adapter class should extend FirebaseRecyclerAdapter class instead in order to be able to call startListening() and stopListening().
For more info, please check the official documentation:
https://firebaseopensource.com/projects/firebase/firebaseui-android/database/readme/

My recycler view not shown for the first time in fragment

I am a beginner at android development. I tried to display data on Recycle View using MVVM. When I opened the fragment the first time it is empty, the second time it showed data. Adapter not called the first time. How to fix this.
Fragment class
public class fragmentEmployee extends Fragment {
private FragmentEmployeeBinding binding;
private ViewGroup viewGroup;
private View view;
private RecyclerView mRecycleView;
private UserAdapter mAdapter;
private EmployeeRegisterViewModel viewModel;
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
binding = DataBindingUtil.inflate(inflater, R.layout.fragment_employee, viewGroup, false);
view = binding.getRoot();
return view;
}
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
Toast.makeText(getContext(), "onViewCreated", Toast.LENGTH_SHORT).show();
mRecycleView = binding.recyleViewEmployee;
viewModel = new ViewModelProvider(this).get(EmployeeRegisterViewModel.class);
viewModel.init();
initRecycleView();
viewModel.getEmployee().observe(getViewLifecycleOwner(), new Observer<List<employeeModel>>() {
#Override
public void onChanged(List<employeeModel> employeeModels) {
mAdapter.notifyDataSetChanged();
}
});
}
private void initRecycleView() {
mAdapter = new UserAdapter(getContext(), viewModel.getEmployee().getValue());
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getContext());
mRecycleView.setLayoutManager(layoutManager);
mRecycleView.setAdapter(mAdapter);
}
}
UserAdapter class
public class UserAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{
public List<employeeModel> employeeModelList= new ArrayList<>();
public Context context1;
public UserAdapter(Context context,List<employeeModel> employeeModels){
employeeModelList = employeeModels;
context1 = context;
}
#NonNull
#Override
public RecyclerView.ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.layout_listitem,parent,false);
ViewHolder viewHolder=new ViewHolder(view);
return viewHolder;
}
#Override
public void onBindViewHolder(#NonNull RecyclerView.ViewHolder holder, int position) {
(ViewHolder)holder).username.setText(employeeModelList.get(position).getName());
}
#Override
public int getItemCount() {
return employeeModelList.size();
}
public class ViewHolder extends RecyclerView.ViewHolder{
TextView username;
public ViewHolder(#NonNull View itemView) {
super(itemView);
username=itemView.findViewById(R.id.userText);
}
}
}
Try reordering like this.
Remove
mAdapter = new UserAdapter(getContext(), viewModel.getEmployee().getValue());
from initRecycleView
mAdapter = new UserAdapter(getContext(), viewModel.getEmployee().getValue());
viewModel.getEmployee().observe(getViewLifecycleOwner(), new Observer<List<employeeModel>>() {
#Override
public void onChanged(List<employeeModel> employeeModels) {
mAdapter.notifyDataSetChanged();
}
});
initRecycleView();
mAdapter.notifyDataSetChanged();
Above method will work if the list declared inside adapter has any change. So, calling above method without changing adapter's list is useless.
Add a method to UserAdapter class to update list data. Like:
public void updateData(List<employeeModel> updatedList){
employeeModelList.clear();
employeeModelList.addAll(updatedList);
notifyDataSetChanged();
}
And call this method inside observer. Like:
viewModel.getEmployee().observe(getViewLifecycleOwner(), new
Observer<List<employeeModel>>() {
#Override
public void onChanged(List<employeeModel> employeeModels) {
mAdapter.updateData(employeeModels);
}
});
where are you get your network data?
If your get in here -> viewModel.init();
I think it just timing problem.
Just change code sequence
initRecycleView();
viewModel.getEmployee().observe(getViewLifecycleOwner(), new Observer<List<employeeModel>>() {
#Override
public void onChanged(List<employeeModel> employeeModels) {
mAdapter.notifyDataSetChanged();
}
});
viewModel.init();

Why the second RecyclerView is not working?

I'm using two firebase UI Recycler views in a single activity. The first recycler view is working fine but I don't know why the second Recycler view is not populating. One thing I noticed that in the second recycler view 'OnBind' and 'OnCreate' methods are not called up?
Basically, I'm trying to use two horizontal recycler views within a single activity.
public class MainActivity extends AppCompatActivity {
private FirebaseRecyclerOptions<Video> options;
private FirebaseRecyclerAdapter<Video, MyViewHolder> adapter;
private RecyclerView recyclerViewVideo;
private FirebaseRecyclerOptions<Meme> optionsForHindiJokes;
private FirebaseRecyclerAdapter<Meme, MyViewHolder> adapterForHindiJokes;
private RecyclerView recyclerViewForHindiJokes;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerViewVideo = findViewById(R.id.recycler_view_video);
recyclerViewVideo.setHasFixedSize(true);
recyclerViewVideo.setLayoutManager(new LinearLayoutManager(this,LinearLayoutManager.HORIZONTAL,false));
recyclerViewForHindiJokes = findViewById(R.id.recycler_view_hindi_jokes);
recyclerViewForHindiJokes.setHasFixedSize(true);
recyclerViewForHindiJokes.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false));
/* **/
final FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference refToVideo1 = database.getReferenceFromUrl("https://memlo-a9291-default-rtdb.firebaseio.com/AppStructure/Videos/Video");
refToVideo1.keepSynced(true);
Query refToVideo = database.getReferenceFromUrl("https://memlo-a9291-default-rtdb.firebaseio.com/AppStructure/Videos/Video").limitToLast(20);
options = new FirebaseRecyclerOptions.Builder<Video>().setQuery(refToVideo, Video.class).build();
adapter= new FirebaseRecyclerAdapter<Video, MyViewHolder>(options) {
#Override
protected void onBindViewHolder(#NonNull MyViewHolder holder, int position, #NonNull final Video model) {
RequestOptions requestOptions = new RequestOptions();
requestOptions.placeholder(R.drawable.ic_memlo_without_background);
requestOptions.error(R.drawable.ic_memlo_without_background);
Glide.with(MainActivity.this)
.load(model.getVideoUrl())
.apply(requestOptions)
.thumbnail(Glide.with(MainActivity.this).load(model.getVideoUrl()))
// .centerCrop()
.into(holder.imageOnCard);
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent1 = new Intent(MainActivity.this, VideoPlayer.class);
intent1.putExtra("VIDEO_URL", model.getVideoUrl());
startActivity(intent1);
}
});
}
#NonNull
#Override
public MyViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.single_cards_layout, parent, false);
return new MyViewHolder(v);
}
};
adapter.startListening();
recyclerViewVideo.setAdapter(adapter);
////////////////////////////////////////////////
Query refToHindiJokes = database.getReferenceFromUrl("https://memlo-a9291-default-rtdb.firebaseio.com/AppStructure/Memes/Category/Hindi%20Jokes");
optionsForHindiJokes = new FirebaseRecyclerOptions.Builder<Meme>().setQuery(refToHindiJokes, Meme.class).build();
adapterForHindiJokes = new FirebaseRecyclerAdapter<Meme, MyViewHolder>(optionsForHindiJokes) {
#Override
protected void onBindViewHolder(#NonNull MyViewHolder holder, int position, #NonNull Meme model) {
Toast.makeText(getApplicationContext(),"Calling", Toast.LENGTH_LONG).show();
Glide.with(getApplicationContext())
.load(model.getImageUrl())
.into(holder.imageOnCard);
}
#NonNull
#Override
public MyViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View v1=LayoutInflater.from(getApplicationContext()).inflate(R.layout.single_cards_layout, parent,false);
return new MyViewHolder(v1);
}
};
adapterForHindiJokes.startListening();
adapterForHindiJokes.notifyDataSetChanged();
recyclerViewForHindiJokes.setAdapter(adapterForHindiJokes);
}
}

Firebase Recycler Adapter is not populated

I am having trouble with populating my Firebase recycler adapter. What I want to do in the end is that a user searches for a name and the result from the database will populate the recyclerView.
The database structure looks like this:
The code to populate looks like this, this is all in onCreate():
Query mQuery = FirebaseDatabase.getInstance().getReference().orderByChild("users");
FirebaseRecyclerOptions<Users> options =
new FirebaseRecyclerOptions.Builder<Users>()
.setQuery(mQuery, Users.class)
.build();
mAdapter = new FirebaseRecyclerAdapter<Users, UsersViewHolder>(options) {
#NonNull
#Override
public UsersViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.user_single_layout, parent, false);
return new UsersViewHolder(view);
}
#Override
protected void onBindViewHolder(#NonNull UsersViewHolder holder, int position, #NonNull Users model) {
holder.setName(model.getFirstName());
}
};
mUserList.setAdapter(mAdapter);
Right now I just want it to populate with all the users in the database but nothing seems to be populated.
mUserList is a recyclerView.
This is the UsersViewHolder class:
public static class UsersViewHolder extends RecyclerView.ViewHolder {
View mView;
TextView mUsername;
UsersViewHolder(View itemView) {
super(itemView);
mView = itemView;
mUsername = mView.findViewById(R.id.user_single_name);
}
public void setName(String name) {
mUsername.setText(name);
}
}
To solve this, change the following line of code:
Query mQuery = FirebaseDatabase.getInstance().getReference().orderByChild("users");
with:
Query mQuery = FirebaseDatabase.getInstance().getReference()
.child("users")
.orderByChild("first_name");
You are missing a child. Don't also forget to start listening for changes:
#Override
protected void onStart() {
super.onStart();
mAdapter.startListening();
}
And also to stop listening when not needed.
#Override
protected void onStop() {
super.onStop();
if( mAdapter!= null) {
mAdapter.stopListening();
}
}
Use that way. Follow my code for yourself.
FirebaseRecyclerOptions<Data> options=
new FirebaseRecyclerOptions.Builder<Data>()
.setQuery(mIncomeDatabase,Data.class)
.setLifecycleOwner(this)
.build();
FirebaseRecyclerAdapter<Data, MyViewHolder> firebaseRecyclelerAdapter = new FirebaseRecyclerAdapter<Data, MyViewHolder>(options) {
#NonNull
#Override
public MyViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
return new MyViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.income_recycler_data,parent,false));
}
#Override
protected void onBindViewHolder(#NonNull MyViewHolder holder, int position, #NonNull Data model) {
holder.setName(model.getName());
holder.setAmount(model.getAmount());
holder.setType(model.getType());
holder.setNote(model.getNote());
holder.setAmount(model.getAmount());
holder.setDate(model.getDate());
}
};
recyclerView.setAdapter(firebaseRecyclelerAdapter);

How to do RecyclerView scroll save

I have a recyclerView. Values are lost when recycler is scrolled down.I would like to have values greater than 7. Values come up when first opened but When I go down the scroll bar, it returns to its original state.
FragmentB.java
public class FragmentB extends Fragment{
View view ;
TextView textView;
RecyclerView recyclerView ;
ArrayList<OnemliDepremler> onemliDepremler;
BuyukRecyclerAdapter buyukRecyclerAdapter;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, Bundle savedInstanceState) {
view = inflater.inflate(R.layout.fragment_sabit,container,false);
// textView=view.findViewById(R.id.textView3);
recyclerView = view.findViewById(R.id.recyclerView);
LinearLayoutManager layoutManager=new LinearLayoutManager(getActivity());
layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
layoutManager.scrollToPosition(0);
recyclerView.setLayoutManager(layoutManager);
onemliDepremler=new ArrayList<OnemliDepremler>();
Factory.getInstance().buyukDepremModel().enqueue(new Callback<OnemliDepremModel>() {
#Override
public void onResponse(Call<OnemliDepremModel> call, Response<OnemliDepremModel> response) {
buyukRecyclerAdapter=new BuyukRecyclerAdapter(response.body().data.subList(0, 10));
recyclerView.setAdapter(buyukRecyclerAdapter);
}
#Override
public void onFailure(Call<OnemliDepremModel> call, Throwable t) {
}
});
return view;
}
}
BuyukRecyclerAdapter.java
public class BuyukRecyclerAdapter extends RecyclerView.Adapter<BuyukRecyclerAdapter.ViewHolder> {
public static class ViewHolder extends RecyclerView.ViewHolder{
public TextView buyukluk;
public TextView yer;
public TextView tarih;
public CardView cardView ;
FrameLayout frameLayout;
public ViewHolder(View itemView) {
super(itemView);
cardView = itemView.findViewById(R.id.card_view);
buyukluk=itemView.findViewById(R.id.text_buyukluk);
yer=itemView.findViewById(R.id.text_yer);
tarih=itemView.findViewById(R.id.text_tarih);
frameLayout=itemView.findViewById(R.id.frame_layout);
}
}
List<Datum> onemliDepremler;
public BuyukRecyclerAdapter(List<Datum> onemliDepremler) {
this.onemliDepremler = onemliDepremler;
}
#Override
public BuyukRecyclerAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v= LayoutInflater.from(parent.getContext()).inflate(R.layout.onemli_custom,parent,false);
final ViewHolder view_holder=new ViewHolder(v);
return view_holder;
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.buyukluk.setText(onemliDepremler.get(position).siddeti);
holder.tarih.setText("Tarih :"+onemliDepremler.get(position).tarih);
holder.yer.setText(onemliDepremler.get(position).lokasyon);
if(Float.parseFloat(onemliDepremler.get(position).siddeti)>7){
holder.frameLayout.setBackgroundColor(Color.RED);
}
}
#Override
public int getItemCount() {
return onemliDepremler.size();
}
#Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
}
}
Your advice important for me
Thank you very much !
if(Float.parseFloat(onemliDepremler.get(position).siddeti)>7){
holder.frameLayout.setBackgroundColor(Color.RED);
}else{
holder.frameLayout.setBackgroundColor(Color.YELLOW);
}
Try this.

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