Develop Reference

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();

How to load an url from recyclerview newsapi

Im working on a news reader app that uses fragments. I get my data from the newsapi. So far I have managed to pull the data from the api and display it in a recyclerview but when I click on an item, nothing happens!
public class HomeFragment extends Fragment implements RecyclerViewAdapter.OnItemClickListener {
public static final String API_KEY= "c03ceb6a99b14050875f56xxxxxxxx";
private RecyclerView recyclerView;
private List<Article> articles = new ArrayList<>();
private RecyclerViewAdapter recyclerViewAdapter;
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_home,container,false);
recyclerView = rootView.findViewById(R.id.recycler_view);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
recyclerViewAdapter = new RecyclerViewAdapter(articles,getActivity());
recyclerViewAdapter.setOnItemClickListener(HomeFragment.this);
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setNestedScrollingEnabled(false);
LoadJsonData();
return rootView;
}
public void LoadJsonData(){
ApiInterface apiInterface = ApiClient.getApiClient().create(ApiInterface.class);
String country = Utils.getCountry();
Call <News> call;
call = apiInterface.getNews(country,API_KEY);
call.enqueue(new Callback<News>() {
#Override
public void onResponse(Call<News> call, Response<News> response) {
if (response.isSuccessful() && response.body().getArticle() != null){
if (!articles.isEmpty()){
articles.clear();
}
articles = response.body().getArticle();
recyclerViewAdapter = new RecyclerViewAdapter(articles,getActivity());
recyclerView.setAdapter(recyclerViewAdapter);
recyclerViewAdapter.setOnItemClickListener(HomeFragment.this);
recyclerViewAdapter.notifyDataSetChanged();
} else {
Toast.makeText(getActivity(),"No result",Toast.LENGTH_SHORT).show();
}
}
#Override
public void onFailure(Call<News> call, Throwable t) {
}
});
}
#Override
public void onItemClick(int position) {
articles.get(position);
}
}
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder> {
private List<Article> articles;
private Context context;
private OnItemClickListener onItemClickListener;
public interface OnItemClickListener {
void onItemClick(int position);
}
public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
this.onItemClickListener = onItemClickListener;
}
public RecyclerViewAdapter(List<Article> articles, Context context) {
this.articles = articles;
this.context = context;
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(context).inflate((R.layout.card_view_layout), viewGroup, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull ViewHolder viewHolder, int i) {
final ViewHolder holder = viewHolder;
Article model = articles.get(i);
RequestOptions requestOptions = new RequestOptions();
requestOptions.placeholder(Utils.getRandomDrawbleColor());
requestOptions.error(Utils.getRandomDrawbleColor());
requestOptions.diskCacheStrategy(DiskCacheStrategy.ALL);
requestOptions.centerCrop();
Glide.with(context)
.load(model.getUrlToImage())
.apply(requestOptions)
.listener(new RequestListener<Drawable>() {
#Override
public boolean onLoadFailed(#Nullable GlideException e, Object model, Target<Drawable> target, boolean isFirstResource) {
holder.progressBar.setVisibility(View.GONE);
return false;
}
#Override
public boolean onResourceReady(Drawable resource, Object model, Target<Drawable> target, DataSource dataSource, boolean isFirstResource) {
holder.progressBar.setVisibility(View.GONE);
return false;
}
})
.transition(DrawableTransitionOptions.withCrossFade())
.into(holder.imageView);
holder.title.setText(model.getTitle());
holder.desc.setText(model.getDescription());
holder.source.setText(model.getSource().getName());
holder.time.setText(" \u2022 " + Utils.DateToTimeFormat(model.getPublishedAt()));
}
#Override
public int getItemCount() {
return articles.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
TextView title, desc, source, time;
ImageView imageView;
ProgressBar progressBar;
public ViewHolder(#NonNull View itemView) {
super(itemView);
title = itemView.findViewById(R.id.title);
desc = itemView.findViewById(R.id.description);
source = itemView.findViewById(R.id.source);
time = itemView.findViewById(R.id.time);
imageView = itemView.findViewById(R.id.headline_image);
progressBar = itemView.findViewById(R.id.progress_load);
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (onItemClickListener != null){
int position = getAdapterPosition();
if (position != RecyclerView.NO_POSITION){
onItemClickListener.onItemClick(position);
}
}
}
});
}
}
}

It seems all you are doing inside your onClick is getting the item position. It is now up to you to do something with that position.
So the question comes down to, what do you want to do?
Launch a details activity/fragment to display more info? That is a typical pattern for mobile.
Intent i = new Intent(context,DetailActivity.class);
i.putExtra(Your Data);
startActivity(i);

How do i setOnClickListener on RecyclerView on Android Studio

i want to put setOnClickListener on the recyclerview that i follow on a tutorial, the problem is, i don't know where to put it, i got mixed with all other features of the app, i believe the code must be put somewhere here :
this is my ExampleAdapter :
public class ExampleAdapter extends RecyclerView.Adapter<ExampleAdapter.ExampleViewHolder>{
private ArrayList<ExampleItem> mExampleList;
public static class ExampleViewHolder extends RecyclerView.ViewHolder {
public ImageView mImageView;
public TextView mTextView1;
public TextView mTextView2;
public ExampleViewHolder(View itemView) {
super(itemView);
mImageView = itemView.findViewById(R.id.imageView);
mTextView1 = itemView.findViewById(R.id.textView);
mTextView2 = itemView.findViewById(R.id.textView2);
}
}
public ExampleAdapter(ArrayList<ExampleItem> exampleList) {
mExampleList = exampleList;
}
#Override
public ExampleViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.example_item,
parent, false);
ExampleViewHolder evh = new ExampleViewHolder(v);
return evh;
}
#Override
public void onBindViewHolder(ExampleViewHolder holder, int position) {
ExampleItem currentItem = mExampleList.get(position);
holder.mImageView.setImageResource(currentItem.getImageResource());
holder.mTextView1.setText(currentItem.getText1());
holder.mTextView2.setText(currentItem.getText2());
}
#Override
public int getItemCount() {
return mExampleList.size();
}
public void filterList(ArrayList<ExampleItem> filteredList) {
mExampleList = filteredList;
notifyDataSetChanged();
}
}
really appreciate you guys, if you could help me.

Use this in your activity in which you have recyclerview
rv= (RecyclerView) findViewById(R.id.rv);
rv.setLayoutManager(new LinearLayoutManager(this));
rv.addOnItemTouchListener(
new RecyclerItemClickListener(this, rv ,new RecyclerItemClickListener.OnItemClickListener() {
#Override public void onItemClick(View view, int position) {
// do whatever
}
#Override public void onLongItemClick(View view, int position) {
// do whatever
}
})
);

Just edit extends RecyclerView.ViewHolder implements View.OnClickListener
and implement OnClick method ,edit as public ExampleViewHolder(View itemView) {
super(itemView);
itemView.setOnClickListener(this);
#Override
public void onClick(View v) {
}

Using ParseRecyclerQueryAdapter

Please I would like someone to help point me in the right direction with using the ParseRecyclerQueryAdapter. I'm trying to retrieve articles with my current adapter class that implements the standard RecyclerView. my implementation of pagination is not working properly soIi would like a demonstration from anyone that has used the ParseRecyclerQueryAdapter to achieve the following. By translating it from me so I get the implementation.
public class ArticleRVAdapter extends RecyclerView.Adapter {
List<Article> articleData = Collections.emptyList();
private LayoutInflater inflater;
private Context context;
public ArticleRVAdapter(Context context, List<Article> data){
inflater=LayoutInflater.from(context);
this.articleData= data;
this.context = context;
}
#Override
public ArticleViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = inflater.inflate(R.layout.article_item, parent, false);
ArticleViewHolder viewHolder = new ArticleViewHolder(view);
return viewHolder;
}
#Override
public int getItemCount() {
return articleData.size();
}
public class ArticleViewHolder extends RecyclerView.ViewHolder
implements View.OnClickListener {
CardView cardView;
TextView title;
TextView body;
Date dateCreated;
TextView author;
ImageView headImage;
String objectId;
public ArticleViewHolder(final View itemView) {
super(itemView);
itemView.setClickable(true);
itemView.setLongClickable(true);
itemView.setOnClickListener(this);
cardView = (CardView) itemView.findViewById(R.id.card_article);
title = (TextView) itemView.findViewById(R.id.text_title);
body = (TextView) itemView.findViewById(R.id.text_article_body);
//dateCreated = itemView.findViewById(R.id.text_article_body);
author = (TextView) itemView.findViewById(R.id.text_author);
headImage = (ImageView) itemView.findViewById(R.id.imageView_thumb);
}
#Override
public void onClick(View v) {
Intent intent = new Intent(v.getContext(), ArticleInformationActivity.class);
intent.putExtra("article_id", articleData.get(getLayoutPosition()).getObjectId());
intent.putExtra("article_title", articleData.get(getLayoutPosition()).getArticleTitle());
intent.putExtra("article_body", articleData.get(getLayoutPosition()).getArticleBody());
intent.putExtra("article_author", articleData.get(getLayoutPosition()).getArticleAuthor());
intent.putExtra("article_date", articleData.get(getLayoutPosition()).getDateCreated());
v.getContext().startActivity(intent);
}
}

After a lot of testing, I got the solution in my project:
Fragment (or Activity):
private RecyclerView mRecyclerView;
private MyQueryAdapter myQueryAdapter;
private SwipeRefreshLayout swipeRefreshLayout;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.list_fragment, container, false);
mRecyclerView = (RecyclerView) view.findViewById(R.id.rv);
myQueryAdapter = new MyQueryAdapter(true);
mRecyclerView.setAdapter(myQueryAdapter);
mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
myQueryAdapter.addOnQueryLoadListener(new ParseRecyclerQueryAdapter.OnQueryLoadListener<MY_MODEL>() {
#Override
public void onLoaded(List<MY_MODEL> objects, Exception e) {
if (swipeRefreshLayout.isRefreshing()) {
swipeRefreshLayout.setRefreshing(false);
}
}
#Override
public void onLoading() {
if (!swipeRefreshLayout.isRefreshing()) {
swipeRefreshLayout.setRefreshing(true);
}
}
});
swipeRefreshLayout = (SwipeRefreshLayout) view.findViewById(R.id.swipe_container);
swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
myQueryAdapter.loadObjects();
}
});
return view;
}
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
#Override
public void onResume() {
super.onResume();
myQueryAdapter.loadObjects();
}
Adapter
public class MyQueryAdapter extends ParseRecyclerQueryAdapter<MY_MODEL, MyQueryAdapter.MyViewHolder>{
public MyQueryAdapter(boolean hasStableIds) {
super(MY_MODEL.class, hasStableIds);
}
public MarcacionesAdapter(ParseQueryAdapter.QueryFactory<Marcaciones> factory, boolean hasStableIds) {
super(factory, hasStableIds);
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.cardview, parent, false);
MyViewHolder myViewHolder = new MyViewHolder(v);
return myViewHolder;
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
MY_MODEL model = getItem(position);
holder.name.setText(model.getName());
holder.year.setText(model.getYear());
}
public static class MyViewHolder extends RecyclerView.ViewHolder {
CardView cv;
TextView name;
TextView year;
MyViewHolder(View itemView) {
super(itemView);
cv = (CardView)itemView.findViewById(R.id.card_view);
name = (TextView)itemView.findViewById(R.id.name);
year = (TextView)itemView.findViewById(R.id.year);
}
}
}
If you want to configure a custom query, you can do it in this way:
factory =
new ParseQueryAdapter.QueryFactory<MY_MODEL>() {
public ParseQuery< MY_MODEL > create() {
ParseQuery<MY_MODEL> query = MY_MODEL.getQuery();
query.include("user");
//Filter by date
query.whereGreaterThan("createdAt", midnight);
query.whereLessThan("createdAt", now);
query.orderByDescending("createdAt");
return query;
}
};
adapter = new MyQueryAdapter(factory, true);