Capture selected Recyclerview item to another screen

Question

I have my search screen. When typing, it brings the search result. The result is shown in a recyclerview. My Recyclerview was modeled with some textviews and an image. I wanted when touching the item of Recyclerview, that the text of the textview was passed to another Fragment (screen) that I have. I can even do the part of the screen call. I just can’t rescue the text from the textview on the other screen. I even instantiated the textviews of the other screen that modeled the Recycler.

My class of adapter:

public class CursosAdapterImg extends RecyclerView.Adapter<CursosAdapterImg.CursosHolder> {

List<Curso>listaCursos;
private OnNoteListener mOnNoteListener;


public CursosAdapterImg(List<Curso> listaCursos, Context context,OnNoteListener onNoteListener) {
    this.listaCursos = listaCursos;
    this.mOnNoteListener = onNoteListener;
}

@NonNull
@Override
public CursosHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

    View vista = LayoutInflater.from(parent.getContext()).inflate(R.layout.lista_cursos_img, parent, false);
    RecyclerView.LayoutParams layoutParams =
            new RecyclerView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
                    ViewGroup.LayoutParams.WRAP_CONTENT
            );

    vista.setLayoutParams(layoutParams);
    return new CursosHolder(vista, mOnNoteListener);
}

@Override
public void onBindViewHolder(@NonNull CursosHolder holder, int position) {
   // holder.txtCodigo.setText(listaCursos.get(position).getCodigo().toString());



    holder.txtNome.setText(listaCursos.get(position).getNome().toString());
    holder.txtProfessor.setText(listaCursos.get(position).getProfessor().toString());
    holder.txtCategoria.setText(listaCursos.get(position).getCategoria().toString());



    if(listaCursos.get(position).getImagem()!=null){
        holder.idImagem.setImageBitmap(listaCursos.get(position).getImagem());
    }else{
        holder.idImagem.setImageResource(R.drawable.sem_foto);
    }

}

@Override
public int getItemCount() {
    return listaCursos.size();
}

public class CursosHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

    TextView txtNome,txtCodigo,txtProfessor, txtCategoria;
    ImageView idImagem;

    OnNoteListener onNoteListener;

    public CursosHolder(View itemView,OnNoteListener onNoteListener) {
        super(itemView);
        txtNome= (TextView) itemView.findViewById(R.id.nomeCurso);
        //txtCodigo= (TextView) itemView.findViewById(R.id.txtCodigo);
        txtProfessor= (TextView) itemView.findViewById(R.id.Professor);
        txtCategoria= (TextView) itemView.findViewById(R.id.Categoria);
        idImagem=  itemView.findViewById(R.id.idImagem);

        this.onNoteListener = onNoteListener;
        itemView.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        onNoteListener.onNoteClick(getAdapterPosition());


    }
}

public interface OnNoteListener{
    void onNoteClick(int position);

}

}

Below is my search screen that returns a Recyclerview:

 @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 vista = inflater.inflate(R.layout.fragment_consultar_lista_nome, container, false);
    listaCursos=new ArrayList<>();

    recyclerCursos= (RecyclerView) vista.findViewById(R.id.idRecyclerNome);   // se der problema, mude aqui
    recyclerCursos.setLayoutManager(new LinearLayoutManager(this.getContext()));
    recyclerCursos.setHasFixedSize(true);
    txt_titulo = (TextView) vista.findViewById(R.id.titulo);
    professor = (TextView) vista.findViewById(R.id.Professor);
    campoNome = (EditText) vista.findViewById(R.id.campoNome);

    botaoConsultar = (Button) vista.findViewById(R.id.btnConsultar);

    request= Volley.newRequestQueue(getContext());

    botaoConsultar.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            carregarWEBService();
        }
    });

    return vista;
}

private void carregarWEBService() {

    progresso = new ProgressDialog(getContext());
    progresso.setMessage("Buscando...");
    progresso.show();

    String url = "http://192.168.0.5/webservices/consultarListaImagemUrlNome.php?nome="+ campoNome.getText().toString();


    jsonObjectReq = new JsonObjectRequest(Request.Method.GET, url, null, this, this);
    request.add(jsonObjectReq);

}


@Override
public void onErrorResponse(VolleyError error) {

    progresso.hide();
    Toast.makeText(getContext(), "Não foi possível listar os cursos " +error.toString() , Toast.LENGTH_SHORT).show();
    Log.i("ERROR", error.toString());

}

@Override
public void onResponse(JSONObject response) {

    progresso.hide();

    Curso curso = null;
    JSONArray json = response.optJSONArray("curso"); // nome da tabela curso


    try {
        for(int i=0; i<json.length();i++){
            curso = new Curso();

            JSONObject jsonObject = null;
            jsonObject = json.getJSONObject(i);

            curso.setNome(jsonObject.optString("nome"));
            curso.setProfessor(jsonObject.optString("professor"));
            curso.setCategoria(jsonObject.optString("categoria"));
            curso.setDado(jsonObject.optString("imagem"));
            listaCursos.add(curso);
        }

        progresso.hide();
        CursosAdapterImg adapter = new CursosAdapterImg(listaCursos,getContext(),this);
        recyclerCursos.setAdapter(adapter);



    }catch (JSONException e){
        e.printStackTrace();
        progresso.hide();
        Toast.makeText(getContext(), "Não foi possível listar os cursos " +response , Toast.LENGTH_SHORT).show();

    }


}

 @Override
public void onNoteClick(int position) {

    listaCursos.get(position);

    //Falta passar os parâmetros


    consultarCursoUrl fragmentConsulta = new consultarCursoUrl();
 /*  Estava testando nesse bloco passagem de parâmetros para outra fragment
    Bundle arguments = new Bundle();
    arguments.putString( "professor" , "Testando a passagem");
    fragmentConsulta.setArguments(arguments); */

    FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
    fragmentTransaction.replace(R.id.content_main,fragmentConsulta).commit();


}

And this code below, is my screen that is called after touching the item of the Recycle:

@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 vista = inflater.inflate(R.layout.fragment_consultar_curso_url, container, false);

    campoCodigo = vista.findViewById(R.id.codigo);
    campoNome = vista.findViewById(R.id.txt_nome);
    campoCategoria = vista.findViewById(R.id.txt_categoria);
    campoProfessor = vista.findViewById(R.id.txt_professor);
    btnAtualizar = vista.findViewById(R.id.btnAtualizar);
    btnDeletar = vista.findViewById(R.id.btnDeletar);
    btnConsultar = vista.findViewById(R.id.btnConsultar);
    imgFoto = vista.findViewById(R.id.imagemId);

  /*  Estava fazendo teste de parametros nesse bloco

    Bundle arguments = getArguments();
    String nomeProfessor = arguments.getString("professor");

    campoNome.setText(nomeProfessor);
    */

    request = Volley.newRequestQueue(getContext());

    btnConsultar.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            carregarWEBService();
        }
    });

    if(solicitarPermissoesVersoesSuperiores()){
        imgFoto.setEnabled(true);
    }else{
        imgFoto.setEnabled(false);
    }


    imgFoto.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

           carregarDialog();
        }
    });

    btnAtualizar.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            carregarWEBServiceAtualizar();

        }
    });

    btnDeletar.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {


            carregarWEBServiceDeletar();

        }
    });

    return vista;
}

Answer 1

Dealing with data contained in Recyclerview is a bit complex as it does not contain the Onitemclicklistiner() method as in a Listview. To do this, you will have to create an interface in the Recyclerview Adapter to capture the position of the clicked item.

See my example below the Recyclerview Adapter code:

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AnimationUtils;
import android.widget.Filter;
import android.widget.Filterable;
import android.widget.RelativeLayout;
import android.widget.TextView;

import com.exemplifique.apfarma.R;

import java.util.ArrayList;
import java.util.List;

public class Adapter_Construtor_Bula extends RecyclerView.Adapter<Adapter_Construtor_Bula.NewsViewHolder> implements Filterable {


    private Context mContext;
    private List<Constructor_Bula> mData ;
    private List<Constructor_Bula> mDataFiltered ;
    private ContactsAdapterListener listener;

    /*É necessário criar uma interface para capturar o evento de click*/
    public interface ContactsAdapterListener {
        void onContactSelected(Constructor_Bula construtorBula);
    }

    Adapter_Construtor_Bula(Context mContext, List<Constructor_Bula> mData, ContactsAdapterListener listener) {
        this.mContext = mContext;
        this.mData = mData;
        this.mDataFiltered = mData;
        this.listener = listener;

    }

    @NonNull
    @Override
    public NewsViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {

        View layout;
        layout = LayoutInflater.from(mContext).inflate(R.layout.custon_recycleview,viewGroup,false);
        return new NewsViewHolder(layout);
    }

    @Override
    public void onBindViewHolder(@NonNull NewsViewHolder newsViewHolder, int position) {

        newsViewHolder.container.setAnimation(AnimationUtils.loadAnimation(mContext,R.anim.fade_scale_animation));
        newsViewHolder.txtTitle.setText(mDataFiltered.get(position).getTitle());
        newsViewHolder.txtDescription.setText(mDataFiltered.get(position).getDescription());
    }

    @Override
    public int getItemCount() {
        return mDataFiltered.size();
    }

    @Override
    public Filter getFilter() {

        return new Filter() {
            @Override
            protected FilterResults performFiltering(CharSequence constraint) {

                String Key = constraint.toString();
                if (Key.isEmpty()) {

                    mDataFiltered = mData ;

                }
                else {
                    List<Constructor_Bula> lstFiltered = new ArrayList<>();
                    for (Constructor_Bula row : mData) {

                        if (row.getTitle().toLowerCase().contains(Key.toLowerCase())){
                            lstFiltered.add(row);
                        }

                    }

                    mDataFiltered = lstFiltered;

                }


                FilterResults filterResults = new FilterResults();
                filterResults.values= mDataFiltered;
                return filterResults;

            }

            @Override
            protected void publishResults(CharSequence constraint, FilterResults results) {


                mDataFiltered = (List<Constructor_Bula>) results.values;
                notifyDataSetChanged();

            }
        };




    }

    class NewsViewHolder extends RecyclerView.ViewHolder {

        TextView txtTitle,txtDescription;
        RelativeLayout container;

        NewsViewHolder(@NonNull View itemView) {
            super(itemView);
            container = itemView.findViewById(R.id.container);

            txtTitle = itemView.findViewById(R.id.txtTitleMed);
            txtDescription = itemView.findViewById(R.id.txtDescription);


            //Esta parte também é escencial.
            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    listener.onContactSelected(mDataFiltered.get(getAdapterPosition()));
                }
            });

        }
    }
}

Then I capture the click event in the Activity position, in my case in the Fragment, as follows:

public class Fragment_Bula extends Fragment implements Adapter_Construtor_Bula.ContactsAdapterListener{


    CollectionReference collectionReference;

    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_bula, container, false);

        /*
         * Aqui eu pego os valores da minha coleção do firebase e adiciono na minha lista de nome ''list''.
         * 
         * Não se apegue nesta parte pois é só um complemento para melhor entendimento.
         * 
         */

        FirebaseFirestore db = FirebaseFirestore.getInstance();
        List<Constructor_Bula> list = new ArrayList<>();
        collectionReference =   db.collection("Livro");
        collectionReference.get()
                .addOnSuccessListener(new OnSuccessListener<QuerySnapshot>() {
                    @Override
                    public void onSuccess(QuerySnapshot queryDocumentSnapshots) {

                        for (QueryDocumentSnapshot documentSnapshot : queryDocumentSnapshots){
                            String nome          =   documentSnapshot.getString("Nome");
                            String formula       =   documentSnapshot.getString("Principio ativo");
                            String tipo          =   documentSnapshot.getString("Tipo");

                            for (int i = 0 ; i < 10 ; i++){

                                //Adicionando valores a lista.
                                list.add(new Constructor_Bula(nome,formula,tipo));
                            }

                        }

                    }
                });


            // O que você precisa entender é daqui para baixo.  

        RecyclerView recyclerView        =   view.findViewById(R.id.recyclerView);
        Adapter_Construtor_Bula adapter  =   new Adapter_Construtor_Bula(getContext(),list,Fragment_Bula.this);
        recyclerView.setAdapter(adapter);
        recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));

        /*
         *  Usei getContext() e "view.findViewById(...)" pois estou em um fragmento mas se você tiver em uma acitivity pode *  fazer assim:
         *      
         *  RecyclerView recyclerView        =   findViewById(R.id.recyclerView);
         *  Adapter_Construtor_Bula adapter  =   new Adapter_Construtor_Bula(this,list,Fragment_Bula.this);
         *  recyclerView.setLayoutManager(new LinearLayoutManager(this);
         */

        return view;
    }


    //Método de captura dos valores da posição do recyclerView semelhante ao onItemClikLister() do ListView;
    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
    @Override
    public void onContactSelected(Constructor_Bula construtorBula) {

        // Para capturar o valor da posição  eu faço daseguinte maneira
        String nome = construtorBula.getTitle();

        /* o .getTitle() é o valor contido no Getter do meu construtor contido na
         * minha classe Construtor_Bula da variável ''private String title'' 
         * no qual eu uso para configurar meu RecyclerView
         */

         //Por fim, basta usar o valor contido na String nome da forma que quiser.

    }


}