Getting same item position in RecyclerView, when click on back button

Question

I have implemented one app where I am using RecyclerView in fragments. There are 3 buttons, 1 image and some text on every item. If I scroll and click on "View Profile" button then new activity will open which is running successfully but when I call back button then the Item is coming on start position. I need item will come at the same position.

Item Image

Code for Fragment

public class Broader_Match_Tab extends Fragment{

int lastVisibleItemPosition;
SessionManager session;
private List<SuperHero> listSuperHeroes;
private RecyclerView recyclerView;
private RecyclerView.LayoutManager layoutManager;
private RecyclerView.Adapter adapter;
public ProgressBar progressBar;
private RequestQueue requestQueue;
private int requestCount1 = 1;
private Boolean isStarted = false;
private Boolean isVisible = false;

boolean isLastPageLoaded = false;

public String email;
TextView tvMSG;
public Broader_Match_Tab() {}

@Override
public void onStart() {
    super.onStart();
    isStarted = true;
    if (isVisible && isStarted){
        getData();
    }
}

@Override
public void setUserVisibleHint(boolean isVisibleToUser) {
    super.setUserVisibleHint(isVisibleToUser);
    isVisible = isVisibleToUser;
    if (isStarted && isVisible && (! isLastPageLoaded)) { getData(); } }

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view= inflater.inflate(R.layout.activity_main_test, container, false);

    session = new SessionManager(getActivity());
    // get user data from session
    HashMap<String, String> user = session.getUserDetails();
    email = user.get(SessionManager.KEY_EMAIL);
    return view;
}

public void onViewCreated(View v, Bundle savedInstanceState) {
    super.onViewCreated(v, savedInstanceState);
    recyclerView = (RecyclerView) v.findViewById(R.id.recyclerView);
    recyclerView.setHasFixedSize(true);
    layoutManager = new LinearLayoutManager(getContext());
    recyclerView.setLayoutManager(layoutManager);
    listSuperHeroes = new ArrayList<>();
    requestQueue = Volley.newRequestQueue(getContext());
    adapter = new CardAdapter(listSuperHeroes, getActivity());
    recyclerView.setAdapter(adapter);
    progressBar = (ProgressBar) v.findViewById(R.id.progressBar1);
    tvMSG = (TextView)v.findViewById(R.id.tvMSG);

    recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
        @Override
        public void onScrollStateChanged(RecyclerView recyclerView, int
                newState) {
            super.onScrollStateChanged(recyclerView, newState);
            if (isLastItemDisplaying(recyclerView)) {
                    getData();
            }
        }
    });
}

private JsonArrayRequest getDataFromServer(int requestCount) {
    final String DATA_URL = "https://www.example.com";
    JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(DATA_URL + String.valueOf(requestCount),
            new Response.Listener<JSONArray>() {
                @Override
                public void onResponse(JSONArray response) {
                    if (response.length() == 0) {
                        progressBar.setVisibility(View.GONE);
                        tvMSG.setText("There is no broader matches");
                        isLastPageLoaded = true;
                    }
                    else {
                        parseData(response);
                        tvMSG.setVisibility(View.GONE);
                        progressBar.setVisibility(View.GONE);
                    }
                }
            },
            new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    progressBar.setVisibility(View.GONE);
                    Toast.makeText(getActivity(), "No More Items Available", Toast.LENGTH_SHORT).show();
                }
            });
    return jsonArrayRequest;
}

private void getData() {
    if(!isLastPageLoaded){
        requestQueue.add(getDataFromServer(requestCount1));
        requestCount1++;
    }}

private void parseData(JSONArray array) {
    for (int i = 0; i < array.length(); i++) {
        SuperHero superHero = new SuperHero();
        JSONObject json = null;
        try {
            json = array.getJSONObject(i);
            superHero.setImageUrl(json.getString(Config_Test.TAG_IMAGE_URL));
            superHero.setMglId(json.getString(Config_Test.TAG_MGLID));
            superHero.setAge(json.getString(Config_Test.TAG_AGE));
            superHero.setAgeHeight(json.getString(Config_Test.TAG_AGEHEIGHT));
            superHero.setCommunity(json.getString(Config_Test.TAG_COMMUNITY));
            superHero.setCaste(json.getString(Config_Test.TAG_CASTE));
            superHero.setOccupation(json.getString(Config_Test.TAG_OCCUPATION));
            superHero.setIncome(json.getString(Config_Test.TAG_INCOME));
            superHero.setShortlist(json.getString(Config_Test.TAG_SHORTLIST));
            superHero.setExpress_Intrest(json.getString(Config_Test.TAG_EXPRESSINTREST));
        } catch (JSONException e) {
            e.printStackTrace();
        }
        listSuperHeroes.add(superHero);
    }
    adapter.notifyDataSetChanged();
}
private boolean isLastItemDisplaying(RecyclerView recyclerView) {
    if (recyclerView.getAdapter().getItemCount() != 0) {
        lastVisibleItemPosition = ((LinearLayoutManager) recyclerView.getLayoutManager()).findLastCompletelyVisibleItemPosition();
        if (lastVisibleItemPosition != RecyclerView.NO_POSITION && lastVisibleItemPosition == recyclerView.getAdapter().getItemCount() - 1)
            return true;
    }
    return false;
  }
}

Adapter Code

public class CardAdapter extends RecyclerView.Adapter<CardAdapter.ViewHolder>
{
private static final String url ="https://www.example.com";
private static final String url1 = "https://www.example.com";
private static final String KEY_MATRI_ID_TO="matriID_to";
private static final String KEY_MATRI_ID_BY="matriID_by";

SessionManager session;
public String matri_id_to, matri_id_by, str_gender;
String str_shortlist,str_EI;

//Imageloader to load image
private ImageLoader imageLoader;
private Context context;

//List to store all superheroes
List<SuperHero> superHeroes;

//Constructor of this class
public CardAdapter(List<SuperHero> superHeroes, Context context){
    super();
    //Getting all superheroes
    this.superHeroes = superHeroes;
    this.context = context;
}

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View v = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.superheroes_list, parent, false);
    // Session class instance
    session = new SessionManager(context);
    session.checkLogin();
    // get user data from session
    HashMap<String, String> user = session.getUserDetails();
    matri_id_by = user.get(SessionManager.KEY_EMAIL);
    str_gender = user.get(SessionManager.KEY_GENDER);

    ViewHolder viewHolder = new ViewHolder(v);
    return viewHolder;
}

@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {

    //Getting the particular item from the list
    final SuperHero superHero =  superHeroes.get(position);

    //Loading image from url
    imageLoader = CustomVolleyRequest.getInstance(context).getImageLoader();
    if(str_gender.equalsIgnoreCase("Male")) {
        imageLoader.get(superHero.getImageUrl(), ImageLoader.getImageListener(holder.imageView, R.drawable.image, R.drawable.girl));
    }
    else {
        imageLoader.get(superHero.getImageUrl(), ImageLoader.getImageListener(holder.imageView, R.drawable.image, R.drawable.boy));
    }

    int pos = getItemViewType(position);
    if(superHeroes.get(pos).getImageUrl() == null) {
        holder.imageView.setVisibility(View.GONE);
    } else {
        holder.imageView.setImageUrl(superHero.getImageUrl(), imageLoader);
    }

    holder.textViewId.setText(superHero.getMglId());
    holder.AgeHeight.setText(superHero.getAgeHeight()+" / "+superHero.getAge());
    holder.Community.setText(superHero.getCommunity()+" / "+superHero.getCaste());
    holder.Occupation.setText(superHero.getOccupation());
    holder.Income.setText(superHero.getIncome());

    str_shortlist = superHero.getShortlist();
    if(str_shortlist.toString().equalsIgnoreCase("Shortlisted")) {
        holder.btnShortlist.setText(str_shortlist);
        holder.btnShortlist.setBackgroundColor(Color.parseColor("#FF0E3671"));
        holder.btnShortlist.setEnabled(false);
    }
    else{
        holder.btnShortlist.setEnabled(true);
        holder.btnShortlist.setText(str_shortlist);
        holder.btnShortlist.setBackgroundColor(Color.parseColor("#2a7fff"));
    }


    str_EI = superHero.getExpress_Intrest();
    Log.e("str_EI_____",str_EI);
    if(str_EI.toString().equalsIgnoreCase("Accepted")) {
        holder.btnEI.setText(str_EI);
        holder.btnEI.setBackgroundColor(Color.parseColor("#FF045B49"));
        holder.btnEI.setEnabled(false);
    }
    else if(str_EI.toString().equalsIgnoreCase("Reject")){
        holder.btnEI.setText(str_EI);
        holder.btnEI.setBackgroundColor(Color.parseColor("#FF045B49"));
        holder.btnEI.setEnabled(false);
    }
    else if(str_EI.toString().equalsIgnoreCase("Declined")){
        holder.btnEI.setText(str_EI);
        holder.btnEI.setBackgroundColor(Color.parseColor("#FF045B49"));
        holder.btnEI.setEnabled(false);
    }
    else if(str_EI.toString().equalsIgnoreCase("Pending..")){
        holder.btnEI.setText(str_EI);
        holder.btnEI.setBackgroundColor(Color.parseColor("#FF045B49"));
        holder.btnEI.setEnabled(false);
    }
    else
    {
        holder.btnEI.setEnabled(true);
        holder.btnEI.setText(str_EI);
        holder.btnEI.setBackgroundColor(Color.parseColor("#00aa88"));
    }


    holder.btnShortlist.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            superHero.setShortlist("Wait...");
            holder.btnShortlist.setText(superHero.getShortlist());
            matri_id_to = superHero.getMglId();
            holder.shortlist(position);
        }
    });

    holder.btnViewProfile.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent n = new Intent(holder.itemView.getContext(),BlankActivity.class);
            String str_id = holder.textViewId.getText().toString();
            n.putExtra("ID",str_id);
            holder.itemView.getContext().startActivity(n);
        }
    });


    holder.btnEI.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            superHero.setExpress_Intrest("Wait...");
            holder.btnEI.setText(superHero.getExpress_Intrest());
            matri_id_to = superHero.getMglId();
            holder.expressInterest(position);
        }
    });

}

public SuperHero getItem(int position){
    return superHeroes.get(position);
}

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

    @Override
    public int getItemViewType(int position) {
        return position;
    }

class ViewHolder extends RecyclerView.ViewHolder{
    public NetworkImageView imageView;
    public TextView textViewId;
    public TextView AgeHeight;
    public TextView Community;
    public TextView Occupation;
    public TextView Income;

    public Button btnShortlist;
    public Button btnViewProfile;
    public Button btnEI;

    //Initializing Views
    public ViewHolder(final View itemView) {
        super(itemView);
        imageView = (NetworkImageView) itemView.findViewById(R.id.imageViewHero);
        textViewId = (TextView) itemView.findViewById(R.id.textViewId);
        AgeHeight = (TextView) itemView.findViewById(R.id.AgeHeight);
        Community = (TextView) itemView.findViewById(R.id.Community);
        Occupation = (TextView) itemView.findViewById(R.id.Occupation);
        Income = (TextView) itemView.findViewById(R.id.Income);
        btnShortlist = (Button) itemView.findViewById(R.id.btnshort);
        btnViewProfile = (Button) itemView.findViewById(R.id.buttonViewProfile);
        btnEI = (Button) itemView.findViewById(R.id.btnExpressIntrest);
    }

    public void shortlist(final int position) {
        StringRequest stringRequest = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                if (response.trim().equalsIgnoreCase("success")) {
                    superHeroes.get(position).setShortlist("Shortlisted");
                    // holder.btnShortlist.setText(superHero.getShortlist());
                    notifyDataSetChanged();
                }
            }
        },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        Toast.makeText(context, error.toString(), Toast.LENGTH_LONG).show();
                    }
                }) {
            @Override
            protected Map<String, String> getParams() {
                Map<String, String> params = new HashMap<String, String>();
                params.put(KEY_MATRI_ID_BY, matri_id_by);
                params.put(KEY_MATRI_ID_TO, matri_id_to);
                return params;
            }
        };
        RequestQueue requestQueue = Volley.newRequestQueue(context);
        requestQueue.add(stringRequest);
    }

    public void expressInterest(final int position) {
        StringRequest stringRequest1 = new StringRequest(Request.Method.POST, url1, new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                if(response.trim().equalsIgnoreCase("success")) {
                    superHeroes.get(position).setExpress_Intrest("Pending..");
                    notifyDataSetChanged();
                }
            }
        },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        Toast.makeText(context, error.toString(), Toast.LENGTH_LONG).show();
                    }
                }) {
            @Override
            protected Map<String, String> getParams() {
                Map<String, String> params = new HashMap<String, String>();
                params.put(KEY_MATRI_ID_BY,matri_id_by);
                params.put(KEY_MATRI_ID_TO,matri_id_to);
                return params;
            }
        };
        RequestQueue requestQueue = Volley.newRequestQueue(context);
        requestQueue.add(stringRequest1);
    }
   }
  }

Answer 1

Save Instance Code:

Parcelable mListState;

protected void onSaveInstanceState(Bundle state) {
     super.onSaveInstanceState(state);

     // Save list state
     mListState = mLayoutManager.onSaveInstanceState();
     state.putParcelable(LIST_STATE_KEY, mListState);
}

Restore State Code:

protected void onRestoreInstanceState(Bundle state) {
    super.onRestoreInstanceState(state);

    // Retrieve list state and list/item positions
    if(state != null)
        mListState = state.getParcelable(LIST_STATE_KEY);
}

Here in onResume() update the layout manager:

@Override
protected void onResume() {
    super.onResume();

    if (mListState != null) {
        mLayoutManager.onRestoreInstanceState(mListState);
    }
}

Hope this helps

Answer 2

The main problem is that onPause you are clearing the whole data and when the fragment getting visible again you are requesting to server from the page 1. Comment the following code.

    @Override
public void onPause(){
    super.onPause();
    //listSuperHeroes.clear();
    //adapter.notifyDataSetChanged();
    //requestCount1=1;
   }
  }

update the isLastPageLoaded here:

private boolean isLastPageUpdated = false;
     private JsonArrayRequest getDataFromServer(int requestCount) {
            final String DATA_URL = "https://www.XYZ.php?matri_id="+email+"&page=";
            JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(DATA_URL + String.valueOf(requestCount),
                    new Response.Listener<JSONArray>() {
                        @Override
                        public void onResponse(JSONArray response) {
                            if (response.length() == 0) {
                                progressBar.setVisibility(View.GONE);
                                tvMSG.setText("There is no broader matches");
                    isLastPageLoaded = true;
                            }
                            else {
                                parseData(response);
                                tvMSG.setVisibility(View.GONE);
                                progressBar.setVisibility(View.GONE);
                            }
                        }
                    },
                    new Response.ErrorListener() {
                        @Override
                        public void onErrorResponse(VolleyError error) {
                            progressBar.setVisibility(View.GONE);
                            Toast.makeText(getActivity(), "No More Items 
                            Available", Toast.LENGTH_SHORT).show();
                        }
                    });
            return jsonArrayRequest;
        }

and in getData()

 private void getData() {
if(!isLastPageUpdated){
    requestQueue.add(getDataFromServer(requestCount1));
    requestCount1++;
}}