Develop Reference

Scrolling RecyclerView inside a RecyclerView Item

I have a RecyclerView with some dummy string data in each item. Each item has also a recyclerview which contains some other dummy data (A - Z, see below) that will be visible when a button is clicked.
The problem I have is that I can not scroll the recyclerview within the item as I want. When I scroll, only the outer recyclerview scrolls (as you seen below)
Here how is it look like:
Here are the code I wrote:
//MainActivity.java
public class MainActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private StringAdapter mStringAdapter;
private ArrayList<String> mStrings = new ArrayList<>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mStrings.add("This");
mStrings.add("is");
mStrings.add("a");
mStrings.add("test");
mRecyclerView = (RecyclerView) findViewById(R.id.recyclerview);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
mStringAdapter = new StringAdapter(mStrings, this);
mRecyclerView.setAdapter(mStringAdapter);
}
}
Here, the adapter resonsible for the outer main recyclerview. Note that the recyclerview of each main recyclerview item gets visible when the button is clicked :
public class StringAdapter extends RecyclerView.Adapter<StringAdapter.ViewHolder> {
private ArrayList<String> mStrings;
private Context mContext;
private SomeInnerDataAdapter mSomeInnerDataAdapter;
public StringAdapter(ArrayList<String> strings, Context context) {
mStrings = strings;
mContext = context;
}
#NonNull
#Override
public StringAdapter.ViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
LayoutInflater inflater = LayoutInflater.from(viewGroup.getContext());
View view = inflater.inflate(R.layout.item, viewGroup, false);
return new StringAdapter.ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull StringAdapter.ViewHolder viewHolder, int i) {
String text = mStrings.get(i);
viewHolder.onBindText(text);
}
#Override
public int getItemCount() {
return mStrings.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
private TextView mTextView;
private RecyclerView mRecyclerView;
private Button mButton;
public ViewHolder(#NonNull View itemView) {
super(itemView);
mTextView = (TextView) itemView.findViewById(R.id.textView);
mRecyclerView = (RecyclerView) itemView.findViewById(R.id.someOtherData);
mButton = (Button) itemView.findViewById(R.id.button);
mButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Toast.makeText(mContext, "Item is clicked", Toast.LENGTH_LONG).show();
mRecyclerView.setVisibility(View.VISIBLE);
ArrayList<String> strings = new ArrayList<>();
strings.add("A");
strings.add("B");
strings.add("C");
strings.add("D");
strings.add("E");
strings.add("F");
strings.add("G");
strings.add("H");
strings.add("I");
strings.add("J");
strings.add("K");
strings.add("L");
strings.add("M");
strings.add("N");
strings.add("O");
strings.add("P");
strings.add("R");
strings.add("S");
strings.add("T");
strings.add("U");
strings.add("V");
strings.add("W");
strings.add("X");
strings.add("Y");
strings.add("Z");
mRecyclerView.setLayoutManager(new LinearLayoutManager(mContext, LinearLayoutManager.VERTICAL, false));
mSomeInnerDataAdapter = new SomeInnerDataAdapter(strings, mContext);
mRecyclerView.setAdapter(mSomeInnerDataAdapter);
}
});
}
public void onBindText(String text){
mTextView.setText(text);
}
}
}
The adapter responsible for the recyclerview within a item:
public class SomeInnerDataAdapter extends RecyclerView.Adapter<SomeInnerDataAdapter.ViewHolder> {
private ArrayList<String> mStrings;
private Context mContext;
public SomeInnerDataAdapter(ArrayList<String> strings, Context context) {
mStrings = strings;
mContext = context;
}
#NonNull
#Override
public SomeInnerDataAdapter.ViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
LayoutInflater inflater = LayoutInflater.from(viewGroup.getContext());
View view = inflater.inflate(R.layout.someotherdata_item, viewGroup, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull SomeInnerDataAdapter.ViewHolder viewHolder, int i) {
String text = mStrings.get(i);
viewHolder.onBindString(text);
}
#Override
public int getItemCount() {
return mStrings.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
private TextView mTextView;
public ViewHolder(#NonNull View itemView) {
super(itemView);
mTextView = (TextView) itemView.findViewById(R.id.someotherdata_textview);
}
public void onBindString(String text){
mTextView.setText(text);
}
}
}
The xml layouts are the following:
// item.xml
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/textView"
android:layout_gravity="center"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<android.support.v7.widget.RecyclerView
android:id="#+id/someOtherData"
android:layout_gravity="right"
android:visibility="invisible"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:scrollbars="vertical" />
<Button
android:id="#+id/button"
android:text="show comment"
android:layout_gravity="bottom|center"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</FrameLayout>
and someotherdata_item.xml:
<TextView
android:id="#+id/someotherdata_textview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="8dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:text="TextView"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android" />

RecyclerView items not displayed

I am getting really frustrated with this. I don't understand why my CardView grid items are not displayed in my RecyclerView
Here is CardView grid item fragment_album_cardview_item.xml
<android.support.v7.widget.CardView
xmlns:card_view="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/card_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
card_view:cardUseCompatPadding="true"
card_view:cardCornerRadius="8dp"
android:layout_marginBottom="16dp"
card_view:cardBackgroundColor="#android:color/white">
</android.support.v7.widget.CardView>
Here I set the adapter
public void setGridViewAdapter(){
GridLayoutManager layoutManager = new GridLayoutManager(getActivity(), 2);
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setLayoutManager(layoutManager);
mRecyclerViewAdapter = new RecyclerViewAdapter(App.mApp.mAlbums);
mRecyclerView.setAdapter(mRecyclerViewAdapter);
}
And here is my adapter
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.Holder> {
private List<Album> itemList;
//private Context context;
// TODO adapter may be initialized by the time some of the albums have been added to the list
public RecyclerViewAdapter(List<Album> itemList) {
this.itemList = itemList;
Timber.d("itemList.size = "+String.valueOf(itemList.size()));
Timber.d("itemList.get(0).name = "+itemList.get(0).name);
//this.context = context;
}
#Override
public Holder onCreateViewHolder(ViewGroup parent, int viewType) {
Timber.d("onCreateViewHolder");
View cardView = LayoutInflater.from(parent.getContext()).inflate(R.layout.fragment_album_cardview_item, null);
Timber.d("cardView = "+String.valueOf(cardView));
Holder rcv = new Holder(cardView);
return rcv;
}
#Override
public void onBindViewHolder(Holder holder, int position) {
//holder.countryName.setText(itemList.get(position).getName());
//holder.countryPhoto.setImageResource(itemList.get(position).getPhoto());
}
#Override
public int getItemCount() {
return this.itemList.size();
}
// HOLDER
public class Holder extends RecyclerView.ViewHolder implements View.OnClickListener{
public TextView countryName;
public ImageView countryPhoto;
public Holder(View itemView) {
super(itemView);
//itemView.setOnClickListener(this);
//countryName = (TextView)itemView.findViewById(R.id.country_name);
//countryPhoto = (ImageView)itemView.findViewById(R.id.country_photo);
}
#Override
public void onClick(View view) {
Toast.makeText(view.getContext(), "Clicked Country Position = " + getPosition(), Toast.LENGTH_SHORT).show();
}
}
}

Apparently, just adding a some kind of widget for example a TextView to my CardView results in some grid items being shown
<android.support.v7.widget.CardView
android:id="#+id/card_view"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="10dp"
android:layout_height="100dp"
card_view:cardUseCompatPadding="true"
card_view:cardCornerRadius="8dp"
android:layout_marginBottom="16dp"
card_view:cardBackgroundColor="#android:color/white">
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Bleh"/>
</android.support.v7.widget.CardView>

Horizontal RecyclerView Like Paytm

I have to implement a custom horizontal RecyclerView having a header (title) at top and a section (See All) right side at the end of the RecyclerView.
I created a RecyclerView with a header and footer but I want to have a right sided section (See All) of which onclick event I wish to fire some event.
In Paytm App, it is implemented
I wish to get results as follows

This will Gives You Idea
activity_main.xml
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="5dp"
android:paddingLeft="5dp"
android:paddingRight="5dp"
android:paddingTop="5dp">
<android.support.v7.widget.RecyclerView
android:id="#+id/verticalScrollRecyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</android.support.v7.widget.RecyclerView></RelativeLayout>
vertical_scroll_single_entry.xml
<?xml version="1.0" encoding="utf-8"?><LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="100dp"
android:weightSum="1"
android:gravity="center_vertical">
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1">
</android.support.v7.widget.RecyclerView>
<Button
android:id="#+id/selectAllButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="See All >>"
android:textAllCaps="false"/></LinearLayout>
Custom Adapter class For Vertical Scroller
public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.CustomViewHolder> {
private Context context;
private ArrayList arrayList;
private LayoutInflater layoutInflater;
public CustomAdapter(Context context, ArrayList arrayList) {
this.context = context;
this.layoutInflater = LayoutInflater.from(context);
this.arrayList = arrayList;
}
#Override
public CustomViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = layoutInflater.inflate(R.layout.vertical_scroll_single_entry, parent, false);
return new CustomViewHolder(view);
}
#Override
public void onBindViewHolder(CustomViewHolder holder, int position) {
//initialise values to views inside holder at runtime
holder.recyclerView.setAdapter(new CustomAdapterTwo(context, arrayList));
holder.recyclerView.setLayoutManager(new LinearLayoutManager(context, LinearLayoutManager.HORIZONTAL, false));
holder.recyclerView.setHasFixedSize(true);
}
#Override
public int getItemCount() {
return arrayList.size();
}
class CustomViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
RecyclerView recyclerView;
Button selectAllButton;
public CustomViewHolder(View itemView) {
super(itemView);
recyclerView = (RecyclerView) itemView.findViewById(R.id.recyclerView);
selectAllButton = (Button) itemView.findViewById(R.id.selectAllButton);
selectAllButton.setOnClickListener(this);
}
#Override
public void onClick(View v) {
Toast.makeText(context, "Select All At : " + String.valueOf(getLayoutPosition()), Toast.LENGTH_SHORT).show();
}
}}
horizontal adapter single entry file recycler_view_single_item.xml
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="wrap_content"
android:layout_height="match_parent" android:gravity="center_horizontal">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Price"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Remove this button \n and put image view"
android:textAllCaps="false"/></LinearLayout>
Horizontal recycler view adapter class
public class CustomAdapterTwo extends RecyclerView.Adapter<CustomAdapterTwo.CustomViewHolder> {
private Context context;
private ArrayList arrayList;
private LayoutInflater layoutInflater;
public CustomAdapterTwo(Context context, ArrayList arrayList) {
this.context = context;
this.arrayList = arrayList;
this.layoutInflater = LayoutInflater.from(context);
}
#Override
public CustomViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = layoutInflater.inflate(R.layout.recycler_view_single_item, parent, false);
return new CustomViewHolder(view);
}
#Override
public void onBindViewHolder(CustomViewHolder holder, int position) {
}
#Override
public int getItemCount() {
return arrayList.size();
}
class CustomViewHolder extends RecyclerView.ViewHolder {
public CustomViewHolder(View itemView) {
super(itemView);
}
}}
Your main activity class
public class MainActivity extends AppCompatActivity {
private RecyclerView verticalScrollRecyclerView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initialiseView();
}
private void initialiseView() {
verticalScrollRecyclerView = (RecyclerView) findViewById(R.id.verticalScrollRecyclerView);
ArrayList<String> stringArrayList = new ArrayList<>();
stringArrayList.add("One");
stringArrayList.add("Two");
stringArrayList.add("Three");
stringArrayList.add("Four");
stringArrayList.add("Five");
stringArrayList.add("Six");
stringArrayList.add("Seven");
stringArrayList.add("Eight");
stringArrayList.add("Nine");
stringArrayList.add("Ten");
//setting adapter and layout manager to recyclerView
verticalScrollRecyclerView.setLayoutManager(new LinearLayoutManager(this));
verticalScrollRecyclerView.setAdapter(new CustomAdapter(this, stringArrayList));
verticalScrollRecyclerView.setHasFixedSize(true);
}}
Looks Like

How to create a cardView programatically?

So I have this list of city objects (which contain an image, the name of the city, and a integer value). And for each of these city objects I want to programatically create a new cardView and insert it into a fragment. Currently, nothing shows up...
Here is my fragment xml code.
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.NestedScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingTop="24dp"
android:id="#+id/fragCards_LL">
</LinearLayout>
</android.support.v4.widget.NestedScrollView>
Here is the code for my fragment activity.
public class FragmentCards extends Fragment
{
private ArrayList<CityFolders> cityFolders = new ArrayList<>();
private OnCardsFragmentListener mListener;
private LinearLayout linearLayout;
private View view;
public FragmentCards() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
// Inflate the layout for this fragment
view = inflater.inflate(R.layout.fragment_fragment_cards, container, false);
setUpLinearLayout();
setUpCityFolders();
//TextView myText = (TextView) view.findViewById(R.id.fragCards_numberOfCardsTextContent);
//Toast.makeText(getActivity(), myText.getText(), Toast.LENGTH_SHORT).show();
return inflater.inflate(R.layout.fragment_fragment_cards, container, false);
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnCardsFragmentListener)
{
mListener = (OnCardsFragmentListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnCheeseCategoriesFragmentListener");
}
}
private void setUpLinearLayout()
{
linearLayout = (LinearLayout) view.findViewById(R.id.fragCards_LL);
linearLayout.setOrientation(LinearLayout.VERTICAL);
linearLayout.setLayoutParams(new NestedScrollView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
}
private void setUpCityFolders()
{
if(!Global_Class.getInstance().getValue().cityFoldersArrayList.isEmpty())
{
cityFolders = Global_Class.getInstance().getValue().cityFoldersArrayList;
for(CityFolders cityFolder : cityFolders)
{
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
lp.setMargins(64,64,64,64);
lp.height = 200;//180dp = 720pixels
lp.width = 1408;//330dp = 1320 pixels.
CardView cityCardView = new CardView(getActivity());// ERROR
cityCardView.setBackgroundColor(000000);
cityCardView.setLayoutParams(lp);
linearLayout.addView(cityCardView, 0);
}
}
}
public interface OnCardsFragmentListener
{
void disableCollapse();
}
}
So, don't know what I am doing wrong here... hope someone can help, maybe point out what im doing wrong?
Also, in my cardView, going horizontally, I want to have an imageview, then a textview, followed by another textview. How would I inflate those parts of the cardView and fill them with an image, and 2 texts from my cityFolder object? Hope you guys can help me with an answer!
Cheers
EDIT:
So i implemented a recycler view and..nothing shows up on the screen... This recycler view just holds simple views with each view having an imageview and a textview, and nothing shows up..
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingTop="24dp"
android:id="#+id/fragCards_LL">
<android.support.v7.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/fragCards_RecyclerView">
</android.support.v7.widget.RecyclerView>
</LinearLayout>
Here is my xml code for the view for each item in the recycler view
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:layout_width="100dp"
android:layout_height="100dp"
android:src="#drawable/fullstar"
android:id="#+id/fragCardsCity_imageview"
android:layout_gravity="center_vertical"
android:padding="8dp"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Star City"
android:layout_gravity="center_vertical"
android:id="#+id/fragCardsCity_textView"
android:padding="8dp"/>
</LinearLayout>
And finally, here is my java code.
public class FragmentCards extends Fragment
{
private ArrayList<CityFolders> cityFolders = new ArrayList<>();
private LinearLayout linearLayout;
private View rootView;
private RecyclerView recyclerView;
private CityViewAdapter cityAdapter;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
// Inflate the layout for this fragment
rootView = inflater.inflate(R.layout.fragment_cards, container, false);
linearLayout = (LinearLayout) rootView.findViewById(R.id.fragCards_LL);
recyclerView = (RecyclerView) rootView.findViewById(R.id.fragCards_RecyclerView);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
cityAdapter = new CityViewAdapter(getActivity(),getData());
recyclerView.setAdapter(cityAdapter);
recyclerView.setItemAnimator(new DefaultItemAnimator());
return rootView;
}
public static ArrayList<myData> getData()
{
ArrayList<myData> data = new ArrayList<>();
int[] icons = {R.drawable.fullstar,R.drawable.fullstar,R.drawable.fullstar,R.drawable.fullstar};
String[] titles = {"San Francisco","Seattle","Tokyo","Osaka"};
for(int i = 0; i < titles.length && i < icons.length; i++)
{
myData current = new myData();
current.iconId = icons[i];
current.cityName = titles[i];
data.add(current);
}
return data;
}
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
private static class myData
{
private int iconId;
private String cityName;
}
private class CityViewAdapter extends RecyclerView.Adapter<CityViewAdapter.MyViewHolder>
{
private LayoutInflater inflater;
private ArrayList<myData> infoList = new ArrayList<>();
public CityViewAdapter(Context context, ArrayList<myData> data)
{
inflater = LayoutInflater.from(context);
this.infoList = data;
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
{
View view = inflater.inflate(R.layout.fragment_cards_cityview,parent,false);
MyViewHolder holder = new MyViewHolder(view);//special way to avoid "findViewById everytime you make a view
return holder;
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position)
{
myData current = infoList.get(position);
holder.title.setText(current.cityName);
holder.icon.setImageResource(current.iconId);
}
#Override
public int getItemCount() {
return 0;
}
class MyViewHolder extends RecyclerView.ViewHolder
{
TextView title;
ImageView icon;
public MyViewHolder(View itemView)
{
super(itemView);
title = (TextView) itemView.findViewById(R.id.fragCardsCity_textView);
icon = (ImageView) itemView.findViewById(R.id.fragCardsCity_imageview);
}
}
}
}

ReclyclerView and CardView, onclick method perform the action on several CardViews at same time

I've got a RecyclerView which populates from an ArrayList. The output is a CardView layout.
In the Cardview, there are 2 buttons amongst other Views.
They only have to read the current value of a TextView, which by default is 1, and increase or decrease it.
The Arraylist contains 8 items.
When I run the app the UI works fine. Trouble is when I try to modify the value of the TextView.
The value is correctly increased and decreased on the CardView I'm working on, but ALSO the value is modified on another CardView. And in that second CardView, modifying its TextView value, also modifies the first one.
So, what am I doing wrong?
This is my Fragment:
public class Fragment_rosas extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.layout_rosas,container,false);
RecyclerView recyclerview_rosas;
RecyclerView.Adapter adaptador_rv_rosas;
RecyclerView.LayoutManager lm_rosas;
List rosas = new ArrayList();
rosas.add(new Tropa(1,R.drawable.minibarbaro, getResources().getString(R.string.barbaro),7,1));
recyclerview_rosas = (RecyclerView) view.findViewById(R.id.recyclerView_tropasRosas);
recyclerview_rosas.setHasFixedSize(true);
lm_rosas = new LinearLayoutManager(getContext());
recyclerview_rosas.setLayoutManager(lm_rosas);
adaptador_rv_rosas = new AdaptadorTropa(rosas);
recyclerview_rosas.setAdapter(adaptador_rv_rosas);
return view;
}
}
And here the part of code on my Adapter:
#Override
public void onBindViewHolder(final TropaViewHolder viewHolder, int i) {
viewHolder.imagen.setImageResource(items.get(i).getImagen());
viewHolder.nombre.setText(items.get(i).getNombre());
viewHolder.maxnivel.setText(String.valueOf(items.get(i).getNivelMax()));
viewHolder.espacioencamp.setText((String.valueOf(items.get(i).getEspacioEnCamp())));
final String nombre = items.get(i).getNombre();
final int maxnivel = items.get(i).getNivelMax();
viewHolder.nivelmas.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String niveltemp = viewHolder.nivel.getText().toString();
String nivelmaxtemp = viewHolder.maxnivel.getText().toString();
int nivel = Integer.parseInt(niveltemp);
int maxxnivel = Integer.parseInt(nivelmaxtemp);
int nuevonivel = nivel+1 ;
if (nuevonivel<=maxxnivel) {
viewHolder.txtv_nivel.setText(String.valueOf(nuevonivel));
}
}
});
My OnCreateViewHolder (nothing really happens here):
#Override
public TropaViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
View v = LayoutInflater.from(viewGroup.getContext())
.inflate(R.layout.cardview, viewGroup, false);
return new TropaViewHolder(v);
}

Here is the solution, as mentioned in the comment above, it addresses two problems:
1. positiontoValueMap - saves current value for each position
2. onclicklistener is passed to the ViewHolder in onCreateViewHolder
Adapter Class
public class MyAdapter extends RecyclerView.Adapter {
private Context context;
private List<String> dataList;
private Map<Integer, Integer> positionToValueMap = new HashMap<>();
public MyAdapter(Context context, List<String> dataList) {
this.context = context;
this.dataList = dataList;
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.recycler_view_item, null, false);
return new MyViewHolder(view, new OnRecyclerItemClickListener());
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
((MyViewHolder) holder).onRecyclerItemClickListener.updatePosition(position);
((MyViewHolder) holder).position.setText("" + position);
((MyViewHolder) holder).title.setText(dataList.get(position));
int valueToDisplay = 1;
if(positionToValueMap.containsKey(position)) {
valueToDisplay = positionToValueMap.get(position);
} else {
positionToValueMap.put(position, valueToDisplay);
}
((MyViewHolder) holder).valueView.setText("value: " + valueToDisplay);
}
#Override
public int getItemCount() {
return dataList.size();
}
private class MyViewHolder extends RecyclerView.ViewHolder {
private OnRecyclerItemClickListener onRecyclerItemClickListener;
private TextView position;
private TextView title;
private TextView valueView;
public MyViewHolder(View itemView, OnRecyclerItemClickListener onRecyclerItemClickListener) {
super(itemView);
itemView.setOnClickListener(onRecyclerItemClickListener);
this.onRecyclerItemClickListener = onRecyclerItemClickListener;
this.position = (TextView) itemView.findViewById(R.id.position);
this.title = (TextView) itemView.findViewById(R.id.title);
this.valueView = (TextView) itemView.findViewById(R.id.value_view);
}
}
private class OnRecyclerItemClickListener implements View.OnClickListener {
private int position = -1;
public void updatePosition(int position) {
this.position = position;
}
#Override
public void onClick(View v) {
int oldValue = positionToValueMap.get(position); // get current value
oldValue++; // increment
positionToValueMap.put(position, oldValue); // save current value
notifyItemChanged(position); // update clicked view so that it picks up the new saved value from the positionToValueMap in onBindViewHolder
}
}
}
RecyclerView item layout
<TextView
android:id="#+id/position"
android:layout_width="30dp"
android:layout_height="50dp"
android:textColor="#android:color/white"
android:gravity="center"
android:background="#android:color/holo_green_light"
android:layout_alignParentLeft="true"/>
<TextView
android:id="#+id/title"
android:layout_width="50dp"
android:layout_height="50dp"
android:textColor="#android:color/white"
android:gravity="center"
android:background="#android:color/holo_green_dark"
android:layout_toRightOf="#id/position" />
<TextView
android:id="#+id/value_view"
android:layout_width="match_parent"
android:layout_height="50dp"
android:textColor="#android:color/white"
android:gravity="center"
android:background="#android:color/holo_green_light"
android:layout_toRightOf="#id/title"
android:layout_alignParentRight="true"/>
</RelativeLayout>
And Activity to test it out
public class MainActivity extends AppCompatActivity {
private RecyclerView recyclerView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
recyclerView.setLayoutManager(new LinearLayoutManager(getApplicationContext()));
recyclerView.setAdapter(new MyAdapter(getApplicationContext(), getSampleData()));
}
private static List<String> getSampleData() {
List<String> dataList = new ArrayList<>();
dataList.add("zero");
dataList.add("one");
dataList.add("two");
dataList.add("three");
dataList.add("four");
dataList.add("five");
dataList.add("six");
dataList.add("seven");
dataList.add("eight");
dataList.add("nine");
dataList.add("ten");
dataList.add("eleven");
dataList.add("twelve");
dataList.add("thirteen");
dataList.add("fourteen");
dataList.add("fifteen");
dataList.add("sixteen");
dataList.add("seventeen");
dataList.add("eighteen");
dataList.add("nineteen");
dataList.add("twenty");
return dataList;
}
}
activity layout
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/root_view"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v7.widget.RecyclerView
android:id="#+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/white"/>
</RelativeLayout>