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How can I get a variable from RecyclerView Adapter passed to MainActivity?

I was just playing around with some code, learning new things, when I ran into this problem... I'm trying to pass a variable from my RecylcerViewAdapter to a method in MainActivity, but I just can't seem to accomplish it.
I tried a lot of different thing with interfaces and casting, but nothing did the trick. Since I'm fairly new to all of this, maybe I'm making a trivial mistake somewhere?
My Interface:
public interface AdapterCallback {
void onMethodCallback(int id);
}
This is my adapter class:
public class PostAdapter extends RecyclerView.Adapter<PostAdapter.ViewHolder> {
private List<Post> postList;
private Context context;
private AdapterCallback listener;
public PostAdapter() {
}
public PostAdapter(List<Post> postList, Context context) {
this.postList = postList;
this.context = context;
}
public void setListener(AdapterCallback listener) {
this.listener = listener;
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.recycler_layout, viewGroup, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull final ViewHolder viewHolder, final int position) {
viewHolder.tvTitle.setText(postList.get(position).getTitle());
viewHolder.tvBody.setText(new StringBuilder(postList.get(position).getBody().substring(0, 20)).append("..."));
viewHolder.tvId.setText(String.valueOf(postList.get(position).getUserId()));
viewHolder.parentLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int id = postList.get(position).getId();
if (listener != null) {
listener.onMethodCallback(id);
}
}
});
}
#Override
public int getItemCount() {
return postList.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
TextView tvTitle;
TextView tvBody;
TextView tvId;
LinearLayout parentLayout;
public ViewHolder(View itemView) {
super(itemView);
tvTitle = itemView.findViewById(R.id.tvTitle);
tvBody = itemView.findViewById(R.id.tvBody);
tvId = itemView.findViewById(R.id.tvId);
parentLayout = itemView.findViewById(R.id.parentLayout);
}
}
}
And my MainActivity:
public class MainActivity extends AppCompatActivity {
public static final String TAG = "MainActivityLog";
private CompositeDisposable disposable = new CompositeDisposable();
#BindView(R.id.rvPosts)
RecyclerView rvPosts;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ButterKnife.bind(this);
rvPosts.setHasFixedSize(true);
rvPosts.setLayoutManager(new LinearLayoutManager(this));
populateList();
logItems();
}
private void populateList() {
MainViewModel viewModel = ViewModelProviders.of(MainActivity.this).get(MainViewModel.class);
viewModel.makeQuery().observe(MainActivity.this, new Observer<List<Post>>() {
#Override
public void onChanged(#Nullable List<Post> posts) {
PostAdapter adapter = new PostAdapter(posts, getApplicationContext());
rvPosts.setAdapter(adapter);
}
});
}
public void logItems() {
PostAdapter adapter = new PostAdapter();
adapter.setListener(new AdapterCallback() {
#Override
public void onMethodCallback(int id) {
MainViewModel viewModel = ViewModelProviders.of(MainActivity.this).get(MainViewModel.class);
viewModel.makeSingleQuery(id).observe(MainActivity.this, new Observer<Post>() {
#Override
public void onChanged(#Nullable final Post post) {
Log.d(TAG, "onChanged: data response");
Log.d(TAG, "onChanged: " + post);
}
});
}
});
}
#Override
protected void onDestroy() {
super.onDestroy();
disposable.clear();
}
}
The populateList() method works just fine, but the logItems() method is the problem.
So when i click on a view in RecyclerView I expect the log to output the title, description and ID of the post that was clicked. nut nothing happens...
So, any help would be appreciated.

Make adapter global variable i.e. a field. Use the same object to set every properties.
private PostAdapter adapter;
Replace your logItems method with this:
public void logItems() {
adapter.setListener(new AdapterCallback() {
#Override
public void onMethodCallback(int id) {
MainViewModel viewModel = ViewModelProviders.of(MainActivity.this).get(MainViewModel.class);
viewModel.makeSingleQuery(id).observe(MainActivity.this, new Observer<Post>() {
#Override
public void onChanged(#Nullable final Post post) {
Log.d(TAG, "onChanged: data response");
Log.d(TAG, "onChanged: " + post);
}
});
}
});
}
And populateList with this:
private void populateList() {
MainViewModel viewModel = ViewModelProviders.of(MainActivity.this).get(MainViewModel.class);
viewModel.makeQuery().observe(MainActivity.this, new Observer<List<Post>>() {
#Override
public void onChanged(#Nullable List<Post> posts) {
adapter = new PostAdapter(posts, getApplicationContext());
rvPosts.setAdapter(adapter);
logItems();
}
});
}
And don't call logItems() from onCreate

This is how I implement with my ListAdapters:
public class FeedbackListAdapter extends RecyclerView.Adapter<FeedbackListAdapter.ViewHolder> {
private final ArrayList<Feedback> feedbacks;
private View.OnClickListener onItemClickListener;
private View.OnLongClickListener onItemLongClickListener;
private final Context context;
public FeedbackListAdapter(ArrayList<Feedback> feedbacks, Context context) {
this.feedbacks = feedbacks;
this.context = context;
}
public void setItemClickListener(View.OnClickListener onItemClickListener) {
this.onItemClickListener = onItemClickListener;
}
public void setOnItemLongClickListener(View.OnLongClickListener onItemLongClickListener){
this.onItemLongClickListener = onItemLongClickListener;
}
public class ViewHolder extends RecyclerView.ViewHolder{
final TextView feedback, created, updated;
final LinearLayout mainLayout;
ViewHolder(View iv) {
super(iv);
/*
* Associate layout elements to Java declarations
* */
mainLayout = iv.findViewById(R.id.main_layout);
feedback = iv.findViewById(R.id.feedback);
created = iv.findViewById(R.id.created_string);
updated = iv.findViewById(R.id.updated_string);
}
}
#Override
public int getItemCount() {
return feedbacks.size();
}
#Override
#NonNull
public FeedbackListAdapter.ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.fragment_feedback_table_row, parent, false);
return new FeedbackListAdapter.ViewHolder(view);
}
#Override
public void onBindViewHolder(final #NonNull FeedbackListAdapter.ViewHolder holder, final int position) {
/*
* Bind data to layout
* */
try{
Feedback feedback = feedbacks.get(position);
holder.feedback.setText(feedback.getContent());
holder.created.setText(feedback.getCreated());
holder.updated.setText(feedback.getUpdated());
holder.mainLayout.setOnClickListener(this.onItemClickListener);
holder.mainLayout.setOnLongClickListener(this.onItemLongClickListener);
holder.mainLayout.setTag(feedback.getDbID());
TypedValue outValue = new TypedValue();
context.getTheme().resolveAttribute(android.R.attr.selectableItemBackground, outValue, true);
holder.mainLayout.setBackgroundResource(outValue.resourceId);
}catch(IndexOutOfBoundsException e){
e.printStackTrace();
}
}
}

In onPopulateList you create an adaptor:
PostAdapter adapter = new PostAdapter(posts, getApplicationContext());
rvPosts.setAdapter(adapter);
However in public void logItems() { you used a different adapter
PostAdapter adapter = new PostAdapter();
adapter.setListener(new AdapterCallback() {
#Override
public void onMethodCallback(int id) {
...
}
});
Therefore the list is being populated with 1 adapter, but you are setting the listener on an unused second adapter.
The fix is to use the same adapter for both. If you make the adapater a field, and don't create a new one inside of logItems, but just set your listener it should work.
i.e.
// as a field in your class
private PostAdapter adapter;
then
// in `populateList()`
adapter = new PostAdapter(posts, getApplicationContext());
rvPosts.setAdapter(adapter);
and
// in `logItems()`
adapter.setListener(new AdapterCallback() {
#Override
public void onMethodCallback(int id) {
...
}
});

In Adapter
public class CustomerListAdapter extends RecyclerView.Adapter<CustomerListAdapter.OrderItemViewHolder> {
private Context mCtx;
ProgressDialog progressDialog;
//we are storing all the products in a list
private List<CustomerModel> customeritemList;
public CustomerListAdapter(Context mCtx, List<CustomerModel> orderitemList) {
this.mCtx = mCtx;
this.customeritemList = orderitemList;
progressDialog = new ProgressDialog(mCtx);
}
#NonNull
#Override
public OrderItemViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(mCtx);
View view = inflater.inflate(R.layout.activity_customer_list, null);
return new OrderItemViewHolder(view, mCtx, customeritemList);
}
#Override
public void onBindViewHolder(#NonNull OrderItemViewHolder holder, int position) {
CustomerModel customer = customeritemList.get(position);
try {
//holder.textViewPINo.setText("PINo \n"+Integer.toString( order.getPINo()));
holder.c_name.setText(customer.getCustomerName());
holder.c_address.setText(customer.getAddress());
holder.c_contact.setText(customer.getMobile());
holder.i_name.setText(customer.getInteriorName());
holder.i_contact.setText(customer.getInteriorMobile());
holder.i_address.setText(customer.getAddress());
} catch (Exception E) {
E.printStackTrace();
}
}
#Override
public int getItemCount() {
return customeritemList.size();
}
class OrderItemViewHolder extends RecyclerView.ViewHolder implements View.OnLongClickListener, View.OnClickListener {
AlertDialog.Builder alert;
private Context mCtx;
TextView c_name, c_contact, c_address, i_name, i_contact, i_address;
TextView OrderItemID, MaterialType, Price2, Qty, AQty;
//we are storing all the products in a list
private List<CustomerModel> orderitemList;
public OrderItemViewHolder(View itemView, Context mCtx, List<CustomerModel> orderitemList) {
super(itemView);
this.mCtx = mCtx;
this.orderitemList = orderitemList;
itemView.setOnClickListener(this);
itemView.setOnLongClickListener(this);
// CatelogOrderDetailModel catelogOrderDetailModel = new CatelogOrderDetailModel();
c_name = itemView.findViewById(R.id.customerName);
c_contact = itemView.findViewById(R.id.contact);
c_address = itemView.findViewById(R.id.address);
i_name = itemView.findViewById(R.id.interiorName);
i_address = itemView.findViewById(R.id.interiorAddress);
i_contact = itemView.findViewById(R.id.interiorContact);
}
#Override
public void onClick(View v) {
int position = getAdapterPosition();
CustomerModel orderitem = this.orderitemList.get(position);
}
#Override
public boolean onLongClick(View v) {
int position = getAdapterPosition();
CustomerModel orderitem = this.orderitemList.get(position);
if (v.getId() == itemView.getId()) {
// showUpdateDeleteDialog(order);
try {
} catch (Exception E) {
E.printStackTrace();
}
Toast.makeText(mCtx, "lc: ", Toast.LENGTH_SHORT).show();
}
return true;
}
}
}

How to show an onClick message when clicking on an item of my RecyclerView list?

I am actually working on a group project and I want to develop a functionnality for our application. My goal is to have a list of several items with their images and when I click on an Item of that list I want to have a text pop in the midle of the screen related to that particular item. I'm afraid I might be using the wrong technical Tools to do so. I am actually using a csv file for the list details, an adapter and a viewHolder for the list. Since I have no idea on what is wrong and what to do I link a big part of my code so you can check how I did until now. I can also give you my xml files if you need to check them out, a really big thanks in advance to all the answers and time spent on my problem
I already managed to have my list of items with the title and the picture (text from csv file) of each list item but I'm stuck on how to show a specific text for each ViewHolder.
this is my Adapter
public class Adapter extends RecyclerView.Adapter<ViewHolder> {
List<Departement> list;
Activity activity;
public Adapter(List<Departement> list, Activity activity) {
this.list = list;
this.activity = activity;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int itemType) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.departement,viewGroup,false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(ViewHolder viewHolder, int position) {
Departement departement = list.get(position);
viewHolder.bind(departement, activity);
}
#Override
public int getItemCount() {
return list.size();
}
}
my ViewHolder
public class ViewHolder extends RecyclerView.ViewHolder {
private TextView textViewView;
private ImageView imageView;
public ViewHolder(View itemView) {
super(itemView);
textViewView = (TextView) itemView.findViewById(R.id.text);
imageView = (ImageView) itemView.findViewById(R.id.image);
}
public void bind(Departement departement, Activity activity){
textViewView.setText(departement.getText());
String uri = departement.getImageUrl();
int imageResource = activity.getResources().getIdentifier(uri, null, activity.getPackageName());
Drawable res = activity.getResources().getDrawable(imageResource);
imageView.setImageDrawable(res);
}
}
each item of the list is a Departement
public class Departement {
private String text;
private String imageUrl;
public Departement(String text, String imageUrl) {
this.text = text;
this.imageUrl = imageUrl;
}
public String getText() {
return text;
}
public String getImageUrl() {
return imageUrl;
}
public void setText(String text) {
this.text = text;
}
public void setImageUrl(String imageUrl) {
this.imageUrl = imageUrl;
}
}
and finally my fragment
public class FragmentEspecesProches extends Fragment {
public final static char SEPARATOR=',';
private RecyclerView recyclerView;
private List<Departement> departementsList = new ArrayList<>();
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
View view = inflater.inflate(R.layout.fragment_especes_proches, container, false);
ajouterDepartements();
recyclerView = (RecyclerView) view.findViewById(R.id.recyclerView);
recyclerView.setLayoutManager(new GridLayoutManager(this,2));
recyclerView.setAdapter(new Adapter(departementsList, getActivity()));
return view;
}
private void ajouterDepartements() {
ArrayList<String> lines = new ArrayList<>();
ArrayList<String[]> data = new ArrayList<>();
String sep = new Character(SEPARATOR).toString();
lines = UtilitaireResultat.readFile(getActivity().getResources().openRawResource(R.raw.departement));
for(String line : lines){
String[] oneData = line.split(sep);
data.add(oneData);
}
for(int i=0 ; i<data.size() ; i++){
String[] tabStr = data.get(i);
departementsList.add( new Departement( tabStr[2]+" - "+tabStr[3] ,"#drawable/"+tabStr[5] ));
}
}
}

you can implement item click listener like this
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public TextView tvName;
public TextView tvHometown;
private Context context;
public ViewHolder(Context context, View itemView) {
super(itemView);
this.tvName = (TextView) itemView.findViewById(R.id.tvName);
this.tvHometown = (TextView) itemView.findViewById(R.id.tvHometown);
// Store the context
this.context = context;
// Attach a click listener to the entire row view
itemView.setOnClickListener(this);
}
// Handles the row being being clicked
#Override
public void onClick(View view) {
int position = getAdapterPosition(); // gets item position
// if (position != RecyclerView.NO_POSITION) { // Check if an item was deleted, but the user clicked it before the UI removed it
User user = users.get(position);
// We can access the data within the views
Toast.makeText(context, tvName.getText(), Toast.LENGTH_SHORT).show();
// }
}
}

Use onBindViewHolder to handle any interaction on your list items
#Override
public void onBindViewHolder(ViewHolder viewHolder, int position) {
Departement departement = list.get(position);
viewHolder.bind(departement, activity);
viewHolder.itemView.setOnClickListener(//your action//);
}
ItemView is the whole item; you can access your textviews or imageviews as you use it on your bind method,
You can use your bind method to apply listeners.

Handle on click of the item inside your ViewHolder constructor
like ,
public ViewHolder(View itemView) {
super(itemView);
textViewView = (TextView) itemView.findViewById(R.id.text);
imageView = (ImageView) itemView.findViewById(R.id.image);
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
int position=getAdapterPosition();
Toast.makeText(context, list.get(position).getText(), Toast.LENGTH_SHORT).show();
}
});
}

Create your onClickListner interface as
interface RecylerViewItemClickListner
{
void onItemClick(Department item)
}
set the listner in Adapter class
private final RecylerViewItemClickListner mOnClickListener;
public Adapter(List<Departement> list, Activity activity) {
this.list = list;
this.activity = activity;
this.mOnClickListener = activity;
}
Now in ViewHolder class
public void bind(final Departement item, final mOnClickListener listener) {
itemView.setOnClickListener(new View.OnClickListener() {
#Override public void onClick(View v) {
mOnClickListener.onItemClick(item);
}
});
}
and change onBindViewHolder as below
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.bind(items.get(position), mOnClickListener);
}
Override onItemClick(Department item) in activity
#override
onItemClick(Department item)
{
//show toast here...
}

implement OnClickListener in your ViewHolder class
public class ViewHolder extends RecyclerView.ViewHolder implements
View.OnClickListener
{
#Override
public void onClick(View v)
{
//do action
}
}

Implement below method in your ViewHolder class.
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
final User currentItem = users.get(getAdapterPosition());
Toast.makeText(mContext,currentItem.getText()+" is selected!",Toast.LENGTH_SHORT).show();
}
});

Using multiple RecyclerView with one Adapter class

I have 3 RecyclerView to display most visited market, close by markets and favorite markets.
I have created 3 difference instance of MarketAdapter class for the three RecyclerView
Everything works fine, but my Activity implements one OnClickListener and I cant figure out which adapter was clicked. Is it possible to programmatically determine the Adapter that was clicked from the OnClickListener?
Here is my MarketAdapter Class
public class MarketAdapter extends RecyclerView.Adapter<MarketAdapter.ViewHolder> {
ArrayList<Markets> mMarket = new ArrayList<>();
Context mContext;
private final MarketsItemsClickListener mItemsClickListener;
private final MarketLongClickListener mLongClickListener;
private final MarketClickListener mClickListener;
public MarketAdapter(Context context, MarketsItemsClickListener itemsClickListener, MarketClickListener clickListener, MarketLongClickListener longClickListener){
mContext = context;
mItemsClickListener = itemsClickListener;
mLongClickListener = longClickListener;
mClickListener = clickListener;
}
public interface MarketLongClickListener{
void onLongClick(int position);
}
public interface MarketClickListener{
void onClick(int position);
}
public interface MarketsItemsClickListener{
void imageViewOnClickListener(View view, int position);
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
Context context = viewGroup.getContext();
int layoutForListItem = R.layout.list_market;
LayoutInflater inflater = LayoutInflater.from(context);
boolean shouldAttachToParentImmediately = false;
View view = inflater.inflate(layoutForListItem, viewGroup, shouldAttachToParentImmediately);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull ViewHolder viewHolder, int i) {
viewHolder.bindView(i);
}
#Override
public int getItemCount() {
if(mMarket != null) return mMarket.size();
return 0;
}
public void setData(ArrayList<Markets> markets){
mMarket = markets;
notifyDataSetChanged();
}
public void addData(Markets market, int position){
mMarket.add(0, market);
notifyDataSetChanged();
}
public Markets getItem(int position){return mMarket.get(position);}
class ViewHolder extends RecyclerView.ViewHolder implements View.OnLongClickListener, View.OnClickListener{
ImageView mImageView;
TextView mNameTextView, mCityTextView;
public ViewHolder(#NonNull View itemView) {
super(itemView);
mImageView = itemView.findViewById(R.id.image_view);
mNameTextView = itemView.findViewById(R.id.name_text_view);
mCityTextView = itemView.findViewById(R.id.city_text_view);
itemView.setOnLongClickListener(this);
itemView.setOnClickListener(this);
}
void bindView(int position){
Markets market = getItem(position);
mCityTextView.setText(market.getCity());
mNameTextView.setText(market.getName());
}
#Override
public void onClick(View v) {
//Get position of Adapter
int position = getAdapterPosition();
//Handle the click
mClickListener.onClick(position);
}
#Override
public boolean onLongClick(View v) {
return false;
}
}
}
and OnClickListener from Activity
#Override
public void onClick(int position) {}

You can pass a tag in the constructor and get that tag back via a click listener to identify the click as
private final MarketsItemsClickListener mItemsClickListener;
private final MarketLongClickListener mLongClickListener;
private final MarketClickListener mClickListener;
private final String mTag;
public MarketAdapter(Context context, MarketsItemsClickListener itemsClickListener, MarketClickListener clickListener, MarketLongClickListener longClickListener, String tag){
mTag = tag
mContext = context;
mItemsClickListener = itemsClickListener;
mLongClickListener = longClickListener;
mClickListener = clickListener;
}
Modify the listener as
public interface MarketClickListener{
void onClick(int position, String tag);
}
and the listener code in activity as
#Override
public void onClick(int position, String tag) {
switch(tag){
case "adapter1":
break;
case "adapter2":
break;
case "adapter3":
break;
}
}
and create adapter object as
MarketAdapter adapter = new MarketAdapter("adapter1"....);
MarketAdapter adapter1 = new MarketAdapter("adapter2"....);
MarketAdapter adapter2 = new MarketAdapter("adapter3"....);
and use
mClickListener.onClick(position, mTag);
Note: You can use enums as well

You can add a attribute inside MarketAdapter so that you can tell what instance is that adapter.
Change your custom click listener to receive the adapter type:
public interface MarketClickListener {
//You can change this to receive any data you want from the adapter
void onClick(int position, int adapterType);
}
Add the constants, the identifier attribute and change the listener in your adatper:
public class MarketAdapter extends RecyclerView.Adapter<MarketAdapter.ViewHolder> {
//The constants types
public static int MOST_VISITED_MARKETS = 1;
public static int CLOSE_BY_MARKETS = 2;
public static int FAVORITE_MARKETS = 3;
//New attribute
private int adapterType;
...
//Keep the listener
private final MarketClickListener mClickListener;
public MarketAdapter(Context context, MarketsItemsClickListener itemsClickListener, MarketClickListener clickListener, MarketLongClickListener longClickListener, int adapterType){
...
//Set the type
adapterType = adapterType;
}
...
}
In your activity:
mostVisitedRecyclerView.setAdapter(new MarketAdapter(this,itemsClickListener,clickListener,longClickListener,MarketAdapter.MOST_VISITED_MARKETS ));
closeByRecyclerView.setAdapter(new MarketAdapter(this,itemsClickListener,clickListener,longClickListener,MarketAdapter.CLOSE_BY_MARKETS));
favoritesRecyclerView.setAdapter(new MarketAdapter(this,itemsClickListener,clickListener,longClickListener,MarketAdapter.FAVORITE_MARKETS));
In your view holder, change the onClick:
#Override
public void onClick(View v) {
//Get position of Adapter
int position = getAdapterPosition();
//Handle the click
mClickListener.onClick(position,adapterType);
}
I didn't test this but I think it will do the trick. Try it out.

If you want to do it this way, I would add a new variable to the adapters constructor, and then use a case/if statement to determine what you want to do in your onbindviewholder.

attempting to use incompatible return type

Can someone help me with this error that I keep getting? The program that I'm trying to implement admob banner ad between items in recyclerview. every thing is ok but still this one error that blocked me from go on.
public class RecipeAdapter extends RecyclerView.Adapter<RecipeAdapter.ViewHolder> {
public static final String TAG = RecipeAdapter.class.getSimpleName();
public static final HashMap<String, Integer> LABEL_COLORS = new HashMap<String, Integer>() {{
put("Low-Carb", R.color.colorLowCarb);
put("Low-Fat", R.color.colorLowFat);
put("Low-Sodium", R.color.colorLowSodium);
put("Medium-Carb", R.color.colorMediumCarb);
put("Vegetarian", R.color.colorVegetarian);
put("Balanced", R.color.colorBalanced);
}};
private Context mContext;
private LayoutInflater mInflater;
private ArrayList<Recipe> mDataSource;
private static final int DEFAULT_VIEW_TYPE = 1;
private static final int NATIVE_AD_VIEW_TYPE = 2;
public RecipeAdapter(Context context, ArrayList<Recipe> items) {
mContext = context;
mDataSource = items;
mInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE); }
#Override public int getItemViewType(int position) {
// Change the position of the ad displayed here. Current is after 5
if ((position + 1) % 6 == 0) {
return NATIVE_AD_VIEW_TYPE;
}
return DEFAULT_VIEW_TYPE; }
#NonNull
#Override public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view;
LayoutInflater layoutInflater = LayoutInflater.from(mContext);
switch (viewType) {
default:
view = layoutInflater
.inflate(R.layout.list_item_native_ad, parent, false);
return new ViewHolder(view);
case NATIVE_AD_VIEW_TYPE:
view = layoutInflater.inflate(R.layout.list_item_native_ad, parent, false);
return new ViewHolderAdMob(view);
}
}
#Override public void onBindViewHolder(#NonNull ViewHolder holder, int position) {
// Get relevant subviews of row view
TextView titleTextView = holder.titleTextView;
TextView subtitleTextView = holder.subtitleTextView;
TextView detailTextView = holder.detailTextView;
ImageView thumbnailImageView = holder.thumbnailImageView;
//Get corresponding recipe for row final Recipe recipe = (Recipe) getItem(position);
// Update row view's textviews to display recipe information
titleTextView.setText(recipe.title);
subtitleTextView.setText(recipe.description);
detailTextView.setText(recipe.label);
// Use Picasso to load the image. Temporarily have a placeholder in case it's slow to load
Picasso.with(mContext).load(recipe.imageUrl).placeholder(R.mipmap
.ic_launcher).into(thumbnailImageView);
holder.parentView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent detailIntent = new Intent(mContext, RecipeDetailActivity.class);
detailIntent.putExtra("title", recipe.title);
detailIntent.putExtra("url", recipe.instructionUrl);
mContext.startActivity(detailIntent);
}
});
// Style text views
Typeface titleTypeFace = Typeface.createFromAsset(mContext.getAssets(),
"fonts/JosefinSans-Bold.ttf");
titleTextView.setTypeface(titleTypeFace);
Typeface subtitleTypeFace = Typeface.createFromAsset(mContext.getAssets(),
"fonts/JosefinSans-SemiBoldItalic.ttf");
subtitleTextView.setTypeface(subtitleTypeFace);
Typeface detailTypeFace = Typeface.createFromAsset(mContext.getAssets(),
"fonts/Quicksand-Bold.otf");
detailTextView.setTypeface(detailTypeFace);
detailTextView.setTextColor(android.support.v4.content.ContextCompat.getColor(mContext, LABEL_COLORS
.get(recipe.label)));
}
#Override public int getItemCount() {
return mDataSource.size(); }
#Override public long getItemId(int position) {
return position; }
public Object getItem(int position) {
return mDataSource.get(position); }
public class ViewHolder extends RecyclerView.ViewHolder {
private TextView titleTextView;
private TextView subtitleTextView;
private TextView detailTextView;
private ImageView thumbnailImageView; private View parentView;
public ViewHolder(#NonNull View view){
super(view);
// create a new "Holder" with subviews
this.parentView = view;
this.thumbnailImageView = (ImageView) view.findViewById(R.id.recipe_list_thumbnail);
this.titleTextView = (TextView) view.findViewById(R.id.recipe_list_title);
this.subtitleTextView = (TextView) view.findViewById(R.id.recipe_list_subtitle);
this.detailTextView = (TextView) view.findViewById(R.id.recipe_list_detail);
// hang onto this holder for future recyclage
view.setTag(this);
}
}
public class ViewHolderAdMob extends RecyclerView.ViewHolder {
private final AdView mNativeAd;
public ViewHolderAdMob(View itemView) {
super(itemView);
mNativeAd = itemView.findViewById(R.id.nativeAd);
mNativeAd.setAdListener(new AdListener() {
#Override
public void onAdLoaded() {
super.onAdLoaded();
// if (mItemClickListener != null) {
Log.i("AndroidBash", "onAdLoaded");
// }
}
#Override
public void onAdClosed() {
super.onAdClosed();
// if (mItemClickListener != null) {
Log.i("AndroidBash", "onAdClosed");
// }
}
#Override
public void onAdFailedToLoad(int errorCode) {
super.onAdFailedToLoad(errorCode);
// if (mItemClickListener != null) {
Log.i("AndroidBash", "onAdFailedToLoad");
// }
}
#Override
public void onAdLeftApplication() {
super.onAdLeftApplication();
// if (mItemClickListener != null) {
Log.i("AndroidBash", "onAdLeftApplication");
// }
}
#Override
public void onAdOpened() {
super.onAdOpened();
// if (mItemClickListener != null) {
Log.i("AndroidBash", "onAdOpened");
// }
}
});
AdRequest adRequest = new AdRequest.Builder()
.addTestDevice("") // Remove this before publishing app
.build();
mNativeAd.loadAd(adRequest);
}
}
}

The return type needs to be whatever ViewHolder type you declared for your adapter class.
For example, from the Android RecyclerView example page:
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {
// ^^^^^^^^^^^^^^^^^^^^^^
// It should return this type ^
public static class MyViewHolder extends RecyclerView.ViewHolder {
// your adapter
}
#Override
public MyAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent,int viewType) {
// Note: returns MyAdapter.MyViewHolder, not RecyclerView.ViewHolder
}
}
In your case, you have
public class RecipeAdapter extends RecyclerView.Adapter<RecipeAdapter.ViewHolder>
which means your onCreateViewHolder has to return RecipeAdapter.ViewHolder not RecyclerView.ViewHolder.
There is a separate issue too, which is that you have two ViewHolder types in the same adapter. To do this, you would need to change the ViewHolder type that your RecyclerView is based on to the generic type (RecyclerView.ViewHolder).
Please review this question, it has good answers for how to do this.

Passing RecyclerView CardView Clicked Item Data To Activity

I have a question about passing clicked cardview data to activity, and here the full story :
I have an Activity called "Details", which contains 2 TextViews in it's layout, Title & Description .
I have setup a fragment ( tab_1 ) which contain the recyclerview codes and the the items data, each item of those contain : title & description .
What i want :
When the user click the item, it will open the Details Activity, and change Details layout title, with clicked item title, and the same for description .
I've manged to create the other activity as an example, and made intent to start it, plus adding "addOnTouchlistener" thanks to Stackoverflow, i've found the way to make it .
So, how to make this alive? I've tried many ways of the available answers on Stackoverflow, but all of them not working, or not related to my request .
Here are my files :
itemsdata.java :
public class itemsdata {
int CatPic;
String title;
String Descr;
int Exapnd;
int expand_no;
tab_1.java ( fragment )
public class tab_1 extends Fragment implements SearchView.OnQueryTextListener {
private RecyclerView mRecyclerView;
public RecyclingViewAdapter adapter;
private Activity context;
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View layout = inflater.inflate(R.layout.tab_1, container, false);
mRecyclerView = (RecyclerView)layout.findViewById(R.id.recycler_view);
mRecyclerView.addOnItemTouchListener(new RecyclerItemClickListener
(getContext(), new RecyclerItemClickListener.OnItemClickListener() {
#Override
public void onItemClick(View view, int position) {
Intent i = new Intent(view.getContext(), DetailsActivity.class);
view.getContext().startActivity(i);
}
}));
mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
adapter = new RecyclingViewAdapter(getActivity(),Listed());
mRecyclerView.setAdapter(adapter);
return layout;
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.main, menu);
final MenuItem item = menu.findItem(R.id.action_search);
final SearchView searchView = (SearchView) MenuItemCompat.getActionView(item);
searchView.setOnQueryTextListener(this);
}
#Override
public boolean onQueryTextChange(String query) {
final List<itemsdata> filteredModelList = filter(Listed(), query);
adapter.animateTo(filteredModelList);
mRecyclerView.scrollToPosition(0);
return true;
}
#Override
public boolean onQueryTextSubmit(String query) {
return true;
}
private List<itemsdata> filter(List<itemsdata> models, String query) {
query = query.toLowerCase();
final List<itemsdata> filteredModelList = new ArrayList<>();
for (itemsdata model : models) {
final String text = model.title.toLowerCase();
if (text.contains(query)) {
filteredModelList.add(model);
}
}
return filteredModelList;
}
public List<itemsdata> Listed()
{
//Titles Strings
String sys_title1 = getString(R.string.system_item_title_1);
String sys_title2 = getString(R.string.system_item_title_2);
String sys_title3 = getString(R.string.system_item_title_3);
//Description Strings
String sys_descr1 = getString(R.string.system_item_desc_1);
String sys_descr2 = getString(R.string.system_item_desc_2);
String sys_descr3 = getString(R.string.system_item_desc_3);
//Adding New Cards
List<itemsdata> data = new ArrayList<>();
//Categories Icons New Items ** Make It The Same
int[] icons = {
R.drawable.facebook_icon ,
R.drawable.twitter_icon ,
R.drawable.twitter_icon
};
//Expand Button New Items
int[] expandbutton = {
R.drawable.expanded ,
R.drawable.expanded ,
R.drawable.expanded
};
//UnExpand Button New Items
int[] unexpandbutton = {
R.drawable.ca_expand ,
R.drawable.ca_expand ,
R.drawable.ca_expand
};
//Titles New Items
String[] titles = {
sys_title1 ,
sys_title2 ,
sys_title3
};
//Description New Items
String[] Description = {
sys_descr1 ,
sys_descr2 ,
sys_descr3
};
for(int i = 0;i<titles.length && i < icons.length && i < Description.length && i < unexpandbutton.length && i < expandbutton.length ; i++)
{
itemsdata current = new itemsdata();
current.CatPic = icons[i];
current.title = titles[i];
current.Descr = Description[i];
current.expand_no = unexpandbutton[i];
current.Exapnd = expandbutton[i];
data.add(current);
}
return data;
}
}
Details Activity :
public class DetailsActivity extends AppCompatActivity{
TextView title;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.details);
title = (TextView)findViewById(R.id.details_title);
}
EDIT : I've made it, i have added a button which open the fragment, and passed the data, in the Adapter, but i want it via tab_1.java, not the Adapter, i mean i want to click on the item to open the fragment, not on a button, here a snap from my Adapter code ( i've added it in OnBindViewHolder )
I've setup a OnClick and implemented the Vew.setOnClick ..etc, but when i click the item, nothing happen.
#Override
public void onBindViewHolder(final MyRecycleViewHolder holder, int position) {
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(v.getContext(),DetailsActivity.class);
v.getContext().startActivity(i);
}
});
//Referencing Data
final itemsdata currentobject = mdata.get(position);
//Referencing Items
holder.ProbTitle.setText(currentobject.title);
holder.ProbDescr.setText(currentobject.Descr);
holder.CategoryPic.setImageResource(currentobject.CatPic);
holder.ExpandButton.setImageResource(currentobject.Exapnd);
holder.ExpandNoButton.setImageResource(currentobject.expand_no);
//What Happen When You Click Expand Button .
holder.ExpandButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(v.getContext(), DetailsActivity.class);
i.putExtra("TitleKey",holder.ProbTitle.getText().toString());
v.getContext().startActivity(i);
}
}
);
public static class MyRecycleViewHolder extends RecyclerView.ViewHolder
{
SwipeLayout swipeLayout;
//Defining Items .
TextView ProbTitle;
ImageButton ExpandButton;
TextView ProbDescr;
ImageButton ExpandNoButton;
ImageView CategoryPic;
/*
TextView Card_Star;
TextView Card_UnStar;
*/
TextView Card_Share;
//Referencing Resources
public MyRecycleViewHolder(final View itemView) {
super(itemView);
ProbTitle = (TextView) itemView.findViewById(R.id.prob_title);
CategoryPic = (ImageView) itemView.findViewById(R.id.cat_pic);
ProbDescr = (TextView) itemView.findViewById(R.id.prob_descr);
ExpandButton = (ImageButton) itemView.findViewById(R.id.expand_button);
ExpandNoButton = (ImageButton) itemView.findViewById(R.id.expand_no_button);
/*
Card_Star = (TextView) itemView.findViewById(R.id.card_star);
Card_UnStar = (TextView) itemView.findViewById(R.id.card_unstar);
*/
Card_Share = (TextView) itemView.findViewById(R.id.card_share);
swipeLayout = (SwipeLayout) itemView.findViewById(R.id.swipe);
}

create an Interface inside your adapter containing methods. And while implementing your Adapter, those methods will be implemented in your activity and you can perform whatever action you want.
public class Adapter extends RecyclerView.Adapter<MyRecycleViewHolder> {
public interface Callbacks {
public void onButtonClicked(String titleKey);
}
private Callbacks mCallbacks;
public Adapter() {
}
#Override
public MyRecycleViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.layout_details, null);
return new MyRecycleViewHolder(v);
}
#Override
public void onBindViewHolder(final MyRecycleViewHolder holder, final int i) {
holder.ExpandButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (mCallbacks != null) {
mCallbacks.onButtonClicked(holder.ProbTitle.getText().toString());
}
}
});
}
#Override
public int getItemCount() {
return;
}
public void setCallbacks(Callbacks callbacks) {
this.mCallbacks = callbacks;
}
}

you may try do this on your onItemClick()
Intent i = new Intent(view.getContext(), DetailsActivity.class);
i.putExtra("title", yourTitle);
i.putExtra("description", yourDescription);
view.getContext().startActivity(i);
and when oncreate in your DetailActivity,do this
String title = getIntent().getStringExtra("title");
String description = getIntent().getStringExtra("description");
so you can pass title and description to DetailActivity

IMO, you implement setOnClickListener inside Adapter of RecyclerView. You can refer to my following sample code, then apply its logic to your code. Hope it helps!
public class MyRVAdapter extends RecyclerView.Adapter<MyRVAdapter.ViewHolder> {
Context mContext;
List<String> mStringList;
public MyRVAdapter(Context mContext, List<String> mStringList) {
this.mContext = mContext;
this.mStringList = mStringList;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.cardview, parent, false);
v.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
TextView textView1 = (TextView) v.findViewById(R.id.textView1);
TextView textView2 = (TextView) v.findViewById(R.id.textView2);
Bundle bundle = new Bundle();
bundle.putString("key1", textView1.getText().toString());
bundle.putString("key2", textView2.getText().toString());
passToAnotherActivity(bundle);
}
});
return new ViewHolder(v);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
// do something...
}
#Override
public int getItemCount() {
if (mStringList != null) {
return mStringList.size();
}
return 0;
}
private void passToAnotherActivity(Bundle bundle) {
if (mContext == null)
return;
if (mContext instanceof MainActivity) {
MainActivity activity = (MainActivity) mContext;
activity.passToAnotherActivity(bundle); // this method must be implemented inside `MainActivity`
}
}
public static class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public ViewHolder(View itemView) {
super(itemView);
// do something...
}
#Override
public void onClick(View v) {
}
}
}

First of all make your "itemsdata" object to implement Parcelable. You can check it here . In your onItemClick method you pass the object to your Details activity using intent.putExtra("key",listOfDataItems.get(position));
In your DetailsActivity you can get your custom object with getParcelable("key")

All above methods worked, but kinda long, so this one worked for me :
Cardview cardview;
cardView = (CardView)itemView.findViewById(R.id.cv);
cardView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent i = new Intent (view.getContext(), DetailsActivity.class);
i.putExtra("TitleKey",ProbTitle.getText().toString());
i.putExtra("DescrKey",ProbDescr.getText().toString());
view.getContext().startActivity(i);
}
});
And in Details.java :
TextView title;
TextView Descr;
title = (TextView)findViewById(R.id.details_title);
Descr = (TextView)findViewById(R.id.details_descr);
String titleresult = result.getExtras().getString("TitleKey");
String Descrresult = result.getExtras().getString("DescrKey");
title.setText(titleresult);
Descr.setText(Descrresult);