Styjun

I'm trying to figure out how to get data from a clicked item in a RecyclerView to a listview in a Fragment. I can't seem to figure out how to do this, as I can't get my bundle to work.

I've tried various solutions offered here on Stackoverflow, but none of them have worked. I have managed to get the info from the recyclerview, but I am stuck trying to figure out how I can pass it to the fragment. Can someone please help me?

The Adapter class:

public class FoodAdapter extends RecyclerView.Adapter<FoodAdapter.ViewHolder> 

 private Context context;

 ArrayList<FoodActivity> list;
 public FoodAdapter(ArrayList<FoodActivity> list)
 this.list = list;
 


 @NonNull
 @Override
 public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) 
 View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.listview_item_food, parent, false);

 return new ViewHolder(view);
 

 @Override
 public void onBindViewHolder(@NonNull final ViewHolder holder, final int position) 
 holder.foods.setText(list.get(position).getName());
 holder.carbo.setText(list.get(position).getCarbohydrates());
 holder.protein.setText(list.get(position).getProtein());
 holder.fats.setText(list.get(position).getFats());

 //Get items from recyclerview when user clicks them. Then send them to FoodFragment
 holder.itemView.setOnClickListener(new View.OnClickListener() 
 @Override
 public void onClick(View v) 

 String foods = list.get(position).getName();
 String carbo = list.get(position).getCarbohydrates();
 String protein = list.get(position).getProtein();
 String fats = list.get(position).getFats();

 Toast.makeText(v.getContext(), "test: " + foods, Toast.LENGTH_SHORT).show();


 
 );
 


 @Override
 public int getItemCount() 
 return list.size();
 

 class ViewHolder extends RecyclerView.ViewHolder 
 TextView foods, carbo, fats, protein;

 public ViewHolder(View itemView) 
 super(itemView);

 carbo = itemView.findViewById(R.id.carbo);
 protein = itemView.findViewById(R.id.protein);
 fats = itemView.findViewById(R.id.fats);
 foods = itemView.findViewById(R.id.food);
 
 

The Fragment where the data comes from:

public class TrackingFragment extends Fragment 

 DatabaseReference databaseReference;
 ArrayList<FoodActivity> list;
 RecyclerView recyclerView;
 SearchView searchView;

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

 databaseReference = FirebaseDatabase.getInstance().getReference().child("foods");
 recyclerView = view.findViewById(R.id.rv);
 searchView = view.findViewById(R.id.searchFood);

 return view;
 

 @Override
 public void onStart() 
 super.onStart();

 if(databaseReference != null)
 databaseReference.addValueEventListener(new ValueEventListener() 
 @Override
 public void onDataChange(@NonNull DataSnapshot dataSnapshot) 
 if(dataSnapshot.exists())
 list = new ArrayList<>();
 for(DataSnapshot ds : dataSnapshot.getChildren())
 list.add(ds.getValue(FoodActivity.class));
 
 FoodAdapter adapter = new FoodAdapter(list);
 recyclerView.setAdapter(adapter);


 
 

 @Override
 public void onCancelled(@NonNull DatabaseError databaseError) 
 Toast.makeText(getActivity(), databaseError.getMessage(), Toast.LENGTH_SHORT).show();
 
 );
 
 if(searchView != null)
 searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() 
 @Override
 public boolean onQueryTextSubmit(String query) 
 return false;
 

 @Override
 public boolean onQueryTextChange(String newText) 
 search(newText);
 return true;
 
 );
 
 

 private void search(String str)
 ArrayList<FoodActivity> searchList = new ArrayList<>();
 for(FoodActivity object : list)
 if(object.getName().toLowerCase().contains(str.toLowerCase()))
 searchList.add(object);
 
 
 FoodAdapter foodAdapter = new FoodAdapter(searchList);
 recyclerView.setAdapter(foodAdapter);
 

And the class where it needs to go:

public class FoodFragment extends Fragment 

 ImageButton addFood;

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

 addFood = view.findViewById(R.id.addFood);

 addFood.setOnClickListener(new View.OnClickListener() 
 @Override
 public void onClick(View v) 

 FragmentTransaction fr = getFragmentManager().beginTransaction();
 fr.replace(R.id.fragment_container, new TrackingFragment());
 fr.addToBackStack(null).commit();
 
 );

 return view;
 

To get your data from FoodAdapter to TrackingFragment, you can add TrackingFragment (or an interface it implements, ideally) as a parameter to the FoodAdapter constructor, then use that instance to forward your ViewHolder clicks to TrackingFragment for handling.

To get your data from TrackingFragment to FoodFragment, use the setTargetFragment/onActivityResult pattern for fragment <-> fragment communication. This answer has an example: https://stackoverflow.com/a/13733914/3238938

The most simple is to add variables you need to your activity, set their values with onClick() and then retrieve data in other fragment:

• 
  

  in activity:

  
  
  

  String foods;
  
  public String getFoods() 
   return foods;
  
  
  public void setFoods(String foods) 
   this.foods = foods;
  
  

  
  


• 
  

  in adapter:

  
  
  

   holder.itemView.setOnClickListener(new View.OnClickListener() 
   @Override
   public void onClick(View v) 
   ((YourActivity)getActivity()).setFoods("Any value");
   
   );
  

  
  


• 
  

  in destination fragment:

  
  
  

  String foods = ((YourActivity)getActivity()).getFoods();

  
  

Add an interface to your adapter as follow

public class FoodAdapter extends RecyclerView.Adapter<FoodAdapter.ViewHolder> 

interface OnClickListener 
 void onClick(FoodActivity clickedItem);


private OnClickListener mCallback; 
private ArrayList<FoodActivity> list;

public FoodAdapter(ArrayList<FoodActivity> list)
 this.list = list;


public void setOnClickListener(OnClickListener callback) 
 mCallback = callback;



@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) 
 View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.listview_item_food, parent, false);

 return new ViewHolder(view);


@Override
public void onBindViewHolder(@NonNull final ViewHolder holder, final int position) 
 holder.foods.setText(list.get(position).getName());
 holder.carbo.setText(list.get(position).getCarbohydrates());
 holder.protein.setText(list.get(position).getProtein());
 holder.fats.setText(list.get(position).getFats());

 //Get items from recyclerview when user clicks them. Then send them to FoodFragment
 holder.itemView.setOnClickListener(new View.OnClickListener() 
 @Override
 public void onClick(View v) 
 if (mCallback != null)
 mCallback.onClick(list.get(position));
 
 );



@Override
public int getItemCount() 
 return list.size();


class ViewHolder extends RecyclerView.ViewHolder 
 TextView foods, carbo, fats, protein;

 public ViewHolder(View itemView) 
 super(itemView);

 carbo = itemView.findViewById(R.id.carbo);
 protein = itemView.findViewById(R.id.protein);
 fats = itemView.findViewById(R.id.fats);
 foods = itemView.findViewById(R.id.food);