How to create a interface in main activity and pass the data from adapter to main activity through the interface?

Question

I have created a RecyclerView in my fragment one and I have created a RecyclerViewAdapter to bind my date set to views that are displayed within the RecyclerView in my fragment one. I have loaded my fragment one in my main activity. Now I have a problem is that I need to create an interface in the main activity and pass the data from my adapter to main activity through the interface so that I can wrap the data into bundle and load fragment two. But i do not know how to do this. Can someone help me?

Here is my main activity.

public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    FragmentOne fragmentOne = new FragmentOne();
    FragmentManager fragmentManager = getSupportFragmentManager();
    fragmentManager.beginTransaction().add(R.id.fragment_container,fragmentOne).commit();

}}

Here is my Fragment One.

public class FragmentOne extends Fragment {
public RecyclerView recyclerView;
public ArrayList<Promotion> promotionArrayList;
public MyAdapter myAdapter;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    // Inflate the layout for this fragment
    View view = inflater.inflate(R.layout.fragment_fragment_one, container, false);
    recyclerView = (RecyclerView)view.findViewById(R.id.recyclerView);
    recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
    DividerItemDecoration divider = new DividerItemDecoration(getActivity(),DividerItemDecoration.VERTICAL);
    recyclerView.addItemDecoration(divider);
    promotionArrayList = Promotion.createPromotionList();
    myAdapter = new MyAdapter(promotionArrayList);
    recyclerView.setAdapter(myAdapter);
    return view;
}}

Here is my adapter.

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {

public ArrayList<Promotion> promotionArrayList;


public MyAdapter(ArrayList<Promotion>promotionArrayList) {
    this.promotionArrayList = promotionArrayList;
}

@NonNull
@Override
public MyAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
    View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.row_layout,viewGroup,false);
    return new ViewHolder(view);
}

@Override
public void onBindViewHolder(@NonNull ViewHolder viewHolder, int i) {
    Promotion promotion = promotionArrayList.get(i);
    viewHolder.imageView.setImageResource(promotion.getImgId());
    viewHolder.promotion_period.setText(promotion.getPromotion_period());
    viewHolder.promotion_deals.setText(promotion.getPromotion_deals());
    viewHolder.shop_name.setText(promotion.getShop_name());
}

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

public static class ViewHolder extends RecyclerView.ViewHolder{

    public TextView shop_name,promotion_deals, promotion_period;
    public ImageView imageView;

    public ViewHolder(@NonNull View itemView) {
        super(itemView);
        shop_name = (TextView)itemView.findViewById(R.id.shop_name);
        promotion_deals = (TextView)itemView.findViewById(R.id.promotion_deals);
        promotion_period = (TextView)itemView.findViewById(R.id.promotion_period);
        imageView = (ImageView)itemView.findViewById(R.id.imageView);
    }
}}

score 1 · Answer 1 · answered Oct 22 '18 at 03:42

Step 1. Create Interface

public interface RecyclerViewItemInterface {

    void onItemClick(int position, String path);

}

Step 2. write set method in Adapter

private RecyclerViewItemInterface viewItemInterface;

 public void setViewItemInterface(RecyclerViewItemInterface viewItemInterface) {
        this.viewItemInterface = viewItemInterface;
    }

Step 3. Pass data & call Method like this

holder.itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    if (viewItemInterface != null) {
                        viewItemInterface.onItemClick(holder.getAdapterPosition(),"");
                    }
                }
            });

Step 4. Implement interface like this

bgImageAdapterNEW.setViewItemInterface(new RecyclerViewItemInterface() {

            @Override
            public void onItemClick(int position, String path) {

            }
        });

score 0 · Answer 2 · answered Oct 19 '18 at 06:39

as you talk above : In MyAdapter you can add

public interface onItemClickListener {
    public void onItemCLickListener(int position);
}

In onBindViewHolder you set listener on click with specific view you want:

holder.viewYouWant.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (onItemClickListener != null)
                    onItemClickListener.onItemCLickListener(position,data);
            }
 });

In MainActivity implements OnItemClickListener then wrap data in bundles and send it to fragment you can following here : Click listener for RecyclerView adapter

How to create a interface in main activity and pass the data from adapter to main activity through the interface?

2 Answers2

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