Click on RecyclerView Item for details

Question

I have a RecyclerView with items (Books) inside it, and I want that when clicking on one item - a new activity will be opened (DetailsActivity) with item details.

import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.app.Fragment;
import android.support.v4.view.MenuItemCompat;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.SearchView;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.view.inputmethod.InputMethodManager;
import android.widget.EditText;
import entities.Book;
import model.BackEnd.BackEnd;
import model.BackEnd.BackEndFactory;

/**
 * A simple {@link Fragment} subclass.
 */
public class HomeFragment extends Fragment implements BookAdapter.ClickListener {

    private static BackEnd backEnd;
    private RecyclerView rvBooks;
    private BookAdapter adapter;

    public HomeFragment() {
        // Required empty public constructor
    }
  
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_home, container, false);
        rvBooks = (RecyclerView) view.findViewById(R.id.rv_books);
        rvBooks.setLayoutManager(new LinearLayoutManager(getActivity()));
        adapter = new BookAdapter(getActivity());
        adapter.setClickListener(this);
        rvBooks.setAdapter(adapter);
        adapter.setBookList(backEnd.getBooksList());
        return view;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        setHasOptionsMenu(true);
    }

    @Override
    public void itemClicked(View view, int position) {
        startActivity(new Intent(getActivity(), DetailsActivity.class));
    }
}

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.ArrayList;
import entities.Book;

public class BookAdapter extends RecyclerView.Adapter<BookAdapter.bookHolder> {

    private LayoutInflater inflater;
    private ArrayList<Book> bookList = new ArrayList<>();
    private ClickListener clickListener;

    public BookAdapter(Context context) {
        inflater = LayoutInflater.from(context);
    }

    public void setBookList(ArrayList<Book> bookList) {
        this.bookList = bookList;
        notifyItemRangeChanged(0, bookList.size());
    }

    @Override
    public bookHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = inflater.inflate(R.layout.row_layout, parent, false);
        return new bookHolder(view);
    }

    @Override
    public void onBindViewHolder(bookHolder holder, int position) {
        Book current = bookList.get(position);
        holder.bookPicture.setImageResource(current.getBookPicture());
        holder.bookName.setText(current.getBookName());
    }

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

    public void setClickListener(ClickListener clickListener) {
        this.clickListener = clickListener;
    }

    public interface ClickListener {
        void itemClicked(View view, int position);
    }

    class bookHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

        private ImageView bookPicture;
        private TextView bookName;

        public bookHolder(View itemView) {
            super(itemView);
            itemView.setOnClickListener(this);
            bookPicture = (ImageView) itemView.findViewById(R.id.book_picture);
            bookName = (TextView) itemView.findViewById(R.id.book_name);
        }

        @Override
        public void onClick(View v) {
            if (clickListener != null)
                clickListener.itemClicked(v, getAdapterPosition());
        }
    }
}

In addition, I have DetailsActivity. For now it's almost empty.

How to move on?

Answer 1

BookAdapter

Change

public interface ClickListener {
    void itemClicked(View view, int position);
}

to

public interface ClickListener {
    void itemClicked(Book book);
}

BookAdapter.BookHolder

Change

@Override
public void onClick(View v) {
    if (clickListener != null)
        clickListener.itemClicked(v, getAdapterPosition());
}

to

@Override
public void onClick(View v) {
    if (clickListener != null)
        clickListener.itemClicked(bookList.get(getAdapterPosition()));
}

This will allow you to retrieve the book in your fragment, and send it via an Intent to the newly opened DetailsActivity:

HomeFragment

@Override
public void itemClicked(Book book) {
    Intent intent = new Intent(getActivity(), DetailsActivity.class);
    // Pass the book's details via this intent. Use the passed-in book parameter
    intent.putExtra(...)
    startActivity(intent);
}