See the shareButton part. Line 135.

CardFragment.java

package com.example.sep.loveartlearnart;


import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import org.parceler.Parcels;

import java.util.ArrayList;


/**
 * Created by Eni on 2016-12-04.
 */

public class CardFragment extends Fragment {

    ArrayList<ArtModel> listitems = new ArrayList<>();
    RecyclerView MyRecyclerView;
    String[] art;
    String Art[];
    int  Images[] = {R.drawable.after_leger,R.drawable.mouth_15,R.drawable.mgodoyi,R.drawable.revival_meeting,R.drawable.the_value_of_pictures};

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Art = getResources().getStringArray(R.array.art_works);
        initializeList();
        getActivity().setTitle("Love Art.Learn Art");
    }



    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_card, container, false);
        MyRecyclerView = (RecyclerView) view.findViewById(R.id.cardView);
        MyRecyclerView.setHasFixedSize(true);
        LinearLayoutManager MyLayoutManager = new LinearLayoutManager(getActivity());
        MyLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
        if (listitems.size() > 0 & MyRecyclerView != null) {
            MyRecyclerView.setAdapter(new MyAdapter(listitems));
        }
        MyRecyclerView.setLayoutManager(MyLayoutManager);

        return view;
    }

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

    public class MyAdapter extends RecyclerView.Adapter<MyViewHolder> {
        private ArrayList<ArtModel> list;

        public MyAdapter(ArrayList<ArtModel> Data) {
            list = Data;
        }

        @Override
        public MyViewHolder onCreateViewHolder(ViewGroup parent,int viewType) {
            // creates a new view
            View view = LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.recycle_items, parent, false);
            MyViewHolder holder = new MyViewHolder(view);


            return holder;
        }
        @Override
        public void onBindViewHolder(final MyViewHolder holder, int position) {

            holder.titleTextView.setText(list.get(position).getCardName());
            holder.coverImageView.setImageResource(list.get(position).getImageResourceId());
            holder.coverImageView.setTag(list.get(position).getImageResourceId());
            holder.likeImageView.setTag(R.drawable.ic_like);

            /**
             * Added an onclick listener to the ImageView
             * NB: You need to add "android:clickable = "true"" to the imageView in the layout file.
             * If you don't it won't respond to clicks.
             *
             * 1. I got the selected art model from the List list (wierd name)
             * 2. Sent it as a Parcelable in the intent
             * 3. Fired the intent.
             */
            holder.coverImageView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    ArtModel selected = list.get(holder.getAdapterPosition());
                    Intent intent = new Intent(getActivity(), FullScreenImage.class);
                    intent.putExtra("selected_art", Parcels.wrap(selected));
                    startActivity(intent);
                }
            });

        }

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

    public class MyViewHolder extends RecyclerView.ViewHolder {

        public TextView titleTextView;
        public ImageView coverImageView;
        public ImageView likeImageView;
        public Button shareButton;

        public MyViewHolder(View v) {
            super(v);
            titleTextView = (TextView) v.findViewById(R.id.titleTextView);
            coverImageView = (ImageView) v.findViewById(R.id.coverImageView);
            likeImageView = (ImageView) v.findViewById(R.id.likeImageView);
            shareButton = (Button) v.findViewById(R.id.share_button);

            shareButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    int pos = getAdapterPosition();

                    int share_drawable = Images[pos];


                    String _ImageFile = "android.resource://" + getResources().
                    getResourceName(share_drawable).replace(":", "/");
                    Uri imageUri = Uri.parse(_ImageFile);
                    Intent intent = new Intent(Intent.ACTION_SEND);
                    intent.setType("image/*");
                    intent.putExtra(Intent.EXTRA_STREAM, imageUri);
                    startActivity(Intent.createChooser(intent, "Share"));
                }
            });


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


                    int id = (int)likeImageView.getTag();
                    if( id == R.drawable.ic_like){

                        likeImageView.setTag(R.drawable.ic_liked);
                        likeImageView.setImageResource(R.drawable.ic_liked);

                        Toast.makeText(getActivity(),titleTextView.getText()+" added to favourites",Toast.LENGTH_SHORT).show();

                    }else{

                        likeImageView.setTag(R.drawable.ic_like);
                        likeImageView.setImageResource(R.drawable.ic_like);
                        Toast.makeText(getActivity(),titleTextView.getText()+" removed from favourites",Toast.LENGTH_SHORT).show();


                    }

                }
            });



        }
    }



    public void initializeList() {
        listitems.clear();

        for(int i =0;i<5;i++){


            ArtModel item = new ArtModel();
            item.setCardName(Art[i]);
            item.setImageResourceId(Images[i]);
            item.setIsfav(0);
            item.setIsturned(0);
            listitems.add(item);

        }

    }
}