Answers for "recyclerview tutorial"

RecyclerView tutorial

Create activity layout:
    <?xml version="1.0" encoding="utf-8"?>
    <RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <android.support.v7.widget.RecyclerView
            android:id="@+id/rvAnimals"
            android:layout_width="match_parent"
            android:layout_height="match_parent"/>

    </RelativeLayout>
  
  
  
  
  
  
  
  
Create row layout :
    <?xml version="1.0" encoding="utf-8"?>
    <LinearLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:padding="10dp">

        <TextView
            android:id="@+id/tvAnimalName"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="20sp"/>

    </LinearLayout>
    
    
    
    
    
    
    
    
    
Create the adapter :
    public class MyRecyclerViewAdapter extends RecyclerView.Adapter<MyRecyclerViewAdapter.ViewHolder> {

        private List<String> mData;
        private LayoutInflater mInflater;
        private ItemClickListener mClickListener;

        // data is passed into the constructor
        MyRecyclerViewAdapter(Context context, List<String> data) {
            this.mInflater = LayoutInflater.from(context);
            this.mData = data;
        }

        // inflates the row layout from xml when needed
        @Override
        public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            View view = mInflater.inflate(R.layout.recyclerview_row, parent, false);
            return new ViewHolder(view);
        }

        // binds the data to the TextView in each row
        @Override
        public void onBindViewHolder(ViewHolder holder, int position) {
            String animal = mData.get(position);
            holder.myTextView.setText(animal);
        }

        // total number of rows
        @Override
        public int getItemCount() {
            return mData.size();
        }


        // stores and recycles views as they are scrolled off screen
        public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
            TextView myTextView;

            ViewHolder(View itemView) {
                super(itemView);
                myTextView = itemView.findViewById(R.id.tvAnimalName);
                itemView.setOnClickListener(this);
            }

            @Override
            public void onClick(View view) {
                if (mClickListener != null) mClickListener.onItemClick(view, getAdapterPosition());
            }
        }

        // convenience method for getting data at click position
        String getItem(int id) {
            return mData.get(id);
        }

        // allows clicks events to be caught
        void setClickListener(ItemClickListener itemClickListener) {
            this.mClickListener = itemClickListener;
        }

        // parent activity will implement this method to respond to click events
        public interface ItemClickListener {
            void onItemClick(View view, int position);
        }
    }
    
    
    
    
    
    
Initialize RecyclerView in Activity :
    public class MainActivity extends AppCompatActivity implements MyRecyclerViewAdapter.ItemClickListener {

        MyRecyclerViewAdapter adapter;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);

            // data to populate the RecyclerView with
            ArrayList<String> animalNames = new ArrayList<>();
            animalNames.add("Horse");
            animalNames.add("Cow");
            animalNames.add("Camel");
            animalNames.add("Sheep");
            animalNames.add("Goat");

            // set up the RecyclerView
            RecyclerView recyclerView = findViewById(R.id.rvAnimals);
            recyclerView.setLayoutManager(new LinearLayoutManager(this));
            adapter = new MyRecyclerViewAdapter(this, animalNames);
            adapter.setClickListener(this);
            recyclerView.setAdapter(adapter);
        }

        @Override
        public void onItemClick(View view, int position) {
            Toast.makeText(this, "You clicked " + adapter.getItem(position) + " on row number " + position, Toast.LENGTH_SHORT).show();
        }
    }
    
    
    
    
    
Adding a divider between rows :
    DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(recyclerView.getContext(),
        layoutManager.getOrientation());
    recyclerView.addItemDecoration(dividerItemDecoration);