Simple item decoration for RecyclerView footer

MainActivity.java

package com.company.user.recyclerviewdecorationtest;

import android.graphics.Rect;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.DividerItemDecoration;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import java.util.Arrays;
import java.util.Random;

public class MainActivity extends AppCompatActivity {
    public static String REMOVE_METHOD = "";

    public static class ViewHolder extends RecyclerView.ViewHolder {
        private int currentPosition;

        public ViewHolder(View itemView) {
            super(itemView);
        }

        public int getCurrentPosition() {
            return currentPosition;
        }

        public void setCurrentPosition(int currentPosition) {
            this.currentPosition = currentPosition;
        }
    }

    public class FooterDecoration extends RecyclerView.ItemDecoration {
        @Override
        public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
            int position_1 = parent.getChildAdapterPosition(view);
            int count_1 = parent.getLayoutManager().getItemCount();

            int position_2 = parent.getChildLayoutPosition(view);
            int count_2 = state.getItemCount();

            ViewHolder viewHolder = (ViewHolder) parent.getChildViewHolder(view);
            int position_3 = viewHolder.getCurrentPosition();
            int count_3 = testList.length;

            int position =
                    REMOVE_METHOD.equals("REMOVE_1") ? position_1 :
                            REMOVE_METHOD.equals("REMOVE_2") ? position_2 :
                                    position_3;

            int count =
                    REMOVE_METHOD.equals("REMOVE_1") ? count_1 :
                            REMOVE_METHOD.equals("REMOVE_2") ? count_2 :
                                    count_3;

            Log.d("TEST", String.format("UPDATE: POS_1(%d), CNT_1(%d); POS_2(%d), CNT_2(%d); POS_3(%d), CNT_3(%d)", position_1, count_1, position_2, count_2, position_3, count_3));

            if (position >= count - 1) {
                outRect.set(0, 0, 0, 100);
            }
        }
    }

    private String[] testList;
    private RecyclerView.Adapter<ViewHolder> modelAdapter;

    private static final String alphabet = "0123456789 ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz";

    private static String[] generateTestData() {
        Random random = new Random();

        int count = 10;// + random.nextInt(100);
        String[] dataList = new String[count];
        for (int i = 0; i < count; i++) {
            int length = 10 + random.nextInt(100);
            StringBuilder stringBuilder = new StringBuilder(length);
            stringBuilder.append(i);
            stringBuilder.append('\n');

            for (int j = 0; j < length; j++) {
                stringBuilder.append(alphabet.charAt(random.nextInt(alphabet.length())));
            }

            dataList[i] = stringBuilder.toString();
        }

        return dataList;
    }

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

        testList = generateTestData();

        RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
        recyclerView.setHasFixedSize(true);

        LinearLayoutManager layoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
        recyclerView.setLayoutManager(layoutManager);

        DividerItemDecoration itemDecoration = new DividerItemDecoration(this, layoutManager.getOrientation());
        recyclerView.addItemDecoration(itemDecoration);

        FooterDecoration footerDecoration = new FooterDecoration();
        recyclerView.addItemDecoration(footerDecoration);

        modelAdapter = new RecyclerView.Adapter<ViewHolder>() {
            @Override
            public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
                View root = getLayoutInflater().inflate(R.layout.list_item, parent, false);
                return new ViewHolder(root);
            }

            @Override
            public void onBindViewHolder(ViewHolder holder, int position) {
                TextView textView = (TextView) holder.itemView.findViewById(R.id.text_view);
                textView.setText(testList[position]);
                holder.setCurrentPosition(position);
            }

            @Override
            public int getItemCount() {
                return testList.length;
            }
        };
        recyclerView.setAdapter(modelAdapter);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        menu.add("NEW").setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS);
        menu.add("REMOVE_1").setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS);
        menu.add("REMOVE_2").setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS);
        menu.add("REMOVE_3").setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS);

        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (item.getTitle().equals("NEW")) {
            testList = generateTestData();
            modelAdapter.notifyDataSetChanged();

            return true;
        }

        if (item.getTitle().toString().contains("REMOVE")) {
            REMOVE_METHOD = item.getTitle().toString();

            int removeIndex = testList.length - 1;

            Log.d("TEST", String.format("REMOVE: POS(%d), CNT(%d)", removeIndex, testList.length));

            testList = Arrays.copyOfRange(testList, 0, removeIndex);
            modelAdapter.notifyItemRemoved(removeIndex);

            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}