PPartisan

public class TouchDelegatingRecyclerView extends RecyclerView {

    private static final String TAG = TouchDelegatingRecyclerView.class.getSimpleName();

    private static final int UP_SWIPE = 803;
    private static final int DOWN_SWIPE = UP_SWIPE + 1;

    private float originalY = 0;

    private int swipeDirection = 0;

PPartisan

public class MainActivity extends AppCompatActivity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    
    ViewPager viewPager = (ViewPager) findViewById(R.id.view_pager);
    MyViewPagerAdapter adapter = new MyViewPagerAdapter(getSupportFragmentManager());
    viewPager.setAdapter(adapter);

PPartisan

/**
 * SparseBooleanArray that is also Parcelable. Had to put this together so I could pass this to a
 * {@code Fragment} bundle.
 */
public class ParcelableSparseBooleanArray extends SparseBooleanArray implements Parcelable {

    public ParcelableSparseBooleanArray(){
        super();
    }

PPartisan

public static boolean isTriangularNumber(int number) {
    return (((Math.sqrt((8*number)+1)) % 1) == 0)
}

PPartisan

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.design.widget.FloatingActionButton;
import android.util.DisplayMetrics;
import android.view.MotionEvent;
import android.view.WindowManager;
import android.view.animation.AccelerateInterpolator;
import android.view.animation.DecelerateInterpolator;

public class FloatingActionButtonBehavior {

PPartisan

import android.graphics.Color;

public final class PaintUtils {

    private PaintUtils() { throw new AssertionError(); }

    public static int createInterimColor(int colorFrom, int colorTo, float percentage) {
        int[] colorFromArray, colorToArray;

        colorFromArray = new int[] {