Simply add sequential animations to any RecyclerView

SequentialRecyclerViewAnimationAdapter.java

package com.example.view;

import android.animation.Animator;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.RecyclerView.Adapter;
import android.support.v7.widget.RecyclerView.ViewHolder;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Interpolator;
import android.view.animation.LinearInterpolator;


public class SequentialRecyclerViewAnimationAdapter extends Adapter<ViewHolder> {
	private static final int DEFAULT_ANIMATION_DURATION = 100;
	private static final int DEFAULT_ANIMATION_ITEM_DELAY = 150;

	private final RecyclerView mRecyclerView;
	private Adapter mAdapter;
	private int mDuration;
	private Interpolator mInterpolator = new LinearInterpolator();
	private int mCounter;
	private boolean mAnimsInitialized;
	private int mItemDelay;
	private AnimatorProvider mAnimatorProvider;


	public interface AnimatorProvider {
		Animator[] getAnimators(View v);
	}


	/**
	 * Creates a wrapping adapter that can be used for any RecyclerView
	 *
	 * @param adapter
	 * @param recyclerView
	 * @param animationDuration
	 * @param animationItemDelay
	 * @param animatorProvider
	 */
	public SequentialRecyclerViewAnimationAdapter(Adapter<ViewHolder> adapter, RecyclerView recyclerView, int animationDuration, int animationItemDelay, AnimatorProvider animatorProvider) {
		mAdapter = adapter;
		mAdapter.registerAdapterDataObserver(new RecyclerView.AdapterDataObserver() {
			@Override
			public void onChanged() {
				notifyDataSetChanged();
			}


			@Override
			public void onItemRangeChanged(int positionStart, int itemCount) {
				notifyItemRangeChanged(positionStart, itemCount);
			}


			@Override
			public void onItemRangeChanged(int positionStart, int itemCount, Object payload) {
				notifyItemRangeChanged(positionStart, itemCount, payload);
			}


			@Override
			public void onItemRangeInserted(int positionStart, int itemCount) {
				notifyItemRangeInserted(positionStart, itemCount);
			}


			@Override
			public void onItemRangeRemoved(int positionStart, int itemCount) {
				notifyItemRangeRemoved(positionStart, itemCount);
			}


			@Override
			public void onItemRangeMoved(int fromPosition, int toPosition, int itemCount) {
				notifyItemMoved(fromPosition, toPosition);
			}
		});
		mRecyclerView = recyclerView;
		mAnimatorProvider = animatorProvider;
		mDuration = animationDuration;
		mItemDelay = animationItemDelay;
	}


	/**
	 * Apply to an existing {@link RecyclerView} with an attached adapter.
	 * This will wrap and replace the original adapter
	 *
	 * @param recyclerView     RecyclerView instance with an attached adapter
	 * @param animatorProvider {@link Animator} provider for the item views
	 */
	public static void applyTo(RecyclerView recyclerView, AnimatorProvider animatorProvider) {
		applyTo(recyclerView, DEFAULT_ANIMATION_DURATION, DEFAULT_ANIMATION_ITEM_DELAY, animatorProvider);
	}


	/**
	 * Apply to an existing {@link RecyclerView} with an attached adapter.
	 * This will wrap and replace the original adapter
	 *
	 * @param recyclerView       RecyclerView instance with an attached adapter
	 * @param animationDuration  Single animation duration in ms
	 * @param animationItemDelay Delay between each item's animation in ms
	 * @param animatorProvider   {@link Animator} provider for the item views
	 */
	public static void applyTo(RecyclerView recyclerView, int animationDuration, int animationItemDelay, AnimatorProvider animatorProvider) {
		if(recyclerView.getAdapter() == null)
			throw new IllegalStateException("RecyclerView must have an adapter attached");
		SequentialRecyclerViewAnimationAdapter adapter = new SequentialRecyclerViewAnimationAdapter(recyclerView.getAdapter(), recyclerView, animationDuration, animationItemDelay, animatorProvider);
		recyclerView.setAdapter(adapter);
	}


	public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
		return mAdapter.onCreateViewHolder(parent, viewType);
	}


	public void onBindViewHolder(ViewHolder holder, int position) {
		mAdapter.onBindViewHolder(holder, position);

		Animator[] animators = getAnimators(holder.itemView);

		LinearLayoutManager layoutManager = ((LinearLayoutManager) getRecyclerView().getLayoutManager());
		int firstVisiblePosition = layoutManager.findFirstVisibleItemPosition();

		if(!mAnimsInitialized && (firstVisiblePosition == 0 || position == 0))
			for(Animator anim : animators) {
				anim.setDuration((long) mDuration);
				anim.setInterpolator(mInterpolator);
				increaseCounter();
				anim.setStartDelay(getItemDelay() * position);
				anim.addListener(new Animator.AnimatorListener() {
					@Override
					public void onAnimationStart(Animator animation) {
					}


					@Override
					public void onAnimationEnd(Animator animation) {
						if(decreaseCounter())
							mAnimsInitialized = true;
					}


					@Override
					public void onAnimationCancel(Animator animation) {
					}


					@Override
					public void onAnimationRepeat(Animator animation) {
					}
				});
				anim.start();
			}
		else
			for(Animator animator : animators) {
				animator.setDuration(0);
				animator.start();
			}
	}


	public int getItemDelay() {
		return mItemDelay;
	}


	public void setAdapter(Adapter adapter) {
		mAdapter = adapter;
	}


	public AnimatorProvider getAnimatorProvider() {
		return mAnimatorProvider;
	}


	protected synchronized boolean decreaseCounter() {
		mCounter--;
		return mCounter == 0;
	}


	public synchronized int getCounter() {
		return mCounter;
	}


	public synchronized void increaseCounter() {
		mCounter++;
	}


	public int getItemCount() {
		return mAdapter.getItemCount();
	}


	public void setDuration(int duration) {
		mDuration = duration;
	}


	public void setItemDelay(int itemDelay) {
		mItemDelay = itemDelay;
	}


	public void setInterpolator(Interpolator interpolator) {
		mInterpolator = interpolator;
	}


	private Animator[] getAnimators(View view) {
		return getAnimatorProvider().getAnimators(view);
	}


	public RecyclerView getRecyclerView() {
		return mRecyclerView;
	}


	public int getItemViewType(int position) {
		return mAdapter.getItemViewType(position);
	}


	public Adapter<ViewHolder> getWrappedAdapter() {
		return mAdapter;
	}
}

Whatever.java

// Alpha animation (0->1)
// When the recyclerView has an adapter attached
SequentialRecyclerViewAnimationAdapter.applyTo(getBinding().eventList, view -> {
	view.setAlpha(0);
	return new Animator[]{ObjectAnimator.ofFloat(view, "alpha", 0.0F, 1.0F)};
});