LottieSample/src/main/java/com/airbnb/lottie/samples/AppIntroFragment.java

package com.airbnb.lottie.samples;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewTreeObserver;
import android.view.animation.Interpolator;
import android.widget.Scroller;

import com.airbnb.lottie.LottieAnimationView;

import java.lang.reflect.Field;

import butterknife.BindView;

public class AppIntroFragment extends Fragment {
    private static int PAGES = 3;

    static AppIntroFragment newInstance() {
        return new AppIntroFragment();
    }

    @BindView(R.id.animation_view) LottieAnimationView animationView;
    @BindView(R.id.view_pager) ViewPager viewPager;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_app_intro, container, false);

        setViewPagerScroller();
        viewPager.setAdapter(new PagerAdapter() {
            @Override
            public int getCount() {
                return PAGES + 1;
            }

            @Override
            public boolean isViewFromObject(View view, Object object) {
                return object == view;
            }

            @Override
            public Object instantiateItem(ViewGroup container, int position) {
                View view = LayoutInflater.from(container.getContext()).inflate(R.layout.pager_item_app_intro, container, false);
                container.addView(view);
                return view;
            }

            @Override
            public void destroyItem(ViewGroup container, int position, Object object) {
                container.removeView((View) object);
            }
        });

        viewPager.addOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
                animationView.setProgress(position / (float) PAGES + positionOffset / (float) PAGES);
            }
        });

        viewPager.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                viewPager.getViewTreeObserver().removeOnGlobalLayoutListener(this);
                viewPager.setCurrentItem(1, true);
            }
        });

        return view;
    }

    private void setViewPagerScroller() {
        //noinspection TryWithIdenticalCatches
        try {
            Field scrollerField = ViewPager.class.getDeclaredField("mScroller");
            scrollerField.setAccessible(true);
            Field interpolator = ViewPager.class.getDeclaredField("sInterpolator");
            interpolator.setAccessible(true);

            Scroller scroller = new Scroller(getContext(), (Interpolator) interpolator.get(null)) {
                @Override
                public void startScroll(int startX, int startY, int dx, int dy, int duration) {
                    super.startScroll(startX, startY, dx, dy, duration * 15);
                }
            };
            scrollerField.set(viewPager, scroller);
        } catch (NoSuchFieldException e) {
            // Do nothing.
        } catch (IllegalAccessException e) {
            // Do nothing.
        }
    }
}