Background color animation not working with setOnTabSelectedListener

This is my code:
```import android.animation.Animator;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.v4.view.ViewPager;
import android.support.v4.view.animation.LinearOutSlowInInterpolator;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.app.AppCompatDelegate;
import android.view.View;
import android.view.animation.OvershootInterpolator;
import android.widget.Toast;

import com.aurelhubert.ahbottomnavigation.AHBottomNavigation;
import com.aurelhubert.ahbottomnavigation.AHBottomNavigationItem;
import com.aurelhubert.ahbottomnavigation.AHBottomNavigationViewPager;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity implements PageFragment.OnFragmentInteractionListener {

private MainViewPagerAdapter adapter;
private ArrayList bottomNavigationItems = new ArrayList<>();

// UI
private AHBottomNavigationViewPager viewPager;
private AHBottomNavigation bottomNavigation;
private FloatingActionButton floatingActionButton;

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

initUI();
}

/**
* Init UI
*/
private void initUI() {

if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
AppCompatDelegate.setCompatVectorFromResourcesEnabled(true);
}

bottomNavigation = findViewById(R.id.bottom_navigation);

viewPager = findViewById(R.id.view_pager);
viewPager.setPagingEnabled(true);
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}

@Override
public void onPageSelected(int position) {
bottomNavigation.setCurrentItem(position);
animateFloatingButton(position);
}

@Override
public void onPageScrollStateChanged(int state) {

}
});
floatingActionButton = findViewById(R.id.floating_action_button);

AHBottomNavigationItem item1 = new AHBottomNavigationItem(R.string.tab_1, R.drawable.ic_apps_black_24dp, R.color.color_tab_1);
AHBottomNavigationItem item2 = new AHBottomNavigationItem(R.string.tab_2, R.drawable.ic_maps_local_bar, R.color.color_tab_2);
AHBottomNavigationItem item3 = new AHBottomNavigationItem(R.string.tab_3, R.drawable.ic_maps_local_restaurant, R.color.color_tab_3);

bottomNavigationItems.add(item1);
bottomNavigationItems.add(item2);
bottomNavigationItems.add(item3);

bottomNavigation.addItems(bottomNavigationItems);

bottomNavigation.setColored(true);
bottomNavigation.setSelectedBackgroundVisible(true);

bottomNavigation.manageFloatingActionButtonBehavior(floatingActionButton);
bottomNavigation.setTranslucentNavigationEnabled(true);

bottomNavigation.setOnTabSelectedListener(new AHBottomNavigation.OnTabSelectedListener() {
@Override
public boolean onTabSelected(int position, boolean wasSelected) {
if (wasSelected) {
return true;
}

viewPager.setCurrentItem(position);

animateFloatingButton(position);

return true;
}
});

viewPager.setOffscreenPageLimit(3);
adapter = new MainViewPagerAdapter(getSupportFragmentManager());
viewPager.setAdapter(adapter);

bottomNavigation.setCurrentItem(1);
}

@Override
public void onFragmentInteraction(Uri uri) {

}

void animateFloatingButton(int position) {
if (position == 1) {
floatingActionButton.setVisibility(View.VISIBLE);
floatingActionButton.setAlpha(0f);
floatingActionButton.setScaleX(0f);
floatingActionButton.setScaleY(0f);
floatingActionButton.animate()
.alpha(1)
.scaleX(1)
.scaleY(1)
.setDuration(300)
.setInterpolator(new OvershootInterpolator())
.setListener(new Animator.AnimatorListener() {
@Override
public void onAnimationStart(Animator animation) {

}

@Override
public void onAnimationEnd(Animator animation) {
floatingActionButton.animate()
.setInterpolator(new LinearOutSlowInInterpolator())
.start();
}

@Override
public void onAnimationCancel(Animator animation) {

}

@Override
public void onAnimationRepeat(Animator animation) {

}
})
.start();

} else {
if (floatingActionButton.getVisibility() == View.VISIBLE) {
floatingActionButton.animate()
.alpha(0)
.scaleX(0)
.scaleY(0)
.setDuration(300)
.setInterpolator(new LinearOutSlowInInterpolator())
.setListener(new Animator.AnimatorListener() {
@Override
public void onAnimationStart(Animator animation) {

}

@Override
public void onAnimationEnd(Animator animation) {
floatingActionButton.setVisibility(View.GONE);
}

@Override
public void onAnimationCancel(Animator animation) {
floatingActionButton.setVisibility(View.GONE);
}

@Override
public void onAnimationRepeat(Animator animation) {

}
})
.start();
}
}
}
}
```

When I slide the view pager, background color animation will be triggered; but when I click on each tab it won't!!
Where is the problem?!

Thanks!

Start in MainActivity, comparing the ViewPager onPageSelected callback with the AHBottomNavigation setOnTabSelectedListener callback. Trace which callback changes the selected item and triggers the background color behavior when swiping versus clicking a tab. Done means tab clicks produce the same background color animation as ViewPager swipes.

Written by the indexing model from the issue text.