Why doesn't work animation in viewPager method?

Question

I have viewPager with 2 views. I need to get the second view by click and by flip. It works. But when I an in the second view I have to have button animation. This button is my customView. This animation doesn't work. And I don't know why. onPageSelected(int position) method works, because I get log.

my customView class:

public class CustomView extends LinearLayout {
    private LayoutInflater mInflater;
    private Button button;
    private ViewPager viewPager;
    private float buttonWidth;

    public void setPager(ViewPager viewPager) {
        this.viewPager = viewPager;

        viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
              setClick();
            }

            @Override
            public void onPageSelected(int position) {

                ViewTreeObserver vto = button.getViewTreeObserver();
                vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
                    @Override
                    public void onGlobalLayout() {
                        buttonWidth = button.getWidth();
                    }
                });

                DisplayMetrics metrics = new DisplayMetrics();
                ((Activity) getContext()).getWindowManager().getDefaultDisplay().getRealMetrics(metrics);

                boolean isDisplayPortrait = getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT;
                float middleScreen = isDisplayPortrait ? metrics.widthPixels / 2 : metrics.heightPixels / 2;
                float movingDistanceForButton = middleScreen - buttonWidth / 2;

                final TranslateAnimation animation = new TranslateAnimation(0, movingDistanceForButton, 0, 0);
                animation.setDuration(3000);
                animation.setFillAfter(true);
                if (position == 1) {
                    button.setAnimation(animation);
                    Log.e("position1", "pos1");
                } else {
                    button.getAnimation().cancel();
                }
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });
    }

   public CustomView(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        mInflater = LayoutInflater.from(context);

        View v = mInflater.inflate(R.layout.custom_view, this, true);
        button = v.findViewById(R.id.nextBotton);
 }

        public void setClick() {

        button.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
               viewPager.setCurrentItem(viewPager.getCurrentItem() + 1, true);

            }
        });
    }

and my activity class:

public class Activity extends AppCompatActivity {
    private ViewPager viewPager;
    private PagerAdapter customPagerAdapter;
    private CustomView customView;


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

        customPagerAdapter = new PagerAdapter(this);
        viewPager = findViewById(R.id.viewPager);
       customView = findViewById(R.id.myCustomView);

        viewPager.setAdapter(customPagerAdapter);
       customView.setPager(viewPager);
}