tabindicator is not sliding from one to another tab in tablayout when I swipe between fragments. Highlighting of font is also not changing

public class LoginRegister extends AppCompatActivity implements SignUpFragment.OnFragmentInteractionListener ,SignInFragment.OnFragmentInteractionListener{
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_login_register);
    final TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout_signup);
    tabLayout.addTab(tabLayout.newTab().setText("Sign Up"));
    tabLayout.addTab(tabLayout.newTab().setText("Sign in"));
    tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);        
    final ViewPager pager =(ViewPager) findViewById(R.id.loginpager);
    final SigninPagerAdapter adapter = new SigninPagerAdapter(getSupportFragmentManager(),tabLayout.getTabCount());
    pager.setAdapter(adapter);
    tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {
            pager.setCurrentItem(tab.getPosition());
        }
        @Override
        public void onTabUnselected(TabLayout.Tab tab) {
}
        @Override
        public void onTabReselected(TabLayout.Tab tab) {
        }
    });

when I slide through fragments, the highlights of the tab does not changes, But it works fine when I touch the tabs.When I touch them, the tab indicator slides well from left to right and font color of tabs also looks highlighted. I think Problem is in this piece of code

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

        @Override
        public void onPageSelected(int position) {


        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });

}


@Override
public void onFragmentInteraction(Uri uri) {

}
}

What should I do to Highlight current tab...