Android Scroll To Hide Toolbar

1) build.gradle

    implementation 'com.android.support:design:28.0.0'

2) Style.xml
res/values/style.xml

<resources>

    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>

        <item name="windowActionBar">false</item>
        <item name="windowNoTitle">true</item>
    </style>

</resources>

3) MainActivity.xml

<android.support.design.widget.CoordinatorLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/main_content"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:layout_scrollFlags="scroll|enterAlways"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
            app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" />

        <android.support.design.widget.TabLayout
            android:id="@+id/tab_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar" />

    </android.support.design.widget.AppBarLayout>

    <android.support.v4.view.ViewPager
        android:id="@+id/viewpager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />

</android.support.design.widget.CoordinatorLayout>

add a  layout_scrollFlags in Toolbar and layout_behavior in ViewPager 

4) MAinActivity.java

public class MainActivity extends AppCompatActivity {

    private Toolbar toolbar;
    private ViewPager viewPager;
    private TabLayout tabLayout;

    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        toolbar = (Toolbar) findViewById(R.id.toolbar);
        viewPager = (ViewPager) findViewById(R.id.viewpager);
        tabLayout = (TabLayout) findViewById(R.id.tab_layout);

        setSupportActionBar(toolbar);
        setupViewPager(viewPager);
        tabLayout.setupWithViewPager(viewPager);
    }

    private void setupViewPager(ViewPager viewPager) {
        Adapter adapter = new Adapter(getSupportFragmentManager());
        adapter.addFragment(new One(), "TAB ONE");
        adapter.addFragment(new Two(), "TAB TWO");
        adapter.addFragment(new Three(), "TAB THREE");
        viewPager.setAdapter(adapter);
    }

    static class Adapter extends FragmentPagerAdapter {
        private final List<Fragment> mFragments = new ArrayList<>();
        private final List<String> mFragmentTitles = new ArrayList<>();

        public Adapter(FragmentManager fm) {
            super(fm);
        }

        public void addFragment(Fragment fragment, String title) {
            mFragments.add(fragment);
            mFragmentTitles.add(title);
        }

        @Override
        public Fragment getItem(int position) {
            return mFragments.get(position);
        }

        @Override
        public int getCount() {
            return mFragments.size();
        }

        @Override
        public CharSequence getPageTitle(int position) {
            return mFragmentTitles.get(position);
        }
    }

}

3) In Fragment which i add on above code is just have a one textview don't need to add in here