Tablayout doesn't show tab title at the bottom of viewpager

Question

I'm new to android and would really appreciate some help.

I'm trying to show tabs at the bottom of my ViewPager. But the issue is that the TabLayout shows up without any text.

This is what I wrote inside UploadActivity.java class

public class UploadActivity extends AppCompatActivity {

    @Override
    public void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_upload);

        ViewPager vpager = (ViewPager)findViewById(R.id.upload_viewpager);
        PagerAdapter adapter = new UploadPagerAdapter(getSupportFragmentManager());
        vpager.setAdapter(adapter);
    }

    public static class UploadPagerAdapter extends FragmentPagerAdapter{

        String[] titles = new String[]{"Gallery", "Photo", "Video"};
        public UploadPagerAdapter(FragmentManager manager){
            super(manager);
        }
        @Override
        public Fragment getItem(int position) {
            switch(position){
                case 0:
                    return new RestaurantListFragment();
                case 1:
                    return new Fragment();
                case 2:
                    return new Fragment();
            }

            return null;
        }

        @Override
        public CharSequence getPageTitle(int position) {
            // Generate title based on item position
            return titles[position];
        }

        @Override
        public int getCount() {
            return 3;
        }
    } 
}

and inside XML, I have

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.raziabbasi.app.first.Activity.UploadActivity">

    <android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/upload_viewpager"
        android:layout_width="match_parent"
        android:layout_height="355dp">

    </android.support.v4.view.ViewPager>

    <android.support.design.widget.TabLayout
        android:id="@+id/upload-tab"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:background="@color/White"
        android:minHeight="25dp"
        app:tabGravity="fill"
        app:tabMode="fixed" />
</LinearLayout>

I have already tried multiple examples on SOC but that didn't help. Please advice.

Thanks in advance

Answer 1

Found the issue here:

Made string Array a static variable and its started working:

public static String[] titles = new String[]{"Gallery", "Photo", "Video"};