How to "RE-SELECT" tab in TabLayout programmatically?

Question

TabLayout.OnTabSelectedListener has one callback which is onTabReselected(TabLayout.Tab tab)

We can reselect tab manually by tapping on selected tab again.

So my question is how to reselect tab programatically?

Answer 1

This is how I got my tabs working

Layout for tabs:

 <?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:background="#ffffff">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:layout_scrollFlags="scroll|enterAlways"
            app:layout_collapseMode="pin"
            android:background="#000000"
            app:titleTextColor="#ffffff"

            app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
            app:popupTheme="@style/PopupMenuStyle">

            <TextView
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:id="@+id/textview"
                android:textColor="@color/colorTrueWhite"/>

        </android.support.v7.widget.Toolbar>

        <!-- our tablayout to display tabs  -->
        <android.support.design.widget.TabLayout
            android:id="@+id/tabLayout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="@color/colorBlack"
            android:minHeight="?attr/actionBarSize"

            app:tabIndicatorColor="@color/colorTrueWhite"
            app:tabIndicatorHeight="5dp"
            android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"/>

        <!-- View pager to swipe views -->


        <android.support.v4.view.ViewPager
            android:id="@+id/pager"
            android:layout_width="match_parent"
            android:layout_height="fill_parent"/>


    </LinearLayout>

Activity using that layout:

public class Main2Activity extends AppCompatActivity implements TabLayout.OnTabSelectedListener {

    private TabLayout tabLayout;
    public static ViewPager viewPager;
    public static Context ctx;
    Pager adapter;
    public static int expired, paid;
    Boolean isConnection;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);

        Toolbar tb = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(tb);

        TextView tv = (TextView) findViewById(R.id.textview);

        //getSupportActionBar().setDisplayHomeAsUpEnabled(true);


        ctx = getApplicationContext();


        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);


        tabLayout = (TabLayout) findViewById(R.id.tabLayout);
        viewPager = (ViewPager) findViewById(R.id.pager);


        tabLayout.addTab(tabLayout.newTab().setText("title1"));
        tabLayout.addTab(tabLayout.newTab().setText("title2"));
        tabLayout.addTab(tabLayout.newTab().setText("title3"));
        tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
        tabLayout.setupWithViewPager(viewPager);

        adapter = new Pager(getSupportFragmentManager(), tabLayout.getTabCount(), ctx);
        viewPager.setAdapter(adapter);


        if(some condition)
        {
            viewPager.setCurrentItem(2);
        }
        else
        {
            viewPager.setCurrentItem(1);
        }
        viewPager.setOffscreenPageLimit(2);

        tabLayout.addOnTabSelectedListener(this);

        ViewGroup vg = (ViewGroup) tabLayout.getChildAt(0);
        int tabsCount = vg.getChildCount();
        for (int j = 0; j < tabsCount; j++) {
            ViewGroup vgTab = (ViewGroup) vg.getChildAt(j);
            int tabChildsCount = vgTab.getChildCount();
            for (int i = 0; i < tabChildsCount; i++) {
                View tabViewChild = vgTab.getChildAt(i);
                if (tabViewChild instanceof TextView) {
                    ((TextView) tabViewChild).setTypeface(Typeface.DEFAULT, Typeface.BOLD);
                }
            }
        }
    }


    @Override
    public void onTabSelected(TabLayout.Tab tab) {
        viewPager.setCurrentItem(tab.getPosition());
    }

    @Override
    public void onTabReselected(TabLayout.Tab tab) {
    }

    @Override
    public void onTabUnselected(TabLayout.Tab tab) {
    }


}

Pager code:

public class Pager extends FragmentStatePagerAdapter
{
    int tabcount;
    Context ctx;
    private String [] Titles = {"title1", "title2", "title3"};

    public Pager(FragmentManager fm, int tabcount, Context ctx)
    {
        super(fm);
        this.tabcount = tabcount;
        this.ctx = ctx;
    }

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

    @Override
    public CharSequence getPageTitle(int position) {
        return Titles[position];
    }

    @Override
    public Fragment getItem(int position) {

        switch (position) {

            case 0:
                Tab1 tab1 = new Tab1();
                return tab1;

            case 1:
                Tab2 tab2 = new Tab2();
                return tab2;

            case 2:
                Tab3 tab3 = new Tab3();
                return tab3;

            default:
                return null;
        }
    }


}