Ytukyg

I have an Activity named RegisterActivity inside it I am impementing ViewPager that contains two fragments. Here is the code of activity

public class RegisterActivity extends AppCompatActivity{



private Context context;

private Toolbar toolbar;

private TabLayout tabLayout;

public static ViewPager viewPager;

private ViewPagerAdapter adapter;



@Override

protected void onCreate(@Nullable Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_register);

    context = RegisterActivity.this;



    viewPager = findViewById(R.id.viewpager);

    setupViewPager(viewPager);



    tabLayout = findViewById(R.id.tabs);

    tabLayout.setupWithViewPager(viewPager);



}



private void setupViewPager(ViewPager viewPager) {

    adapter = new ViewPagerAdapter(getSupportFragmentManager());

    adapter.addFragment(new FragmentOne(), "Step 1");

    adapter.addFragment(new FragmentTwo(), "Step 2");

    viewPager.setAdapter(adapter);

}



class ViewPagerAdapter extends FragmentPagerAdapter {



    private final List<Fragment> fragmentList = new ArrayList<>();

    private final List<String> fragmentTitleList = new ArrayList<>();



    public ViewPagerAdapter(FragmentManager manager) {

        super(manager);

    }



    @Override

    public Fragment getItem(int position) {

        return fragmentList.get(position);

    }



    @Override

    public int getCount() {

        return fragmentList.size();

    }



    public void addFragment(Fragment fragment, String title) {

        fragmentList.add(fragment);

        fragmentTitleList.add(title);

    }



    @Nullable

    @Override

    public CharSequence getPageTitle(int position) {

        return fragmentTitleList.get(position);

    }

}

}

Fragment one has a NEXT button. When this button is pressed I want the view pager to scroll to FragmentTWo. Again FragmentTwo has a BACK button, I want the view pager to scroll to fragmentOne when BACK button (which is present in the FragmentTwo layout) is pressed.

RegisterActivity.viewpager.setCurrentItem(position of the fragment);

//Do this onClick of the button in the fragment you are in just you need to be specific about the position of fragment in the pager adapter