ViewPager switch without showing the in between fragments

Question

I have a ViewPager that holds 4 fragments. When I switch from fragment1 to fragment3 or fragment4 by clicking on my bottom navigation bar, it always shows the in between fragments for a fraction amount of time. The behavior is like it has to pass fragment 2 and 3 to arrive to fragment 4. Is this normal? If so, is there a way to disable this in between animation?

Code in my home activity which holds the 4 fragments are like this:

/**
 * view pager.
 */

public void setupViewPager(ViewPager viewPager){
    Log.d(TAG, "setupViewPager: setting up viewPager.");
    SectionsStatePagerAdapter adapter = new SectionsStatePagerAdapter(getSupportFragmentManager());
    adapter.addFragment(new HomeFragment(), "HomeFragment");
    adapter.addFragment(new HashtagFragment(), "HashtagFragment");
    adapter.addFragment(new ChattingFragment(), "ChattingFragment");
    adapter.addFragment(new SettingFragment(), "SettingFragment");
    viewPager.setAdapter(adapter);
}


public void setViewPager(int fragmentNumber){

        mViewPager.setCurrentItem(fragmentNumber);

}



public void enableViewPagerSwitch(){

    mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            if(bottomNavigationView.getMenu().getItem(position).isChecked()){
                bottomNavigationView.getMenu().getItem(position).setChecked(false);
                Log.d(TAG, "onPageScrolled: position is " + position);
            }
        }

        @Override
        public void onPageSelected(int position) {

            bottomNavigationView.getMenu().getItem(position).setChecked(true);

        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });

}



/**
 * navigation bar.
 */

private void setupBottomNavigationView(){
    Log.d(TAG, "setupBottomNavigationView: setting up Bottom navigation bar.");
    BottomNavigationViewHelper.setupBottomNavigationView(bottomNavigationView);
    Menu menu = bottomNavigationView.getMenu();
    MenuItem menuItem = menu.getItem(ACTIVITY_NUM);
    menuItem.setChecked(true);
}

private void enableNavigation(){
    bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
        @Override
        public boolean onNavigationItemSelected(@NonNull MenuItem item) {

            switch (item.getItemId()){
                case R.id.ic_home:
                    setViewPager(0);
                    break;

                case R.id.ic_hashtag:
                    setViewPager(1);
                    break;

                case R.id.ic_chat:
                    setViewPager(2);
                    break;

                case R.id.ic_setting:
                    setViewPager(3);
                    break;
            }

            return false;
        }
    });

}

ViewPager adapter:

public class SectionsStatePagerAdapter extends FragmentStatePagerAdapter{

private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();

public SectionsStatePagerAdapter(FragmentManager fm) {
    super(fm);

}

public void addFragment(Fragment fragment, String title){
    mFragmentList.add(fragment);
    mFragmentTitleList.add(title);
}

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

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

Thanks!

Answer 1

You can use ViewPager#setCurrentItem(position, false);

The second boolean tells the ViewPager not to scroll to the item, but show it immediately.

Check the documentation here