setOnTabSelectedListener is deprecated

I always see a crossed out line setOnTabSelectedListener for the following code

viewPager.setAdapter(adapter);
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
    @Override
    public void onTabSelected(TabLayout.Tab tab) {
        viewPager.setCurrentItem(tab.getPosition());
    }
}

And the error shown is:

> setOnTabSelectedListener is deprecated

However, the program seems to work just fine. May I know what's going on?

> May i know whats going on ?

Deprecated means that they decided this is not a good way to do it or they have found a better way of doing it, and this deprecated method will be removed in the future.

The fix is to use addOnTabSelectedListener instead of setOnTabSelectedListener.
It works almost the same way.

The difference is that with addOnTabSelectedListener:

• you can add multiple listeners. With setOnTabSelectedListener you could only have one.
• you should remove the listener when you're done with it, with removeOnTabSelectedListener.

---

General rule of thumb: never use deprecated methods.

As setOnTabSelectedListener is deprecated now, you can use the new method

addOnTabSelectedListener(OnTabSelectedListener)

This change allows to add multiple tab selection listeners to a single TabLayout.

in kotlin usage like below code;

   tabLayoutView.addOnTabSelectedListener(object : TabLayout.OnTabSelectedListener {
                override fun onTabReselected(p0: TabLayout.Tab?) {
                }
    
                override fun onTabUnselected(p0: TabLayout.Tab?) {
    
                }
    
                override fun onTabSelected(p0: TabLayout.Tab?) {
                    viewPager.currentItem = tabLayoutView.selectedTabPosition
                }
    
    
            })

Use below codes instead :

tablayout.addOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(viewPager));
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tablayout));

And if you want to sync them when clicking on tabs or swiping the viewpager above codes are the key for syncing.