onTabSelected Selected Not Called

Question

I have just migrated my old ActionBar to new TabLayout ( Support Material Design ).

Everything is great but I can\'t intercept tab selectio

Answer 1

Here is a somewhat fuller example with three tabs. It uses the newer addOnTabSelectedListener rather than setOnTabSelectedListener.

TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
tabLayout.addTab(tabLayout.newTab().setText("Tab 1"));
tabLayout.addTab(tabLayout.newTab().setText("Tab 2"));
tabLayout.addTab(tabLayout.newTab().setText("Tab 3"));
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);

final ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
final PagerAdapter adapter = new PagerAdapter
        (getSupportFragmentManager(), tabLayout.getTabCount());
viewPager.setAdapter(adapter);
viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
    @Override
    public void onTabSelected(TabLayout.Tab tab) {
        viewPager.setCurrentItem(tab.getPosition());
        Log.i("TAG", "onTabSelected: " + tab.getPosition());
    }

    @Override
    public void onTabUnselected(TabLayout.Tab tab) {
        Log.i("TAG", "onTabUnselected: " + tab.getPosition());
    }

    @Override
    public void onTabReselected(TabLayout.Tab tab) {
        Log.i("TAG", "onTabReselected: " + tab.getPosition());
    }
});

Notes:

• onTabSelected and onTabUnselected are called every time there is a change in tabs.
• onTabReselected is called whenever a tab is clicked again while it is already showing.

Answer 2

When you call setupWithViewPager, this will internally call setOnTabSelectedListener(new ViewPagerOnTabSelectedListener(viewPager));, overriding your OnTabSelectedListener.

Instead, your listener should extend TabLayout.ViewPagerOnTabSelectedListener, then override onTabSelected() and call setOnTabSelectedListener() after setupWithViewPager():

tabLayout.setupWithViewPager(mViewPager);
tabLayout.setOnTabSelectedListener(
  new TabLayout.ViewPagerOnTabSelectedListener(mViewPager) {
    @Override
    public void onTabSelected(TabLayout.Tab tab) {
        super.onTabSelected(tab);
        numTab = tab.getPosition();
        prefs.edit().putInt("numTab", numTab).apply();
    }
});