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 selection The method onTabSelected is only called the first time TabLayout is displayed, but when clicking tabs, nothing happens! Any idea what's wrong with this code?

 tabLayout = (TabLayout) findViewById(R.id.tabs);     tabLayout.setTabMode(TabLayout.MODE_SCROLLABLE);     mViewPager = (ViewPager) findViewById(R.id.pager);     if (mViewPager != null) {         setupViewPager();     }     tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {         @Override         public void onTabSelected(TabLayout.Tab tab) {              numTab = tab.getPosition();             prefs.edit().putInt("numTab", numTab).apply();          }          @Override         public void onTabUnselected(TabLayout.Tab tab) {          }          @Override         public void onTabReselected(TabLayout.Tab tab) {          }     });      tabLayout.setupWithViewPager(mViewPager); 

Answer 1

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();     } }); 

Answer 2

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.