TabLayout tab selection

Question

How should I select a tab in TabLayout programmatically?

 TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
 tabLayout.setupWithViewPager(viewPager         


        

Answer 1

With the TabLayout provided by the Material Components Library just use the selectTab method:

TabLayout tabLayout = findViewById(R.id.tab_layout);
tabLayout.selectTab(tabLayout.getTabAt(index));

It requires version 1.1.0.

Answer 2

If it so happens that your default tab is the first one(0) and you happen to switch to a fragment, then you must manually replace the fragment for the first time. This is because the tab is selected before the listener gets registered.

private TabLayout mTabLayout;

...

@Override
public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_tablayout, container, false);
    mTabLayout = view.findViewById(R.id.sliding_tabs);
    mTabLayout.addOnTabSelectedListener(mOnTabSelectedListener);

    getActivity().getSupportFragmentManager().beginTransaction()
        .replace(R.id.tabContent, MyFirstFragment.newInstance()).commit();
    return view;
}

Alternatively, you can consider calling getTabAt(0).select() and overriding onTabReselected like so:

@Override
public void onTabReselected(TabLayout.Tab tab) {
    // Replace the corresponding tab fragment.
}

This would work because you are essentially replacing the fragment on every tab reselect.

Answer 3

This is probably not the ultimate solution, and it requires that you use the TabLayout together with a ViewPager, but this is how I solved it:

void selectPage(int pageIndex)
{
    viewPager.setCurrentItem(pageIndex);
    tabLayout.setupWithViewPager(viewPager);
}

I tested how big the performance impact of using this code is by first looking at the CPU- and memory monitors in Android Studio while running the method, then comparing it to the load that was put on the CPU and memory when I navigated between the pages myself (using swipe gestures), and the difference isn't significantly big, so at least it's not a horrible solution...

Hope this helps someone!

Answer 4

Use this:

<android.support.design.widget.TabLayout
    android:id="@+id/patienthomescreen_tabs"
    android:layout_width="match_parent"
    android:layout_height="72sp"
    app:tabGravity="fill"
    app:tabMode="fixed"
    app:tabIndicatorColor="@android:color/white"
    app:tabSelectedTextColor="@color/green"/>

After in OnClickListener:

TabLayout tabLayout = (TabLayout) findViewById(R.id.patienthomescreen_tabs);
TabLayout.Tab tab = tabLayout.getTabAt(someIndex);
tab.select();

Answer 5

A bit late but might be a useful solution. I am using my TabLayout directly in my Fragment and trying to select a tab quite early in the Fragment's Lifecycle. What worked for me was to wait until the TabLayout finished drawing its child views by using android.view.View#post method. i.e:

int myPosition = 0;
myFilterTabLayout.post(() -> { filterTabLayout.getTabAt(myPosition).select(); });

Answer 6

You can try solving it with this:

TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(mViewPager);

TabLayout.Tab tab = tabLayout.getTabAt(pos);
if (tab != null) {
    tab.select();
}