Set selected item in Android BottomNavigationView

Question

I am using the new android.support.design.widget.BottomNavigationView from the support library. How can I set the current selection from code? I realized, that

Answer 1

For those, who still use SupportLibrary < 25.3.0

I'm not sure whether this is a complete answer to this question, but my problem was very similar - I had to process back button press and bring user to previous tab where he was. So, maybe my solution will be useful for somebody:

private void updateNavigationBarState(int actionId){
    Menu menu = bottomNavigationView.getMenu();

    for (int i = 0, size = menu.size(); i < size; i++) {
        MenuItem item = menu.getItem(i);
        item.setChecked(item.getItemId() == actionId);
    }
}

Please, keep in mind that if user press other navigation tab BottomNavigationView won't clear currently selected item, so you need to call this method in your onNavigationItemSelected after processing of navigation action:

@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
    switch (item.getItemId()) {
        case R.id.some_id_1:
            // process action
            break;
        case R.id.some_id_2:
            // process action
            break;
        ...
        default:
            return false;
    }

    updateNavigationBarState(item.getItemId());

    return true;
}

Regarding the saving of instance state I think you could play with same action id of navigation view and find suitable solution.