Reselecting correct NavigationView menu item after pressing back button

Question

I have an android application which has a NavigationView with 4 fragments. I can navigate between fragments via navigation menu and when I select another fragment, I added the previous fragment into back stack to provide back button functionality.

My problem is that when I press back button to go to previous fragment, the NavigationView still shows old fragment as the selected fragment. If it is possible I want to update selected option as the fragment on the screen.

Example:
I start from A, and select B from NavigationView. The current screen is B and NavigationView shows the selected item as B. If I press back button my current screen becomes A again but NavigationView shows B as selected item.

Here is my onNavigationItemSelected method:

public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        int id = item.getItemId();
        HomeFragment fragment = null;
        Class type = null;
        switch (id) {
            case R.id.nav_home:
                type = HomeNavigationFragment.class;
                break;
            case R.id.nav_groups:
                type = GroupsNavigationFragment.class;
                break;
            case R.id.nav_profile:
                type = ProfileNavigationFragment.class;
                break;
            case R.id.nav_messages:
                type = MessageNavigationFragment.class;
                break;
        }
        fragment = HomeFragment.newInstance(mUser, type);
        FragmentManager manager = getSupportFragmentManager();
        manager.beginTransaction().replace(R.id.fragment_container, fragment).addToBackStack("fragment" + code++).commit();
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }

Thanks.

Answer 1

I fixed my problem with overriding onBackPressed like this:

@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        FragmentManager manager = getSupportFragmentManager();
        if(manager.getBackStackEntryCount() > 0) {
            super.onBackPressed();
            HomeFragment currentFragment = (HomeFragment) manager.findFragmentById(R.id.fragment_container);
            if(currentFragment instanceof HomeNavigationFragment){
                mNavigationView.getMenu().getItem(0).setChecked(true);
            }
            else if(currentFragment instanceof GroupsNavigationFragment){
                mNavigationView.getMenu().getItem(2).setChecked(true);
            }
            else if(currentFragment instanceof ProfileNavigationFragment){
                mNavigationView.getMenu().getItem(1).setChecked(true);
            }
            else if(currentFragment instanceof MessageNavigationFragment){
                mNavigationView.getMenu().getItem(3).setChecked(true);
            }
        }
    }

}