How to add a collapsible menu item inside navigation drawer in android?

Question

I have a DrawerLayout enclosing a NavigationView and this layout activity serves as a common Navigation drawer for all the activities in my app. I am p

Answer 1

In menu layout file:

In MyActivity.java - load desired menu:

public void LoadNavMenu(int iMenu){
    navigationView.getMenu().clear();
    navigationView.inflateMenu(iMenu);
    navigationView.getMenu().setGroupVisible(R.id.HelpGroup,false);
    navigationView.getMenu().setGroupVisible(R.id.SetupGroup,false);
}

And OnNavigationItemSelected:

public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    int id = item.getItemId();
    navigationView.getMenu().setGroupVisible(R.id.HelpGroup,false);
    navigationView.getMenu().setGroupVisible(R.id.SetupGroup,false);
    switch (item.getItemId()){
        case R.id.HelpGr:
            navigationView.getMenu().setGroupVisible(R.id.HelpGroup,true);
            navigationView.getMenu().setGroupVisible(R.id.SetupGroup,false);
            return true;
        case R.id.SetupGr:
            navigationView.getMenu().setGroupVisible(R.id.SetupGroup,true);
            navigationView.getMenu().setGroupVisible(R.id.HelpGroup,false);
            return true;
    }    
    base.closeDrawer(GravityCompat.START);
    return true;
}

I have 1 item - Setup - and when user select it - I set Group with id - SetupGroup - visible and return without closing drawer. Else - I set all groups invisible.