public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
    super.onCreateContextMenu(menu, v, menuInfo);
}

@Override
public boolean onNavigationItemSelected(MenuItem item){
    int id = item.getItemId();
    switch (id) {
                    case R.id.item1:
                        this.openContextMenu(mNavigationView);
                        break;
                    case R.id.item2:
                        this.openContextMenu(mNavigationView);
                        break;
                    case R.id.item3:
                        this.openContextMenu(mNavigationView);
                        break;
                    default:
                        break;
                }

@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
    super.onCreateContextMenu(menu, v, menuInfo);
    //I would need info here to determine what context menu to open
    //according to the item's id in onNavigationItemSelected
}

registerForContextMenu(mNavigationView);