Google Android - это несложно

Код: Выделить всё

public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        int id = item.getItemId();
        TextView country = (TextView) findViewById(R.id.country);
        ImageView triangle=(ImageView) findViewById(R.id.triangle);

        switch (id)
        {
            case R.id.tree_cats:
                break;
            case R.id.favorite:
                country.setText(item.getTitle());
                triangle.setVisibility(View.INVISIBLE);
                setContentView(R.layout.favorite);
                break;
        }


        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }