// region selection activity
import android.os.Bundle;
import android.app.Activity;
import android.content.SharedPreferences;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.AdapterView;
import android.view.View;
import android.widget.AdapterView.OnItemSelectedListener;

public class RegionSelectionActivity extends Activity {
    private String[] regions = {"US", "Europe", "Asia"};
    private SharedPreferences preferences;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_region_selection);

        final Spinner regionSpinner = (Spinner) findViewById(R.id.regionSpinner);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, regions);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        regionSpinner.setAdapter(adapter);

        preferences = getSharedPreferences("MyAppPrefs", MODE_PRIVATE);
        int savedPosition = preferences.getInt("selected_region_position", 0);
        regionSpinner.setSelection(savedPosition);

        regionSpinner.setOnItemSelectedListener(new OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                SharedPreferences.Editor editor = preferences.edit();
                editor.putInt("selected_region_position", position);
                editor.apply();
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {
                // Do nothing
            }
        });
    }
}