Force user to select option in dialog

Question

On starting the application for the first time I wanted to prompt the user (by dialog) to select their city, which would then consequently save their preference and load the proper data into the listview. However, I've noticed that a dialog can be closed by the back button, or pushing anywhere outside of the dialog box, which then triggers a null value for the database.

Is there anyway I can force the dialog box to stay open until the user has selected an option?

I've already implemented .setCancelable(false) and this does not seem to work. My code is below, DialogSetup being the inner class that I'm working with.

Any help/ideas would be appreciated.

public class MainActivity extends ListActivity {
private Cursor lines;
private MetroSleepDb db;
private ListAdapter adapter;
public static final String PREFS_NAME = "METROSLEEP_PREFS";

@Override
protected void onCreate(Bundle savedInstanceState) {


    super.onCreate(savedInstanceState);



    chooseCityDialog();




}




public void setAdapters() {

    db = new MetroSleepDb(this);
    lines = db.getLines(); // you would not typically call this on the main thread
    //ListView listView = (ListView) findViewById(R.id.li);
    adapter = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_1, 
            lines, 
            new String[] {"line_id"}, 
            new int[] {android.R.id.text1}, 0);


    getListView().setAdapter(adapter);
    getListView().setOnItemClickListener(onAnswerClicked);

}


public String getItem(int pos) {

    Cursor c = (Cursor) adapter.getItem(pos);
    String value = c.getString(c.getColumnIndex("line_id"));
    return value;
}

private OnItemClickListener onAnswerClicked = new OnItemClickListener() {
    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position,
            long id) {

        String line_value = getItem(position);
        Intent intent = new Intent(MainActivity.this, ChooseStations.class);
        intent.putExtra("line", line_value);
        startActivity(intent);
    }

};

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
}


@Override
public boolean onOptionsItemSelected(MenuItem  item) {
    switch (item.getItemId()) {
    case android.R.id.home:
        // This ID represents the Home or Up button. In the case of this
        // activity, the Up button is shown. Use NavUtils to allow users
        // to navigate up one level in the application structure. For
        // more details, see the Navigation pattern on Android Design:
        //
        // http://developer.android.com/design/patterns/navigation.html#up-vs-back
        //
        NavUtils.navigateUpFromSameTask(this);
        return true;

    case R.id.menu_settings:
        Intent intent = new Intent(this, SettingsActivity.class);
        startActivity(intent);
        return true;
    }
    return super.onOptionsItemSelected(item);
}

public void chooseCityDialog() {
    DialogFragment newFragment = new DialogSetup();
    newFragment.show(getFragmentManager(), "citypref");
}

public static final class DialogSetup extends DialogFragment {
    public Dialog onCreateDialog(Bundle savedInstanceState) {

        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        builder.setTitle(R.string.prompt_choose_city)
               .setCancelable(false) 
               .setItems(R.array.Cities, new DialogInterface.OnClickListener() {
                   public void onClick(DialogInterface dialog, int which) {
                       //
               }
        });

        return builder.create();
    }



}

}

Answer 1

Aha! You have to call setCancelable(false) on the DialogFragment, not the AlertDialog.builder. See this question: AlertDialog's setCancelable(false) method not working.

The documentation for DialogFragment.setCancelable(boolean cancelable) states:

Control whether the shown Dialog is cancelable. Use this instead of directly calling Dialog.setCancelable(boolean), because DialogFragment needs to change its behavior based on this.

You just need to add 1 line of code:

public void chooseCityDialog() {
    DialogFragment newFragment = new DialogSetup();
    newFragment.setCancelable(false);
    newFragment.show(getFragmentManager(), "citypref");
}

Also, it would be a nice safety check to have a default city to fall back to, if somehow the city returned from the Dialog is null.

Answer 2

I would just use an AlertDialog instead of DialogFragment for this.

    AlertDialog dlgBuilder = new AlertDialog.Builder(this);
    dlgBuilder.setMessage("Title");
    dlgBuilder.setCancelable(false)
            .setPositiveButton("OK", new OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {
                    okCalledMethodInactivity();
                    dialogInterface.dismiss();
                }
            })
            .setNegativeButton("Exit app", new OnClickListener() {
                @Override
                public void onClick(DialogInterface dialogInterface, int i) {
                    finish();
                }
            });
    AlertDialog dlg = dlgBuilder.create();
    dlg.show();