startActivityForResult to an activity that only displays a progressdialog

Question

I'm trying to make an activity that is asked for some result. This result is normally returned instantly (in the onCreate), however, sometimes it is nesesary to wait for some internet-content to download which causes the "loader"-activity to show. What I want is that the loader-activity don't display anything more than a progressdialog (and that you can still se the old activity calling the loader-activity in the background) and I'm wondering wheather or not this is possible.

The code I'm using as of now is:

//ListComicsActivity.java
public class ListComicsActivity extends Activity
{
    private static final int REQUEST_COMICS = 1;


    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.list_comics);

        Button button = (Button)findViewById(R.id.Button01);
        button.setOnClickListener(new OnClickListener()
        {

            @Override
            public void onClick(View v) {
                Intent intent = new Intent();
                intent.setAction(Intents.ACTION_GET_COMICS);
                startActivityForResult(intent, REQUEST_COMICS);
            }
        });
    }

    /** Called when an activity called by using startActivityForResult finishes. */
    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data)
    {
        Toast toast = Toast.makeText(this, "The activity finnished", Toast.LENGTH_SHORT);
        toast.show();
    }
}


//LoaderActivity.java (answers to Intents.ACTION_GET_COMICS action-filter)
public class LoaderActivity extends Activity
{
    private Intent result = null;
    private ProgressDialog pg = null;
    private Runnable returner = new Runnable()
    {
        public void run()
        {
            if(pg != null)
                pg.dismiss();
            LoaderActivity.this.setResult(Activity.RESULT_OK, result);
            LoaderActivity.this.finish();
        }
    };

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);


        String action = getIntent().getAction();
        if(action.equals(Intents.ACTION_GET_COMICS))
        {
            Runnable loader = new Runnable()
            {
                public void run()
                {
                    WebProvider.DownloadComicList();
                    Intent intent = new Intent();
                    intent.setDataAndType(ComicContentProvider.COMIC_URI, "vnd.android.cursor.dir/vnd.mymir.comic");
                    returnResult(intent);
                }
            };
            pg = ProgressDialog.show(this, "Downloading", "Please wait, retrieving data....");
            Thread thread = new Thread(null, loader, "LoadComicList");
            thread.start();
        }
        else
        {
            setResult(Activity.RESULT_CANCELED);
            finish();
        }
    }

    private void returnResult(Intent intent)
    {
        result = intent;
        runOnUiThread(returner);
    }
}

Answer 1

It turns out you can do this by setting the activitys theme-attribute to @android:style/Theme.Dialog and calling this.setVisible(false); in the onCreate-method of the activity.