Android Activity in Dialog Style

I was working on an Application where I had created a custom settings Activity (Not using the Android built-in settings tools), in order to adopt the same layout style as in the rest of the Application. It worked fine, and now I wanted to add some additional tablet styles as well. When using the Application on a tablet, I wanted a more dialog like view, something without a panel and did not take up the whole screen, but instead placed itself on top of the main activity. When searching the web for a solution to this, the only thing that I could find over and over again, was to add the Dialog Theme to the Activity via AndroidManifest.xml. I had two issues with this. For one, I did not want a Dialog like Activity for all devices, but only for tablets. And second, I have my own custom themes that I apply to all Activities. So I went another way which I was sure would work.

public class ActivityAppSettings extends Activity {
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  if (getApplication() != null && ((ApplicationBase) getApplication()).mTheme > 0) {
   setTheme( ((ApplicationBase) getApplication()).mTheme );
  }
  
  super.onCreate(savedInstanceState);
  
  if (getResources().getString(R.string.config_screen_type).equals("xlarge")) {
   requestWindowFeature(Window.FEATURE_NO_TITLE);
  
   Rect display = new Rect();
   getWindow().getDecorView().getWindowVisibleDisplayFrame(display);
   getWindow().setBackgroundDrawable(new ColorDrawable(0));

   getWindow().setLayout(
     (int) ((display.width() > display.height() ? display.height() : display.width()) * 0.7), 
     (int) (display.height() * 0.7)
   );
  }
  
  setContentView(R.layout.activity_app_settings);
 }
}

Sure enough it worked, but with one little issue. The space around the Activity was not transparent. It seamed that you could not change the window background from within the Activity. The panel however was removed, the size was set at 70% of the screen size and my custom theme had been applied to the content within, but with a black background surrounding it all.

I needed another work-around. I went to AndroidManifest.xml and applied Androids's Translucent theme to the Activity.

<activity android:theme="@android:style/Theme.Translucent"

The Activity theme would still be replaced by my Custom theme from within the Activity, but since you cannot change the window background from within there, the transparency would still stick. And then on Phones, you just apply a background to the main View, which you then configure as match_parent for both height and width, which will overlay the transparent window background, making it seam like a regular full-screen Activity.