Pick image from gallery in fullscreen mode

in my options menu I have a function that can change the applications background. To do this, I start an Activity where the user can pick an image from his gallery.

Now to the problem: I want the gallery to be displayed in fullscreen-mode.

My AndroidManifest.xml contains

<application android:icon="@drawable/icon"
             android:t开发者_运维技巧heme="@android:style/Theme.NoTitleBar.Fullscreen"
             android:label="@string/app_name">

And I'm showing the gallery via

 Intent i = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.INTERNAL_CONTENT_URI);
 i.setType("image/*");
 startActivityForResult(i, PICK_REQUEST);

Does anybody have an idea how to do this?

Whether the gallery is displayed full-screen or not is dependent on the gallery app itself. As far as I know, that cannot be changed unless you supply your own gallery app and use a custom intent to call that