In onCreate
of your activity you can check for the current orientation using the this
Configuration newConfig = getResources().getConfiguration();
if (newConfig.orientation == Configuration.ORIENTATION_LANDSCAPE) {
Toast.makeText(this, "landscape", Toast.LENGTH_SHORT).show();
// set background for landscape
} else if (newConfig.orientation == Configuration.ORIENTATION_PORTRAIT) {
Toast.makeText(this, "portrait", Toast.LENGTH_SHORT).show();
// set background for portrait
}