reverse portrait not working in android

Question

As the title says when calling

setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_REVERSE_PORTRAIT);

or declaring in the manifest

android:screenOrientation="reversePortrait"

Doesn't rotate the screen at all. When I try to use reverse landscape it works fine. This doesn't make nay sense. Did I do something wrong? Thanks in advance.

Answer 1

Try this code.

public class MainActivity extends AppCompatActivity {

    @Override protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    protected void onResume() {
        super.onResume();
        Settings.System.putInt(getContentResolver(), Settings.System.ACCELEROMETER_ROTATION, 0);// turn off rotation according to accelerometer
        Settings.System.putInt(getContentResolver(), Settings.System.USER_ROTATION, Surface.ROTATION_180);//reverse portrait
    }

    @Override
    protected void onPause() {
        super.onPause();
        Settings.System.putInt(getContentResolver(), Settings.System.USER_ROTATION, Surface.ROTATION_0);//portrait
        Settings.System.putInt(getContentResolver(), Settings.System.ACCELEROMETER_ROTATION, 1);//turn on rotation according to accelerometer
    }
}

Do not forget adding permission to AndroidManifest.xml

<uses-permission android:name="android.permission.WRITE_SETTINGS"/>