example.java

RxPermissions.getInstance(this, new HandleOutOfActivityObject(viewIdOfResultView))
                .request(Manifest.permission.CAMERA)
                .subscribe(granted -> {
                  if (granted) resultView.permissionGranted();
                }
                
resultView {
  public void permissionGranted();
}

// This object you'd want to save to state if the request fails and you need to leave the activity:
class HandleOutOfActivityObject {
  int viewId;
  
  public void resolve() {
    findViewById(viewId).permissionGranted();
  }
}

Implemented RxActivityDelegate.java

public class RxActivityDelegate {
    private static final String KEY_OBJECT = "rxActivityController.object";
    private static final String KEY_OBJECTTYPE = "rxActivityController.object.type";
    private static final String KEY_REQUESTCODE = "rxActivityController.requestCode";


    public static void setResponse(Activity activity, int requestCode, RxResponseHandler rxResponseHandler) {
        Intent intent = activity.getIntent();
        intent.putExtra(KEY_OBJECT, JsonUtils.toBytes(rxResponseHandler));
        intent.putExtra(KEY_OBJECTTYPE, rxResponseHandler.getClass().getName());
        intent.putExtra(KEY_REQUESTCODE, requestCode);
    }

    public static void onActivityResult(Activity activity, int requestCode, int resultCode, Intent data) {
        if (activity.getIntent().hasExtra(KEY_REQUESTCODE)) {
            int ourRequestCode = activity.getIntent().getIntExtra(KEY_REQUESTCODE, Integer.MIN_VALUE);
            if (ourRequestCode == requestCode) {
                try {
                    Class<Object> objectType = (Class<Object>) Class.forName(activity.getIntent().getStringExtra(KEY_OBJECTTYPE));
                    RxResponseHandler responseHandler = JsonUtils.getSmileReader(objectType).readValue(activity.getIntent().getByteArrayExtra(KEY_OBJECT));
                    responseHandler.onActivityResult(activity, requestCode, resultCode, data);
                } catch (ClassNotFoundException e) {
                    e.printStackTrace();
                    throw new IllegalStateException(e);
                } catch (JsonProcessingException e) {
                    e.printStackTrace();
                    throw new IllegalStateException(e);
                } catch (IOException e) {
                    e.printStackTrace();
                    throw new IllegalStateException(e);
                }

            }
        }
    }

    public interface RxResponseHandler {
        void onActivityResult(Activity activity, int requestCode, int resultCode, Intent data);
    }
}