Usage of https://github.com/hotchemi/PermissionsDispatcher

BarcodeLoggerActivity.java

@Override
protected void onCreate(Bundle savedInstanceState) {
    ...
    BarcodeLoggerActivityPermissionsDispatcher.startBarcodeCaptureWithCheck(this);
}

@NeedsPermission(Manifest.permission.CAMERA)
void startBarcodeCapture() {
    int orientation = WindowManagerHelper.getCurrentAccurateOrientation(this);
    Intent intent = CaptureActivity.buildIntent(this, orientation);
    startActivityForResult(intent, REQUEST_CODE_BARCODE_SCAN);
    overridePendingTransition(R.anim.open_slide_enter,
            R.anim.open_slide_exit);
}

@ShowsRationale(Manifest.permission.CAMERA)
void showRationaleForCamera() {
    Toast.makeText(this, "Please?", Toast.LENGTH_LONG).show();
}

@DeniedPermission(Manifest.permission.CAMERA)
void showDeniedForCamera() {
    Toast.makeText(this, "I need to see!", Toast.LENGTH_LONG).show();
}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    BarcodeLoggerActivityPermissionsDispatcher.onRequestPermissionsResult(this, requestCode, grantResults);
}