How to not take picture pressing capture button?

[kawi15]

Hi, I am mixing barcode scanning with taking pictures and I want to take picture only when it's QR Code visible on camera.

CameraAwesomeBuilder.awesome(
        saveConfig: SaveConfig.photo(),
        sensorConfig: SensorConfig.single(
          aspectRatio: CameraAspectRatios.ratio_16_9,
        ),
        availableFilters: [],
        onImageForAnalysis: (image) async {
          final inputImage = image.toInputImage();
          try {
            recognizedBarcodes = await _barcodeScanner.processImage(inputImage);
            print(recognizedBarcodes.length);
            for (Barcode barcode in recognizedBarcodes) {
              debugPrint("Barcode: [${barcode.format}]: ${barcode.rawValue}");
            }
          } catch (error) {
            debugPrint("...sending image resulted error $error");
          }
        },
        bottomActionsBuilder: (state) => AwesomeBottomActions(
          state: state,
          right: Container(),
          left: Container(),
          captureButton: AwesomeCaptureButton(
            state: state,
          ),
        ),
        onMediaCaptureEvent: (event) async {
          print(recognizedBarcodes.length);
          if (recognizedBarcodes.length == 1) {
            switch ((event.status, event.isPicture, event.isVideo)) {
              case (MediaCaptureStatus.capturing, true, false):
                debugPrint('Capturing picture...');
              case (MediaCaptureStatus.success, true, false):
                event.captureRequest.when(
                  single: (single) {
                    debugPrint('Picture saved: ${single.file?.path}');
                    Navigator.of(context, rootNavigator: true).push(
                      MaterialPageRoute(
                        builder: (context) => DisplayPictureScreen(
                          // Pass the automatically generated path to
                          // the DisplayPictureScreen widget.
                          imagePath: single.file!.path,
                        ),
                      ),
                    );
                  },
                );
              case (MediaCaptureStatus.failure, true, false):
                debugPrint('Failed to capture picture: ${event.exception}');
              default:
                debugPrint('Unknown event: $event');
            }
          } else {
            ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('No Qr Code in picture')));
          }
        },
      )

I tried something like this but it is saving picture on phone. I want to show snackbar, if there is no QR code without saving picture, and save picture when QR Code is on picture.
Is this possible somehow?