How to Disable multiple barcode detection android Vision API

Question

I'm trying to disable multiple Barcode detection at time. How to disable MultiProcessor using Google Vision API, I couldn't find any solution from official site here

I have downloaded sample from here

Code

BarcodeDetector barcodeDetector = new BarcodeDetector.Builder(context).build();
    BarcodeTrackerFactory barcodeFactory = new BarcodeTrackerFactory(mGraphicOverlay);
    barcodeDetector.setProcessor(
            new MultiProcessor.Builder<>(barcodeFactory).build());

Even if remove below line, I cannot detect at all.

 barcodeDetector.setProcessor(
        new MultiProcessor.Builder<>(barcodeFactory).build());

Answer 1

I have resolved this multiple Barcode detection at same time by exploring sample code and some logic implementation.

Solution is : stop mPreview and start again after 1 second delay

Create callback listener

public interface BarCodeDetectListener {
void onBarCodeDetect(Barcode barcode);
}

BarcodeGraphicTracker

When device detected Barcode inside onNewItem() callback to Barcodefragment

class BarcodeGraphicTracker extends Tracker<Barcode> {
...
...
private BarcodeGraphic mGraphic;
private BarCodeDetectListener barCodeDetectListener;
...

 /**
  * Start tracking the detected item instance within the item overlay.
  */
 @Override
 public void onNewItem(int id, Barcode item) {
    mGraphic.setId(id);
    barCodeDetectListener.onBarCodeDetect(item);
 }
}

BarCodeFragment

@SuppressLint("NewApi")
public class SurveyBarCodeFragment extends Fragment implements BarCodeDetectListener {
  ...
  private CameraSourcePreview mPreview;
  private CameraSource mCameraSource;
  ...



 @Override
 public void onBarCodeDetect(final Barcode barcode) {
  new Handler().post(new Runnable() {
        @Override
        public void run() {
            mPreview.stop(); //Stop preview
            new Handler().postDelayed(new Runnable() {
                @Override
                public void run() {
                    try {
                        if (ActivityCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
                            // TODO: Consider calling
                            //    ActivityCompat#requestPermissions
                            // here to request the missing permissions, and then overriding
                            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
                            //                                          int[] grantResults)
                            // to handle the case where the user grants the permission. See the documentation
                            // for ActivityCompat#requestPermissions for more details.
                            return;
                        }
                        //Start preview after 1s delay
                        mPreview.start(mCameraSource);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }, 1000);
        }
    });

 }
}

Answer 2

Update your BarcodeGraphicTracker and implement onNewItem function as below:

public class BarcodeGraphicTracker extends Tracker<Barcode> {

        private static final String TAG = "Barcode-reader";
        @Override
        public void onNewItem(int id, final Barcode item) {
            Log.d(TAG, "Detected!!"+ item.toString());
                Runnable r=new Runnable()
                {
                    public void run()
                    {
                        //write your code here
                        }
                    }
                };
                getActivity().runOnUiThread(r);
        }

        @Override
        public void onUpdate(Detector.Detections<Barcode> detectionResults, Barcode item) {

        }
    }

and BarcodeTrackerFactory as:

public class BarcodeTrackerFactory implements MultiProcessor.Factory<Barcode> {

        @Override
        public Tracker<Barcode> create(Barcode barcode) {
            return new BarcodeGraphicTracker();
        }

    }