Android Vision - Reduce bar code tracking window

Question

I\'m trying to implement Google Visions scanner into an app im working on. By default its a full screen activity and barcodes are tracked over the entire screen.

How

Answer 1

Based on @pm0733464's answer with an example of how to get the barcode that's nearest to the center of the preview.

public class CentralBarcodeFocusingProcessor extends FocusingProcessor {

    public CentralBarcodeFocusingProcessor(Detector detector, Tracker tracker) {
        super(detector, tracker);
    }

    @Override
    public int selectFocus(Detector.Detections detections) {

        SparseArray barcodes = detections.getDetectedItems();
        Frame.Metadata meta = detections.getFrameMetadata();
        double nearestDistance = Double.MAX_VALUE;
        int id = -1;

        for (int i = 0; i < barcodes.size(); ++i) {
            int tempId = barcodes.keyAt(i);
            Barcode barcode = barcodes.get(tempId);
            float dx = Math.abs((meta.getWidth() / 2) - barcode.getBoundingBox().centerX());
            float dy = Math.abs((meta.getHeight() / 2) - barcode.getBoundingBox().centerY());

            double distanceFromCenter =  Math.sqrt((dx * dx) + (dy * dy));

            if (distanceFromCenter < nearestDistance) {
                id = tempId;
                nearestDistance = distanceFromCenter;
            }
        }
        return id;
    }
}