@Override
            public void cameraError(Exception error) {

            }
This view is overlaid on top of the camera preview. It adds the viewfinder rectangle and partial
transparency outside it, as well as the laser scanner animation and result points.

@author dswitkin@google.com (Daniel Switkin)
zxing-android-embedded/src/com/journeyapps/barcodescanner/ViewfinderView.java