+ // While we have the image data in a BitArray, it's fairly cheap to reverse it in place to
+ // handle decoding upside down barcodes.
+ for (int attempt = 0; attempt < 2; attempt++) {
+ if (attempt == 1) { // trying again?
+ row.reverse(); // reverse the row and continue
+ // This means we will only ever draw result points *once* in the life of this method
+ // since we want to avoid drawing the wrong points after flipping the row, and,
+ // don't want to clutter with noise from every single row scan -- just the scans
+ // that start on the center line.
+ if (hints != null && hints.containsKey(DecodeHintType.NEED_RESULT_POINT_CALLBACK)) {
+ hints = (Hashtable) hints.clone();
+ hints.remove(DecodeHintType.NEED_RESULT_POINT_CALLBACK);
+ }
+ }
+ try {
+ // Look for a barcode
+ Result result = decodeRow(rowNumber, row, hints);
+ // We found our barcode
+ if (attempt == 1) {
+ // But it was upside down, so note that
+ result.putMetadata(ResultMetadataType.ORIENTATION, new Integer(180));
+ // And remember to flip the result points horizontally.
+ ResultPoint[] points = result.getResultPoints();
+ points[0] = new ResultPoint(width - points[0].getX() - 1, points[0].getY());
+ points[1] = new ResultPoint(width - points[1].getX() - 1, points[1].getY());
+ }
+ return result;
+ } catch (ReaderException re) {
+ // continue -- just couldn't decode this row
+ }
+ }