/*
- * Copyright 2008 Google Inc.
+ * Copyright 2008 ZXing authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
/**
* <p>A reader that can read all available UPC/EAN formats. If a caller wants to try to
- * read all such formats, it is most efficent to use this implementation rather than invoke
+ * read all such formats, it is most efficient to use this implementation rather than invoke
* individual readers.</p>
*
- * @author srowen@google.com (Sean Owen)
+ * @author Sean Owen
*/
public final class MultiFormatUPCEANReader extends AbstractOneDReader {
- public Result decodeRow(int rowNumber, BitArray row, Hashtable hints) throws ReaderException {
- Hashtable possibleFormats = hints == null ? null : (Hashtable) hints.get(DecodeHintType.POSSIBLE_FORMATS);
- Vector readers = new Vector();
+ private final Vector readers;
+
+ public MultiFormatUPCEANReader(Hashtable hints) {
+ Vector possibleFormats = hints == null ? null :
+ (Vector) hints.get(DecodeHintType.POSSIBLE_FORMATS);
+ readers = new Vector();
if (possibleFormats != null) {
if (possibleFormats.contains(BarcodeFormat.EAN_13)) {
readers.addElement(new EAN13Reader());
- }
- if (possibleFormats.contains(BarcodeFormat.UPC_A)) {
+ } else if (possibleFormats.contains(BarcodeFormat.UPC_A)) {
readers.addElement(new UPCAReader());
}
if (possibleFormats.contains(BarcodeFormat.EAN_8)) {
}
}
if (readers.isEmpty()) {
- readers.addElement(new EAN13Reader());
- readers.addElement(new UPCAReader());
+ readers.addElement(new EAN13Reader());
+ // UPC-A is covered by EAN-13
readers.addElement(new EAN8Reader());
readers.addElement(new UPCEReader());
}
+ }
+ public Result decodeRow(int rowNumber, BitArray row, Hashtable hints) throws ReaderException {
// Compute this location once and reuse it on multiple implementations
int[] startGuardPattern = AbstractUPCEANReader.findStartGuardPattern(row);
- for (int i = 0; i < readers.size(); i++) {
+ int size = readers.size();
+ for (int i = 0; i < size; i++) {
UPCEANReader reader = (UPCEANReader) readers.elementAt(i);
Result result;
try {
- result = reader.decodeRow(rowNumber, row, startGuardPattern);
+ result = reader.decodeRow(rowNumber, row, startGuardPattern, hints);
} catch (ReaderException re) {
continue;
}
// Special case: a 12-digit code encoded in UPC-A is identical to a "0"
// followed by those 12 digits encoded as EAN-13. Each will recognize such a code,
// UPC-A as a 12-digit string and EAN-13 as a 13-digit string starting with "0".
- // Individually these are correct.
- //
- // These cases can't be distinguished, so we defer to the UPC-A decoder and
- // treat this case as a UPC-A code. But if we let the UPC-A decoder look at
- // symbols first, it will recognize any EAN-13 code as a 12-digit string,
- // which is wrong. So EAN-13 has to try first.
+ // Individually these are correct and their readers will both read such a code
+ // and correctly call it EAN-13, or UPC-A, respectively.
//
- // Here is, therefore, where we implement this logic:
+ // In this case, if we've been looking for both types, we'd like to call it
+ // a UPC-A code. But for efficiency we only run the EAN-13 decoder to also read
+ // UPC-A. So we special case it here, and convert an EAN-13 result to a UPC-A
+ // result if appropriate.
if (result.getBarcodeFormat().equals(BarcodeFormat.EAN_13) &&
result.getText().charAt(0) == '0') {
- return new Result(result.getText().substring(1), result.getResultPoints(), BarcodeFormat.UPC_A);
+ return new Result(result.getText().substring(1), null, result.getResultPoints(),
+ BarcodeFormat.UPC_A);
}
return result;
}
- throw new ReaderException("No barcode was detected in this image.");
+ throw ReaderException.getInstance();
}
-}
\ No newline at end of file
+}