/*
* 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.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.zxing.oned;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.DecodeHintType;
import com.google.zxing.NotFoundException;
import com.google.zxing.Reader;
import com.google.zxing.ReaderException;
import com.google.zxing.Result;
import com.google.zxing.common.BitArray;
import java.util.Hashtable;
import java.util.Vector;
/**
* <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 efficient to use this implementation rather than invoke
* individual readers.</p>
*
* @author Sean Owen
*/
public final class MultiFormatUPCEANReader extends OneDReader {
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());
} else if (possibleFormats.contains(BarcodeFormat.UPC_A)) {
readers.addElement(new UPCAReader());
}
if (possibleFormats.contains(BarcodeFormat.EAN_8)) {
readers.addElement(new EAN8Reader());
}
if (possibleFormats.contains(BarcodeFormat.UPC_E)) {
readers.addElement(new UPCEReader());
}
}
if (readers.isEmpty()) {
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 NotFoundException {
// Compute this location once and reuse it on multiple implementations
int[] startGuardPattern = UPCEANReader.findStartGuardPattern(row);
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, 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 and their readers will both read such a code
// and correctly call it EAN-13, or UPC-A, respectively.
//
// 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.
//
// But, don't return UPC-A if UPC-A was not a requested format!
boolean ean13MayBeUPCA =
BarcodeFormat.EAN_13.equals(result.getBarcodeFormat()) &&
result.getText().charAt(0) == '0';
Vector possibleFormats = hints == null ? null : (Vector) hints.get(DecodeHintType.POSSIBLE_FORMATS);
boolean canReturnUPCA = possibleFormats == null || possibleFormats.contains(BarcodeFormat.UPC_A);
if (ean13MayBeUPCA && canReturnUPCA) {
return new Result(result.getText().substring(1), null, result.getResultPoints(), BarcodeFormat.UPC_A);
}
return result;
}
throw NotFoundException.getNotFoundInstance();
}
public void reset() {
int size = readers.size();
for (int i = 0; i < size; i++) {
Reader reader = (Reader) readers.elementAt(i);
reader.reset();
}
}
}