2 * Copyright 2008 ZXing authors
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 package com.google.zxing.oned;
19 import com.google.zxing.BarcodeFormat;
20 import com.google.zxing.DecodeHintType;
21 import com.google.zxing.ReaderException;
22 import com.google.zxing.Result;
23 import com.google.zxing.common.BitArray;
25 import java.util.Hashtable;
26 import java.util.Vector;
29 * <p>A reader that can read all available UPC/EAN formats. If a caller wants to try to
30 * read all such formats, it is most efficient to use this implementation rather than invoke
31 * individual readers.</p>
35 public final class MultiFormatUPCEANReader extends OneDReader {
37 private final Vector readers;
39 public MultiFormatUPCEANReader(Hashtable hints) {
40 Vector possibleFormats = hints == null ? null :
41 (Vector) hints.get(DecodeHintType.POSSIBLE_FORMATS);
42 readers = new Vector();
43 if (possibleFormats != null) {
44 if (possibleFormats.contains(BarcodeFormat.EAN_13)) {
45 readers.addElement(new EAN13Reader());
46 } else if (possibleFormats.contains(BarcodeFormat.UPC_A)) {
47 readers.addElement(new UPCAReader());
49 if (possibleFormats.contains(BarcodeFormat.EAN_8)) {
50 readers.addElement(new EAN8Reader());
52 if (possibleFormats.contains(BarcodeFormat.UPC_E)) {
53 readers.addElement(new UPCEReader());
56 if (readers.isEmpty()) {
57 readers.addElement(new EAN13Reader());
58 // UPC-A is covered by EAN-13
59 readers.addElement(new EAN8Reader());
60 readers.addElement(new UPCEReader());
64 public Result decodeRow(int rowNumber, BitArray row, Hashtable hints) throws ReaderException {
65 // Compute this location once and reuse it on multiple implementations
66 int[] startGuardPattern = UPCEANReader.findStartGuardPattern(row);
67 int size = readers.size();
68 for (int i = 0; i < size; i++) {
69 UPCEANReader reader = (UPCEANReader) readers.elementAt(i);
72 result = reader.decodeRow(rowNumber, row, startGuardPattern, hints);
73 } catch (ReaderException re) {
76 // Special case: a 12-digit code encoded in UPC-A is identical to a "0"
77 // followed by those 12 digits encoded as EAN-13. Each will recognize such a code,
78 // UPC-A as a 12-digit string and EAN-13 as a 13-digit string starting with "0".
79 // Individually these are correct and their readers will both read such a code
80 // and correctly call it EAN-13, or UPC-A, respectively.
82 // In this case, if we've been looking for both types, we'd like to call it
83 // a UPC-A code. But for efficiency we only run the EAN-13 decoder to also read
84 // UPC-A. So we special case it here, and convert an EAN-13 result to a UPC-A
85 // result if appropriate.
86 if (result.getBarcodeFormat().equals(BarcodeFormat.EAN_13) &&
87 result.getText().charAt(0) == '0') {
88 return new Result(result.getText().substring(1), null, result.getResultPoints(),
94 throw ReaderException.getInstance();