cpp/core/src/zxing/oned/MultiFormatUPCEANReader.cpp

   1 /*
   2  *  MultiFormatUPCEANReader.cpp
   3  *  ZXing
   4  *
   5  *  Created by Lukasz Warchol on 10-01-25.
   6  *  Copyright 2010 ZXing authors All rights reserved.
   7  *
   8  * Licensed under the Apache License, Version 2.0 (the "License");
   9  * you may not use this file except in compliance with the License.
  10  * You may obtain a copy of the License at
  11  *
  12  *      http://www.apache.org/licenses/LICENSE-2.0
  13  *
  14  * Unless required by applicable law or agreed to in writing, software
  15  * distributed under the License is distributed on an "AS IS" BASIS,
  16  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  17  * See the License for the specific language governing permissions and
  18  * limitations under the License.
  19  */
  20 #include "MultiFormatUPCEANReader.h"
  21
  22 #include <zxing/oned/EAN13Reader.h>
  23 #include <zxing/oned/EAN8Reader.h>
  24 #include <zxing/oned/UPCEReader.h>
  25 #include <zxing/oned/OneDResultPoint.h>
  26 #include <zxing/common/Array.h>
  27 #include <zxing/ReaderException.h>
  28 #include <math.h>
  29
  30 namespace zxing {
  31         namespace oned {
  32
  33                 MultiFormatUPCEANReader::MultiFormatUPCEANReader() : readers() {
  34                         readers.push_back(Ref<OneDReader>(new EAN13Reader()));
  35                         // UPC-A is covered by EAN-13
  36                         readers.push_back(Ref<OneDReader>(new EAN8Reader()));
  37                         readers.push_back(Ref<OneDReader>(new UPCEReader()));
  38                 }
  39
  40                 Ref<Result> MultiFormatUPCEANReader::decodeRow(int rowNumber, Ref<BitArray> row){
  41                         // Compute this location once and reuse it on multiple implementations
  42                         int size = readers.size();
  43                         for (int i = 0; i < size; i++) {
  44                                 Ref<OneDReader> reader = readers[i];
  45                                 Ref<Result> result;
  46                                 try {
  47                                         result = reader->decodeRow(rowNumber, row);//decodeRow(rowNumber, row, startGuardPattern);
  48                                 } catch (ReaderException re) {
  49                                         continue;
  50                                 }
  51                                 // Special case: a 12-digit code encoded in UPC-A is identical to a "0"
  52                                 // followed by those 12 digits encoded as EAN-13. Each will recognize such a code,
  53                                 // UPC-A as a 12-digit string and EAN-13 as a 13-digit string starting with "0".
  54                                 // Individually these are correct and their readers will both read such a code
  55                                 // and correctly call it EAN-13, or UPC-A, respectively.
  56                                 //
  57                                 // In this case, if we've been looking for both types, we'd like to call it
  58                                 // a UPC-A code. But for efficiency we only run the EAN-13 decoder to also read
  59                                 // UPC-A. So we special case it here, and convert an EAN-13 result to a UPC-A
  60                                 // result if appropriate.
  61                                 if (result->getBarcodeFormat() == BarcodeFormat_EAN_13) {
  62                                         const std::string& text = (result->getText())->getText();
  63                                         if (text[0] == '0') {
  64                                                 Ref<String> resultString(new String(text.substr(1)));
  65                                                 Ref<Result> res(new Result(resultString, result->getRawBytes(), result->getResultPoints(), BarcodeFormat_UPC_A));
  66                                                 return res;
  67                                         }
  68                                 }
  69                                 return result;
  70                         }
  71                         throw ReaderException("No EAN code detected");
  72                 }
  73         }
  74 }