csharp/oned/UPCEReader.cs

   1 /*\r
   2 * Copyright 2008 ZXing authors\r
   3 *\r
   4 * Licensed under the Apache License, Version 2.0 (the "License");\r
   5 * you may not use this file except in compliance with the License.\r
   6 * You may obtain a copy of the License at\r
   7 *\r
   8 *      http://www.apache.org/licenses/LICENSE-2.0\r
   9 *\r
  10 * Unless required by applicable law or agreed to in writing, software\r
  11 * distributed under the License is distributed on an "AS IS" BASIS,\r
  12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
  13 * See the License for the specific language governing permissions and\r
  14 * limitations under the License.\r
  15 */\r
  16 using System;\r
  17 using BarcodeFormat = com.google.zxing.BarcodeFormat;\r
  18 using ReaderException = com.google.zxing.ReaderException;\r
  19 using BitArray = com.google.zxing.common.BitArray;\r
  20 namespace com.google.zxing.oned\r
  21 {\r
  22         \r
  23         /// <summary> <p>Implements decoding of the UPC-E format.</p>\r
  24         /// <p/>\r
  25         /// <p><a href="http://www.barcodeisland.com/upce.phtml">This</a> is a great reference for\r
  26         /// UPC-E information.</p>\r
  27         /// \r
  28         /// </summary>\r
  29         /// <author>  Sean Owen\r
  30         /// </author>\r
  31         /// <author>www.Redivivus.in (suraj.supekar@redivivus.in) - Ported from ZXING Java Source \r
  32         /// </author>\r
  33         public sealed class UPCEReader:UPCEANReader\r
  34         {\r
  35                 override internal BarcodeFormat BarcodeFormat\r
  36                 {\r
  37                         get\r
  38                         {\r
  39                                 return BarcodeFormat.UPC_E;\r
  40                         }\r
  41                         \r
  42                 }\r
  43                 \r
  44                 /// <summary> The pattern that marks the middle, and end, of a UPC-E pattern.\r
  45                 /// There is no "second half" to a UPC-E barcode.\r
  46                 /// </summary>\r
  47                 //UPGRADE_NOTE: Final was removed from the declaration of 'MIDDLE_END_PATTERN'. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"\r
  48                 private static readonly int[] MIDDLE_END_PATTERN = new int[]{1, 1, 1, 1, 1, 1};\r
  49                 \r
  50                 /// <summary> See {@link #L_AND_G_PATTERNS}; these values similarly represent patterns of\r
  51                 /// even-odd parity encodings of digits that imply both the number system (0 or 1)\r
  52                 /// used, and the check digit.\r
  53                 /// </summary>\r
  54                 //UPGRADE_NOTE: Final was removed from the declaration of 'NUMSYS_AND_CHECK_DIGIT_PATTERNS'. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"\r
  55                 private static readonly int[][] NUMSYS_AND_CHECK_DIGIT_PATTERNS = new int[][]{new int[]{0x38, 0x34, 0x32, 0x31, 0x2C, 0x26, 0x23, 0x2A, 0x29, 0x25}, new int[]{0x07, 0x0B, 0x0D, 0x0E, 0x13, 0x19, 0x1C, 0x15, 0x16, 0x1A}};\r
  56                 \r
  57                 //UPGRADE_NOTE: Final was removed from the declaration of 'decodeMiddleCounters '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"\r
  58                 private int[] decodeMiddleCounters;\r
  59                 \r
  60                 public UPCEReader()\r
  61                 {\r
  62                         decodeMiddleCounters = new int[4];\r
  63                 }\r
  64                 \r
  65                 protected internal override int decodeMiddle(BitArray row, int[] startRange, System.Text.StringBuilder result)\r
  66                 {\r
  67                         int[] counters = decodeMiddleCounters;\r
  68                         counters[0] = 0;\r
  69                         counters[1] = 0;\r
  70                         counters[2] = 0;\r
  71                         counters[3] = 0;\r
  72                         int end = row.Size;\r
  73                         int rowOffset = startRange[1];\r
  74                         \r
  75                         int lgPatternFound = 0;\r
  76                         \r
  77                         for (int x = 0; x < 6 && rowOffset < end; x++)\r
  78                         {\r
  79                                 int bestMatch = decodeDigit(row, counters, rowOffset, L_AND_G_PATTERNS);\r
  80                                 result.Append((char) ('0' + bestMatch % 10));\r
  81                                 for (int i = 0; i < counters.Length; i++)\r
  82                                 {\r
  83                                         rowOffset += counters[i];\r
  84                                 }\r
  85                                 if (bestMatch >= 10)\r
  86                                 {\r
  87                                         lgPatternFound |= 1 << (5 - x);\r
  88                                 }\r
  89                         }\r
  90                         \r
  91                         determineNumSysAndCheckDigit(result, lgPatternFound);\r
  92                         \r
  93                         return rowOffset;\r
  94                 }\r
  95                 \r
  96                 protected internal override int[] decodeEnd(BitArray row, int endStart)\r
  97                 {\r
  98                         return findGuardPattern(row, endStart, true, MIDDLE_END_PATTERN);\r
  99                 }\r
 100                 \r
 101                 protected internal override bool checkChecksum(System.String s)\r
 102                 {\r
 103                         return base.checkChecksum(convertUPCEtoUPCA(s));\r
 104                 }\r
 105                 \r
 106                 private static void  determineNumSysAndCheckDigit(System.Text.StringBuilder resultString, int lgPatternFound)\r
 107                 {\r
 108                         \r
 109                         for (int numSys = 0; numSys <= 1; numSys++)\r
 110                         {\r
 111                                 for (int d = 0; d < 10; d++)\r
 112                                 {\r
 113                                         if (lgPatternFound == NUMSYS_AND_CHECK_DIGIT_PATTERNS[numSys][d])\r
 114                                         {\r
 115                                                 resultString.Insert(0, (char) ('0' + numSys));\r
 116                                                 resultString.Append((char) ('0' + d));\r
 117                                                 return ;\r
 118                                         }\r
 119                                 }\r
 120                         }\r
 121                         throw ReaderException.Instance;\r
 122                 }\r
 123                 \r
 124                 /// <summary> Expands a UPC-E value back into its full, equivalent UPC-A code value.\r
 125                 /// \r
 126                 /// </summary>\r
 127                 /// <param name="upce">UPC-E code as string of digits\r
 128                 /// </param>\r
 129                 /// <returns> equivalent UPC-A code as string of digits\r
 130                 /// </returns>\r
 131                 public static System.String convertUPCEtoUPCA(System.String upce)\r
 132                 {\r
 133                         char[] upceChars = new char[6];\r
 134                         SupportClass.GetCharsFromString(upce, 1, 7, upceChars, 0);\r
 135                         System.Text.StringBuilder result = new System.Text.StringBuilder(12);\r
 136                         result.Append(upce[0]);\r
 137                         char lastChar = upceChars[5];\r
 138                         switch (lastChar)\r
 139                         {\r
 140                                 \r
 141                                 case '0': \r
 142                                 case '1': \r
 143                                 case '2': \r
 144                                         result.Append(upceChars, 0, 2);\r
 145                                         result.Append(lastChar);\r
 146                                         result.Append("0000");\r
 147                                         result.Append(upceChars, 2, 3);\r
 148                                         break;\r
 149                                 \r
 150                                 case '3': \r
 151                                         result.Append(upceChars, 0, 3);\r
 152                                         result.Append("00000");\r
 153                                         result.Append(upceChars, 3, 2);\r
 154                                         break;\r
 155                                 \r
 156                                 case '4': \r
 157                                         result.Append(upceChars, 0, 4);\r
 158                                         result.Append("00000");\r
 159                                         result.Append(upceChars[4]);\r
 160                                         break;\r
 161                                 \r
 162                                 default: \r
 163                                         result.Append(upceChars, 0, 5);\r
 164                                         result.Append("0000");\r
 165                                         result.Append(lastChar);\r
 166                                         break;\r
 167                                 \r
 168                         }\r
 169                         result.Append(upce[7]);\r
 170                         return result.ToString();\r
 171                 }\r
 172         }\r
 173 }