csharp/MultiFormatReader.cs

   1 /*\r
   2 * Copyright 2007 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 MultiFormatOneDReader = com.google.zxing.oned.MultiFormatOneDReader;\r
  18 using PDF417Reader = com.google.zxing.pdf417.PDF417Reader;\r
  19 using QRCodeReader = com.google.zxing.qrcode.QRCodeReader;\r
  20 using DataMatrixReader = com.google.zxing.datamatrix.DataMatrixReader;\r
  21 namespace com.google.zxing\r
  22 {\r
  23         \r
  24         /// <summary> MultiFormatReader is a convenience class and the main entry point into the library for most uses.\r
  25         /// By default it attempts to decode all barcode formats that the library supports. Optionally, you\r
  26         /// can provide a hints object to request different behavior, for example only decoding QR codes.\r
  27         /// \r
  28         /// </summary>\r
  29         /// <author>  Sean Owen\r
  30         /// </author>\r
  31         /// <author>  dswitkin@google.com (Daniel Switkin)\r
  32         /// </author>\r
  33         /// <author>www.Redivivus.in (suraj.supekar@redivivus.in) - Ported from ZXING Java Source \r
  34         /// </author>\r
  35         public sealed class MultiFormatReader : Reader\r
  36         {\r
  37                 /// <summary> This method adds state to the MultiFormatReader. By setting the hints once, subsequent calls\r
  38                 /// to decodeWithState(image) can reuse the same set of readers without reallocating memory. This\r
  39                 /// is important for performance in continuous scan clients.\r
  40                 /// \r
  41                 /// </summary>\r
  42                 /// <param name="hints">The set of hints to use for subsequent calls to decode(image)\r
  43                 /// </param>\r
  44                 public System.Collections.Hashtable Hints\r
  45                 {\r
  46                         set\r
  47                         {\r
  48                                 this.hints = value;\r
  49                                 \r
  50                                 bool tryHarder = value != null && value.ContainsKey(DecodeHintType.TRY_HARDER);\r
  51                                 System.Collections.ArrayList formats = value == null?null:(System.Collections.ArrayList) value[DecodeHintType.POSSIBLE_FORMATS];\r
  52                                 readers = System.Collections.ArrayList.Synchronized(new System.Collections.ArrayList(10));\r
  53                                 if (formats != null)\r
  54                                 {\r
  55                                         bool addOneDReader = formats.Contains(BarcodeFormat.UPC_A) || formats.Contains(BarcodeFormat.UPC_E) || formats.Contains(BarcodeFormat.EAN_13) || formats.Contains(BarcodeFormat.EAN_8) || formats.Contains(BarcodeFormat.CODE_39) || formats.Contains(BarcodeFormat.CODE_128) || formats.Contains(BarcodeFormat.ITF);\r
  56                                         // Put 1D readers upfront in "normal" mode\r
  57                                         if (addOneDReader && !tryHarder)\r
  58                                         {\r
  59                                                 readers.Add(new MultiFormatOneDReader(value));\r
  60                                         }\r
  61                                         if (formats.Contains(BarcodeFormat.QR_CODE))\r
  62                                         {\r
  63                                                 readers.Add(new QRCodeReader());\r
  64                                         }\r
  65                                         if (formats.Contains(BarcodeFormat.DATAMATRIX))\r
  66                                         {\r
  67                                                 readers.Add(new DataMatrixReader());\r
  68                                         }\r
  69                                         if (formats.Contains(BarcodeFormat.PDF417))\r
  70                                         {\r
  71                                                 readers.Add(new PDF417Reader());\r
  72                                         }\r
  73                                         // At end in "try harder" mode\r
  74                                         if (addOneDReader && tryHarder)\r
  75                                         {\r
  76                                                 readers.Add(new MultiFormatOneDReader(value));\r
  77                                         }\r
  78                                 }\r
  79                                 if ((readers.Count == 0))\r
  80                                 {\r
  81                                         if (!tryHarder)\r
  82                                         {\r
  83                                                 readers.Add(new MultiFormatOneDReader(value));\r
  84                                         }\r
  85                                         readers.Add(new QRCodeReader());\r
  86                                         \r
  87                                         // TODO re-enable once Data Matrix is ready\r
  88                                         // readers.addElement(new DataMatrixReader());\r
  89                                         \r
  90                                         // TODO: Enable once PDF417 has passed QA\r
  91                                         //readers.addElement(new PDF417Reader());\r
  92                                         \r
  93                                         if (tryHarder)\r
  94                                         {\r
  95                                                 readers.Add(new MultiFormatOneDReader(value));\r
  96                                         }\r
  97                                 }\r
  98                         }\r
  99                         \r
 100                 }\r
 101                 \r
 102                 private System.Collections.Hashtable hints;\r
 103                 private System.Collections.ArrayList readers;\r
 104                 \r
 105                 /// <summary> This version of decode honors the intent of Reader.decode(BinaryBitmap) in that it\r
 106                 /// passes null as a hint to the decoders. However, that makes it inefficient to call repeatedly.\r
 107                 /// Use setHints() followed by decodeWithState() for continuous scan applications.\r
 108                 /// \r
 109                 /// </summary>\r
 110                 /// <param name="image">The pixel data to decode\r
 111                 /// </param>\r
 112                 /// <returns> The contents of the image\r
 113                 /// </returns>\r
 114                 /// <throws>  ReaderException Any errors which occurred </throws>\r
 115                 public Result decode(BinaryBitmap image)\r
 116                 {\r
 117                         Hints = null;\r
 118                         return decodeInternal(image);\r
 119                 }\r
 120                 \r
 121                 /// <summary> Decode an image using the hints provided. Does not honor existing state.\r
 122                 /// \r
 123                 /// </summary>\r
 124                 /// <param name="image">The pixel data to decode\r
 125                 /// </param>\r
 126                 /// <param name="hints">The hints to use, clearing the previous state.\r
 127                 /// </param>\r
 128                 /// <returns> The contents of the image\r
 129                 /// </returns>\r
 130                 /// <throws>  ReaderException Any errors which occurred </throws>\r
 131                 public Result decode(BinaryBitmap image, System.Collections.Hashtable hints)\r
 132                 {\r
 133                         Hints = hints;\r
 134                         return decodeInternal(image);\r
 135                 }\r
 136                 \r
 137                 /// <summary> Decode an image using the state set up by calling setHints() previously. Continuous scan\r
 138                 /// clients will get a <b>large</b> speed increase by using this instead of decode().\r
 139                 /// \r
 140                 /// </summary>\r
 141                 /// <param name="image">The pixel data to decode\r
 142                 /// </param>\r
 143                 /// <returns> The contents of the image\r
 144                 /// </returns>\r
 145                 /// <throws>  ReaderException Any errors which occurred </throws>\r
 146                 public Result decodeWithState(BinaryBitmap image)\r
 147                 {\r
 148                         // Make sure to set up the default state so we don't crash\r
 149                         if (readers == null)\r
 150                         {\r
 151                                 Hints = null;\r
 152                         }\r
 153                         return decodeInternal(image);\r
 154                 }\r
 155                 \r
 156                 private Result decodeInternal(BinaryBitmap image)\r
 157                 {\r
 158                         int size = readers.Count;\r
 159                         for (int i = 0; i < size; i++)\r
 160                         {\r
 161                                 Reader reader = (Reader) readers[i];\r
 162                                 try\r
 163                                 {\r
 164                                         return reader.decode(image, hints);\r
 165                                 }\r
 166                                 catch (ReaderException re)\r
 167                                 {\r
 168                                         // continue\r
 169                                 }\r
 170                         }\r
 171                         \r
 172                         throw ReaderException.Instance;\r
 173                 }\r
 174         }\r
 175 }