csharp/MultiFormatReader.cs

   1 /*\r
   2 * Licensed under the Apache License, Version 2.0 (the "License");\r
   3 * you may not use this file except in compliance with the License.\r
   4 * You may obtain a copy of the License at\r
   5 *\r
   6 *      http://www.apache.org/licenses/LICENSE-2.0\r
   7 *\r
   8 * Unless required by applicable law or agreed to in writing, software\r
   9 * distributed under the License is distributed on an "AS IS" BASIS,\r
  10 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
  11 * See the License for the specific language governing permissions and\r
  12 * limitations under the License.\r
  13 */\r
  14 \r
  15 using System;\r
  16 using System.Collections;\r
  17 using com.google.zxing.qrcode;\r
  18 using com.google.zxing.oned;\r
  19 \r
  20 namespace com.google.zxing\r
  21 {\r
  22     public sealed class MultiFormatReader : Reader\r
  23     { \r
  24           private Hashtable hints;\r
  25           private ArrayList readers;\r
  26 \r
  27           /**\r
  28            * This version of decode honors the intent of Reader.decode(MonochromeBitmapSource) in that it\r
  29            * passes null as a hint to the decoders. However, that makes it inefficient to call repeatedly.\r
  30            * Use setHints() followed by decodeWithState() for continuous scan applications.\r
  31            *\r
  32            * @param image The pixel data to decode\r
  33            * @return The contents of the image\r
  34            * @throws ReaderException Any errors which occurred\r
  35            */\r
  36           public Result decode(MonochromeBitmapSource image){\r
  37               try{\r
  38                 setHints(null);\r
  39                 return decodeInternal(image);\r
  40               }\r
  41               catch(Exception e){\r
  42                 throw new ReaderException(e.Message);\r
  43               }           \r
  44           }\r
  45 \r
  46           /**\r
  47            * Decode an image using the hints provided. Does not honor existing state.\r
  48            *\r
  49            * @param image The pixel data to decode\r
  50            * @param hints The hints to use, clearing the previous state.\r
  51            * @return The contents of the image\r
  52            * @throws ReaderException Any errors which occurred\r
  53            */\r
  54           public Result decode(MonochromeBitmapSource image, Hashtable hints){\r
  55               try{\r
  56                  setHints(hints);\r
  57                  return decodeInternal(image);\r
  58               }catch(Exception e){\r
  59                 throw new ReaderException (e.Message);\r
  60               }           \r
  61           }\r
  62 \r
  63           /**\r
  64            * Decode an image using the state set up by calling setHints() previously. Continuous scan\r
  65            * clients will get a <b>large</b> speed increase by using this instead of decode().\r
  66            *\r
  67            * @param image The pixel data to decode\r
  68            * @return The contents of the image\r
  69            * @throws ReaderException Any errors which occurred\r
  70            */\r
  71           public Result decodeWithState(MonochromeBitmapSource image){\r
  72               try{\r
  73                 // Make sure to set up the default state so we don't crash\r
  74                 if (readers == null) {\r
  75                   setHints(null);\r
  76                 }\r
  77                 return decodeInternal(image);\r
  78               }catch(Exception e){\r
  79                 throw new ReaderException(e.Message);\r
  80               }            \r
  81           }\r
  82 \r
  83           /**\r
  84            * This method adds state to the MultiFormatReader. By setting the hints once, subsequent calls\r
  85            * to decodeWithState(image) can reuse the same set of readers without reallocating memory. This\r
  86            * is important for performance in continuous scan clients.\r
  87            *\r
  88            * @param hints The set of hints to use for subsequent calls to decode(image)\r
  89            */\r
  90           public void setHints(Hashtable hints) {\r
  91               this.hints = hints;\r
  92 \r
  93               bool tryHarder = hints != null && hints.ContainsKey(DecodeHintType.TRY_HARDER);\r
  94 \r
  95               ArrayList possibleFormats = hints == null ? null : (ArrayList)hints[(DecodeHintType.POSSIBLE_FORMATS)];\r
  96               readers = new ArrayList();\r
  97               if (possibleFormats != null)\r
  98               {\r
  99                   bool addOneDReader =\r
 100                   possibleFormats.Contains(BarcodeFormat.UPC_A) ||\r
 101                       possibleFormats.Contains(BarcodeFormat.UPC_E) ||\r
 102                       possibleFormats.Contains(BarcodeFormat.EAN_13) ||\r
 103                       possibleFormats.Contains(BarcodeFormat.EAN_8) ||\r
 104                       possibleFormats.Contains(BarcodeFormat.CODE_39) ||\r
 105                       possibleFormats.Contains(BarcodeFormat.CODE_128);\r
 106                   // Put 1D readers upfront in "normal" mode\r
 107 \r
 108                   if (addOneDReader && !tryHarder)\r
 109                   {\r
 110                       readers.Add(new MultiFormatOneDReader(hints));\r
 111                   }\r
 112 \r
 113                   if (possibleFormats.Contains(BarcodeFormat.QR_CODE))\r
 114                   {\r
 115                       readers.Add(new QRCodeReader());\r
 116                   }\r
 117                   // TODO re-enable once Data Matrix is ready\r
 118                   if (possibleFormats.Contains(BarcodeFormat.DATAMATRIX)) {\r
 119                     //readers.Add(new DataMatrixReader());\r
 120                   }\r
 121                   // At end in "try harder" mode\r
 122                   if (addOneDReader && tryHarder)\r
 123                   {\r
 124                       readers.Add(new MultiFormatOneDReader(hints));\r
 125                   }\r
 126               }\r
 127 \r
 128               if (readers.Count == 0)\r
 129               {\r
 130                   if (!tryHarder)\r
 131                   {\r
 132                       //readers.Add(new MultiFormatOneDReader(hints));\r
 133                   }\r
 134                   readers.Add(new QRCodeReader());\r
 135                   // TODO re-enable once Data Matrix is ready\r
 136                   // readers.addElement(new DataMatrixReader());\r
 137                   if (tryHarder)\r
 138                   {\r
 139                       //readers.Add(new MultiFormatOneDReader(hints));\r
 140                   }\r
 141               }\r
 142           }\r
 143 \r
 144           private Result decodeInternal(MonochromeBitmapSource image) {\r
 145               try\r
 146               {\r
 147                   int size = readers.Count;\r
 148                   for (int i = 0; i < size; i++)\r
 149                   {\r
 150                       Reader reader = (Reader)readers[i];\r
 151                       try\r
 152                       {\r
 153                           return reader.decode(image, hints);\r
 154                       }\r
 155                       catch (ReaderException re)\r
 156                       {\r
 157                           // continue\r
 158                       }\r
 159                   }\r
 160 \r
 161                   throw new ReaderException("");\r
 162               }\r
 163               catch (Exception e) {\r
 164                   throw new ReaderException(e.Message);\r
 165               }\r
 166           }\r
 167     \r
 168     \r
 169     }\r
 170 }