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