class/I18N/CJK/JISConvert.cs

   1 /*
   2  * JISConvert.cs - Implementation of the "System.Text.JISConvert" class.
   3  *
   4  * Copyright (c) 2002  Southern Storm Software, Pty Ltd
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining
   7  * a copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 namespace I18N.CJK
  26 {
  27
  28 using System;
  29
  30 // This class assists other encoding classes in converting back
  31 // and forth between JIS character sets and Unicode.  It uses
  32 // several large tables to do this, some of which are stored in
  33 // the resource section of the assembly for efficient access.
  34
  35 internal unsafe sealed class JISConvert
  36 {
  37         // Table identifiers.
  38         private const int JISX0208_To_Unicode = 1;
  39         private const int JISX0212_To_Unicode = 2;
  40         private const int CJK_To_JIS          = 3;
  41         private const int Greek_To_JIS        = 4;
  42         private const int Extra_To_JIS        = 5;
  43
  44         // Public access to the conversion tables.
  45 #if __PNET__
  46         public byte *jisx0208ToUnicode;
  47         public byte *jisx0212ToUnicode;
  48         public byte *cjkToJis;
  49         public byte *greekToJis;
  50         public byte *extraToJis;
  51 #else
  52         public byte[] jisx0208ToUnicode;
  53         public byte[] jisx0212ToUnicode;
  54         public byte[] cjkToJis;
  55         public byte[] greekToJis;
  56         public byte[] extraToJis;
  57 #endif
  58
  59         // Constructor.
  60         private JISConvert()
  61                         {
  62                                 // Load the conversion tables.
  63                                 CodeTable table = new CodeTable("jis.table");
  64                                 jisx0208ToUnicode = table.GetSection(JISX0208_To_Unicode);
  65                                 jisx0212ToUnicode = table.GetSection(JISX0212_To_Unicode);
  66                                 cjkToJis = table.GetSection(CJK_To_JIS);
  67                                 greekToJis = table.GetSection(Greek_To_JIS);
  68                                 extraToJis = table.GetSection(Extra_To_JIS);
  69                                 table.Dispose();
  70                         }
  71
  72         // The one and only JIS conversion object in the system.
  73         private static JISConvert convert;
  74         static readonly object lockobj = new object ();
  75         // Get the primary JIS conversion object.
  76         public static JISConvert Convert
  77                         {
  78                                 get
  79                                 {
  80                                         lock(lockobj)
  81                                         {
  82                                                 if(convert != null)
  83                                                 {
  84                                                         return convert;
  85                                                 }
  86                                                 else
  87                                                 {
  88                                                         convert = new JISConvert();
  89                                                         return convert;
  90                                                 }
  91                                         }
  92                                 }
  93                         }
  94
  95 }; // class JISConvert
  96
  97 }; // namespace I18N.CJK