mcs/class/I18N/Common/ByteEncoding.cs

   1 /*
   2  * ByteEncoding.cs - Implementation of the "I18N.Common.ByteEncoding" 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.Common
  26 {
  27
  28 using System;
  29 using System.Text;
  30
  31 // This class provides an abstract base for encodings that use a single
  32 // byte per character.  The bulk of the work is done in this class, with
  33 // subclasses providing implementations of the "ToBytes" methods to perform
  34 // the char->byte conversion.
  35
  36 public abstract class ByteEncoding : Encoding
  37 {
  38         // Internal state.
  39         protected char[] toChars;
  40         protected String encodingName;
  41         protected String bodyName;
  42         protected String headerName;
  43         protected String webName;
  44         protected bool isBrowserDisplay;
  45         protected bool isBrowserSave;
  46         protected bool isMailNewsDisplay;
  47         protected bool isMailNewsSave;
  48         protected int windowsCodePage;
  49
  50         // Constructor.
  51         protected ByteEncoding(int codePage, char[] toChars,
  52                                                    String encodingName, String bodyName,
  53                                                    String headerName, String webName,
  54                                                    bool isBrowserDisplay, bool isBrowserSave,
  55                                                    bool isMailNewsDisplay, bool isMailNewsSave,
  56                                                    int windowsCodePage)
  57                         : base(codePage)
  58                         {
  59                                 this.toChars = toChars;
  60                                 this.encodingName = encodingName;
  61                                 this.bodyName = bodyName;
  62                                 this.headerName = headerName;
  63                                 this.webName = webName;
  64                                 this.isBrowserDisplay = isBrowserDisplay;
  65                                 this.isBrowserSave = isBrowserSave;
  66                                 this.isMailNewsDisplay = isMailNewsDisplay;
  67                                 this.isMailNewsSave = isMailNewsSave;
  68                                 this.windowsCodePage = windowsCodePage;
  69                         }
  70
  71         // Get the number of bytes needed to encode a character buffer.
  72         public override int GetByteCount(char[] chars, int index, int count)
  73                         {
  74                                 if(chars == null)
  75                                 {
  76                                         throw new ArgumentNullException("chars");
  77                                 }
  78                                 if(index < 0 || index > chars.Length)
  79                                 {
  80                                         throw new ArgumentOutOfRangeException
  81                                                 ("index", Strings.GetString("ArgRange_Array"));
  82                                 }
  83                                 if(count < 0 || count > (chars.Length - index))
  84                                 {
  85                                         throw new ArgumentOutOfRangeException
  86                                                 ("count", Strings.GetString("ArgRange_Array"));
  87                                 }
  88                                 return count;
  89                         }
  90
  91         // Convenience wrappers for "GetByteCount".
  92         public override int GetByteCount(String s)
  93                         {
  94                                 if(s == null)
  95                                 {
  96                                         throw new ArgumentNullException("s");
  97                                 }
  98                                 return s.Length;
  99                         }
 100
 101         // Convert an array of characters into a byte buffer,
 102         // once the parameters have been validated.
 103         protected abstract void ToBytes(char[] chars, int charIndex, int charCount,
 104                                                                         byte[] bytes, int byteIndex);
 105
 106         // Convert a string into a byte buffer, once the parameters
 107         // have been validated.
 108         protected abstract void ToBytes(String s, int charIndex, int charCount,
 109                                                                         byte[] bytes, int byteIndex);
 110
 111         // Get the bytes that result from encoding a character buffer.
 112         public override int GetBytes(char[] chars, int charIndex, int charCount,
 113                                                                  byte[] bytes, int byteIndex)
 114                         {
 115                                 if(chars == null)
 116                                 {
 117                                         throw new ArgumentNullException("chars");
 118                                 }
 119                                 if(bytes == null)
 120                                 {
 121                                         throw new ArgumentNullException("bytes");
 122                                 }
 123                                 if(charIndex < 0 || charIndex > chars.Length)
 124                                 {
 125                                         throw new ArgumentOutOfRangeException
 126                                                 ("charIndex", Strings.GetString("ArgRange_Array"));
 127                                 }
 128                                 if(charCount < 0 || charCount > (chars.Length - charIndex))
 129                                 {
 130                                         throw new ArgumentOutOfRangeException
 131                                                 ("charCount", Strings.GetString("ArgRange_Array"));
 132                                 }
 133                                 if(byteIndex < 0 || byteIndex > bytes.Length)
 134                                 {
 135                                         throw new ArgumentOutOfRangeException
 136                                                 ("byteIndex", Strings.GetString("ArgRange_Array"));
 137                                 }
 138                                 if((bytes.Length - byteIndex) < charCount)
 139                                 {
 140                                         throw new ArgumentException
 141                                                 (Strings.GetString("Arg_InsufficientSpace"));
 142                                 }
 143                                 ToBytes(chars, charIndex, charCount, bytes, byteIndex);
 144                                 return charCount;
 145                         }
 146
 147         // Convenience wrappers for "GetBytes".
 148         public override int GetBytes(String s, int charIndex, int charCount,
 149                                                                  byte[] bytes, int byteIndex)
 150                         {
 151                                 if(s == null)
 152                                 {
 153                                         throw new ArgumentNullException("s");
 154                                 }
 155                                 if(bytes == null)
 156                                 {
 157                                         throw new ArgumentNullException("bytes");
 158                                 }
 159                                 if(charIndex < 0 || charIndex > s.Length)
 160                                 {
 161                                         throw new ArgumentOutOfRangeException
 162                                                 ("charIndex",
 163                                                  Strings.GetString("ArgRange_StringIndex"));
 164                                 }
 165                                 if(charCount < 0 || charCount > (s.Length - charIndex))
 166                                 {
 167                                         throw new ArgumentOutOfRangeException
 168                                                 ("charCount",
 169                                                  Strings.GetString("ArgRange_StringRange"));
 170                                 }
 171                                 if(byteIndex < 0 || byteIndex > bytes.Length)
 172                                 {
 173                                         throw new ArgumentOutOfRangeException
 174                                                 ("byteIndex", Strings.GetString("ArgRange_Array"));
 175                                 }
 176                                 if((bytes.Length - byteIndex) < charCount)
 177                                 {
 178                                         throw new ArgumentException
 179                                                 (Strings.GetString("Arg_InsufficientSpace"));
 180                                 }
 181                                 ToBytes(s, charIndex, charCount, bytes, byteIndex);
 182                                 return charCount;
 183                         }
 184
 185         // Get the number of characters needed to decode a byte buffer.
 186         public override int GetCharCount(byte[] bytes, int index, int count)
 187                         {
 188                                 if(bytes == null)
 189                                 {
 190                                         throw new ArgumentNullException("bytes");
 191                                 }
 192                                 if(index < 0 || index > bytes.Length)
 193                                 {
 194                                         throw new ArgumentOutOfRangeException
 195                                                 ("index", Strings.GetString("ArgRange_Array"));
 196                                 }
 197                                 if(count < 0 || count > (bytes.Length - index))
 198                                 {
 199                                         throw new ArgumentOutOfRangeException
 200                                                 ("count", Strings.GetString("ArgRange_Array"));
 201                                 }
 202                                 return count;
 203                         }
 204
 205         // Get the characters that result from decoding a byte buffer.
 206         public override int GetChars(byte[] bytes, int byteIndex, int byteCount,
 207                                                                  char[] chars, int charIndex)
 208                         {
 209                                 if(bytes == null)
 210                                 {
 211                                         throw new ArgumentNullException("bytes");
 212                                 }
 213                                 if(chars == null)
 214                                 {
 215                                         throw new ArgumentNullException("chars");
 216                                 }
 217                                 if(byteIndex < 0 || byteIndex > bytes.Length)
 218                                 {
 219                                         throw new ArgumentOutOfRangeException
 220                                                 ("byteIndex", Strings.GetString("ArgRange_Array"));
 221                                 }
 222                                 if(byteCount < 0 || byteCount > (bytes.Length - byteIndex))
 223                                 {
 224                                         throw new ArgumentOutOfRangeException
 225                                                 ("byteCount", Strings.GetString("ArgRange_Array"));
 226                                 }
 227                                 if(charIndex < 0 || charIndex > chars.Length)
 228                                 {
 229                                         throw new ArgumentOutOfRangeException
 230                                                 ("charIndex", Strings.GetString("ArgRange_Array"));
 231                                 }
 232                                 if((chars.Length - charIndex) < byteCount)
 233                                 {
 234                                         throw new ArgumentException
 235                                                 (Strings.GetString("Arg_InsufficientSpace"));
 236                                 }
 237                                 int count = byteCount;
 238                                 char[] cvt = toChars;
 239                                 while(count-- > 0)
 240                                 {
 241                                         chars[charIndex++] = cvt[(int)(bytes[byteIndex++])];
 242                                 }
 243                                 return byteCount;
 244                         }
 245
 246         // Get the maximum number of bytes needed to encode a
 247         // specified number of characters.
 248         public override int GetMaxByteCount(int charCount)
 249                         {
 250                                 if(charCount < 0)
 251                                 {
 252                                         throw new ArgumentOutOfRangeException
 253                                                 ("charCount",
 254                                                  Strings.GetString("ArgRange_NonNegative"));
 255                                 }
 256                                 return charCount;
 257                         }
 258
 259         // Get the maximum number of characters needed to decode a
 260         // specified number of bytes.
 261         public override int GetMaxCharCount(int byteCount)
 262                         {
 263                                 if(byteCount < 0)
 264                                 {
 265                                         throw new ArgumentOutOfRangeException
 266                                                 ("byteCount",
 267                                                  Strings.GetString("ArgRange_NonNegative"));
 268                                 }
 269                                 return byteCount;
 270                         }
 271
 272         // Decode a buffer of bytes into a string.
 273         public override String GetString(byte[] bytes, int index, int count)
 274                         {
 275                                 if(bytes == null)
 276                                 {
 277                                         throw new ArgumentNullException("bytes");
 278                                 }
 279                                 if(index < 0 || index > bytes.Length)
 280                                 {
 281                                         throw new ArgumentOutOfRangeException
 282                                                 ("index", Strings.GetString("ArgRange_Array"));
 283                                 }
 284                                 if(count < 0 || count > (bytes.Length - index))
 285                                 {
 286                                         throw new ArgumentOutOfRangeException
 287                                                 ("count", Strings.GetString("ArgRange_Array"));
 288                                 }
 289                                 StringBuilder s = new StringBuilder();
 290                                 char[] cvt = toChars;
 291                                 while(count-- > 0)
 292                                 {
 293                                         s.Append(cvt[(int)(bytes[index++])]);
 294                                 }
 295                                 return s.ToString();
 296                         }
 297         public override String GetString(byte[] bytes)
 298                         {
 299                                 if(bytes == null)
 300                                 {
 301                                         throw new ArgumentNullException("bytes");
 302                                 }
 303                                 int count = bytes.Length;
 304                                 int posn = 0;
 305                                 StringBuilder s = new StringBuilder();
 306                                 char[] cvt = toChars;
 307                                 while(count-- > 0)
 308                                 {
 309                                         s.Append(cvt[(int)(bytes[posn++])]);
 310                                 }
 311                                 return s.ToString();
 312                         }
 313
 314 #if !ECMA_COMPAT
 315
 316         // Get the mail body name for this encoding.
 317         public override String BodyName
 318                         {
 319                                 get
 320                                 {
 321                                         return bodyName;
 322                                 }
 323                         }
 324
 325         // Get the human-readable name for this encoding.
 326         public override String EncodingName
 327                         {
 328                                 get
 329                                 {
 330                                         return encodingName;
 331                                 }
 332                         }
 333
 334         // Get the mail agent header name for this encoding.
 335         public override String HeaderName
 336                         {
 337                                 get
 338                                 {
 339                                         return headerName;
 340                                 }
 341                         }
 342
 343         // Determine if this encoding can be displayed in a Web browser.
 344         public override bool IsBrowserDisplay
 345                         {
 346                                 get
 347                                 {
 348                                         return isBrowserDisplay;
 349                                 }
 350                         }
 351
 352         // Determine if this encoding can be saved from a Web browser.
 353         public override bool IsBrowserSave
 354                         {
 355                                 get
 356                                 {
 357                                         return isBrowserSave;
 358                                 }
 359                         }
 360
 361         // Determine if this encoding can be displayed in a mail/news agent.
 362         public override bool IsMailNewsDisplay
 363                         {
 364                                 get
 365                                 {
 366                                         return isMailNewsDisplay;
 367                                 }
 368                         }
 369
 370         // Determine if this encoding can be saved from a mail/news agent.
 371         public override bool IsMailNewsSave
 372                         {
 373                                 get
 374                                 {
 375                                         return isMailNewsSave;
 376                                 }
 377                         }
 378
 379         // Get the IANA-preferred Web name for this encoding.
 380         public override String WebName
 381                         {
 382                                 get
 383                                 {
 384                                         return webName;
 385                                 }
 386                         }
 387
 388         // Get the Windows code page represented by this object.
 389         public override int WindowsCodePage
 390                         {
 391                                 get
 392                                 {
 393                                         return windowsCodePage;
 394                                 }
 395                         }
 396
 397 #endif // !ECMA_COMPAT
 398
 399 }; // class ByteEncoding
 400
 401 }; // namespace I18N.Encoding