err.no Git - sope/blob - Recycler/iCalSaxDriver/unicode.h

   1 /*
   2   Copyright (C) 2000-2003 SKYRIX Software AG
   3
   4   This file is part of OGo
   5
   6   OGo is free software; you can redistribute it and/or modify it under
   7   the terms of the GNU Lesser General Public License as published by the
   8   Free Software Foundation; either version 2, or (at your option) any
   9   later version.
  10
  11   OGo is distributed in the hope that it will be useful, but WITHOUT ANY
  12   WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  14   License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public
  17   License along with OGo; see the file COPYING.  If not, write to the
  18   Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  19   02111-1307, USA.
  20 */
  21 /* Unicode support */
  22
  23 typedef unsigned long   UCS4;
  24 typedef unsigned short  UCS2;
  25 typedef unsigned short  UTF16;
  26 typedef unsigned char   UTF8;
  27 #define unichar UTF16
  28
  29 static const int halfShift             = 10;
  30 static const UCS4 halfBase             = 0x0010000UL;
  31 static const UCS4 halfMask             = 0x3FFUL;
  32 static const UCS4 kSurrogateHighStart  = 0xD800UL;
  33 static const UCS4 kSurrogateHighEnd    = 0xDBFFUL;
  34 static const UCS4 kSurrogateLowStart   = 0xDC00UL;
  35 static const UCS4 kSurrogateLowEnd     = 0xDFFFUL;
  36
  37 static const UCS4 kReplacementCharacter = 0x0000FFFDUL;
  38 static const UCS4 kMaximumUCS2          = 0x0000FFFFUL;
  39 static const UCS4 kMaximumUTF16         = 0x0010FFFFUL;
  40 static const UCS4 kMaximumUCS4          = 0x7FFFFFFFUL;
  41
  42 static UCS4 offsetsFromUTF8[6] = {
  43   0x00000000UL, 0x00003080UL, 0x000E2080UL,
  44   0x03C82080UL, 0xFA082080UL, 0x82082080UL
  45 };
  46 static char bytesFromUTF8[256] = {
  47   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  48   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  49   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  50   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  51   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  52   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  53   1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
  54   2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5
  55 };
  56
  57 static int
  58 _UTF8ToUTF16(unsigned char **sourceStart, unsigned char *sourceEnd,
  59              unichar **targetStart, const unichar *targetEnd)
  60 {
  61   int            result = 0;
  62   register UTF8  *source = *sourceStart;
  63   register UTF16 *target = *targetStart;
  64
  65   while (source < sourceEnd) {
  66     register UCS4 ch = 0;
  67     register unsigned short extraBytesToWrite = bytesFromUTF8[*source];
  68
  69     if (source + extraBytesToWrite > sourceEnd) {
  70       result = 1; break;
  71     };
  72     switch(extraBytesToWrite) { /* note: code falls through cases! */
  73       case 5:   ch += *source++; ch <<= 6;
  74       case 4:   ch += *source++; ch <<= 6;
  75       case 3:   ch += *source++; ch <<= 6;
  76       case 2:   ch += *source++; ch <<= 6;
  77       case 1:   ch += *source++; ch <<= 6;
  78       case 0:   ch += *source++;
  79     };
  80     ch -= offsetsFromUTF8[extraBytesToWrite];
  81
  82     if (target >= targetEnd) {
  83       result = 2; break;
  84     };
  85     if (ch <= kMaximumUCS2) {
  86       *target++ = ch;
  87     } else if (ch > kMaximumUTF16) {
  88       *target++ = kReplacementCharacter;
  89     } else {
  90       if (target + 1 >= targetEnd) {
  91         result = 2; break;
  92       };
  93       ch -= halfBase;
  94       *target++ = (ch >> halfShift) + kSurrogateHighStart;
  95       *target++ = (ch & halfMask) + kSurrogateLowStart;
  96     };
  97   };
  98   *sourceStart = source;
  99   *targetStart = target;
 100   return result;
 101 }