utils/wvwordwrap.cc

   1 /*
   2  * Worldvisions Weaver Software:
   3  *   Copyright (C) 1997-2002 Net Integration Technologies, Inc.
   4  *
   5  * A very simple word wrapping encoder.
   6  */
   7 #include "wvwordwrap.h"
   8
   9 WvWordWrapEncoder::WvWordWrapEncoder(int _maxwidth) :
  10     maxwidth(_maxwidth)
  11 {
  12     line = new char[maxwidth];
  13     _reset();
  14 }
  15
  16
  17 WvWordWrapEncoder::~WvWordWrapEncoder()
  18 {
  19     deletev line;
  20 }
  21
  22
  23 bool WvWordWrapEncoder::_reset()
  24 {
  25     width = 0;
  26     curindex = wordindex = 0;
  27     inword = false;
  28     return true;
  29 }
  30
  31
  32 bool WvWordWrapEncoder::_encode(WvBuf &inbuf, WvBuf &outbuf,
  33     bool flush)
  34 {
  35     while (inbuf.used() != 0)
  36     {
  37         int ch = inbuf.getch();
  38         switch (ch)
  39         {
  40             case '\n':
  41                 if (! inword)
  42                     curindex = 0;
  43                 flushline(outbuf);
  44                 width = 0;
  45                 outbuf.putch('\n');
  46                 break;
  47
  48             case ' ':
  49                 if (inword)
  50                     flushline(outbuf);
  51                 width += 1;
  52                 if (width <= maxwidth)
  53                     line[curindex++] = ch;
  54                 break;
  55
  56             case '\t':
  57                 if (inword)
  58                     flushline(outbuf);
  59                 width = (width + 8) & ~7;
  60                 if (width <= maxwidth)
  61                     line[curindex++] = ch;
  62                 break;
  63
  64             default:
  65                 if (width >= maxwidth)
  66                 {
  67                     if (! inword)
  68                     {
  69                         // discard trailing whitespace
  70                         curindex = wordindex = 0;
  71                         width = 0;
  72                     }
  73                     else if (wordindex == 0)
  74                     {
  75                         // insert hard line break
  76                         flushline(outbuf);
  77                         width = 0;
  78                     }
  79                     else
  80                     {
  81                         // insert soft line break
  82                         curindex -= wordindex;
  83                         memmove(line, line + wordindex, curindex);
  84                         wordindex = 0;
  85                         width = curindex;
  86                     }
  87                     outbuf.putch('\n');
  88                 }
  89                 if (! inword)
  90                 {
  91                     inword = true;
  92                     wordindex = curindex;
  93                 }
  94                 width += 1;
  95                 line[curindex++] = ch;
  96                 break;
  97
  98         }
  99     }
 100     if (flush)
 101         flushline(outbuf);
 102     return true;
 103 }
 104
 105
 106 void WvWordWrapEncoder::flushline(WvBuf &outbuf)
 107 {
 108     outbuf.put(line, curindex);
 109     curindex = wordindex = 0;
 110     inword = false;
 111 }