src/fcformat.c

   1 /*
   2  * Copyright © 2008 Red Hat, Inc.
   3  *
   4  * Red Hat Author(s): Behdad Esfahbod
   5  *
   6  * Permission to use, copy, modify, distribute, and sell this software and its
   7  * documentation for any purpose is hereby granted without fee, provided that
   8  * the above copyright notice appear in all copies and that both that
   9  * copyright notice and this permission notice appear in supporting
  10  * documentation, and that the name of Keith Packard not be used in
  11  * advertising or publicity pertaining to distribution of the software without
  12  * specific, written prior permission.  Keith Packard makes no
  13  * representations about the suitability of this software for any purpose.  It
  14  * is provided "as is" without express or implied warranty.
  15  *
  16  * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  17  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  18  * EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  19  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  20  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  21  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  22  * PERFORMANCE OF THIS SOFTWARE.
  23  */
  24
  25 #include "fcint.h"
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <stdarg.h>
  29
  30
  31 static void
  32 message (const char *fmt, ...)
  33 {
  34     va_list     args;
  35     va_start (args, fmt);
  36     fprintf (stderr, "Fontconfig: ");
  37     vfprintf (stderr, fmt, args);
  38     fprintf (stderr, "\n");
  39     va_end (args);
  40 }
  41
  42
  43 static FcChar8 *scratch1;
  44 static FcChar8 *scratch2;
  45 static const FcChar8 *format_orig;
  46
  47 static const FcChar8 *
  48 interpret_percent (FcPattern *pat,
  49                    FcStrBuf *buf,
  50                    const FcChar8 *format)
  51 {
  52     int width, before;
  53
  54     /* parse an optional width specifier */
  55     width = strtol (format, (char **) &format, 10);
  56
  57     before = buf->len;
  58
  59     switch (*format) {
  60     case '{':
  61     {
  62         FcChar8 *p;
  63         FcPatternElt *e;
  64
  65         format++; /* skip over '{' */
  66
  67         p = (FcChar8 *) strpbrk ((const char *) format, "}");
  68         if (!p)
  69         {
  70             message ("Pattern format missing closing brace");
  71             break;
  72         }
  73         /* extract the element name */
  74         memcpy (scratch1, format, p - format);
  75         scratch1[p - format] = '\0';
  76
  77         e = FcPatternObjectFindElt (pat, FcObjectFromName ((const char *) scratch1));
  78         if (e)
  79         {
  80             FcValueListPtr l;
  81             l = FcPatternEltValues(e);
  82             FcNameUnparseValueList (buf, l, '\0');
  83         }
  84
  85         p++; /* skip over '}' */
  86         format = p;
  87         break;
  88     }
  89     default:
  90         message ("Pattern format has invalid character after '%%' at %d",
  91                  format - format_orig);
  92         break;
  93     }
  94
  95     /* align to width */
  96     if (!buf->failed)
  97     {
  98         int after, len;
  99
 100         after = buf->len;
 101
 102         len = after - before;
 103
 104         if (len < -width)
 105         {
 106             /* left align */
 107             while (len++ < -width)
 108                 FcStrBufChar (buf, ' ');
 109         }
 110         else if (len < width)
 111         {
 112             /* right align */
 113             while (len++ < width)
 114                 FcStrBufChar (buf, ' ');
 115             len = after - before;
 116             memmove (buf->buf + buf->len - len,
 117                      buf->buf + buf->len - width,
 118                      len);
 119             memset (buf->buf + buf->len - width,
 120                     ' ',
 121                     width - len);
 122         }
 123     }
 124
 125     return format;
 126 }
 127
 128 static char escaped_char(const char ch)
 129 {
 130     switch (ch) {
 131     case 'a':   return '\a';
 132     case 'b':   return '\b';
 133     case 'f':   return '\f';
 134     case 'n':   return '\n';
 135     case 'r':   return '\r';
 136     case 't':   return '\t';
 137     case 'v':   return '\v';
 138     default:    return ch;
 139     }
 140 }
 141
 142 static const FcChar8 *
 143 interpret (FcPattern *pat,
 144            FcStrBuf *buf,
 145            const FcChar8 *format,
 146            FcChar8 term)
 147 {
 148     const FcChar8 *end;
 149
 150     for (end = format; *end && *end != term;)
 151     {
 152         switch (*end)
 153         {
 154         case '\\':
 155             end++; /* skip over '\\' */
 156             FcStrBufChar (buf, escaped_char (*end++));
 157             continue;
 158         case '%':
 159             end++; /* skip over '%' */
 160             if (*end == '%')
 161                 break;
 162             end = interpret_percent (pat, buf, end);
 163             continue;
 164         }
 165         FcStrBufChar (buf, *end);
 166         end++;
 167     }
 168     if (*end != term)
 169         message ("Pattern format ended while looking for '%c'", term);
 170
 171     return end;
 172 }
 173
 174 FcChar8 *
 175 FcPatternFormat (FcPattern *pat, const FcChar8 *format)
 176 {
 177     int len;
 178     FcStrBuf buf;
 179
 180     FcStrBufInit (&buf, 0, 0);
 181     len = strlen ((const char *) format);
 182     scratch1 = malloc (len);
 183     scratch2 = malloc (len);
 184     format_orig = format;
 185
 186     interpret (pat, &buf, format, '\0');
 187
 188     free (scratch1);
 189     free (scratch2);
 190     return FcStrBufDone (&buf);
 191 }
 192
 193 #define __fcformat__
 194 #include "fcaliastail.h"
 195 #undef __fcformat__