/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* e-html-utils.c
/*
* Copyright (C) 2000 Helix Code, Inc.
* Author: Dan Winship <danw@helixcode.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "e-html-utils.h"
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <glib.h>
static int etth_interesting[] = {
4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 0x00 - 0x0f */
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 0x10 - 0x1f */
1, 2, 1, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, /* sp - / */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 1, 2, 1, 2, /* 0 - ? */
2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* @ - O */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 2, /* P - _ */
2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* ` - o */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 2, /* p - del */
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 0x80 - 0x8f */
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 0x90 - 0x9f */
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 0xa0 - 0xaf */
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 0xb0 - 0xbf */
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 0xc0 - 0xcf */
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 0xd0 - 0xdf */
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, /* 0xe0 - 0xef */
3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3 /* 0xf0 - 0xff */
};
#define ETTH_SPECIAL 1
#define ETTH_PUNCTUATION 2
#define ETTH_ESCAPED 3
#define ETTH_EOF 4
static char *
check_size (char **buffer, int *buffer_size, char *out, int len)
{
if (out + len > *buffer + *buffer_size) {
int index = out - *buffer;
*buffer_size *= 2;
*buffer = g_realloc (*buffer, *buffer_size);
out = *buffer + index;
}
return out;
}
static char *
url_extract (const char **text, gboolean check)
{
const char *end = *text, *p;
char *out;
while (*end && !isspace (*end) && *end != '"')
end++;
/* Back up if we probably went too far. */
while (end > *text && strchr (",.!?;:>", *(end - 1)))
end--;
if (check) {
/* Make sure we weren't fooled. */
p = memchr (*text, ':', end - *text);
if (!p || end - p < 3)
return NULL;
}
out = g_strndup (*text, end - *text);
*text = end;
return out;
}
/**
* e_text_to_html:
* @input: a NUL-terminated input buffer
* @flags: some combination of the E_TEXT_TO_HTML_* flags defined
* in e-html-utils.h
*
* This takes a buffer of text as input and produces a buffer of
* "equivalent" HTML, subject to certain transformation rules.
*
* The set of possible flags is:
*
* - E_TEXT_TO_HTML_PRE: wrap the output HTML in <PRE> and </PRE>.
* Should only be used if @input is the entire buffer to be
* converted. If e_text_to_html is being called with small pieces
* of data, you should wrap the entire result in <PRE> yourself.
*
* - E_TEXT_TO_HTML_CONVERT_NL: convert "\n" to "<BR>\n" on output.
* (should not be used with E_TEXT_TO_HTML_PRE, since that would
* result in double-newlines).
*
* - E_TEXT_TO_HTML_CONVERT_SPACES: convert a block of N spaces
* into N-1 non-breaking spaces and one normal space. A space
* at the start of the buffer is always converted to a
* non-breaking space, regardless of the following character,
* which probably means you don't want to use this flag on
* pieces of data that aren't delimited by at least line breaks.
*
* - E_TEXT_TO_HTML_CONVERT_URLS: wrap <a href="..."> </a> around
* strings that look like URLs.
**/
char *
e_text_to_html (const char *input, unsigned int flags)
{
const unsigned char *cur = input, *end;
char *buffer = NULL;
char *out = NULL;
int buffer_size = 0;
/* Allocate a translation buffer. */
buffer_size = strlen (input) * 2 + 5;
buffer = g_malloc (buffer_size);
out = buffer;
if (flags & E_TEXT_TO_HTML_PRE)
out += sprintf (out, "<PRE>\n");
while (*cur) {
if (isalpha (*cur) && (flags & E_TEXT_TO_HTML_CONVERT_URLS)) {
char *tmpurl = NULL, *refurl, *dispurl;
if (!strncasecmp (cur, "http://", 7) ||
!strncasecmp (cur, "https://", 8) ||
!strncasecmp (cur, "ftp://", 6) ||
!strncasecmp (cur, "nntp://", 7) ||
!strncasecmp (cur, "mailto:", 7) ||
!strncasecmp (cur, "news:", 5)) {
tmpurl = url_extract (&cur, TRUE);
if (tmpurl) {
refurl = e_text_to_html (tmpurl, 0);
dispurl = g_strdup (refurl);
}
} else if (!strncasecmp (cur, "www.", 4) &&
isalnum (*(cur + 4))) {
tmpurl = url_extract (&cur, FALSE);
dispurl = e_text_to_html (tmpurl, 0);
refurl = g_strdup_printf ("http://%s",
dispurl);
}
if (tmpurl) {
out = check_size (&buffer, &buffer_size, out,
strlen (refurl) +
strlen (dispurl) + 15);
out += sprintf (out,
"<a href=\"%s\">%s</a>",
refurl, dispurl);
g_free (tmpurl);
g_free (refurl);
g_free (dispurl);
}
}
/* Skip until we need to care. */
end = cur;
while (!etth_interesting[*end] ||
(etth_interesting[*end] == ETTH_PUNCTUATION &&
!(flags & E_TEXT_TO_HTML_CONVERT_URLS)))
end++;
out = check_size (&buffer, &buffer_size, out,
end - cur + 10);
memcpy (out, cur, end - cur);
out += end - cur;
if (!*end)
break;
cur = end;
switch (*cur) {
case '<':
strcpy (out, "<");
out += 4;
break;
case '>':
strcpy (out, ">");
out += 4;
break;
case '&':
strcpy (out, "&");
out += 5;
break;
case '"':
strcpy (out, """);
out += 6;
break;
case '\n':
*out++ = *cur;
if (flags & E_TEXT_TO_HTML_CONVERT_NL) {
strcpy (out, "<br>");
out += 4;
}
break;
case ' ':
if (flags & E_TEXT_TO_HTML_CONVERT_SPACES) {
if (cur == input || *(cur + 1) == ' ') {
strcpy (out, " ");
out += 6;
break;
}
}
/* otherwise, FALL THROUGH */
default:
if ((*cur >= 0x20 && *cur < 0x80) ||
(*cur == '\r' || *cur == '\t')) {
/* Default case, just copy. */
*out++ = *cur;
} else
out += g_snprintf(out, 9, "&#%d;", *cur);
break;
}
cur++;
}
out = check_size (&buffer, &buffer_size, out, 7);
if (flags & E_TEXT_TO_HTML_PRE)
strcpy (out, "</PRE>");
else
*out = '\0';
return buffer;
}
