/* -*- 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 * * 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 #include #include #include 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 unsigned char **text, gboolean check) { const unsigned 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
 and 
. * 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
 yourself.
 *
 *   - E_TEXT_TO_HTML_CONVERT_NL: convert "\n" to "
\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. * * If E_TEXT_TO_HTML_CONVERT_NL and E_TEXT_TO_HTML_CONVERT_SPACES * are both defined, then TABs will also be converted to spaces. * * - E_TEXT_TO_HTML_CONVERT_URLS: wrap 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, col; /* 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, "
\n");

	col = 0;
	while (*cur) {
		if (isalpha (*cur) && (flags & E_TEXT_TO_HTML_CONVERT_URLS)) {
			char *tmpurl = NULL, *refurl = NULL, *dispurl = NULL;

			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,
						"%s",
						refurl, dispurl);
				col += strlen (tmpurl);
				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;
		col += end - cur;

		if (!*end)
			break;
		cur = end;

		switch (*cur) {
		case '<':
			strcpy (out, "<");
			out += 4;
			col++;
			break;

		case '>':
			strcpy (out, ">");
			out += 4;
			col++;
			break;

		case '&':
			strcpy (out, "&");
			out += 5;
			col++;
			break;

		case '"':
			strcpy (out, """);
			out += 6;
			col++;
			break;

		case '\n':
			if (flags & E_TEXT_TO_HTML_CONVERT_NL) {
				strcpy (out, "
"); out += 4; } *out++ = *cur; col = 0; break; case '\t': if (flags & (E_TEXT_TO_HTML_CONVERT_SPACES | E_TEXT_TO_HTML_CONVERT_NL)) { do { out = check_size (&buffer, &buffer_size, out, 6); strcpy (out, " "); out += 6; col++; } while (col % 8); break; } /* otherwise, FALL THROUGH */ case ' ': if (flags & E_TEXT_TO_HTML_CONVERT_SPACES) { if (cur == (const unsigned char *)input || *(cur + 1) == ' ' || *(cur + 1) == '\t') { strcpy (out, " "); out += 6; col++; 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); col++; break; } cur++; } out = check_size (&buffer, &buffer_size, out, 7); if (flags & E_TEXT_TO_HTML_PRE) strcpy (out, "
"); else *out = '\0'; return buffer; }