/* -*- 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 #include #include #include #include #include "e-html-utils.h" static char * check_size (char **buffer, int *buffer_size, char *out, int len) { if (out + len + 1> *buffer + *buffer_size) { int index = out - *buffer; *buffer_size = MAX (index + len + 1, *buffer_size * 2); *buffer = g_realloc (*buffer, *buffer_size); out = *buffer + index; } return out; } /* 1 = non-email-address chars: ()<>@,;:\"[] */ /* 2 = trailing garbage: ,.!?;:>)]}`'-_ */ static int special_chars[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* nul - 0x0f */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 0x10 - 0x1f */ 1, 2, 1, 0, 0, 0, 0, 2, 1, 3, 0, 0, 3, 2, 2, 0, /* sp - / */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 1, 0, 3, 2, /* 0 - ? */ 1, 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, 1, 1, 3, 0, 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, 0, 0, 2, 0, 0 /* p - del */ }; #define is_addr_char(c) (isprint (c) && !(special_chars[c] & 1)) #define is_trailing_garbage(c) (!isprint(c) || (special_chars[c] & 2)) static char * url_extract (const unsigned char **text, gboolean check) { const unsigned char *end = *text, *p; char *out; while (*end && !isspace (*end) && (*end != '"') && (*end < 0x80)) end++; /* Back up if we probably went too far. */ while (end > *text && is_trailing_garbage (*(end - 1))) end--; if (check) { /* Make sure we weren't fooled. */ p = memchr (*text, ':', end - *text); if (!p || end - p < 4) return NULL; } out = g_strndup (*text, end - *text); *text = end; return out; } static char * email_address_extract (const unsigned char **cur, char **out, const unsigned char *linestart) { const unsigned char *start, *end, *dot; char *addr; /* *cur points to the '@'. Look backward for a valid local-part */ for (start = *cur; start - 1 >= linestart && is_addr_char (*(start - 1)); start--) ; if (start == *cur) return NULL; /* Now look forward for a valid domain part */ for (end = *cur + 1, dot = NULL; is_addr_char (*end); end++) { if (*end == '.' && !dot) dot = end; } if (!dot) return NULL; /* Remove trailing garbage */ while (is_trailing_garbage (*(end - 1))) end--; if (dot > end) return NULL; addr = g_strndup (start, end - start); *out -= *cur - start; *cur = end; return addr; } static gboolean is_citation (const unsigned char *c, gboolean saw_citation) { gunichar u; gint i; /* A line that starts with a ">" is a citation, unless it's * just mbox From-mangling... */ if (*c == '>') { const unsigned char *p; if (strncmp (c, ">From ", 6) != 0) return TRUE; /* If the previous line was a citation, then say this * one is too. */ if (saw_citation) return TRUE; /* Same if the next line is */ p = (const unsigned char *)strchr ((const char *)c, '\n'); if (p && *++p == '>') return TRUE; /* Otherwise, it was just an isolated ">From" line. */ return FALSE; } /* Check for "Rupert> " and the like... */ for (i = 0; c && *c && *c != '\n' && i < 10; i ++, c = g_utf8_next_char (c)) { u = g_utf8_get_char (c); if (u == '>') return TRUE; if (!g_unichar_isalnum (u)) return FALSE; } return FALSE; } /** * e_text_to_html_full: * @input: a NUL-terminated input buffer * @flags: some combination of the E_TEXT_TO_HTML_* flags defined * in e-html-utils.h * @color: color for citation highlighting * * 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. * * - E_TEXT_TO_HTML_CONVERT_ADDRESSES: wrap around * strings that look like mail addresses. * * - E_TEXT_TO_HTML_MARK_CITATION: wrap around * citations (lines beginning with "> ", etc). **/ char * e_text_to_html_full (const char *input, unsigned int flags, guint32 color) { const unsigned char *cur, *linestart; char *buffer = NULL; char *out = NULL; int buffer_size = 0, col; gboolean colored = FALSE, saw_citation = FALSE; /* 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;

	for (cur = linestart = input; cur && *cur; cur = g_utf8_next_char (cur)) {
		gunichar u;

		if (flags & E_TEXT_TO_HTML_MARK_CITATION && col == 0) {
			saw_citation = is_citation (cur, saw_citation);
			if (saw_citation) {
				if (!colored) {
					gchar font [25];

					g_snprintf (font, 25, "", color);

					check_size (&buffer, &buffer_size, out, 25);
					out += sprintf (out, "%s", font);
					colored = TRUE;
				}
			} else if (colored) {
				gchar *no_font = "";

				check_size (&buffer, &buffer_size, out, 9);
				out += sprintf (out, "%s", no_font);
				colored = FALSE;
			}

			/* Display mbox-mangled ">From" as "From" */
			if (*cur == '>' && !saw_citation)
				cur++;
		}

		u = g_utf8_get_char (cur);
		if (g_unichar_isalpha (u) &&
		    (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) &&
				   (*(cur + 4) < 0x80) &&
				   g_unichar_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);
			}

			if (!*cur)
				break;
			u = g_utf8_get_char (cur);
		}

		if (u == '@' && (flags & E_TEXT_TO_HTML_CONVERT_ADDRESSES)) {
			char *addr, *dispaddr, *outaddr;

			addr = email_address_extract (&cur, &out, linestart);
			if (addr) {
				dispaddr = e_text_to_html (addr, 0);
				outaddr = g_strdup_printf ("%s",
							   addr, dispaddr);
				out = check_size (&buffer, &buffer_size, out, strlen (outaddr));
				out += sprintf (out, "%s", outaddr);
				col += strlen (addr);
				g_free (addr);
				g_free (dispaddr);
				g_free (outaddr);

				u = g_utf8_get_char (cur);
			}
		}

		if (u == (gunichar)-1) {
			/* Sigh. Someone sent undeclared 8-bit data.
			 * Assume it's iso-8859-1.
			 */
			u = *cur;
		}

		out = check_size (&buffer, &buffer_size, out, 10);

		switch (u) {
		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; linestart = 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, 7); 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 ((u >= 0x20 && u < 0x80) || (u == '\r' || u == '\t')) { /* Default case, just copy. */ *out++ = u; } else { out += g_snprintf(out, 9, "&#%d;", u); } col++; break; } } out = check_size (&buffer, &buffer_size, out, 7); if (flags & E_TEXT_TO_HTML_PRE) strcpy (out, "
"); else *out = '\0'; return buffer; } char * e_text_to_html (const char *input, unsigned int flags) { return e_text_to_html_full (input, flags, 0); }