/* -*- 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 <ctype.h> #include <stdio.h> #include <string.h> #include <glib.h> #include <unicode.h> #include "e-html-utils.h" 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 < 0x80)) 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 < 4) return NULL; } out = g_strndup (*text, end - *text); *text = end; return out; } /* FIXME */ static gboolean is_email_address (const unsigned char *c) { gboolean seen_at = FALSE, seen_postat = FALSE; if (*c == '<') ++c; while (*c && (isalnum ((gint) *c) || *c == '-' || *c == '_' || *c == (seen_at ? '.' : '@'))) { if (seen_at && !seen_postat) { if (*c == '.') return FALSE; seen_postat = TRUE; } if (*c == '@') seen_at = TRUE; ++c; } return seen_at && seen_postat && (isspace ((gint) *c) || *c == '>' || !*c); } static gchar * email_address_extract (const unsigned char **text) { const unsigned char *end = *text; char *out; while (*end && !isspace (*end) && (*end != '>') && (*end < 0x80)) ++end; out = g_strndup (*text, end - *text); if (!is_email_address (out)) { g_free (out); return NULL; } *text = end; return out; } static gboolean is_citation (const unsigned char *c) { unicode_char_t u; gint i; for (i = 0; c && *c && i < 10; i ++, c = unicode_next_utf8 (c)) { unicode_get_utf8 (c, &u); if (u == '>') return TRUE; if (!unicode_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 <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. * * 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 <a href="..."> </a> around * strings that look like URLs. * * - E_TEXT_TO_HTML_CONVERT_ADDRESSES: wrap <a href="mailto:..."> </a> around * strings that look like mail addresses. * * - E_TEXT_TO_HTML_MARK_CITATION: wrap <font color="blue"> </font> around * citations (lines beginning with "> "). **/ char * e_text_to_html_full (const char *input, unsigned int flags, guint32 color) { const unsigned char *cur = input; char *buffer = NULL; char *out = NULL; int buffer_size = 0, col; gboolean colored = 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, "<PRE>\n"); col = 0; for (cur = input; cur && *cur; cur = unicode_next_utf8 (cur)) { unicode_char_t u; unicode_get_utf8 (cur, &u); if (flags & E_TEXT_TO_HTML_MARK_CITATION && col == 0) { if (is_citation (cur)) { if (!colored) { gchar font [25]; g_snprintf (font, 25, "<FONT COLOR=\"#%06x\">", color); check_size (&buffer, &buffer_size, out, 25); out += sprintf (out, "%s", font); colored = TRUE; } } else if (colored) { gchar *no_font = "</FONT>"; check_size (&buffer, &buffer_size, out, 9); out += sprintf (out, "%s", no_font); colored = FALSE; } } if (unicode_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) && unicode_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); col += strlen (tmpurl); g_free (tmpurl); g_free (refurl); g_free (dispurl); } if (!*cur) break; unicode_get_utf8 (cur, &u); } if (unicode_isalpha (u) && (flags & E_TEXT_TO_HTML_CONVERT_ADDRESSES) && is_email_address (cur)) { gchar *addr = NULL, *dispaddr = NULL; addr = email_address_extract (&cur); dispaddr = e_text_to_html (addr, 0); if (addr) { gchar *outaddr = g_strdup_printf ("<a href=\"mailto:%s\">" "<!--+GtkHTML:<DATA class=\"Text\" key=\"email\" value=\"%s\">-->" "%s" "<!--+GtkHTML:<DATA class=\"Text\" clear=\"email\">--> " "</a>", addr, 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); } if (!*cur) break; unicode_get_utf8 (cur, &u); } if (u == (unicode_char_t)-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, "<br>"); 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, 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, "</PRE>"); 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); }