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Diffstat (limited to 'e-util/e-html-utils.c')
| -rw-r--r-- | e-util/e-html-utils.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/e-util/e-html-utils.c b/e-util/e-html-utils.c new file mode 100644 index 0000000000..8f872421d7 --- /dev/null +++ b/e-util/e-html-utils.c @@ -0,0 +1,247 @@ +/* -*- 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; +} |