Moved here from the mailer, since it's of general use, and the composer

	* e-html-utils.c (e_text_to_html): Moved here from the mailer,
	since it's of general use, and the composer needs it too.

svn path=/trunk/; revision=2662

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, "&lt;");
+			out += 4;
+			break;
+
+		case '>':
+			strcpy (out, "&gt;");
+			out += 4;
+			break;
+
+		case '&':
+			strcpy (out, "&amp;");
+			out += 5;
+			break;
+
+		case '"':
+			strcpy (out, "&quot;");
+			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, "&nbsp;");
+					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;
+}