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Commit	Line	Data
	1	/*
	2	* This file is part of DisOrder.
	3	* Copyright (C) 2004, 2005, 2007, 2008 Richard Kettlewell
	4	*
	5	* This program is free software: you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License as published by
	7	* the Free Software Foundation, either version 3 of the License, or
	8	* (at your option) any later version.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	17	*/
	18	/** @file lib/charset.c @brief Character set conversion */
	19
	20	#include "common.h"
	21
	22	#include <iconv.h>
	23	#include <errno.h>
	24	#include <langinfo.h>
	25
	26	#include "mem.h"
	27	#include "log.h"
	28	#include "charset.h"
	29	#include "configuration.h"
	30	#include "vector.h"
	31	#include "unicode.h"
	32
	33	/** @brief Low-level converstion routine
	34	* @param from Source encoding
	35	* @param to Destination encoding
	36	* @param ptr First byte to convert
	37	* @param n Number of bytes to convert
	38	* @return Converted text, 0-terminated; or NULL on error.
	39	*/
	40	static void convert(const char from, const char *to,
	41	const void *ptr, size_t n) {
	42	iconv_t i;
	43	size_t len;
	44	char buf = 0, s, *d;
	45	size_t bufsize = 0, sl, dl;
	46
	47	if((i = iconv_open(to, from)) == (iconv_t)-1)
	48	fatal(errno, "error calling iconv_open");
	49	do {
	50	bufsize = bufsize ? 2 * bufsize : 32;
	51	buf = xrealloc_noptr(buf, bufsize);
	52	iconv(i, 0, 0, 0, 0);
	53	s = (char *)ptr;
	54	sl = n;
	55	d = buf;
	56	dl = bufsize;
	57	/* (void ) to work around FreeBSD's nonstandard iconv prototype /
	58	len = iconv(i, (void *)&s, &sl, &d, &dl);
	59	} while(len == (size_t)-1 && errno == E2BIG);
	60	iconv_close(i);
	61	if(len == (size_t)-1) {
	62	error(errno, "error converting from %s to %s", from, to);
	63	return 0;
	64	}
	65	return buf;
	66	}
	67
	68	/** @brief Convert from the local multibyte encoding to UTF-8 */
	69	char mb2utf8(const char mb) {
	70	return convert(nl_langinfo(CODESET), "UTF-8", mb, strlen(mb) + 1);
	71	}
	72
	73	/** @brief Convert from UTF-8 to the local multibyte encoding */
	74	char utf82mb(const char utf8) {
	75	return convert("UTF-8", nl_langinfo(CODESET), utf8, strlen(utf8) + 1);
	76	}
	77
	78	/** @brief Convert from encoding @p from to UTF-8 */
	79	char any2utf8(const char from, const char *any) {
	80	return convert(from, "UTF-8", any, strlen(any) + 1);
	81	}
	82
	83	/** @brief Convert from encoding @p from to the local multibyte encoding */
	84	char any2mb(const char from, const char *any) {
	85	if(from) return convert(from, nl_langinfo(CODESET), any, strlen(any) + 1);
	86	else return xstrdup(any);
	87	}
	88
	89	/** @brief Convert from encoding @p from to encoding @p to */
	90	char any2any(const char from,
	91	const char *to,
	92	const char *any) {
	93	if(from \|\| to) return convert(from, to, any, strlen(any) + 1);
	94	else return xstrdup(any);
	95	}
	96
	97	/** @brief Truncate a string for display purposes
	98	* @param s Pointer to UTF-8 string
	99	* @param max Maximum number of columns
	100	* @return @p or truncated string (never NULL)
	101	*
	102	* Returns a string that is no longer than @p max graphemes long and is either
	103	* (canonically) equal to @p s or is a truncated form of it with an ellipsis
	104	* appended.
	105	*
	106	* We don't take display width into account (tricky for HTML!) and we don't
	107	* attempt to implement the Bidi algorithm. If you have track names for which
	108	* either of these matter in practice then get in touch.
	109	*/
	110	const char truncate_for_display(const char s, long max) {
	111	uint32_t *s32;
	112	size_t l32, cut;
	113	utf32_iterator it;
	114	long graphemes;
	115
	116	/* Convert to UTF-32 for processing */
	117	if(!(s32 = utf8_to_utf32(s, strlen(s), &l32)))
	118	return 0;
	119	it = utf32_iterator_new(s32, l32);
	120	cut = l32;
	121	graphemes = 0; /* # of graphemes left of it */
	122	while(graphemes <= max && utf32_iterator_where(it) < l32) {
	123	if(graphemes == max - 1)
	124	cut = utf32_iterator_where(it);
	125	utf32_iterator_advance(it, 1);
	126	if(utf32_iterator_grapheme_boundary(it))
	127	++graphemes;
	128	}
	129	if(graphemes > max) { /* we need to cut */
	130	s32[cut] = 0x2026; /* HORIZONTAL ELLIPSIS */
	131	l32 = cut + 1;
	132	s = utf32_to_utf8(s32, l32, 0);
	133	}
	134	xfree(s32);
	135	return s;
	136	}
	137
	138	/*
	139	Local Variables:
	140	c-basic-offset:2
	141	comment-column:40
	142	fill-column:79
	143	indent-tabs-mode:nil
	144	End:
	145	*/