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irssi/src/core/wcwidth-wrapper.c
2019-05-01 22:08:45 +02:00

142 lines
3.4 KiB
C

/*
wcwidth-wrapper.c : irssi
Copyright (C) 2018 dequis
This program 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 program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#define _GNU_SOURCE
#include <wchar.h>
#include "module.h"
#include <irssi/src/core/signals.h>
#include <irssi/src/core/settings.h>
#include <irssi/src/core/utf8.h>
#ifdef HAVE_LIBUTF8PROC
#include <utf8proc.h>
#endif
/* wcwidth=2 since unicode 5.2.0 */
#define UNICODE_SQUARE_HIRAGANA_HOKA 0x1F200
/* wcwidth=2 since unicode 9.0.0 */
#define UNICODE_IRSSI_LOGO 0x1F525
enum {
WCWIDTH_IMPL_OLD,
WCWIDTH_IMPL_SYSTEM
#ifdef HAVE_LIBUTF8PROC
,WCWIDTH_IMPL_JULIA
#endif
};
WCWIDTH_FUNC wcwidth_impl_func = mk_wcwidth;
int i_wcwidth(unichar ucs)
{
return (*wcwidth_impl_func)(ucs);
}
static int system_wcwidth(unichar ucs)
{
int retval = wcwidth((wchar_t) ucs);
if (retval < 0) {
/* Treat all unknown characters as taking one cell. This is
* the reason mk_wcwidth and other outdated implementations
* mostly worked with newer unicode, while glibc's wcwidth
* needs updating to recognize new characters.
*
* Instead of relying on that, we keep the behavior of assuming
* one cell even for glibc's implementation, which is still
* highly accurate and less of a headache overall.
*/
return 1;
}
return retval;
}
#ifdef HAVE_LIBUTF8PROC
/* wrapper because the function signatures are different
* (the parameter is unsigned for us, signed for them) */
static int julia_wcwidth(unichar ucs)
{
return utf8proc_charwidth(ucs);
}
#endif
static void read_settings(void)
{
static int choice = -1;
int newchoice;
newchoice = settings_get_choice("wcwidth_implementation");
if (choice == newchoice) {
return;
}
choice = newchoice;
switch (choice) {
case WCWIDTH_IMPL_OLD:
wcwidth_impl_func = &mk_wcwidth;
break;
case WCWIDTH_IMPL_SYSTEM:
wcwidth_impl_func = &system_wcwidth;
break;
#ifdef HAVE_LIBUTF8PROC
case WCWIDTH_IMPL_JULIA:
wcwidth_impl_func = &julia_wcwidth;
break;
#endif
}
}
void wcwidth_wrapper_init(void)
{
int wcwidth_impl_default = 0;
/* Test against characters that have wcwidth=2
* since unicode 5.2 and 9.0 respectively */
if (system_wcwidth(UNICODE_SQUARE_HIRAGANA_HOKA) == 2 ||
system_wcwidth(UNICODE_IRSSI_LOGO) == 2) {
wcwidth_impl_default = WCWIDTH_IMPL_SYSTEM;
} else {
/* Fall back to our own (which implements 5.0) */
wcwidth_impl_default = WCWIDTH_IMPL_OLD;
}
#ifdef HAVE_LIBUTF8PROC
settings_add_choice("misc", "wcwidth_implementation", wcwidth_impl_default, "old;system;julia");
#else
settings_add_choice("misc", "wcwidth_implementation", wcwidth_impl_default, "old;system");
#endif
read_settings();
signal_add_first("setup changed", (SIGNAL_FUNC) read_settings);
}
void wcwidth_wrapper_deinit(void)
{
signal_remove("setup changed", (SIGNAL_FUNC) read_settings);
}