/* Determine the number of screen columns needed for a character.
   Copyright (C) 2006-2007, 2010-2016 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or
   modify it under the terms of either:

     * the GNU Lesser General Public License as published by the Free
       Software Foundation; either version 3 of the License, or (at your
       option) any later version.

   or

     * 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.

   or both in parallel, as here.
   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, see <http://www.gnu.org/licenses/>.  */

#include <config.h>

/* Specification.  */
#include <wchar.h>

/* Get iswprint.  */
#include <wctype.h>

#include "localcharset.h"
#include "streq.h"
#include "uniwidth.h"

int
wcwidth (wchar_t wc)
#undef wcwidth
{
  /* In UTF-8 locales, use a Unicode aware width function.  */
  const char *encoding = locale_charset ();
  if (STREQ_OPT (encoding, "UTF-8", 'U', 'T', 'F', '-', '8', 0, 0, 0 ,0))
    {
      /* We assume that in a UTF-8 locale, a wide character is the same as a
         Unicode character.  */
      return uc_width (wc, encoding);
    }
  else
    {
      /* Otherwise, fall back to the system's wcwidth function.  */
#if HAVE_WCWIDTH
      return wcwidth (wc);
#else
      return wc == 0 ? 0 : iswprint (wc) ? 1 : -1;
#endif
    }
}