1 /* Determine display width of UTF-16 string. 2 Copyright (C) 2001-2002, 2006-2007, 2009-2021 Free Software Foundation, Inc. 3 Written by Bruno Haible <bruno@clisp.org>, 2002. 4 5 This file is free software. 6 It is dual-licensed under "the GNU LGPLv3+ or the GNU GPLv2+". 7 You can redistribute it and/or modify it under either 8 - the terms of the GNU Lesser General Public License as published 9 by the Free Software Foundation; either version 3, or (at your 10 option) any later version, or 11 - the terms of the GNU General Public License as published by the 12 Free Software Foundation; either version 2, or (at your option) 13 any later version, or 14 - the same dual license "the GNU LGPLv3+ or the GNU GPLv2+". 15 16 This file is distributed in the hope that it will be useful, 17 but WITHOUT ANY WARRANTY; without even the implied warranty of 18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 19 Lesser General Public License and the GNU General Public License 20 for more details. 21 22 You should have received a copy of the GNU Lesser General Public 23 License and of the GNU General Public License along with this 24 program. If not, see <https://www.gnu.org/licenses/>. */ 25 26 #include <config.h> 27 28 /* Specification. */ 29 #include "uniwidth.h" 30 31 #include "unistr.h" 32 33 int 34 u16_width (const uint16_t *s, size_t n, const char *encoding) /* */ 35 { 36 const uint16_t *s_end = s + n; 37 int width = 0; 38 39 while (s < s_end) 40 { 41 ucs4_t uc; 42 int w; 43 44 s += u16_mbtouc_unsafe (&uc, s, s_end - s); 45 46 if (uc == 0) 47 break; /* end of string reached */ 48 49 w = uc_width (uc, encoding); 50 if (w >= 0) /* ignore control characters in the string */ 51 width += w; 52 } 53 54 return width; 55 }