src/sig.c

   1 /* quvi
   2  * Copyright (C) 2013  Toni Gundogdu <legatvs@gmail.com>
   3  *
   4  * This file is part of quvi <http://quvi.sourceforge.net/>.
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU Affero General Public License as
   8  * published by the Free Software Foundation, either version 3 of the
   9  * License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Affero General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Affero General Public
  17  * License along with this program.  If not, see
  18  * <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "config.h"
  22
  23 #include <sys/ioctl.h>
  24 #include <glib/gstdio.h>
  25
  26 #include "sig.h"
  27
  28 static volatile sig_atomic_t recv_sigwinch = 0;
  29 static gsize max_width = 0;
  30
  31 static void _sigwinch(int signo)
  32 {
  33   recv_sigwinch = 1;
  34 }
  35
  36 void sigwinch_setup(struct sigaction *san, struct sigaction *sao)
  37 {
  38   san->sa_handler = _sigwinch;
  39   sigemptyset(&san->sa_mask);
  40   san->sa_flags = 0;
  41
  42   sigaction(SIGWINCH, NULL, sao);
  43
  44   if (sao->sa_handler != SIG_IGN)
  45     sigaction(SIGWINCH, san, NULL);
  46 }
  47
  48 void sigwinch_reset(const struct sigaction *sao)
  49 {
  50   if (sao->sa_handler != SIG_IGN)
  51     sigaction(SIGWINCH, sao, NULL);
  52 }
  53
  54 static gsize _get_term_width()
  55 {
  56   struct winsize w;
  57   if (ioctl(fileno(stderr), TIOCGWINSZ, &w) <0)
  58     return (0);
  59   return (w.ws_col);
  60 }
  61
  62 gsize sigwinch_term_spaceleft(const gsize len)
  63 {
  64   static const gsize default_term_width = 80;
  65   if (max_width ==0 || recv_sigwinch ==1)
  66     {
  67       max_width = _get_term_width();
  68       if (max_width ==0)
  69         max_width = default_term_width;
  70     }
  71   return (max_width - len -1);
  72 }
  73
  74 /* vim: set ts=2 sw=2 tw=72 expandtab: */