term_tab.c

   1 /* $Id: term_tab.c,v 1.7 2021/10/04 18:56:31 schwarze Exp $ */
   2 /*
   3  * Copyright (c) 2017, 2021 Ingo Schwarze <schwarze@openbsd.org>
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17 #include "config.h"
  18
  19 #include <sys/types.h>
  20
  21 #include <stddef.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 #include "mandoc_aux.h"
  26 #include "out.h"
  27 #include "term.h"
  28
  29 struct tablist {
  30         size_t  *t;     /* Allocated array of tab positions. */
  31         size_t   s;     /* Allocated number of positions. */
  32         size_t   n;     /* Currently used number of positions. */
  33 };
  34
  35 static struct {
  36         struct tablist   a;     /* All tab positions for lookup. */
  37         struct tablist   p;     /* Periodic tab positions to add. */
  38         struct tablist  *r;     /* Tablist currently being recorded. */
  39         size_t           d;     /* Default tab width in units of n. */
  40 } tabs;
  41
  42
  43 void
  44 term_tab_set(const struct termp *p, const char *arg)
  45 {
  46         struct roffsu    su;
  47         struct tablist  *tl;
  48         size_t           pos;
  49         int              add;
  50
  51         /* Special arguments: clear all tabs or switch lists. */
  52
  53         if (arg == NULL) {
  54                 tabs.a.n = tabs.p.n = 0;
  55                 tabs.r = &tabs.a;
  56                 if (tabs.d == 0) {
  57                         a2roffsu(".8i", &su, SCALE_IN);
  58                         tabs.d = term_hen(p, &su);
  59                 }
  60                 return;
  61         }
  62         if (arg[0] == 'T' && arg[1] == '\0') {
  63                 tabs.r = &tabs.p;
  64                 return;
  65         }
  66
  67         /* Parse the sign, the number, and the unit. */
  68
  69         if (*arg == '+') {
  70                 add = 1;
  71                 arg++;
  72         } else
  73                 add = 0;
  74         if (a2roffsu(arg, &su, SCALE_EM) == NULL)
  75                 return;
  76
  77         /* Select the list, and extend it if it is full. */
  78
  79         tl = tabs.r;
  80         if (tl->n >= tl->s) {
  81                 tl->s += 8;
  82                 tl->t = mandoc_reallocarray(tl->t, tl->s, sizeof(*tl->t));
  83         }
  84
  85         /* Append the new position. */
  86
  87         pos = term_hen(p, &su);
  88         tl->t[tl->n] = pos;
  89         if (add && tl->n)
  90                 tl->t[tl->n] += tl->t[tl->n - 1];
  91         tl->n++;
  92 }
  93
  94 /*
  95  * Simplified version without a parser,
  96  * never incremental, never periodic, for use by tbl(7).
  97  */
  98 void
  99 term_tab_iset(size_t inc)
 100 {
 101         if (tabs.a.n >= tabs.a.s) {
 102                 tabs.a.s += 8;
 103                 tabs.a.t = mandoc_reallocarray(tabs.a.t, tabs.a.s,
 104                     sizeof(*tabs.a.t));
 105         }
 106         tabs.a.t[tabs.a.n++] = inc;
 107 }
 108
 109 size_t
 110 term_tab_next(size_t prev)
 111 {
 112         size_t   i, j;
 113
 114         for (i = 0;; i++) {
 115                 if (i == tabs.a.n) {
 116                         if (tabs.p.n == 0)
 117                                 return prev;
 118                         tabs.a.n += tabs.p.n;
 119                         if (tabs.a.s < tabs.a.n) {
 120                                 tabs.a.s = tabs.a.n;
 121                                 tabs.a.t = mandoc_reallocarray(tabs.a.t,
 122                                     tabs.a.s, sizeof(*tabs.a.t));
 123                         }
 124                         for (j = 0; j < tabs.p.n; j++)
 125                                 tabs.a.t[i + j] = tabs.p.t[j] +
 126                                     (i ? tabs.a.t[i - 1] : 0);
 127                 }
 128                 if (prev < tabs.a.t[i])
 129                         return tabs.a.t[i];
 130         }
 131 }
 132
 133 void
 134 term_tab_free(void)
 135 {
 136         free(tabs.a.t);
 137         free(tabs.p.t);
 138         memset(&tabs, 0, sizeof(tabs));
 139         tabs.r = &tabs.a;
 140 }