contrib/mdocml/term_tab.c

   1 /* $Id: term_tab.c,v 1.6 2020/06/22 19:20:40 schwarze Exp $ */
   2 /*
   3  * Copyright (c) 2017 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
  23 #include "mandoc_aux.h"
  24 #include "out.h"
  25 #include "term.h"
  26
  27 struct tablist {
  28         size_t  *t;     /* Allocated array of tab positions. */
  29         size_t   s;     /* Allocated number of positions. */
  30         size_t   n;     /* Currently used number of positions. */
  31 };
  32
  33 static struct {
  34         struct tablist   a;     /* All tab positions for lookup. */
  35         struct tablist   p;     /* Periodic tab positions to add. */
  36         size_t           d;     /* Default tab width in units of n. */
  37 } tabs;
  38
  39
  40 void
  41 term_tab_set(const struct termp *p, const char *arg)
  42 {
  43         static int       recording_period;
  44
  45         struct roffsu    su;
  46         struct tablist  *tl;
  47         size_t           pos;
  48         int              add;
  49
  50         /* Special arguments: clear all tabs or switch lists. */
  51
  52         if (arg == NULL) {
  53                 tabs.a.n = tabs.p.n = 0;
  54                 recording_period = 0;
  55                 if (tabs.d == 0) {
  56                         a2roffsu(".8i", &su, SCALE_IN);
  57                         tabs.d = term_hen(p, &su);
  58                 }
  59                 return;
  60         }
  61         if (arg[0] == 'T' && arg[1] == '\0') {
  62                 recording_period = 1;
  63                 return;
  64         }
  65
  66         /* Parse the sign, the number, and the unit. */
  67
  68         if (*arg == '+') {
  69                 add = 1;
  70                 arg++;
  71         } else
  72                 add = 0;
  73         if (a2roffsu(arg, &su, SCALE_EM) == NULL)
  74                 return;
  75
  76         /* Select the list, and extend it if it is full. */
  77
  78         tl = recording_period ? &tabs.p : &tabs.a;
  79         if (tl->n >= tl->s) {
  80                 tl->s += 8;
  81                 tl->t = mandoc_reallocarray(tl->t, tl->s, sizeof(*tl->t));
  82         }
  83
  84         /* Append the new position. */
  85
  86         pos = term_hen(p, &su);
  87         tl->t[tl->n] = pos;
  88         if (add && tl->n)
  89                 tl->t[tl->n] += tl->t[tl->n - 1];
  90         tl->n++;
  91 }
  92
  93 /*
  94  * Simplified version without a parser,
  95  * never incremental, never periodic, for use by tbl(7).
  96  */
  97 void
  98 term_tab_iset(size_t inc)
  99 {
 100         if (tabs.a.n >= tabs.a.s) {
 101                 tabs.a.s += 8;
 102                 tabs.a.t = mandoc_reallocarray(tabs.a.t, tabs.a.s,
 103                     sizeof(*tabs.a.t));
 104         }
 105         tabs.a.t[tabs.a.n++] = inc;
 106 }
 107
 108 size_t
 109 term_tab_next(size_t prev)
 110 {
 111         size_t   i, j;
 112
 113         for (i = 0;; i++) {
 114                 if (i == tabs.a.n) {
 115                         if (tabs.p.n == 0)
 116                                 return prev;
 117                         tabs.a.n += tabs.p.n;
 118                         if (tabs.a.s < tabs.a.n) {
 119                                 tabs.a.s = tabs.a.n;
 120                                 tabs.a.t = mandoc_reallocarray(tabs.a.t,
 121                                     tabs.a.s, sizeof(*tabs.a.t));
 122                         }
 123                         for (j = 0; j < tabs.p.n; j++)
 124                                 tabs.a.t[i + j] = tabs.p.t[j] +
 125                                     (i ? tabs.a.t[i - 1] : 0);
 126                 }
 127                 if (prev < tabs.a.t[i])
 128                         return tabs.a.t[i];
 129         }
 130 }