bin/mandoc/term_tab.c

   1 /*      $Id: term_tab.c,v 1.5 2018/12/16 00:21:05 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 <sys/types.h>
  18
  19 #include <stddef.h>
  20
  21 #include "mandoc_aux.h"
  22 #include "out.h"
  23 #include "term.h"
  24
  25 struct tablist {
  26         size_t  *t;     /* Allocated array of tab positions. */
  27         size_t   s;     /* Allocated number of positions. */
  28         size_t   n;     /* Currently used number of positions. */
  29 };
  30
  31 static struct {
  32         struct tablist   a;     /* All tab positions for lookup. */
  33         struct tablist   p;     /* Periodic tab positions to add. */
  34         size_t           d;     /* Default tab width in units of n. */
  35 } tabs;
  36
  37
  38 void
  39 term_tab_set(const struct termp *p, const char *arg)
  40 {
  41         static int       recording_period;
  42
  43         struct roffsu    su;
  44         struct tablist  *tl;
  45         size_t           pos;
  46         int              add;
  47
  48         /* Special arguments: clear all tabs or switch lists. */
  49
  50         if (arg == NULL) {
  51                 tabs.a.n = tabs.p.n = 0;
  52                 recording_period = 0;
  53                 if (tabs.d == 0) {
  54                         a2roffsu(".8i", &su, SCALE_IN);
  55                         tabs.d = term_hen(p, &su);
  56                 }
  57                 return;
  58         }
  59         if (arg[0] == 'T' && arg[1] == '\0') {
  60                 recording_period = 1;
  61                 return;
  62         }
  63
  64         /* Parse the sign, the number, and the unit. */
  65
  66         if (*arg == '+') {
  67                 add = 1;
  68                 arg++;
  69         } else
  70                 add = 0;
  71         if (a2roffsu(arg, &su, SCALE_EM) == NULL)
  72                 return;
  73
  74         /* Select the list, and extend it if it is full. */
  75
  76         tl = recording_period ? &tabs.p : &tabs.a;
  77         if (tl->n >= tl->s) {
  78                 tl->s += 8;
  79                 tl->t = mandoc_reallocarray(tl->t, tl->s, sizeof(*tl->t));
  80         }
  81
  82         /* Append the new position. */
  83
  84         pos = term_hen(p, &su);
  85         tl->t[tl->n] = pos;
  86         if (add && tl->n)
  87                 tl->t[tl->n] += tl->t[tl->n - 1];
  88         tl->n++;
  89 }
  90
  91 /*
  92  * Simplified version without a parser,
  93  * never incremental, never periodic, for use by tbl(7).
  94  */
  95 void
  96 term_tab_iset(size_t inc)
  97 {
  98         if (tabs.a.n >= tabs.a.s) {
  99                 tabs.a.s += 8;
 100                 tabs.a.t = mandoc_reallocarray(tabs.a.t, tabs.a.s,
 101                     sizeof(*tabs.a.t));
 102         }
 103         tabs.a.t[tabs.a.n++] = inc;
 104 }
 105
 106 size_t
 107 term_tab_next(size_t prev)
 108 {
 109         size_t   i, j;
 110
 111         for (i = 0;; i++) {
 112                 if (i == tabs.a.n) {
 113                         if (tabs.p.n == 0)
 114                                 return prev;
 115                         tabs.a.n += tabs.p.n;
 116                         if (tabs.a.s < tabs.a.n) {
 117                                 tabs.a.s = tabs.a.n;
 118                                 tabs.a.t = mandoc_reallocarray(tabs.a.t,
 119                                     tabs.a.s, sizeof(*tabs.a.t));
 120                         }
 121                         for (j = 0; j < tabs.p.n; j++)
 122                                 tabs.a.t[i + j] = tabs.p.t[j] +
 123                                     (i ? tabs.a.t[i - 1] : 0);
 124                 }
 125                 if (prev < tabs.a.t[i])
 126                         return tabs.a.t[i];
 127         }
 128 }