1 /* $Id: term_tab.c,v 1.9 2025/07/16 14:33:08 schwarze Exp $ */
2 /*
3 * Copyright (c) 2017, 2021, 2025 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 [BU]. */
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 basic units. */
40 } tabs;
41
42
43 void
term_tab_set(const struct termp * p,const char * arg)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_hspan(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_hspan(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 size_t
term_tab_next(size_t prev)95 term_tab_next(size_t prev)
96 {
97 size_t i, j;
98
99 for (i = 0;; i++) {
100 if (i == tabs.a.n) {
101 if (tabs.p.n == 0)
102 return prev;
103 tabs.a.n += tabs.p.n;
104 if (tabs.a.s < tabs.a.n) {
105 tabs.a.s = tabs.a.n;
106 tabs.a.t = mandoc_reallocarray(tabs.a.t,
107 tabs.a.s, sizeof(*tabs.a.t));
108 }
109 for (j = 0; j < tabs.p.n; j++)
110 tabs.a.t[i + j] = tabs.p.t[j] +
111 (i ? tabs.a.t[i - 1] : 0);
112 }
113 if (prev < tabs.a.t[i])
114 return tabs.a.t[i];
115 }
116 }
117
118 void
term_tab_free(void)119 term_tab_free(void)
120 {
121 free(tabs.a.t);
122 free(tabs.p.t);
123 memset(&tabs, 0, sizeof(tabs));
124 tabs.r = &tabs.a;
125 }
126