xref: /openbsd/usr.bin/mandoc/term_tab.c (revision 73471bf0)
1 /* $OpenBSD: term_tab.c,v 1.5 2021/10/04 18:56:24 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 <sys/types.h>
18 
19 #include <stddef.h>
20 #include <stdlib.h>
21 #include <string.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 	struct tablist	*r;	/* Tablist currently being recorded. */
37 	size_t		 d;	/* Default tab width in units of n. */
38 } tabs;
39 
40 
41 void
42 term_tab_set(const struct termp *p, const char *arg)
43 {
44 	struct roffsu	 su;
45 	struct tablist	*tl;
46 	size_t		 pos;
47 	int		 add;
48 
49 	/* Special arguments: clear all tabs or switch lists. */
50 
51 	if (arg == NULL) {
52 		tabs.a.n = tabs.p.n = 0;
53 		tabs.r = &tabs.a;
54 		if (tabs.d == 0) {
55 			a2roffsu(".8i", &su, SCALE_IN);
56 			tabs.d = term_hen(p, &su);
57 		}
58 		return;
59 	}
60 	if (arg[0] == 'T' && arg[1] == '\0') {
61 		tabs.r = &tabs.p;
62 		return;
63 	}
64 
65 	/* Parse the sign, the number, and the unit. */
66 
67 	if (*arg == '+') {
68 		add = 1;
69 		arg++;
70 	} else
71 		add = 0;
72 	if (a2roffsu(arg, &su, SCALE_EM) == NULL)
73 		return;
74 
75 	/* Select the list, and extend it if it is full. */
76 
77 	tl = tabs.r;
78 	if (tl->n >= tl->s) {
79 		tl->s += 8;
80 		tl->t = mandoc_reallocarray(tl->t, tl->s, sizeof(*tl->t));
81 	}
82 
83 	/* Append the new position. */
84 
85 	pos = term_hen(p, &su);
86 	tl->t[tl->n] = pos;
87 	if (add && tl->n)
88 		tl->t[tl->n] += tl->t[tl->n - 1];
89 	tl->n++;
90 }
91 
92 /*
93  * Simplified version without a parser,
94  * never incremental, never periodic, for use by tbl(7).
95  */
96 void
97 term_tab_iset(size_t inc)
98 {
99 	if (tabs.a.n >= tabs.a.s) {
100 		tabs.a.s += 8;
101 		tabs.a.t = mandoc_reallocarray(tabs.a.t, tabs.a.s,
102 		    sizeof(*tabs.a.t));
103 	}
104 	tabs.a.t[tabs.a.n++] = inc;
105 }
106 
107 size_t
108 term_tab_next(size_t prev)
109 {
110 	size_t	 i, j;
111 
112 	for (i = 0;; i++) {
113 		if (i == tabs.a.n) {
114 			if (tabs.p.n == 0)
115 				return prev;
116 			tabs.a.n += tabs.p.n;
117 			if (tabs.a.s < tabs.a.n) {
118 				tabs.a.s = tabs.a.n;
119 				tabs.a.t = mandoc_reallocarray(tabs.a.t,
120 				    tabs.a.s, sizeof(*tabs.a.t));
121 			}
122 			for (j = 0; j < tabs.p.n; j++)
123 				tabs.a.t[i + j] = tabs.p.t[j] +
124 				    (i ? tabs.a.t[i - 1] : 0);
125 		}
126 		if (prev < tabs.a.t[i])
127 			return tabs.a.t[i];
128 	}
129 }
130 
131 void
132 term_tab_free(void)
133 {
134 	free(tabs.a.t);
135 	free(tabs.p.t);
136 	memset(&tabs, 0, sizeof(tabs));
137 	tabs.r = &tabs.a;
138 }
139