xref: /freebsd/contrib/mandoc/term_tab.c (revision b64c5a0ace59af62eff52bfe110a521dc73c937b)
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 }
141