xref: /illumos-gate/usr/src/cmd/mandoc/term_tab.c (revision 9b9d39d2a32ff806d2431dbcc50968ef1e6d46b2)
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 }
131