xref: /freebsd/contrib/mandoc/term_tab.c (revision cab6a39d7b343596a5823e65c0f7b426551ec22d)
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 }
129