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
27struct 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
33static 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
40void
41term_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 */
97void
98term_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
108size_t
109term_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