1/*	$OpenBSD: term.c,v 1.119 2017/01/08 18:08:44 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
25struct 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
31static 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
38void
39term_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 */
95void
96term_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
106size_t
107term_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