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      1 /* Id: term_tab.c,v 1.6 2020/06/22 19:20:40 schwarze Exp  */
      2 /*
      3  * Copyright (c) 2017 Ingo Schwarze <schwarze (at) 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