1 #include "a.h"
2 
3 /*
4  * 4 - Text filling, centering, and adjusting.
5  * 	"\ " - unbreakable space
6  * 	.n register - length of last line
7  *	nl register - text baseline position on this page
8  *	.h register - baseline high water mark
9  *	.k register - current horizontal output position
10  *	\p - cause break at end of word, justify
11  *	\& - non-printing zero-width filler
12  *	tr - output translation
13  *	\c - break (but don't) input line in .nf mode
14  *	\c - break (but don't) word in .fi mode
15  */
16 
17 int
18 e_space(void)
19 {
20 	return 0xA0;	/* non-breaking space */
21 }
22 
23 int
24 e_amp(void)
25 {
26 	return Uempty;
27 }
28 
29 int
30 e_c(void)
31 {
32 	getrune();
33 	bol = 1;
34 	return 0;
35 }
36 
37 void
38 r_br(int argc, Rune **argv)
39 {
40 	USED(argc);
41 	USED(argv);
42 	br();
43 }
44 
45 /* fill mode on */
46 void
47 r_fi(int argc, Rune **argv)
48 {
49 	USED(argc);
50 	USED(argv);
51 	nr(L(".fi"), 1);
52 /* warn(".fi"); */
53 }
54 
55 /* no-fill mode */
56 void
57 r_nf(int argc, Rune **argv)
58 {
59 	USED(argc);
60 	USED(argv);
61 	nr(L(".fi"), 0);
62 }
63 
64 /* adjust */
65 void
66 r_ad(int argc, Rune **argv)
67 {
68 	int c, n;
69 
70 	nr(L(".j"), getnr(L(".j"))|1);
71 	if(argc < 2)
72 		return;
73 	c = argv[1][0];
74 	switch(c){
75 	default:
76 		fprint(2, "%L: bad adjust %C\n", c);
77 		return;
78 	case 'r':
79 		n = 2*2|1;
80 		break;
81 	case 'l':
82 		n = 0;
83 		break;
84 	case 'c':
85 		n = 1*2|1;
86 		break;
87 	case 'b':
88 	case 'n':
89 		n = 0*2|1;
90 		break;
91 	case '0':
92 	case '1':
93 	case '2':
94 	case '3':
95 	case '4':
96 	case '5':
97 		n = c-'0';
98 		break;
99 	}
100 	nr(L(".j"), n);
101 }
102 
103 /* no adjust */
104 void
105 r_na(int argc, Rune **argv)
106 {
107 	USED(argc);
108 	USED(argv);
109 
110 	nr(L(".j"), getnr(L(".j"))&~1);
111 }
112 
113 /* center next N lines */
114 void
115 r_ce(int argc, Rune **argv)
116 {
117 	if(argc < 2)
118 		nr(L(".ce"), 1);
119 	else
120 		nr(L(".ce"), eval(argv[1]));
121 	/* XXX set trap */
122 }
123 
124 void
125 t4init(void)
126 {
127 	nr(L(".fi"), 1);
128 	nr(L(".j"), 1);
129 
130 	addreq(L("br"), r_br, 0);
131 	addreq(L("fi"), r_fi, 0);
132 	addreq(L("nf"), r_nf, 0);
133 	addreq(L("ad"), r_ad, -1);
134 	addreq(L("na"), r_na, 0);
135 	addreq(L("ce"), r_ce, -1);
136 
137 	addesc(' ', e_space, 0);
138 	addesc('p', e_warn, 0);
139 	addesc('&', e_amp, 0);
140 	addesc('c', e_c, 0);
141 }