xref: /freebsd/contrib/nvi/vi/v_z.c (revision bdd1243df58e60e85101c09001d9812a789b6bc4)
1 /*-
2  * Copyright (c) 1992, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 1992, 1993, 1994, 1995, 1996
5  *	Keith Bostic.  All rights reserved.
6  *
7  * See the LICENSE file for redistribution information.
8  */
9 
10 #include "config.h"
11 
12 #include <sys/types.h>
13 #include <sys/queue.h>
14 #include <sys/time.h>
15 
16 #include <bitstring.h>
17 #include <limits.h>
18 #include <stdio.h>
19 
20 #include "../common/common.h"
21 #include "vi.h"
22 
23 /*
24  * v_z -- [count]z[count][-.+^<CR>]
25  *	Move the screen.
26  *
27  * PUBLIC: int v_z(SCR *, VICMD *);
28  */
29 int
30 v_z(SCR *sp, VICMD *vp)
31 {
32 	recno_t lno;
33 	e_key_t value;
34 
35 	/*
36 	 * The first count is the line to use.  If the value doesn't
37 	 * exist, use the last line.
38 	 */
39 	if (F_ISSET(vp, VC_C1SET)) {
40 		lno = vp->count;
41 		if (!db_exist(sp, lno) && db_last(sp, &lno))
42 			return (1);
43 	} else
44 		lno = vp->m_start.lno;
45 
46 	/* Set default return cursor line. */
47 	vp->m_final.lno = lno;
48 	vp->m_final.cno = vp->m_start.cno;
49 
50 	/*
51 	 * The second count is the displayed window size, i.e. the 'z' command
52 	 * is another way to get artificially small windows.  Note, you can't
53 	 * grow beyond the size of the window.
54 	 *
55 	 * !!!
56 	 * A window size of 0 was historically allowed, and simply ignored.
57 	 * This could be much more simply done by modifying the value of the
58 	 * O_WINDOW option, but that's not how it worked historically.
59 	 */
60 	if (F_ISSET(vp, VC_C2SET) && vp->count2 != 0) {
61 		if (vp->count2 > O_VAL(sp, O_WINDOW))
62 			vp->count2 = O_VAL(sp, O_WINDOW);
63 		if (vs_crel(sp, vp->count2))
64 			return (1);
65 	}
66 
67 	switch (vp->character) {
68 	case '-':		/* Put the line at the bottom. */
69 		if (vs_sm_fill(sp, lno, P_BOTTOM))
70 			return (1);
71 		break;
72 	case '.':		/* Put the line in the middle. */
73 		if (vs_sm_fill(sp, lno, P_MIDDLE))
74 			return (1);
75 		break;
76 	case '+':
77 		/*
78 		 * If the user specified a line number, put that line at the
79 		 * top and move the cursor to it.  Otherwise, scroll forward
80 		 * a screen from the current screen.
81 		 */
82 		if (F_ISSET(vp, VC_C1SET)) {
83 			if (vs_sm_fill(sp, lno, P_TOP))
84 				return (1);
85 			if (vs_sm_position(sp, &vp->m_final, 0, P_TOP))
86 				return (1);
87 		} else
88 			if (vs_sm_scroll(sp, &vp->m_final, sp->t_rows, Z_PLUS))
89 				return (1);
90 		break;
91 	case '^':
92 		/*
93 		 * If the user specified a line number, put that line at the
94 		 * bottom, move the cursor to it, and then display the screen
95 		 * before that one.  Otherwise, scroll backward a screen from
96 		 * the current screen.
97 		 *
98 		 * !!!
99 		 * Note, we match the off-by-one characteristics of historic
100 		 * vi, here.
101 		 */
102 		if (F_ISSET(vp, VC_C1SET)) {
103 			if (vs_sm_fill(sp, lno, P_BOTTOM))
104 				return (1);
105 			if (vs_sm_position(sp, &vp->m_final, 0, P_TOP))
106 				return (1);
107 			if (vs_sm_fill(sp, vp->m_final.lno, P_BOTTOM))
108 				return (1);
109 		} else
110 			if (vs_sm_scroll(sp, &vp->m_final, sp->t_rows, Z_CARAT))
111 				return (1);
112 		break;
113 	default:		/* Put the line at the top for <cr>. */
114 		value = KEY_VAL(sp, vp->character);
115 		if (value != K_CR && value != K_NL) {
116 			v_emsg(sp, vp->kp->usage, VIM_USAGE);
117 			return (1);
118 		}
119 		if (vs_sm_fill(sp, lno, P_TOP))
120 			return (1);
121 		break;
122 	}
123 	return (0);
124 }
125 
126 /*
127  * vs_crel --
128  *	Change the relative size of the current screen.
129  *
130  * PUBLIC: int vs_crel(SCR *, long);
131  */
132 int
133 vs_crel(SCR *sp, long int count)
134 {
135 	sp->t_minrows = sp->t_rows = count;
136 	if (sp->t_rows > sp->rows - 1)
137 		sp->t_minrows = sp->t_rows = sp->rows - 1;
138 	TMAP = HMAP + (sp->t_rows - 1);
139 	F_SET(sp, SC_SCR_REDRAW);
140 	return (0);
141 }
142