xref: /freebsd/contrib/nvi/vi/v_z.c (revision 3e5645b78f476816ca3b5acc28b29bbafbb9c444)
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 #ifndef lint
13 static const char sccsid[] = "$Id: v_z.c,v 10.13 2011/12/02 17:26:59 zy Exp $";
14 #endif /* not lint */
15 
16 #include <sys/types.h>
17 #include <sys/queue.h>
18 #include <sys/time.h>
19 
20 #include <bitstring.h>
21 #include <limits.h>
22 #include <stdio.h>
23 
24 #include "../common/common.h"
25 #include "vi.h"
26 
27 /*
28  * v_z -- [count]z[count][-.+^<CR>]
29  *	Move the screen.
30  *
31  * PUBLIC: int v_z(SCR *, VICMD *);
32  */
33 int
34 v_z(SCR *sp, VICMD *vp)
35 {
36 	recno_t lno;
37 	e_key_t value;
38 
39 	/*
40 	 * The first count is the line to use.  If the value doesn't
41 	 * exist, use the last line.
42 	 */
43 	if (F_ISSET(vp, VC_C1SET)) {
44 		lno = vp->count;
45 		if (!db_exist(sp, lno) && db_last(sp, &lno))
46 			return (1);
47 	} else
48 		lno = vp->m_start.lno;
49 
50 	/* Set default return cursor line. */
51 	vp->m_final.lno = lno;
52 	vp->m_final.cno = vp->m_start.cno;
53 
54 	/*
55 	 * The second count is the displayed window size, i.e. the 'z' command
56 	 * is another way to get artificially small windows.  Note, you can't
57 	 * grow beyond the size of the window.
58 	 *
59 	 * !!!
60 	 * A window size of 0 was historically allowed, and simply ignored.
61 	 * This could be much more simply done by modifying the value of the
62 	 * O_WINDOW option, but that's not how it worked historically.
63 	 */
64 	if (F_ISSET(vp, VC_C2SET) && vp->count2 != 0) {
65 		if (vp->count2 > O_VAL(sp, O_WINDOW))
66 			vp->count2 = O_VAL(sp, O_WINDOW);
67 		if (vs_crel(sp, vp->count2))
68 			return (1);
69 	}
70 
71 	switch (vp->character) {
72 	case '-':		/* Put the line at the bottom. */
73 		if (vs_sm_fill(sp, lno, P_BOTTOM))
74 			return (1);
75 		break;
76 	case '.':		/* Put the line in the middle. */
77 		if (vs_sm_fill(sp, lno, P_MIDDLE))
78 			return (1);
79 		break;
80 	case '+':
81 		/*
82 		 * If the user specified a line number, put that line at the
83 		 * top and move the cursor to it.  Otherwise, scroll forward
84 		 * a screen from the current screen.
85 		 */
86 		if (F_ISSET(vp, VC_C1SET)) {
87 			if (vs_sm_fill(sp, lno, P_TOP))
88 				return (1);
89 			if (vs_sm_position(sp, &vp->m_final, 0, P_TOP))
90 				return (1);
91 		} else
92 			if (vs_sm_scroll(sp, &vp->m_final, sp->t_rows, Z_PLUS))
93 				return (1);
94 		break;
95 	case '^':
96 		/*
97 		 * If the user specified a line number, put that line at the
98 		 * bottom, move the cursor to it, and then display the screen
99 		 * before that one.  Otherwise, scroll backward a screen from
100 		 * the current screen.
101 		 *
102 		 * !!!
103 		 * Note, we match the off-by-one characteristics of historic
104 		 * vi, here.
105 		 */
106 		if (F_ISSET(vp, VC_C1SET)) {
107 			if (vs_sm_fill(sp, lno, P_BOTTOM))
108 				return (1);
109 			if (vs_sm_position(sp, &vp->m_final, 0, P_TOP))
110 				return (1);
111 			if (vs_sm_fill(sp, vp->m_final.lno, P_BOTTOM))
112 				return (1);
113 		} else
114 			if (vs_sm_scroll(sp, &vp->m_final, sp->t_rows, Z_CARAT))
115 				return (1);
116 		break;
117 	default:		/* Put the line at the top for <cr>. */
118 		value = KEY_VAL(sp, vp->character);
119 		if (value != K_CR && value != K_NL) {
120 			v_emsg(sp, vp->kp->usage, VIM_USAGE);
121 			return (1);
122 		}
123 		if (vs_sm_fill(sp, lno, P_TOP))
124 			return (1);
125 		break;
126 	}
127 	return (0);
128 }
129 
130 /*
131  * vs_crel --
132  *	Change the relative size of the current screen.
133  *
134  * PUBLIC: int vs_crel(SCR *, long);
135  */
136 int
137 vs_crel(SCR *sp, long int count)
138 {
139 	sp->t_minrows = sp->t_rows = count;
140 	if (sp->t_rows > sp->rows - 1)
141 		sp->t_minrows = sp->t_rows = sp->rows - 1;
142 	TMAP = HMAP + (sp->t_rows - 1);
143 	F_SET(sp, SC_SCR_REDRAW);
144 	return (0);
145 }
146