xref: /freebsd/contrib/nvi/vi/v_screen.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
1 /*-
2  * Copyright (c) 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[] = "@(#)v_screen.c	10.10 (Berkeley) 4/27/96";
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_screen -- ^W
29  *	Switch screens.
30  *
31  * PUBLIC: int v_screen __P((SCR *, VICMD *));
32  */
33 int
34 v_screen(sp, vp)
35 	SCR *sp;
36 	VICMD *vp;
37 {
38 	/*
39 	 * You can't leave a colon command-line edit window -- it's not that
40 	 * it won't work, but it gets real weird, real fast when you execute
41 	 * a colon command out of a window that was forked from a window that's
42 	 * now backgrounded...  You get the idea.
43 	 */
44 	if (F_ISSET(sp, SC_COMEDIT)) {
45 		msgq(sp, M_ERR,
46 		    "308|Enter <CR> to execute a command, :q to exit");
47 		return (1);
48 	}
49 
50 	/*
51 	 * Try for the next lower screen, or, go back to the first
52 	 * screen on the stack.
53 	 */
54 	if (sp->q.cqe_next != (void *)&sp->gp->dq)
55 		sp->nextdisp = sp->q.cqe_next;
56 	else if (sp->gp->dq.cqh_first == sp) {
57 		msgq(sp, M_ERR, "187|No other screen to switch to");
58 		return (1);
59 	} else
60 		sp->nextdisp = sp->gp->dq.cqh_first;
61 
62 	F_SET(sp->nextdisp, SC_STATUS);
63 	F_SET(sp, SC_SSWITCH | SC_STATUS);
64 	return (0);
65 }
66