root/usr.bin/vi/vi/v_screen.c
/*      $OpenBSD: v_screen.c,v 1.9 2016/01/06 22:28:52 millert Exp $    */

/*-
 * Copyright (c) 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1992, 1993, 1994, 1995, 1996
 *      Keith Bostic.  All rights reserved.
 *
 * See the LICENSE file for redistribution information.
 */

#include "config.h"

#include <sys/types.h>
#include <sys/queue.h>
#include <sys/time.h>

#include <bitstring.h>
#include <limits.h>
#include <stdio.h>

#include "../common/common.h"
#include "vi.h"

/*
 * v_screen -- ^W
 *      Switch screens.
 *
 * PUBLIC: int v_screen(SCR *, VICMD *);
 */
int
v_screen(SCR *sp, VICMD *vp)
{
        /*
         * You can't leave a colon command-line edit window -- it's not that
         * it won't work, but it gets real weird, real fast when you execute
         * a colon command out of a window that was forked from a window that's
         * now backgrounded...  You get the idea.
         */
        if (F_ISSET(sp, SC_COMEDIT)) {
                msgq(sp, M_ERR,
                    "Enter <CR> to execute a command, :q to exit");
                return (1);
        }
                
        /*
         * Try for the next lower screen, or, go back to the first
         * screen on the stack.
         */
        if (TAILQ_NEXT(sp, q))
                sp->nextdisp = TAILQ_NEXT(sp, q);
        else if (TAILQ_FIRST(&sp->gp->dq) == sp) {
                msgq(sp, M_ERR, "No other screen to switch to");
                return (1);
        } else
                sp->nextdisp = TAILQ_FIRST(&sp->gp->dq);

        F_SET(sp->nextdisp, SC_STATUS);
        F_SET(sp, SC_SSWITCH | SC_STATUS);
        return (0);
}