source: trunk/third/nvi/vi/v_left.c @ 14302

/*-
 * Copyright (c) 1992, 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"

#ifndef lint
static const char sccsid[] = "@(#)v_left.c      10.7 (Berkeley) 3/6/96";
#endif /* not lint */

#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_left -- [count]^H, [count]h
 *      Move left by columns.
 *
 * PUBLIC: int v_left __P((SCR *, VICMD *));
 */
int
v_left(sp, vp)
        SCR *sp;
        VICMD *vp;
{
        recno_t cnt;

        /*
         * !!!
         * The ^H and h commands always failed in the first column.
         */
        if (vp->m_start.cno == 0) {
                v_sol(sp);
                return (1);
        }

        /* Find the end of the range. */
        cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
        if (vp->m_start.cno > cnt)
                vp->m_stop.cno = vp->m_start.cno - cnt;
        else
                vp->m_stop.cno = 0;

        /*
         * All commands move to the end of the range.  Motion commands
         * adjust the starting point to the character before the current
         * one.
         */
        if (ISMOTION(vp))
                --vp->m_start.cno;
        vp->m_final = vp->m_stop;
        return (0);
}

/*
 * v_cfirst -- [count]_
 *      Move to the first non-blank character in a line.
 *
 * PUBLIC: int v_cfirst __P((SCR *, VICMD *));
 */
int
v_cfirst(sp, vp)
        SCR *sp;
        VICMD *vp;
{
        recno_t cnt, lno;

        /*
         * !!!
         * If the _ is a motion component, it makes the command a line motion
         * e.g. "d_" deletes the line.  It also means that the cursor doesn't
         * move.
         *
         * The _ command never failed in the first column.
         */
        if (ISMOTION(vp))
                F_SET(vp, VM_LMODE);
        /*
         * !!!
         * Historically a specified count makes _ move down count - 1
         * rows, so, "3_" is the same as "2j_".
         */
        cnt = F_ISSET(vp, VC_C1SET) ? vp->count : 1;
        if (cnt != 1) {
                --vp->count;
                return (v_down(sp, vp));
        }

        /*
         * Move to the first non-blank.
         *
         * Can't just use RCM_SET_FNB, in case _ is used as the motion
         * component of another command.
         */
        vp->m_stop.cno = 0;
        if (nonblank(sp, vp->m_stop.lno, &vp->m_stop.cno))
                return (1);

        /*
         * !!!
         * The _ command has to fail if the file is empty and we're doing
         * a delete.  If deleting line 1, and 0 is the first nonblank,
         * make the check.
         */
        if (vp->m_stop.lno == 1 &&
            vp->m_stop.cno == 0 && ISCMD(vp->rkp, 'd')) {
                if (db_last(sp, &lno))
                        return (1);
                if (lno == 0) {
                        v_sol(sp);
                        return (1);
                }
        }

        /*
         * Delete and non-motion commands move to the end of the range,
         * yank stays at the start.  Ignore others.
         */
        vp->m_final =
            ISMOTION(vp) && ISCMD(vp->rkp, 'y') ? vp->m_start : vp->m_stop;
        return (0);
}

/*
 * v_first -- ^
 *      Move to the first non-blank character in this line.
 *
 * PUBLIC: int v_first __P((SCR *, VICMD *));
 */
int
v_first(sp, vp)
        SCR *sp;
        VICMD *vp;
{
        /*
         * !!!
         * Yielding to none in our quest for compatibility with every
         * historical blemish of vi, no matter how strange it might be,
         * we permit the user to enter a count and then ignore it.
         */

        /*
         * Move to the first non-blank.
         *
         * Can't just use RCM_SET_FNB, in case ^ is used as the motion
         * component of another command.
         */
        vp->m_stop.cno = 0;
        if (nonblank(sp, vp->m_stop.lno, &vp->m_stop.cno))
                return (1);

        /*
         * !!!
         * The ^ command succeeded if used as a command when the cursor was
         * on the first non-blank in the line, but failed if used as a motion
         * component in the same situation.
         */
        if (ISMOTION(vp) && vp->m_start.cno == vp->m_stop.cno) {
                v_sol(sp);
                return (1);
        }

        /*
         * If moving right, non-motion commands move to the end of the range.
         * Delete and yank stay at the start.  Motion commands adjust the
         * ending point to the character before the current ending charcter.
         *
         * If moving left, all commands move to the end of the range.  Motion
         * commands adjust the starting point to the character before the
         * current starting character.
         */
        if (vp->m_start.cno < vp->m_stop.cno)
                if (ISMOTION(vp)) {
                        --vp->m_stop.cno;
                        vp->m_final = vp->m_start;
                } else
                        vp->m_final = vp->m_stop;
        else {
                if (ISMOTION(vp))
                        --vp->m_start.cno;
                vp->m_final = vp->m_stop;
        }
        return (0);
}

/*
 * v_ncol -- [count]|
 *      Move to column count or the first column on this line.  If the
 *      requested column is past EOL, move to EOL.  The nasty part is
 *      that we have to know character column widths to make this work.
 *
 * PUBLIC: int v_ncol __P((SCR *, VICMD *));
 */
int
v_ncol(sp, vp)
        SCR *sp;
        VICMD *vp;
{
        if (F_ISSET(vp, VC_C1SET) && vp->count > 1) {
                --vp->count;
                vp->m_stop.cno =
                    vs_colpos(sp, vp->m_start.lno, (size_t)vp->count);
                /*
                 * !!!
                 * The | command succeeded if used as a command and the cursor
                 * didn't move, but failed if used as a motion component in the
                 * same situation.
                 */
                if (ISMOTION(vp) && vp->m_stop.cno == vp->m_start.cno) {
                        v_nomove(sp);
                        return (1);
                }
        } else {
                /*
                 * !!!
                 * The | command succeeded if used as a command in column 0
                 * without a count, but failed if used as a motion component
                 * in the same situation.
                 */
                if (ISMOTION(vp) && vp->m_start.cno == 0) {
                        v_sol(sp);
                        return (1);
                }
                vp->m_stop.cno = 0;
        }

        /*
         * If moving right, non-motion commands move to the end of the range.
         * Delete and yank stay at the start.  Motion commands adjust the
         * ending point to the character before the current ending charcter.
         *
         * If moving left, all commands move to the end of the range.  Motion
         * commands adjust the starting point to the character before the
         * current starting character.
         */
        if (vp->m_start.cno < vp->m_stop.cno)
                if (ISMOTION(vp)) {
                        --vp->m_stop.cno;
                        vp->m_final = vp->m_start;
                } else
                        vp->m_final = vp->m_stop;
        else {
                if (ISMOTION(vp))
                        --vp->m_start.cno;
                vp->m_final = vp->m_stop;
        }
        return (0);
}

/*
 * v_zero -- 0
 *      Move to the first column on this line.
 *
 * PUBLIC: int v_zero __P((SCR *, VICMD *));
 */
int
v_zero(sp, vp)
        SCR *sp;
        VICMD *vp;
{
        /*
         * !!!
         * The 0 command succeeded if used as a command in the first column
         * but failed if used as a motion component in the same situation.
         */
        if (ISMOTION(vp) && vp->m_start.cno == 0) {
                v_sol(sp);
                return (1);
        }

        /*
         * All commands move to the end of the range.  Motion commands
         * adjust the starting point to the character before the current
         * one.
         */
        vp->m_stop.cno = 0;
        if (ISMOTION(vp))
                --vp->m_start.cno;
        vp->m_final = vp->m_stop;
        return (0);
}