OS/2 Spezial/SPEZIAL2_97.zip/SPEZIAL2_97.iso/ANWEND/EDITOR/NVI179B/NVI179B.ZIP/ex/ex_shift.c

C/C++ Source or Header | 1996-09-15 | 5KB | 192 lines

/*-
 * 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[] = "@(#)ex_shift.c    10.11 (Berkeley) 9/15/96";
#endif /* not lint */

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

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

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

enum which {LEFT, RIGHT};
static int shift __P((SCR *, EXCMD *, enum which));

/*
 * ex_shiftl -- :<[<...]
 *
 *
 * PUBLIC: int ex_shiftl __P((SCR *, EXCMD *));
 */
int
ex_shiftl(sp, cmdp)
    SCR *sp;
    EXCMD *cmdp;
{
    return (shift(sp, cmdp, LEFT));
}

/*
 * ex_shiftr -- :>[>...]
 *
 * PUBLIC: int ex_shiftr __P((SCR *, EXCMD *));
 */
int
ex_shiftr(sp, cmdp)
    SCR *sp;
    EXCMD *cmdp;
{
    return (shift(sp, cmdp, RIGHT));
}

/*
 * shift --
 *    Ex shift support.
 */
static int
shift(sp, cmdp, rl)
    SCR *sp;
    EXCMD *cmdp;
    enum which rl;
{
    recno_t from, to;
    size_t blen, len, newcol, newidx, oldcol, oldidx, sw;
    int curset;
    char *p, *bp, *tbp;

    NEEDFILE(sp, cmdp);

    if (O_VAL(sp, O_SHIFTWIDTH) == 0) {
        msgq(sp, M_INFO, "152|shiftwidth option set to 0");
        return (0);
    }

    /* Copy the lines being shifted into the unnamed buffer. */
    if (cut(sp, NULL, &cmdp->addr1, &cmdp->addr2, CUT_LINEMODE))
        return (1);

    /*
     * The historic version of vi permitted the user to string any number
     * of '>' or '<' characters together, resulting in an indent of the
     * appropriate levels.  There's a special hack in ex_cmd() so that
     * cmdp->argv[0] points to the string of '>' or '<' characters.
     *
     * Q: What's the difference between the people adding features
     *    to vi and the Girl Scouts?
     * A: The Girl Scouts have mint cookies and adult supervision.
     */
    for (p = cmdp->argv[0]->bp, sw = 0; *p == '>' || *p == '<'; ++p)
        sw += O_VAL(sp, O_SHIFTWIDTH);

    GET_SPACE_RET(sp, bp, blen, 256);

    curset = 0;
    for (from = cmdp->addr1.lno, to = cmdp->addr2.lno; from <= to; ++from) {
        if (db_get(sp, from, DBG_FATAL, &p, &len))
            goto err;
        if (!len) {
            if (sp->lno == from)
                curset = 1;
            continue;
        }

        /*
         * Calculate the old indent amount and the number of
         * characters it used.
         */
        for (oldidx = 0, oldcol = 0; oldidx < len; ++oldidx)
            if (p[oldidx] == ' ')
                ++oldcol;
            else if (p[oldidx] == '\t')
                oldcol += O_VAL(sp, O_TABSTOP) -
                    oldcol % O_VAL(sp, O_TABSTOP);
            else
                break;

        /* Calculate the new indent amount. */
        if (rl == RIGHT)
            newcol = oldcol + sw;
        else {
            newcol = oldcol < sw ? 0 : oldcol - sw;
            if (newcol == oldcol) {
                if (sp->lno == from)
                    curset = 1;
                continue;
            }
        }

        /* Get a buffer that will hold the new line. */
        ADD_SPACE_RET(sp, bp, blen, newcol + len);

        /*
         * Build a new indent string and count the number of
         * characters it uses.
         */
        for (tbp = bp, newidx = 0;
            newcol >= O_VAL(sp, O_TABSTOP); ++newidx) {
            *tbp++ = '\t';
            newcol -= O_VAL(sp, O_TABSTOP);
        }
        for (; newcol > 0; --newcol, ++newidx)
            *tbp++ = ' ';

        /* Add the original line. */
        memcpy(tbp, p + oldidx, len - oldidx);

        /* Set the replacement line. */
        if (db_set(sp, from, bp, (tbp + (len - oldidx)) - bp)) {
err:            FREE_SPACE(sp, bp, blen);
            return (1);
        }

        /*
         * !!!
         * The shift command in historic vi had the usual bizarre
         * collection of cursor semantics.  If called from vi, the
         * cursor was repositioned to the first non-blank character
         * of the lowest numbered line shifted.  If called from ex,
         * the cursor was repositioned to the first non-blank of the
         * highest numbered line shifted.  Here, if the cursor isn't
         * part of the set of lines that are moved, move it to the
         * first non-blank of the last line shifted.  (This makes
         * ":3>>" in vi work reasonably.)  If the cursor is part of
         * the shifted lines, it doesn't get moved at all.  This
         * permits shifting of marked areas, i.e. ">'a." shifts the
         * marked area twice, something that couldn't be done with
         * historic vi.
         */
        if (sp->lno == from) {
            curset = 1;
            if (newidx > oldidx)
                sp->cno += newidx - oldidx;
            else if (sp->cno >= oldidx - newidx)
                sp->cno -= oldidx - newidx;
        }
    }
    if (!curset) {
        sp->lno = to;
        sp->cno = 0;
        (void)nonblank(sp, to, &sp->cno);
    }

    FREE_SPACE(sp, bp, blen);

    sp->rptlines[L_SHIFT] += cmdp->addr2.lno - cmdp->addr1.lno + 1;
    return (0);
}