contrib/nvi2/ex/ex_shift.c

   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: ex_shift.c,v 10.17 2001/06/25 15:19:20 skimo 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 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #include "../common/common.h"
  27
  28 enum which {LEFT, RIGHT};
  29 static int shift(SCR *, EXCMD *, enum which);
  30
  31 /*
  32  * ex_shiftl -- :<[<...]
  33  *
  34  *
  35  * PUBLIC: int ex_shiftl(SCR *, EXCMD *);
  36  */
  37 int
  38 ex_shiftl(SCR *sp, EXCMD *cmdp)
  39 {
  40         return (shift(sp, cmdp, LEFT));
  41 }
  42
  43 /*
  44  * ex_shiftr -- :>[>...]
  45  *
  46  * PUBLIC: int ex_shiftr(SCR *, EXCMD *);
  47  */
  48 int
  49 ex_shiftr(SCR *sp, EXCMD *cmdp)
  50 {
  51         return (shift(sp, cmdp, RIGHT));
  52 }
  53
  54 /*
  55  * shift --
  56  *      Ex shift support.
  57  */
  58 static int
  59 shift(SCR *sp, EXCMD *cmdp, enum which rl)
  60 {
  61         recno_t from, to;
  62         size_t blen, len, newcol, newidx, oldcol, oldidx, sw;
  63         int curset;
  64         CHAR_T *p;
  65         CHAR_T *bp, *tbp;
  66
  67         NEEDFILE(sp, cmdp);
  68
  69         if (O_VAL(sp, O_SHIFTWIDTH) == 0) {
  70                 msgq(sp, M_INFO, "152|shiftwidth option set to 0");
  71                 return (0);
  72         }
  73
  74         /* Copy the lines being shifted into the unnamed buffer. */
  75         if (cut(sp, NULL, &cmdp->addr1, &cmdp->addr2, CUT_LINEMODE))
  76                 return (1);
  77
  78         /*
  79          * The historic version of vi permitted the user to string any number
  80          * of '>' or '<' characters together, resulting in an indent of the
  81          * appropriate levels.  There's a special hack in ex_cmd() so that
  82          * cmdp->argv[0] points to the string of '>' or '<' characters.
  83          *
  84          * Q: What's the difference between the people adding features
  85          *    to vi and the Girl Scouts?
  86          * A: The Girl Scouts have mint cookies and adult supervision.
  87          */
  88         for (p = cmdp->argv[0]->bp, sw = 0; *p == '>' || *p == '<'; ++p)
  89                 sw += O_VAL(sp, O_SHIFTWIDTH);
  90
  91         GET_SPACE_RETW(sp, bp, blen, 256);
  92
  93         curset = 0;
  94         for (from = cmdp->addr1.lno, to = cmdp->addr2.lno; from <= to; ++from) {
  95                 if (db_get(sp, from, DBG_FATAL, &p, &len))
  96                         goto err;
  97                 if (!len) {
  98                         if (sp->lno == from)
  99                                 curset = 1;
 100                         continue;
 101                 }
 102
 103                 /*
 104                  * Calculate the old indent amount and the number of
 105                  * characters it used.
 106                  */
 107                 for (oldidx = 0, oldcol = 0; oldidx < len; ++oldidx)
 108                         if (p[oldidx] == ' ')
 109                                 ++oldcol;
 110                         else if (p[oldidx] == '\t')
 111                                 oldcol += O_VAL(sp, O_TABSTOP) -
 112                                     oldcol % O_VAL(sp, O_TABSTOP);
 113                         else
 114                                 break;
 115
 116                 /* Calculate the new indent amount. */
 117                 if (rl == RIGHT)
 118                         newcol = oldcol + sw;
 119                 else {
 120                         newcol = oldcol < sw ? 0 : oldcol - sw;
 121                         if (newcol == oldcol) {
 122                                 if (sp->lno == from)
 123                                         curset = 1;
 124                                 continue;
 125                         }
 126                 }
 127
 128                 /* Get a buffer that will hold the new line. */
 129                 ADD_SPACE_RETW(sp, bp, blen, newcol + len);
 130
 131                 /*
 132                  * Build a new indent string and count the number of
 133                  * characters it uses.
 134                  */
 135                 for (tbp = bp, newidx = 0;
 136                     newcol >= O_VAL(sp, O_TABSTOP); ++newidx) {
 137                         *tbp++ = '\t';
 138                         newcol -= O_VAL(sp, O_TABSTOP);
 139                 }
 140                 for (; newcol > 0; --newcol, ++newidx)
 141                         *tbp++ = ' ';
 142
 143                 /* Add the original line. */
 144                 MEMCPY(tbp, p + oldidx, len - oldidx);
 145
 146                 /* Set the replacement line. */
 147                 if (db_set(sp, from, bp, (tbp + (len - oldidx)) - bp)) {
 148 err:                    FREE_SPACEW(sp, bp, blen);
 149                         return (1);
 150                 }
 151
 152                 /*
 153                  * !!!
 154                  * The shift command in historic vi had the usual bizarre
 155                  * collection of cursor semantics.  If called from vi, the
 156                  * cursor was repositioned to the first non-blank character
 157                  * of the lowest numbered line shifted.  If called from ex,
 158                  * the cursor was repositioned to the first non-blank of the
 159                  * highest numbered line shifted.  Here, if the cursor isn't
 160                  * part of the set of lines that are moved, move it to the
 161                  * first non-blank of the last line shifted.  (This makes
 162                  * ":3>>" in vi work reasonably.)  If the cursor is part of
 163                  * the shifted lines, it doesn't get moved at all.  This
 164                  * permits shifting of marked areas, i.e. ">'a." shifts the
 165                  * marked area twice, something that couldn't be done with
 166                  * historic vi.
 167                  */
 168                 if (sp->lno == from) {
 169                         curset = 1;
 170                         if (newidx > oldidx)
 171                                 sp->cno += newidx - oldidx;
 172                         else if (sp->cno >= oldidx - newidx)
 173                                 sp->cno -= oldidx - newidx;
 174                 }
 175         }
 176         if (!curset) {
 177                 sp->lno = to;
 178                 sp->cno = 0;
 179                 (void)nonblank(sp, to, &sp->cno);
 180         }
 181
 182         FREE_SPACEW(sp, bp, blen);
 183
 184         sp->rptlines[L_SHIFT] += cmdp->addr2.lno - cmdp->addr1.lno + 1;
 185         return (0);
 186 }