vi/vs_relative.c

   1 /*-
   2  * Copyright (c) 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  * Copyright (c) 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: vs_relative.c,v 10.17 2001/06/25 15:19:38 skimo Exp $ (Berkeley) $Date: 2001/06/25 15:19:38 $";
  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 <string.h>
  24
  25 #include "../common/common.h"
  26 #include "vi.h"
  27
  28 /*
  29  * vs_column --
  30  *      Return the logical column of the cursor in the line.
  31  *
  32  * PUBLIC: int vs_column __P((SCR *, size_t *));
  33  */
  34 int
  35 vs_column(SCR *sp, size_t *colp)
  36 {
  37         VI_PRIVATE *vip;
  38
  39         vip = VIP(sp);
  40
  41         *colp = (O_ISSET(sp, O_LEFTRIGHT) ?
  42             vip->sc_smap->coff : (vip->sc_smap->soff - 1) * sp->cols) +
  43             vip->sc_col - (O_ISSET(sp, O_NUMBER) ? O_NUMBER_LENGTH : 0);
  44         return (0);
  45 }
  46
  47 /*
  48  * vs_screens --
  49  *      Return the screens necessary to display the line, or if specified,
  50  *      the physical character column within the line, including space
  51  *      required for the O_NUMBER and O_LIST options.
  52  *
  53  * PUBLIC: size_t vs_screens __P((SCR *, db_recno_t, size_t *));
  54  */
  55 size_t
  56 vs_screens(SCR *sp, db_recno_t lno, size_t *cnop)
  57 {
  58         size_t cols, screens;
  59
  60         /* Left-right screens are simple, it's always 1. */
  61         if (O_ISSET(sp, O_LEFTRIGHT))
  62                 return (1);
  63
  64         /*
  65          * Check for a cached value.  We maintain a cache because, if the
  66          * line is large, this routine gets called repeatedly.  One other
  67          * hack, lots of time the cursor is on column one, which is an easy
  68          * one.
  69          */
  70         if (cnop == NULL) {
  71                 if (VIP(sp)->ss_lno == lno)
  72                         return (VIP(sp)->ss_screens);
  73         } else if (*cnop == 0)
  74                 return (1);
  75
  76         /* Figure out how many columns the line/column needs. */
  77         cols = vs_columns(sp, NULL, lno, cnop, NULL);
  78
  79         screens = (cols / sp->cols + (cols % sp->cols ? 1 : 0));
  80         if (screens == 0)
  81                 screens = 1;
  82
  83         /* Cache the value. */
  84         if (cnop == NULL) {
  85                 VIP(sp)->ss_lno = lno;
  86                 VIP(sp)->ss_screens = screens;
  87         }
  88         return (screens);
  89 }
  90
  91 /*
  92  * vs_columns --
  93  *      Return the screen columns necessary to display the line, or,
  94  *      if specified, the physical character column within the line.
  95  *
  96  * PUBLIC: size_t vs_columns __P((SCR *, CHAR_T *, db_recno_t, size_t *, size_t *));
  97  */
  98 size_t
  99 vs_columns(SCR *sp, CHAR_T *lp, db_recno_t lno, size_t *cnop, size_t *diffp)
 100 {
 101         size_t chlen, cno, curoff, last, len, scno;
 102         int ch, leftright, listset;
 103         CHAR_T *p;
 104
 105         /* Need the line to go any further. */
 106         if (lp == NULL) {
 107                 (void)db_get(sp, lno, 0, &lp, &len);
 108                 if (len == 0)
 109                         goto done;
 110         }
 111
 112         /* Missing or empty lines are easy. */
 113         if (lp == NULL) {
 114 done:           if (diffp != NULL)              /* XXX */
 115                         *diffp = 0;
 116                 return (0);
 117         }
 118
 119         /* Store away the values of the list and leftright edit options. */
 120         listset = O_ISSET(sp, O_LIST);
 121         leftright = O_ISSET(sp, O_LEFTRIGHT);
 122
 123         /*
 124          * Initialize the pointer into the buffer and screen and current
 125          * offsets.
 126          */
 127         p = lp;
 128         curoff = scno = 0;
 129
 130         /* Leading number if O_NUMBER option set. */
 131         if (O_ISSET(sp, O_NUMBER))
 132                 scno += O_NUMBER_LENGTH;
 133
 134         /* Macro to return the display length of any signal character. */
 135 #define CHLEN(val) (ch = *(UCHAR_T *)p++) == '\t' &&                    \
 136             !listset ? TAB_OFF(val) : KEY_COL(sp, ch);
 137
 138         /*
 139          * If folding screens (the historic vi screen format), past the end
 140          * of the current screen, and the character was a tab, reset the
 141          * current screen column to 0, and the total screen columns to the
 142          * last column of the screen.  Otherwise, display the rest of the
 143          * character in the next screen.
 144          */
 145 #define TAB_RESET {                                                     \
 146         curoff += chlen;                                                \
 147         if (!leftright && curoff >= sp->cols)                           \
 148                 if (ch == '\t') {                                       \
 149                         curoff = 0;                                     \
 150                         scno -= scno % sp->cols;                        \
 151                 } else                                                  \
 152                         curoff -= sp->cols;                             \
 153 }
 154         if (cnop == NULL)
 155                 while (len--) {
 156                         chlen = CHLEN(curoff);
 157                         last = scno;
 158                         scno += chlen;
 159                         TAB_RESET;
 160                 }
 161         else
 162                 for (cno = *cnop;; --cno) {
 163                         chlen = CHLEN(curoff);
 164                         last = scno;
 165                         scno += chlen;
 166                         TAB_RESET;
 167                         if (cno == 0)
 168                                 break;
 169                 }
 170
 171         /* Add the trailing '$' if the O_LIST option set. */
 172         if (listset && cnop == NULL)
 173                 scno += KEY_LEN(sp, '$');
 174
 175         /*
 176          * The text input screen code needs to know how much additional
 177          * room the last two characters required, so that it can handle
 178          * tab character displays correctly.
 179          */
 180         if (diffp != NULL)
 181                 *diffp = scno - last;
 182         return (scno);
 183 }
 184
 185 /*
 186  * vs_rcm --
 187  *      Return the physical column from the line that will display a
 188  *      character closest to the currently most attractive character
 189  *      position (which is stored as a screen column).
 190  *
 191  * PUBLIC: size_t vs_rcm __P((SCR *, db_recno_t, int));
 192  */
 193 size_t
 194 vs_rcm(SCR *sp, db_recno_t lno, int islast)
 195 {
 196         size_t len;
 197
 198         /* Last character is easy, and common. */
 199         if (islast) {
 200                 if (db_get(sp, lno, 0, NULL, &len) || len == 0)
 201                         return (0);
 202                 return (len - 1);
 203         }
 204
 205         /* First character is easy, and common. */
 206         if (sp->rcm == 0)
 207                 return (0);
 208
 209         return (vs_colpos(sp, lno, sp->rcm));
 210 }
 211
 212 /*
 213  * vs_colpos --
 214  *      Return the physical column from the line that will display a
 215  *      character closest to the specified screen column.
 216  *
 217  * PUBLIC: size_t vs_colpos __P((SCR *, db_recno_t, size_t));
 218  */
 219 size_t
 220 vs_colpos(SCR *sp, db_recno_t lno, size_t cno)
 221 {
 222         size_t chlen, curoff, len, llen, off, scno;
 223         int ch, leftright, listset;
 224         CHAR_T *lp, *p;
 225
 226         /* Need the line to go any further. */
 227         (void)db_get(sp, lno, 0, &lp, &llen);
 228
 229         /* Missing or empty lines are easy. */
 230         if (lp == NULL || llen == 0)
 231                 return (0);
 232
 233         /* Store away the values of the list and leftright edit options. */
 234         listset = O_ISSET(sp, O_LIST);
 235         leftright = O_ISSET(sp, O_LEFTRIGHT);
 236
 237         /* Discard screen (logical) lines. */
 238         off = cno / sp->cols;
 239         cno %= sp->cols;
 240         for (scno = 0, p = lp, len = llen; off--;) {
 241                 for (; len && scno < sp->cols; --len)
 242                         scno += CHLEN(scno);
 243
 244                 /*
 245                  * If reached the end of the physical line, return the last
 246                  * physical character in the line.
 247                  */
 248                 if (len == 0)
 249                         return (llen - 1);
 250
 251                 /*
 252                  * If folding screens (the historic vi screen format), past
 253                  * the end of the current screen, and the character was a tab,
 254                  * reset the current screen column to 0.  Otherwise, the rest
 255                  * of the character is displayed in the next screen.
 256                  */
 257                 if (leftright && ch == '\t')
 258                         scno = 0;
 259                 else
 260                         scno -= sp->cols;
 261         }
 262
 263         /* Step through the line until reach the right character or EOL. */
 264         for (curoff = scno; len--;) {
 265                 chlen = CHLEN(curoff);
 266
 267                 /*
 268                  * If we've reached the specific character, there are three
 269                  * cases.
 270                  *
 271                  * 1: scno == cno, i.e. the current character ends at the
 272                  *    screen character we care about.
 273                  *      a: off < llen - 1, i.e. not the last character in
 274                  *         the line, return the offset of the next character.
 275                  *      b: else return the offset of the last character.
 276                  * 2: scno != cno, i.e. this character overruns the character
 277                  *    we care about, return the offset of this character.
 278                  */
 279                 if ((scno += chlen) >= cno) {
 280                         off = p - lp;
 281                         return (scno == cno ?
 282                             (off < llen - 1 ? off : llen - 1) : off - 1);
 283                 }
 284
 285                 TAB_RESET;
 286         }
 287
 288         /* No such character; return the start of the last character. */
 289         return (llen - 1);
 290 }