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 10.16 2000/07/19 17:05:20 skimo Exp $ (Berkeley) $Date: 2000/07/19 17:05:20 $";
  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(sp, colp)
  36         SCR *sp;
  37         size_t *colp;
  38 {
  39         VI_PRIVATE *vip;
  40
  41         vip = VIP(sp);
  42
  43         *colp = (O_ISSET(sp, O_LEFTRIGHT) ?
  44             vip->sc_smap->coff : (vip->sc_smap->soff - 1) * sp->cols) +
  45             vip->sc_col - (O_ISSET(sp, O_NUMBER) ? O_NUMBER_LENGTH : 0);
  46         return (0);
  47 }
  48
  49 /*
  50  * vs_screens --
  51  *      Return the screens necessary to display the line, or if specified,
  52  *      the physical character column within the line, including space
  53  *      required for the O_NUMBER and O_LIST options.
  54  *
  55  * PUBLIC: size_t vs_screens __P((SCR *, db_recno_t, size_t *));
  56  */
  57 size_t
  58 vs_screens(sp, lno, cnop)
  59         SCR *sp;
  60         db_recno_t lno;
  61         size_t *cnop;
  62 {
  63         size_t cols, screens;
  64
  65         /* Left-right screens are simple, it's always 1. */
  66         if (O_ISSET(sp, O_LEFTRIGHT))
  67                 return (1);
  68
  69         /*
  70          * Check for a cached value.  We maintain a cache because, if the
  71          * line is large, this routine gets called repeatedly.  One other
  72          * hack, lots of time the cursor is on column one, which is an easy
  73          * one.
  74          */
  75         if (cnop == NULL) {
  76                 if (VIP(sp)->ss_lno == lno)
  77                         return (VIP(sp)->ss_screens);
  78         } else if (*cnop == 0)
  79                 return (1);
  80
  81         /* Figure out how many columns the line/column needs. */
  82         cols = vs_columns(sp, NULL, lno, cnop, NULL);
  83
  84         screens = (cols / sp->cols + (cols % sp->cols ? 1 : 0));
  85         if (screens == 0)
  86                 screens = 1;
  87
  88         /* Cache the value. */
  89         if (cnop == NULL) {
  90                 VIP(sp)->ss_lno = lno;
  91                 VIP(sp)->ss_screens = screens;
  92         }
  93         return (screens);
  94 }
  95
  96 /*
  97  * vs_columns --
  98  *      Return the screen columns necessary to display the line, or,
  99  *      if specified, the physical character column within the line.
 100  *
 101  * PUBLIC: size_t vs_columns __P((SCR *, CHAR_T *, db_recno_t, size_t *, size_t *));
 102  */
 103 size_t
 104 vs_columns(sp, lp, lno, cnop, diffp)
 105         SCR *sp;
 106         CHAR_T *lp;
 107         db_recno_t lno;
 108         size_t *cnop, *diffp;
 109 {
 110         size_t chlen, cno, curoff, last, len, scno;
 111         int ch, leftright, listset;
 112         CHAR_T *p;
 113
 114         /* Need the line to go any further. */
 115         if (lp == NULL) {
 116                 (void)db_get(sp, lno, 0, &lp, &len);
 117                 if (len == 0)
 118                         goto done;
 119         }
 120
 121         /* Missing or empty lines are easy. */
 122         if (lp == NULL) {
 123 done:           if (diffp != NULL)              /* XXX */
 124                         *diffp = 0;
 125                 return (0);
 126         }
 127
 128         /* Store away the values of the list and leftright edit options. */
 129         listset = O_ISSET(sp, O_LIST);
 130         leftright = O_ISSET(sp, O_LEFTRIGHT);
 131
 132         /*
 133          * Initialize the pointer into the buffer and screen and current
 134          * offsets.
 135          */
 136         p = lp;
 137         curoff = scno = 0;
 138
 139         /* Leading number if O_NUMBER option set. */
 140         if (O_ISSET(sp, O_NUMBER))
 141                 scno += O_NUMBER_LENGTH;
 142
 143         /* Macro to return the display length of any signal character. */
 144 #define CHLEN(val) (ch = *(UCHAR_T *)p++) == '\t' &&                    \
 145             !listset ? TAB_OFF(val) : KEY_COL(sp, ch);
 146
 147         /*
 148          * If folding screens (the historic vi screen format), past the end
 149          * of the current screen, and the character was a tab, reset the
 150          * current screen column to 0, and the total screen columns to the
 151          * last column of the screen.  Otherwise, display the rest of the
 152          * character in the next screen.
 153          */
 154 #define TAB_RESET {                                                     \
 155         curoff += chlen;                                                \
 156         if (!leftright && curoff >= sp->cols)                           \
 157                 if (ch == '\t') {                                       \
 158                         curoff = 0;                                     \
 159                         scno -= scno % sp->cols;                        \
 160                 } else                                                  \
 161                         curoff -= sp->cols;                             \
 162 }
 163         if (cnop == NULL)
 164                 while (len--) {
 165                         chlen = CHLEN(curoff);
 166                         last = scno;
 167                         scno += chlen;
 168                         TAB_RESET;
 169                 }
 170         else
 171                 for (cno = *cnop;; --cno) {
 172                         chlen = CHLEN(curoff);
 173                         last = scno;
 174                         scno += chlen;
 175                         TAB_RESET;
 176                         if (cno == 0)
 177                                 break;
 178                 }
 179
 180         /* Add the trailing '$' if the O_LIST option set. */
 181         if (listset && cnop == NULL)
 182                 scno += KEY_LEN(sp, '$');
 183
 184         /*
 185          * The text input screen code needs to know how much additional
 186          * room the last two characters required, so that it can handle
 187          * tab character displays correctly.
 188          */
 189         if (diffp != NULL)
 190                 *diffp = scno - last;
 191         return (scno);
 192 }
 193
 194 /*
 195  * vs_rcm --
 196  *      Return the physical column from the line that will display a
 197  *      character closest to the currently most attractive character
 198  *      position (which is stored as a screen column).
 199  *
 200  * PUBLIC: size_t vs_rcm __P((SCR *, db_recno_t, int));
 201  */
 202 size_t
 203 vs_rcm(sp, lno, islast)
 204         SCR *sp;
 205         db_recno_t lno;
 206         int islast;
 207 {
 208         size_t len;
 209
 210         /* Last character is easy, and common. */
 211         if (islast) {
 212                 if (db_get(sp, lno, 0, NULL, &len) || len == 0)
 213                         return (0);
 214                 return (len - 1);
 215         }
 216
 217         /* First character is easy, and common. */
 218         if (sp->rcm == 0)
 219                 return (0);
 220
 221         return (vs_colpos(sp, lno, sp->rcm));
 222 }
 223
 224 /*
 225  * vs_colpos --
 226  *      Return the physical column from the line that will display a
 227  *      character closest to the specified screen column.
 228  *
 229  * PUBLIC: size_t vs_colpos __P((SCR *, db_recno_t, size_t));
 230  */
 231 size_t
 232 vs_colpos(sp, lno, cno)
 233         SCR *sp;
 234         db_recno_t lno;
 235         size_t cno;
 236 {
 237         size_t chlen, curoff, len, llen, off, scno;
 238         int ch, leftright, listset;
 239         CHAR_T *lp, *p;
 240
 241         /* Need the line to go any further. */
 242         (void)db_get(sp, lno, 0, &lp, &llen);
 243
 244         /* Missing or empty lines are easy. */
 245         if (lp == NULL || llen == 0)
 246                 return (0);
 247
 248         /* Store away the values of the list and leftright edit options. */
 249         listset = O_ISSET(sp, O_LIST);
 250         leftright = O_ISSET(sp, O_LEFTRIGHT);
 251
 252         /* Discard screen (logical) lines. */
 253         off = cno / sp->cols;
 254         cno %= sp->cols;
 255         for (scno = 0, p = lp, len = llen; off--;) {
 256                 for (; len && scno < sp->cols; --len)
 257                         scno += CHLEN(scno);
 258
 259                 /*
 260                  * If reached the end of the physical line, return the last
 261                  * physical character in the line.
 262                  */
 263                 if (len == 0)
 264                         return (llen - 1);
 265
 266                 /*
 267                  * If folding screens (the historic vi screen format), past
 268                  * the end of the current screen, and the character was a tab,
 269                  * reset the current screen column to 0.  Otherwise, the rest
 270                  * of the character is displayed in the next screen.
 271                  */
 272                 if (leftright && ch == '\t')
 273                         scno = 0;
 274                 else
 275                         scno -= sp->cols;
 276         }
 277
 278         /* Step through the line until reach the right character or EOL. */
 279         for (curoff = scno; len--;) {
 280                 chlen = CHLEN(curoff);
 281
 282                 /*
 283                  * If we've reached the specific character, there are three
 284                  * cases.
 285                  *
 286                  * 1: scno == cno, i.e. the current character ends at the
 287                  *    screen character we care about.
 288                  *      a: off < llen - 1, i.e. not the last character in
 289                  *         the line, return the offset of the next character.
 290                  *      b: else return the offset of the last character.
 291                  * 2: scno != cno, i.e. this character overruns the character
 292                  *    we care about, return the offset of this character.
 293                  */
 294                 if ((scno += chlen) >= cno) {
 295                         off = p - lp;
 296                         return (scno == cno ?
 297                             (off < llen - 1 ? off : llen - 1) : off - 1);
 298                 }
 299
 300                 TAB_RESET;
 301         }
 302
 303         /* No such character; return the start of the last character. */
 304         return (llen - 1);
 305 }