usr.bin/mandoc/term.c

   1 /*      $Id: term.c,v 1.120 2009/10/31 06:10:58 kristaps Exp $ */
   2 /*
   3  * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@kth.se>
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17 #include <assert.h>
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <string.h>
  21 #include <time.h>
  22
  23 #include "chars.h"
  24 #include "out.h"
  25 #include "term.h"
  26 #include "man.h"
  27 #include "mdoc.h"
  28 #include "main.h"
  29
  30 /* FIXME: accomodate non-breaking, non-collapsing white-space. */
  31 /* FIXME: accomodate non-breaking, collapsing white-space. */
  32
  33 static  struct termp     *term_alloc(enum termenc);
  34 static  void              term_free(struct termp *);
  35
  36 static  void              do_escaped(struct termp *, const char **);
  37 static  void              do_special(struct termp *,
  38                                 const char *, size_t);
  39 static  void              do_reserved(struct termp *,
  40                                 const char *, size_t);
  41 static  void              buffer(struct termp *, char);
  42 static  void              encode(struct termp *, char);
  43
  44
  45 void *
  46 ascii_alloc(void)
  47 {
  48
  49         return(term_alloc(TERMENC_ASCII));
  50 }
  51
  52
  53 void
  54 terminal_free(void *arg)
  55 {
  56
  57         term_free((struct termp *)arg);
  58 }
  59
  60
  61 static void
  62 term_free(struct termp *p)
  63 {
  64
  65         if (p->buf)
  66                 free(p->buf);
  67         if (p->symtab)
  68                 chars_free(p->symtab);
  69
  70         free(p);
  71 }
  72
  73
  74 static struct termp *
  75 term_alloc(enum termenc enc)
  76 {
  77         struct termp *p;
  78
  79         p = calloc(1, sizeof(struct termp));
  80         if (NULL == p) {
  81                 perror(NULL);
  82                 exit(EXIT_FAILURE);
  83         }
  84         p->maxrmargin = 78;
  85         p->enc = enc;
  86         return(p);
  87 }
  88
  89
  90 /*
  91  * Flush a line of text.  A "line" is loosely defined as being something
  92  * that should be followed by a newline, regardless of whether it's
  93  * broken apart by newlines getting there.  A line can also be a
  94  * fragment of a columnar list.
  95  *
  96  * Specifically, a line is whatever's in p->buf of length p->col, which
  97  * is zeroed after this function returns.
  98  *
  99  * The usage of termp:flags is as follows:
 100  *
 101  *  - TERMP_NOLPAD: when beginning to write the line, don't left-pad the
 102  *    offset value.  This is useful when doing columnar lists where the
 103  *    prior column has right-padded.
 104  *
 105  *  - TERMP_NOBREAK: this is the most important and is used when making
 106  *    columns.  In short: don't print a newline and instead pad to the
 107  *    right margin.  Used in conjunction with TERMP_NOLPAD.
 108  *
 109  *  - TERMP_TWOSPACE: when padding, make sure there are at least two
 110  *    space characters of padding.  Otherwise, rather break the line.
 111  *
 112  *  - TERMP_DANGLE: don't newline when TERMP_NOBREAK is specified and
 113  *    the line is overrun, and don't pad-right if it's underrun.
 114  *
 115  *  - TERMP_HANG: like TERMP_DANGLE, but doesn't newline when
 116  *    overruning, instead save the position and continue at that point
 117  *    when the next invocation.
 118  *
 119  *  In-line line breaking:
 120  *
 121  *  If TERMP_NOBREAK is specified and the line overruns the right
 122  *  margin, it will break and pad-right to the right margin after
 123  *  writing.  If maxrmargin is violated, it will break and continue
 124  *  writing from the right-margin, which will lead to the above scenario
 125  *  upon exit.  Otherwise, the line will break at the right margin.
 126  */
 127 void
 128 term_flushln(struct termp *p)
 129 {
 130         int              i;     /* current input position in p->buf */
 131         size_t           vis;   /* current visual position on output */
 132         size_t           vbl;   /* number of blanks to prepend to output */
 133         size_t           vsz;   /* visual characters to write to output */
 134         size_t           bp;    /* visual right border position */
 135         int              j;     /* temporary loop index */
 136         size_t           maxvis, mmax;
 137         static int       overstep = 0;
 138
 139         /*
 140          * First, establish the maximum columns of "visible" content.
 141          * This is usually the difference between the right-margin and
 142          * an indentation, but can be, for tagged lists or columns, a
 143          * small set of values.
 144          */
 145
 146         assert(p->offset < p->rmargin);
 147
 148         maxvis = (int)(p->rmargin - p->offset) - overstep < 0 ?
 149                 /* LINTED */
 150                 0 : p->rmargin - p->offset - overstep;
 151         mmax = (int)(p->maxrmargin - p->offset) - overstep < 0 ?
 152                 /* LINTED */
 153                 0 : p->maxrmargin - p->offset - overstep;
 154
 155         bp = TERMP_NOBREAK & p->flags ? mmax : maxvis;
 156
 157         /*
 158          * FIXME: if bp is zero, we still output the first word before
 159          * breaking the line.
 160          */
 161
 162         vis = 0;
 163
 164         /*
 165          * If in the standard case (left-justified), then begin with our
 166          * indentation, otherwise (columns, etc.) just start spitting
 167          * out text.
 168          */
 169
 170         if ( ! (p->flags & TERMP_NOLPAD))
 171                 /* LINTED */
 172                 for (j = 0; j < (int)p->offset; j++)
 173                         putchar(' ');
 174
 175         for (i = 0; i < (int)p->col; i++) {
 176                 /*
 177                  * Count up visible word characters.  Control sequences
 178                  * (starting with the CSI) aren't counted.  A space
 179                  * generates a non-printing word, which is valid (the
 180                  * space is printed according to regular spacing rules).
 181                  */
 182
 183                 /* LINTED */
 184                 for (j = i, vsz = 0; j < (int)p->col; j++) {
 185                         if (j && ' ' == p->buf[j])
 186                                 break;
 187                         else if (8 == p->buf[j])
 188                                 vsz--;
 189                         else
 190                                 vsz++;
 191                 }
 192
 193                 /*
 194                  * Choose the number of blanks to prepend: no blank at the
 195                  * beginning of a line, one between words -- but do not
 196                  * actually write them yet.
 197                  */
 198                 vbl = (size_t)(0 == vis ? 0 : 1);
 199
 200                 /*
 201                  * Find out whether we would exceed the right margin.
 202                  * If so, break to the next line.  (TODO: hyphenate)
 203                  * Otherwise, write the chosen number of blanks now.
 204                  */
 205                 if (vis && vis + vbl + vsz > bp) {
 206                         putchar('\n');
 207                         if (TERMP_NOBREAK & p->flags) {
 208                                 for (j = 0; j < (int)p->rmargin; j++)
 209                                         putchar(' ');
 210                                 vis = p->rmargin - p->offset;
 211                         } else {
 212                                 for (j = 0; j < (int)p->offset; j++)
 213                                         putchar(' ');
 214                                 vis = 0;
 215                         }
 216                         /* Remove the overstep width. */
 217                         bp += (int)/* LINTED */
 218                                 overstep;
 219                         overstep = 0;
 220                 } else {
 221                         for (j = 0; j < (int)vbl; j++)
 222                                 putchar(' ');
 223                         vis += vbl;
 224                 }
 225
 226                 /*
 227                  * Finally, write out the word.
 228                  */
 229                 for ( ; i < (int)p->col; i++) {
 230                         if (' ' == p->buf[i])
 231                                 break;
 232                         putchar(p->buf[i]);
 233                 }
 234                 vis += vsz;
 235         }
 236
 237         p->col = 0;
 238         overstep = 0;
 239
 240         if ( ! (TERMP_NOBREAK & p->flags)) {
 241                 putchar('\n');
 242                 return;
 243         }
 244
 245         if (TERMP_HANG & p->flags) {
 246                 /* We need one blank after the tag. */
 247                 overstep = /* LINTED */
 248                         vis - maxvis + 1;
 249
 250                 /*
 251                  * Behave exactly the same way as groff:
 252                  * If we have overstepped the margin, temporarily move
 253                  * it to the right and flag the rest of the line to be
 254                  * shorter.
 255                  * If we landed right at the margin, be happy.
 256                  * If we are one step before the margin, temporarily
 257                  * move it one step LEFT and flag the rest of the line
 258                  * to be longer.
 259                  */
 260                 if (overstep >= -1) {
 261                         assert((int)maxvis + overstep >= 0);
 262                         /* LINTED */
 263                         maxvis += overstep;
 264                 } else
 265                         overstep = 0;
 266
 267         } else if (TERMP_DANGLE & p->flags)
 268                 return;
 269
 270         /* Right-pad. */
 271         if (maxvis > vis + /* LINTED */
 272                         ((TERMP_TWOSPACE & p->flags) ? 1 : 0))
 273                 for ( ; vis < maxvis; vis++)
 274                         putchar(' ');
 275         else {  /* ...or newline break. */
 276                 putchar('\n');
 277                 for (i = 0; i < (int)p->rmargin; i++)
 278                         putchar(' ');
 279         }
 280 }
 281
 282
 283 /*
 284  * A newline only breaks an existing line; it won't assert vertical
 285  * space.  All data in the output buffer is flushed prior to the newline
 286  * assertion.
 287  */
 288 void
 289 term_newln(struct termp *p)
 290 {
 291
 292         p->flags |= TERMP_NOSPACE;
 293         if (0 == p->col) {
 294                 p->flags &= ~TERMP_NOLPAD;
 295                 return;
 296         }
 297         term_flushln(p);
 298         p->flags &= ~TERMP_NOLPAD;
 299 }
 300
 301
 302 /*
 303  * Asserts a vertical space (a full, empty line-break between lines).
 304  * Note that if used twice, this will cause two blank spaces and so on.
 305  * All data in the output buffer is flushed prior to the newline
 306  * assertion.
 307  */
 308 void
 309 term_vspace(struct termp *p)
 310 {
 311
 312         term_newln(p);
 313         putchar('\n');
 314 }
 315
 316
 317 static void
 318 do_special(struct termp *p, const char *word, size_t len)
 319 {
 320         const char      *rhs;
 321         size_t           sz;
 322         int              i;
 323
 324         rhs = chars_a2ascii(p->symtab, word, len, &sz);
 325
 326         if (NULL == rhs) {
 327 #if 0
 328                 fputs("Unknown special character: ", stderr);
 329                 for (i = 0; i < (int)len; i++)
 330                         fputc(word[i], stderr);
 331                 fputc('\n', stderr);
 332 #endif
 333                 return;
 334         }
 335         for (i = 0; i < (int)sz; i++)
 336                 encode(p, rhs[i]);
 337 }
 338
 339
 340 static void
 341 do_reserved(struct termp *p, const char *word, size_t len)
 342 {
 343         const char      *rhs;
 344         size_t           sz;
 345         int              i;
 346
 347         rhs = chars_a2res(p->symtab, word, len, &sz);
 348
 349         if (NULL == rhs) {
 350 #if 0
 351                 fputs("Unknown reserved word: ", stderr);
 352                 for (i = 0; i < (int)len; i++)
 353                         fputc(word[i], stderr);
 354                 fputc('\n', stderr);
 355 #endif
 356                 return;
 357         }
 358         for (i = 0; i < (int)sz; i++)
 359                 encode(p, rhs[i]);
 360 }
 361
 362
 363 /*
 364  * Handle an escape sequence: determine its length and pass it to the
 365  * escape-symbol look table.  Note that we assume mdoc(3) has validated
 366  * the escape sequence (we assert upon badly-formed escape sequences).
 367  */
 368 static void
 369 do_escaped(struct termp *p, const char **word)
 370 {
 371         int              j, type;
 372         const char      *wp;
 373
 374         wp = *word;
 375         type = 1;
 376
 377         if (0 == *(++wp)) {
 378                 *word = wp;
 379                 return;
 380         }
 381
 382         if ('(' == *wp) {
 383                 wp++;
 384                 if (0 == *wp || 0 == *(wp + 1)) {
 385                         *word = 0 == *wp ? wp : wp + 1;
 386                         return;
 387                 }
 388
 389                 do_special(p, wp, 2);
 390                 *word = ++wp;
 391                 return;
 392
 393         } else if ('*' == *wp) {
 394                 if (0 == *(++wp)) {
 395                         *word = wp;
 396                         return;
 397                 }
 398
 399                 switch (*wp) {
 400                 case ('('):
 401                         wp++;
 402                         if (0 == *wp || 0 == *(wp + 1)) {
 403                                 *word = 0 == *wp ? wp : wp + 1;
 404                                 return;
 405                         }
 406
 407                         do_reserved(p, wp, 2);
 408                         *word = ++wp;
 409                         return;
 410                 case ('['):
 411                         type = 0;
 412                         break;
 413                 default:
 414                         do_reserved(p, wp, 1);
 415                         *word = wp;
 416                         return;
 417                 }
 418
 419         } else if ('f' == *wp) {
 420                 if (0 == *(++wp)) {
 421                         *word = wp;
 422                         return;
 423                 }
 424
 425                 switch (*wp) {
 426                 case ('B'):
 427                         p->bold++;
 428                         break;
 429                 case ('I'):
 430                         p->under++;
 431                         break;
 432                 case ('P'):
 433                         /* FALLTHROUGH */
 434                 case ('R'):
 435                         p->bold = p->under = 0;
 436                         break;
 437                 default:
 438                         break;
 439                 }
 440
 441                 *word = wp;
 442                 return;
 443
 444         } else if ('[' != *wp) {
 445                 do_special(p, wp, 1);
 446                 *word = wp;
 447                 return;
 448         }
 449
 450         wp++;
 451         for (j = 0; *wp && ']' != *wp; wp++, j++)
 452                 /* Loop... */ ;
 453
 454         if (0 == *wp) {
 455                 *word = wp;
 456                 return;
 457         }
 458
 459         if (type)
 460                 do_special(p, wp - j, (size_t)j);
 461         else
 462                 do_reserved(p, wp - j, (size_t)j);
 463         *word = wp;
 464 }
 465
 466
 467 /*
 468  * Handle pwords, partial words, which may be either a single word or a
 469  * phrase that cannot be broken down (such as a literal string).  This
 470  * handles word styling.
 471  */
 472 void
 473 term_word(struct termp *p, const char *word)
 474 {
 475         const char       *sv;
 476
 477         sv = word;
 478
 479         if (word[0] && 0 == word[1])
 480                 switch (word[0]) {
 481                 case('.'):
 482                         /* FALLTHROUGH */
 483                 case(','):
 484                         /* FALLTHROUGH */
 485                 case(';'):
 486                         /* FALLTHROUGH */
 487                 case(':'):
 488                         /* FALLTHROUGH */
 489                 case('?'):
 490                         /* FALLTHROUGH */
 491                 case('!'):
 492                         /* FALLTHROUGH */
 493                 case(')'):
 494                         /* FALLTHROUGH */
 495                 case(']'):
 496                         /* FALLTHROUGH */
 497                 case('}'):
 498                         if ( ! (TERMP_IGNDELIM & p->flags))
 499                                 p->flags |= TERMP_NOSPACE;
 500                         break;
 501                 default:
 502                         break;
 503                 }
 504
 505         if ( ! (TERMP_NOSPACE & p->flags))
 506                 buffer(p, ' ');
 507
 508         if ( ! (p->flags & TERMP_NONOSPACE))
 509                 p->flags &= ~TERMP_NOSPACE;
 510
 511         for ( ; *word; word++)
 512                 if ('\\' != *word)
 513                         encode(p, *word);
 514                 else
 515                         do_escaped(p, &word);
 516
 517         if (sv[0] && 0 == sv[1])
 518                 switch (sv[0]) {
 519                 case('('):
 520                         /* FALLTHROUGH */
 521                 case('['):
 522                         /* FALLTHROUGH */
 523                 case('{'):
 524                         p->flags |= TERMP_NOSPACE;
 525                         break;
 526                 default:
 527                         break;
 528                 }
 529 }
 530
 531
 532 /*
 533  * Insert a single character into the line-buffer.  If the buffer's
 534  * space is exceeded, then allocate more space by doubling the buffer
 535  * size.
 536  */
 537 static void
 538 buffer(struct termp *p, char c)
 539 {
 540         size_t           s;
 541
 542         if (p->col + 1 >= p->maxcols) {
 543                 if (0 == p->maxcols)
 544                         p->maxcols = 256;
 545                 s = p->maxcols * 2;
 546                 p->buf = realloc(p->buf, s);
 547                 if (NULL == p->buf) {
 548                         perror(NULL);
 549                         exit(EXIT_FAILURE);
 550                 }
 551                 p->maxcols = s;
 552         }
 553         p->buf[(int)(p->col)++] = c;
 554 }
 555
 556
 557 static void
 558 encode(struct termp *p, char c)
 559 {
 560
 561         if (' ' != c) {
 562                 if (p->under) {
 563                         buffer(p, '_');
 564                         buffer(p, 8);
 565                 }
 566                 if (p->bold) {
 567                         buffer(p, c);
 568                         buffer(p, 8);
 569                 }
 570         }
 571         buffer(p, c);
 572 }
 573
 574
 575 size_t
 576 term_vspan(const struct roffsu *su)
 577 {
 578         double           r;
 579
 580         switch (su->unit) {
 581         case (SCALE_CM):
 582                 r = su->scale * 2;
 583                 break;
 584         case (SCALE_IN):
 585                 r = su->scale * 6;
 586                 break;
 587         case (SCALE_PC):
 588                 r = su->scale;
 589                 break;
 590         case (SCALE_PT):
 591                 r = su->scale / 8;
 592                 break;
 593         case (SCALE_MM):
 594                 r = su->scale / 1000;
 595                 break;
 596         case (SCALE_VS):
 597                 r = su->scale;
 598                 break;
 599         default:
 600                 r = su->scale - 1;
 601                 break;
 602         }
 603
 604         if (r < 0.0)
 605                 r = 0.0;
 606         return(/* LINTED */(size_t)
 607                         r);
 608 }
 609
 610
 611 size_t
 612 term_hspan(const struct roffsu *su)
 613 {
 614         double           r;
 615
 616         /* XXX: CM, IN, and PT are approximations. */
 617
 618         switch (su->unit) {
 619         case (SCALE_CM):
 620                 r = 4 * su->scale;
 621                 break;
 622         case (SCALE_IN):
 623                 /* XXX: this is an approximation. */
 624                 r = 10 * su->scale;
 625                 break;
 626         case (SCALE_PC):
 627                 r = (10 * su->scale) / 6;
 628                 break;
 629         case (SCALE_PT):
 630                 r = (10 * su->scale) / 72;
 631                 break;
 632         case (SCALE_MM):
 633                 r = su->scale / 1000; /* FIXME: double-check. */
 634                 break;
 635         case (SCALE_VS):
 636                 r = su->scale * 2 - 1; /* FIXME: double-check. */
 637                 break;
 638         default:
 639                 r = su->scale;
 640                 break;
 641         }
 642
 643         if (r < 0.0)
 644                 r = 0.0;
 645         return((size_t)/* LINTED */
 646                         r);
 647 }