term.c

   1 /*      $Id: term.c,v 1.161 2010/07/16 22:33:30 kristaps Exp $ */
   2 /*
   3  * Copyright (c) 2008, 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
   4  * Copyright (c) 2010 Ingo Schwarze <schwarze@openbsd.org>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18 #ifdef HAVE_CONFIG_H
  19 #include "config.h"
  20 #endif
  21
  22 #include <sys/types.h>
  23
  24 #include <assert.h>
  25 #include <ctype.h>
  26 #include <stdint.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30
  31 #include "mandoc.h"
  32 #include "chars.h"
  33 #include "out.h"
  34 #include "term.h"
  35 #include "main.h"
  36
  37 static  void              spec(struct termp *, const char *, size_t);
  38 static  void              res(struct termp *, const char *, size_t);
  39 static  void              buffera(struct termp *, const char *, size_t);
  40 static  void              bufferc(struct termp *, char);
  41 static  void              adjbuf(struct termp *p, size_t);
  42 static  void              encode(struct termp *, const char *, size_t);
  43
  44
  45 void
  46 term_free(struct termp *p)
  47 {
  48
  49         if (p->buf)
  50                 free(p->buf);
  51         if (p->symtab)
  52                 chars_free(p->symtab);
  53
  54         free(p);
  55 }
  56
  57
  58 void
  59 term_begin(struct termp *p, term_margin head,
  60                 term_margin foot, const void *arg)
  61 {
  62
  63         p->headf = head;
  64         p->footf = foot;
  65         p->argf = arg;
  66         (*p->begin)(p);
  67 }
  68
  69
  70 void
  71 term_end(struct termp *p)
  72 {
  73
  74         (*p->end)(p);
  75 }
  76
  77
  78 struct termp *
  79 term_alloc(enum termenc enc)
  80 {
  81         struct termp    *p;
  82
  83         p = calloc(1, sizeof(struct termp));
  84         if (NULL == p) {
  85                 perror(NULL);
  86                 exit(EXIT_FAILURE);
  87         }
  88
  89         p->enc = enc;
  90         return(p);
  91 }
  92
  93
  94 /*
  95  * Flush a line of text.  A "line" is loosely defined as being something
  96  * that should be followed by a newline, regardless of whether it's
  97  * broken apart by newlines getting there.  A line can also be a
  98  * fragment of a columnar list (`Bl -tag' or `Bl -column'), which does
  99  * not have a trailing newline.
 100  *
 101  * The following flags may be specified:
 102  *
 103  *  - TERMP_NOLPAD: when beginning to write the line, don't left-pad the
 104  *    offset value.  This is useful when doing columnar lists where the
 105  *    prior column has right-padded.
 106  *
 107  *  - TERMP_NOBREAK: this is the most important and is used when making
 108  *    columns.  In short: don't print a newline and instead pad to the
 109  *    right margin.  Used in conjunction with TERMP_NOLPAD.
 110  *
 111  *  - TERMP_TWOSPACE: when padding, make sure there are at least two
 112  *    space characters of padding.  Otherwise, rather break the line.
 113  *
 114  *  - TERMP_DANGLE: don't newline when TERMP_NOBREAK is specified and
 115  *    the line is overrun, and don't pad-right if it's underrun.
 116  *
 117  *  - TERMP_HANG: like TERMP_DANGLE, but doesn't newline when
 118  *    overruning, instead save the position and continue at that point
 119  *    when the next invocation.
 120  *
 121  *  In-line line breaking:
 122  *
 123  *  If TERMP_NOBREAK is specified and the line overruns the right
 124  *  margin, it will break and pad-right to the right margin after
 125  *  writing.  If maxrmargin is violated, it will break and continue
 126  *  writing from the right-margin, which will lead to the above scenario
 127  *  upon exit.  Otherwise, the line will break at the right margin.
 128  */
 129 void
 130 term_flushln(struct termp *p)
 131 {
 132         int              i;     /* current input position in p->buf */
 133         size_t           vis;   /* current visual position on output */
 134         size_t           vbl;   /* number of blanks to prepend to output */
 135         size_t           vend;  /* end of word visual position on output */
 136         size_t           bp;    /* visual right border position */
 137         int              j;     /* temporary loop index for p->buf */
 138         int              jhy;   /* last hyph before overflow w/r/t j */
 139         size_t           maxvis; /* output position of visible boundary */
 140         size_t           mmax; /* used in calculating bp */
 141
 142         /*
 143          * First, establish the maximum columns of "visible" content.
 144          * This is usually the difference between the right-margin and
 145          * an indentation, but can be, for tagged lists or columns, a
 146          * small set of values.
 147          */
 148
 149         assert(p->offset < p->rmargin);
 150
 151         maxvis = (int)(p->rmargin - p->offset) - p->overstep < 0 ?
 152                 /* LINTED */
 153                 0 : p->rmargin - p->offset - p->overstep;
 154         mmax = (int)(p->maxrmargin - p->offset) - p->overstep < 0 ?
 155                 /* LINTED */
 156                 0 : p->maxrmargin - p->offset - p->overstep;
 157
 158         bp = TERMP_NOBREAK & p->flags ? mmax : maxvis;
 159
 160         /*
 161          * Indent the first line of a paragraph.
 162          */
 163         vbl = p->flags & TERMP_NOLPAD ? 0 : p->offset;
 164
 165         vis = vend = i = 0;
 166
 167         while (i < (int)p->col) {
 168                 /*
 169                  * Handle literal tab characters: collapse all
 170                  * subsequent tabs into a single huge set of spaces.
 171                  */
 172                 for (j = i; j < (int)p->col; j++) {
 173                         if ('\t' != p->buf[j])
 174                                 break;
 175                         vend = (vis / p->tabwidth + 1) * p->tabwidth;
 176                         vbl += vend - vis;
 177                         vis = vend;
 178                 }
 179
 180                 /*
 181                  * Count up visible word characters.  Control sequences
 182                  * (starting with the CSI) aren't counted.  A space
 183                  * generates a non-printing word, which is valid (the
 184                  * space is printed according to regular spacing rules).
 185                  */
 186
 187                 /* LINTED */
 188                 for (jhy = 0; j < (int)p->col; j++) {
 189                         if ((j && ' ' == p->buf[j]) || '\t' == p->buf[j])
 190                                 break;
 191
 192                         /* Back over the the last printed character. */
 193                         if (8 == p->buf[j]) {
 194                                 assert(j);
 195                                 vend -= (*p->width)(p, p->buf[j - 1]);
 196                                 continue;
 197                         }
 198
 199                         /* Regular word. */
 200                         /* Break at the hyphen point if we overrun. */
 201                         if (vend > vis && vend < bp &&
 202                                         ASCII_HYPH == p->buf[j])
 203                                 jhy = j;
 204
 205                         vend += (*p->width)(p, p->buf[j]);
 206                 }
 207
 208                 /*
 209                  * Find out whether we would exceed the right margin.
 210                  * If so, break to the next line.
 211                  */
 212                 if (vend > bp && 0 == jhy && vis > 0) {
 213                         vend -= vis;
 214                         (*p->endline)(p);
 215                         if (TERMP_NOBREAK & p->flags) {
 216                                 p->viscol = p->rmargin;
 217                                 (*p->advance)(p, p->rmargin);
 218                                 vend += p->rmargin - p->offset;
 219                         } else {
 220                                 p->viscol = 0;
 221                                 vbl = p->offset;
 222                         }
 223
 224                         /* Remove the p->overstep width. */
 225
 226                         bp += (int)/* LINTED */
 227                                 p->overstep;
 228                         p->overstep = 0;
 229                 }
 230
 231                 /*
 232                  * Skip leading tabs, they were handled above.
 233                  */
 234                 while (i < (int)p->col && '\t' == p->buf[i])
 235                         i++;
 236
 237                 /* Write out the [remaining] word. */
 238                 for ( ; i < (int)p->col; i++) {
 239                         if (vend > bp && jhy > 0 && i > jhy)
 240                                 break;
 241                         if ('\t' == p->buf[i])
 242                                 break;
 243                         if (' ' == p->buf[i]) {
 244                                 while (' ' == p->buf[i]) {
 245                                         vbl += (*p->width)(p, p->buf[i]);
 246                                         i++;
 247                                 }
 248                                 break;
 249                         }
 250                         if (ASCII_NBRSP == p->buf[i]) {
 251                                 vbl += (*p->width)(p, ' ');
 252                                 continue;
 253                         }
 254
 255                         /*
 256                          * Now we definitely know there will be
 257                          * printable characters to output,
 258                          * so write preceding white space now.
 259                          */
 260                         if (vbl) {
 261                                 (*p->advance)(p, vbl);
 262                                 p->viscol += vbl;
 263                                 vbl = 0;
 264                         }
 265
 266                         if (ASCII_HYPH == p->buf[i]) {
 267                                 (*p->letter)(p, '-');
 268                                 p->viscol += (*p->width)(p, '-');
 269                         } else {
 270                                 (*p->letter)(p, p->buf[i]);
 271                                 p->viscol += (*p->width)(p, p->buf[i]);
 272                         }
 273                 }
 274                 vend += vbl;
 275                 vis = vend;
 276         }
 277
 278         p->col = 0;
 279         p->overstep = 0;
 280
 281         if ( ! (TERMP_NOBREAK & p->flags)) {
 282                 p->viscol = 0;
 283                 (*p->endline)(p);
 284                 return;
 285         }
 286
 287         if (TERMP_HANG & p->flags) {
 288                 /* We need one blank after the tag. */
 289                 p->overstep = /* LINTED */
 290                         vis - maxvis + (*p->width)(p, ' ');
 291
 292                 /*
 293                  * Behave exactly the same way as groff:
 294                  * If we have overstepped the margin, temporarily move
 295                  * it to the right and flag the rest of the line to be
 296                  * shorter.
 297                  * If we landed right at the margin, be happy.
 298                  * If we are one step before the margin, temporarily
 299                  * move it one step LEFT and flag the rest of the line
 300                  * to be longer.
 301                  */
 302                 if (p->overstep >= -1) {
 303                         assert((int)maxvis + p->overstep >= 0);
 304                         /* LINTED */
 305                         maxvis += p->overstep;
 306                 } else
 307                         p->overstep = 0;
 308
 309         } else if (TERMP_DANGLE & p->flags)
 310                 return;
 311
 312         /* Right-pad. */
 313         if (maxvis > vis + /* LINTED */
 314                         ((TERMP_TWOSPACE & p->flags) ?
 315                          (*p->width)(p, ' ') : 0)) {
 316                 p->viscol += maxvis - vis;
 317                 (*p->advance)(p, maxvis - vis);
 318                 vis += (maxvis - vis);
 319         } else {        /* ...or newline break. */
 320                 (*p->endline)(p);
 321                 p->viscol = p->rmargin;
 322                 (*p->advance)(p, p->rmargin);
 323         }
 324 }
 325
 326
 327 /*
 328  * A newline only breaks an existing line; it won't assert vertical
 329  * space.  All data in the output buffer is flushed prior to the newline
 330  * assertion.
 331  */
 332 void
 333 term_newln(struct termp *p)
 334 {
 335
 336         p->flags |= TERMP_NOSPACE;
 337         if (0 == p->col && 0 == p->viscol) {
 338                 p->flags &= ~TERMP_NOLPAD;
 339                 return;
 340         }
 341         term_flushln(p);
 342         p->flags &= ~TERMP_NOLPAD;
 343 }
 344
 345
 346 /*
 347  * Asserts a vertical space (a full, empty line-break between lines).
 348  * Note that if used twice, this will cause two blank spaces and so on.
 349  * All data in the output buffer is flushed prior to the newline
 350  * assertion.
 351  */
 352 void
 353 term_vspace(struct termp *p)
 354 {
 355
 356         term_newln(p);
 357         p->viscol = 0;
 358         (*p->endline)(p);
 359 }
 360
 361
 362 static void
 363 spec(struct termp *p, const char *word, size_t len)
 364 {
 365         const char      *rhs;
 366         size_t           sz;
 367
 368         rhs = chars_spec2str(p->symtab, word, len, &sz);
 369         if (rhs)
 370                 encode(p, rhs, sz);
 371 }
 372
 373
 374 static void
 375 res(struct termp *p, const char *word, size_t len)
 376 {
 377         const char      *rhs;
 378         size_t           sz;
 379
 380         rhs = chars_res2str(p->symtab, word, len, &sz);
 381         if (rhs)
 382                 encode(p, rhs, sz);
 383 }
 384
 385
 386 void
 387 term_fontlast(struct termp *p)
 388 {
 389         enum termfont    f;
 390
 391         f = p->fontl;
 392         p->fontl = p->fontq[p->fonti];
 393         p->fontq[p->fonti] = f;
 394 }
 395
 396
 397 void
 398 term_fontrepl(struct termp *p, enum termfont f)
 399 {
 400
 401         p->fontl = p->fontq[p->fonti];
 402         p->fontq[p->fonti] = f;
 403 }
 404
 405
 406 void
 407 term_fontpush(struct termp *p, enum termfont f)
 408 {
 409
 410         assert(p->fonti + 1 < 10);
 411         p->fontl = p->fontq[p->fonti];
 412         p->fontq[++p->fonti] = f;
 413 }
 414
 415
 416 const void *
 417 term_fontq(struct termp *p)
 418 {
 419
 420         return(&p->fontq[p->fonti]);
 421 }
 422
 423
 424 enum termfont
 425 term_fonttop(struct termp *p)
 426 {
 427
 428         return(p->fontq[p->fonti]);
 429 }
 430
 431
 432 void
 433 term_fontpopq(struct termp *p, const void *key)
 434 {
 435
 436         while (p->fonti >= 0 && key != &p->fontq[p->fonti])
 437                 p->fonti--;
 438         assert(p->fonti >= 0);
 439 }
 440
 441
 442 void
 443 term_fontpop(struct termp *p)
 444 {
 445
 446         assert(p->fonti);
 447         p->fonti--;
 448 }
 449
 450
 451 /*
 452  * Handle pwords, partial words, which may be either a single word or a
 453  * phrase that cannot be broken down (such as a literal string).  This
 454  * handles word styling.
 455  */
 456 void
 457 term_word(struct termp *p, const char *word)
 458 {
 459         const char      *sv, *seq;
 460         int              sz;
 461         size_t           ssz;
 462         enum roffdeco    deco;
 463
 464         sv = word;
 465
 466         if (word[0] && '\0' == word[1])
 467                 switch (word[0]) {
 468                 case('.'):
 469                         /* FALLTHROUGH */
 470                 case(','):
 471                         /* FALLTHROUGH */
 472                 case(';'):
 473                         /* FALLTHROUGH */
 474                 case(':'):
 475                         /* FALLTHROUGH */
 476                 case('?'):
 477                         /* FALLTHROUGH */
 478                 case('!'):
 479                         /* FALLTHROUGH */
 480                 case(')'):
 481                         /* FALLTHROUGH */
 482                 case(']'):
 483                         if ( ! (TERMP_IGNDELIM & p->flags))
 484                                 p->flags |= TERMP_NOSPACE;
 485                         break;
 486                 default:
 487                         break;
 488                 }
 489
 490         if ( ! (TERMP_NOSPACE & p->flags)) {
 491                 if ( ! (TERMP_KEEP & p->flags)) {
 492                         if (TERMP_PREKEEP & p->flags)
 493                                 p->flags |= TERMP_KEEP;
 494                         bufferc(p, ' ');
 495                         if (TERMP_SENTENCE & p->flags)
 496                                 bufferc(p, ' ');
 497                 } else
 498                         bufferc(p, ASCII_NBRSP);
 499         }
 500
 501         if ( ! (p->flags & TERMP_NONOSPACE))
 502                 p->flags &= ~TERMP_NOSPACE;
 503
 504         p->flags &= ~TERMP_SENTENCE;
 505
 506         /* FIXME: use strcspn. */
 507
 508         while (*word) {
 509                 if ('\\' != *word) {
 510                         encode(p, word, 1);
 511                         word++;
 512                         continue;
 513                 }
 514
 515                 seq = ++word;
 516                 sz = a2roffdeco(&deco, &seq, &ssz);
 517
 518                 switch (deco) {
 519                 case (DECO_RESERVED):
 520                         res(p, seq, ssz);
 521                         break;
 522                 case (DECO_SPECIAL):
 523                         spec(p, seq, ssz);
 524                         break;
 525                 case (DECO_BOLD):
 526                         term_fontrepl(p, TERMFONT_BOLD);
 527                         break;
 528                 case (DECO_ITALIC):
 529                         term_fontrepl(p, TERMFONT_UNDER);
 530                         break;
 531                 case (DECO_ROMAN):
 532                         term_fontrepl(p, TERMFONT_NONE);
 533                         break;
 534                 case (DECO_PREVIOUS):
 535                         term_fontlast(p);
 536                         break;
 537                 default:
 538                         break;
 539                 }
 540
 541                 word += sz;
 542                 if (DECO_NOSPACE == deco && '\0' == *word)
 543                         p->flags |= TERMP_NOSPACE;
 544         }
 545
 546         /*
 547          * Note that we don't process the pipe: the parser sees it as
 548          * punctuation, but we don't in terms of typography.
 549          */
 550         if (sv[0] && 0 == sv[1])
 551                 switch (sv[0]) {
 552                 case('('):
 553                         /* FALLTHROUGH */
 554                 case('['):
 555                         p->flags |= TERMP_NOSPACE;
 556                         break;
 557                 default:
 558                         break;
 559                 }
 560 }
 561
 562
 563 static void
 564 adjbuf(struct termp *p, size_t sz)
 565 {
 566
 567         if (0 == p->maxcols)
 568                 p->maxcols = 1024;
 569         while (sz >= p->maxcols)
 570                 p->maxcols <<= 2;
 571
 572         p->buf = realloc(p->buf, p->maxcols);
 573         if (NULL == p->buf) {
 574                 perror(NULL);
 575                 exit(EXIT_FAILURE);
 576         }
 577 }
 578
 579
 580 static void
 581 buffera(struct termp *p, const char *word, size_t sz)
 582 {
 583
 584         if (p->col + sz >= p->maxcols)
 585                 adjbuf(p, p->col + sz);
 586
 587         memcpy(&p->buf[(int)p->col], word, sz);
 588         p->col += sz;
 589 }
 590
 591
 592 static void
 593 bufferc(struct termp *p, char c)
 594 {
 595
 596         if (p->col + 1 >= p->maxcols)
 597                 adjbuf(p, p->col + 1);
 598
 599         p->buf[(int)p->col++] = c;
 600 }
 601
 602
 603 static void
 604 encode(struct termp *p, const char *word, size_t sz)
 605 {
 606         enum termfont     f;
 607         int               i;
 608
 609         /*
 610          * Encode and buffer a string of characters.  If the current
 611          * font mode is unset, buffer directly, else encode then buffer
 612          * character by character.
 613          */
 614
 615         if (TERMFONT_NONE == (f = term_fonttop(p))) {
 616                 buffera(p, word, sz);
 617                 return;
 618         }
 619
 620         for (i = 0; i < (int)sz; i++) {
 621                 if ( ! isgraph((u_char)word[i])) {
 622                         bufferc(p, word[i]);
 623                         continue;
 624                 }
 625
 626                 if (TERMFONT_UNDER == f)
 627                         bufferc(p, '_');
 628                 else
 629                         bufferc(p, word[i]);
 630
 631                 bufferc(p, 8);
 632                 bufferc(p, word[i]);
 633         }
 634 }
 635
 636
 637 size_t
 638 term_len(const struct termp *p, size_t sz)
 639 {
 640
 641         return((*p->width)(p, ' ') * sz);
 642 }
 643
 644
 645 size_t
 646 term_strlen(const struct termp *p, const char *cp)
 647 {
 648         size_t           sz;
 649
 650         for (sz = 0; *cp; cp++)
 651                 sz += (*p->width)(p, *cp);
 652
 653         return(sz);
 654 }
 655
 656
 657 /* ARGSUSED */
 658 size_t
 659 term_vspan(const struct termp *p, const struct roffsu *su)
 660 {
 661         double           r;
 662
 663         switch (su->unit) {
 664         case (SCALE_CM):
 665                 r = su->scale * 2;
 666                 break;
 667         case (SCALE_IN):
 668                 r = su->scale * 6;
 669                 break;
 670         case (SCALE_PC):
 671                 r = su->scale;
 672                 break;
 673         case (SCALE_PT):
 674                 r = su->scale / 8;
 675                 break;
 676         case (SCALE_MM):
 677                 r = su->scale / 1000;
 678                 break;
 679         case (SCALE_VS):
 680                 r = su->scale;
 681                 break;
 682         default:
 683                 r = su->scale - 1;
 684                 break;
 685         }
 686
 687         if (r < 0.0)
 688                 r = 0.0;
 689         return(/* LINTED */(size_t)
 690                         r);
 691 }
 692
 693
 694 size_t
 695 term_hspan(const struct termp *p, const struct roffsu *su)
 696 {
 697         double           v;
 698
 699         v = ((*p->hspan)(p, su));
 700         if (v < 0.0)
 701                 v = 0.0;
 702         return((size_t) /* LINTED */
 703                         v);
 704 }