term.c

   1 /*      $Id: term.c,v 1.121 2009/11/05 07:21:02 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
 233                         /* The unit sep. is a non-breaking space. */
 234                         if (31 == p->buf[i])
 235                                 putchar(' ');
 236                         else
 237                                 putchar(p->buf[i]);
 238                 }
 239                 vis += vsz;
 240         }
 241
 242         p->col = 0;
 243         overstep = 0;
 244
 245         if ( ! (TERMP_NOBREAK & p->flags)) {
 246                 putchar('\n');
 247                 return;
 248         }
 249
 250         if (TERMP_HANG & p->flags) {
 251                 /* We need one blank after the tag. */
 252                 overstep = /* LINTED */
 253                         vis - maxvis + 1;
 254
 255                 /*
 256                  * Behave exactly the same way as groff:
 257                  * If we have overstepped the margin, temporarily move
 258                  * it to the right and flag the rest of the line to be
 259                  * shorter.
 260                  * If we landed right at the margin, be happy.
 261                  * If we are one step before the margin, temporarily
 262                  * move it one step LEFT and flag the rest of the line
 263                  * to be longer.
 264                  */
 265                 if (overstep >= -1) {
 266                         assert((int)maxvis + overstep >= 0);
 267                         /* LINTED */
 268                         maxvis += overstep;
 269                 } else
 270                         overstep = 0;
 271
 272         } else if (TERMP_DANGLE & p->flags)
 273                 return;
 274
 275         /* Right-pad. */
 276         if (maxvis > vis + /* LINTED */
 277                         ((TERMP_TWOSPACE & p->flags) ? 1 : 0))
 278                 for ( ; vis < maxvis; vis++)
 279                         putchar(' ');
 280         else {  /* ...or newline break. */
 281                 putchar('\n');
 282                 for (i = 0; i < (int)p->rmargin; i++)
 283                         putchar(' ');
 284         }
 285 }
 286
 287
 288 /*
 289  * A newline only breaks an existing line; it won't assert vertical
 290  * space.  All data in the output buffer is flushed prior to the newline
 291  * assertion.
 292  */
 293 void
 294 term_newln(struct termp *p)
 295 {
 296
 297         p->flags |= TERMP_NOSPACE;
 298         if (0 == p->col) {
 299                 p->flags &= ~TERMP_NOLPAD;
 300                 return;
 301         }
 302         term_flushln(p);
 303         p->flags &= ~TERMP_NOLPAD;
 304 }
 305
 306
 307 /*
 308  * Asserts a vertical space (a full, empty line-break between lines).
 309  * Note that if used twice, this will cause two blank spaces and so on.
 310  * All data in the output buffer is flushed prior to the newline
 311  * assertion.
 312  */
 313 void
 314 term_vspace(struct termp *p)
 315 {
 316
 317         term_newln(p);
 318         putchar('\n');
 319 }
 320
 321
 322 static void
 323 do_special(struct termp *p, const char *word, size_t len)
 324 {
 325         const char      *rhs;
 326         size_t           sz;
 327         int              i;
 328
 329         rhs = chars_a2ascii(p->symtab, word, len, &sz);
 330
 331         if (NULL == rhs) {
 332 #if 0
 333                 fputs("Unknown special character: ", stderr);
 334                 for (i = 0; i < (int)len; i++)
 335                         fputc(word[i], stderr);
 336                 fputc('\n', stderr);
 337 #endif
 338                 return;
 339         }
 340         for (i = 0; i < (int)sz; i++)
 341                 encode(p, rhs[i]);
 342 }
 343
 344
 345 static void
 346 do_reserved(struct termp *p, const char *word, size_t len)
 347 {
 348         const char      *rhs;
 349         size_t           sz;
 350         int              i;
 351
 352         rhs = chars_a2res(p->symtab, word, len, &sz);
 353
 354         if (NULL == rhs) {
 355 #if 0
 356                 fputs("Unknown reserved word: ", stderr);
 357                 for (i = 0; i < (int)len; i++)
 358                         fputc(word[i], stderr);
 359                 fputc('\n', stderr);
 360 #endif
 361                 return;
 362         }
 363         for (i = 0; i < (int)sz; i++)
 364                 encode(p, rhs[i]);
 365 }
 366
 367
 368 /*
 369  * Handle an escape sequence: determine its length and pass it to the
 370  * escape-symbol look table.  Note that we assume mdoc(3) has validated
 371  * the escape sequence (we assert upon badly-formed escape sequences).
 372  */
 373 static void
 374 do_escaped(struct termp *p, const char **word)
 375 {
 376         int              j, type;
 377         const char      *wp;
 378
 379         wp = *word;
 380         type = 1;
 381
 382         if (0 == *(++wp)) {
 383                 *word = wp;
 384                 return;
 385         }
 386
 387         if ('(' == *wp) {
 388                 wp++;
 389                 if (0 == *wp || 0 == *(wp + 1)) {
 390                         *word = 0 == *wp ? wp : wp + 1;
 391                         return;
 392                 }
 393
 394                 do_special(p, wp, 2);
 395                 *word = ++wp;
 396                 return;
 397
 398         } else if ('*' == *wp) {
 399                 if (0 == *(++wp)) {
 400                         *word = wp;
 401                         return;
 402                 }
 403
 404                 switch (*wp) {
 405                 case ('('):
 406                         wp++;
 407                         if (0 == *wp || 0 == *(wp + 1)) {
 408                                 *word = 0 == *wp ? wp : wp + 1;
 409                                 return;
 410                         }
 411
 412                         do_reserved(p, wp, 2);
 413                         *word = ++wp;
 414                         return;
 415                 case ('['):
 416                         type = 0;
 417                         break;
 418                 default:
 419                         do_reserved(p, wp, 1);
 420                         *word = wp;
 421                         return;
 422                 }
 423
 424         } else if ('f' == *wp) {
 425                 if (0 == *(++wp)) {
 426                         *word = wp;
 427                         return;
 428                 }
 429
 430                 switch (*wp) {
 431                 case ('B'):
 432                         p->bold++;
 433                         break;
 434                 case ('I'):
 435                         p->under++;
 436                         break;
 437                 case ('P'):
 438                         /* FALLTHROUGH */
 439                 case ('R'):
 440                         p->bold = p->under = 0;
 441                         break;
 442                 default:
 443                         break;
 444                 }
 445
 446                 *word = wp;
 447                 return;
 448
 449         } else if ('[' != *wp) {
 450                 do_special(p, wp, 1);
 451                 *word = wp;
 452                 return;
 453         }
 454
 455         wp++;
 456         for (j = 0; *wp && ']' != *wp; wp++, j++)
 457                 /* Loop... */ ;
 458
 459         if (0 == *wp) {
 460                 *word = wp;
 461                 return;
 462         }
 463
 464         if (type)
 465                 do_special(p, wp - j, (size_t)j);
 466         else
 467                 do_reserved(p, wp - j, (size_t)j);
 468         *word = wp;
 469 }
 470
 471
 472 /*
 473  * Handle pwords, partial words, which may be either a single word or a
 474  * phrase that cannot be broken down (such as a literal string).  This
 475  * handles word styling.
 476  */
 477 void
 478 term_word(struct termp *p, const char *word)
 479 {
 480         const char       *sv;
 481
 482         sv = word;
 483
 484         if (word[0] && 0 == word[1])
 485                 switch (word[0]) {
 486                 case('.'):
 487                         /* FALLTHROUGH */
 488                 case(','):
 489                         /* FALLTHROUGH */
 490                 case(';'):
 491                         /* FALLTHROUGH */
 492                 case(':'):
 493                         /* FALLTHROUGH */
 494                 case('?'):
 495                         /* FALLTHROUGH */
 496                 case('!'):
 497                         /* FALLTHROUGH */
 498                 case(')'):
 499                         /* FALLTHROUGH */
 500                 case(']'):
 501                         /* FALLTHROUGH */
 502                 case('}'):
 503                         if ( ! (TERMP_IGNDELIM & p->flags))
 504                                 p->flags |= TERMP_NOSPACE;
 505                         break;
 506                 default:
 507                         break;
 508                 }
 509
 510         if ( ! (TERMP_NOSPACE & p->flags))
 511                 buffer(p, ' ');
 512
 513         if ( ! (p->flags & TERMP_NONOSPACE))
 514                 p->flags &= ~TERMP_NOSPACE;
 515
 516         for ( ; *word; word++)
 517                 if ('\\' != *word)
 518                         encode(p, *word);
 519                 else
 520                         do_escaped(p, &word);
 521
 522         if (sv[0] && 0 == sv[1])
 523                 switch (sv[0]) {
 524                 case('('):
 525                         /* FALLTHROUGH */
 526                 case('['):
 527                         /* FALLTHROUGH */
 528                 case('{'):
 529                         p->flags |= TERMP_NOSPACE;
 530                         break;
 531                 default:
 532                         break;
 533                 }
 534 }
 535
 536
 537 /*
 538  * Insert a single character into the line-buffer.  If the buffer's
 539  * space is exceeded, then allocate more space by doubling the buffer
 540  * size.
 541  */
 542 static void
 543 buffer(struct termp *p, char c)
 544 {
 545         size_t           s;
 546
 547         if (p->col + 1 >= p->maxcols) {
 548                 if (0 == p->maxcols)
 549                         p->maxcols = 256;
 550                 s = p->maxcols * 2;
 551                 p->buf = realloc(p->buf, s);
 552                 if (NULL == p->buf) {
 553                         perror(NULL);
 554                         exit(EXIT_FAILURE);
 555                 }
 556                 p->maxcols = s;
 557         }
 558         p->buf[(int)(p->col)++] = c;
 559 }
 560
 561
 562 static void
 563 encode(struct termp *p, char c)
 564 {
 565
 566         if (' ' != c) {
 567                 if (p->under) {
 568                         buffer(p, '_');
 569                         buffer(p, 8);
 570                 }
 571                 if (p->bold) {
 572                         buffer(p, c);
 573                         buffer(p, 8);
 574                 }
 575         }
 576         buffer(p, c);
 577 }
 578
 579
 580 size_t
 581 term_vspan(const struct roffsu *su)
 582 {
 583         double           r;
 584
 585         switch (su->unit) {
 586         case (SCALE_CM):
 587                 r = su->scale * 2;
 588                 break;
 589         case (SCALE_IN):
 590                 r = su->scale * 6;
 591                 break;
 592         case (SCALE_PC):
 593                 r = su->scale;
 594                 break;
 595         case (SCALE_PT):
 596                 r = su->scale / 8;
 597                 break;
 598         case (SCALE_MM):
 599                 r = su->scale / 1000;
 600                 break;
 601         case (SCALE_VS):
 602                 r = su->scale;
 603                 break;
 604         default:
 605                 r = su->scale - 1;
 606                 break;
 607         }
 608
 609         if (r < 0.0)
 610                 r = 0.0;
 611         return(/* LINTED */(size_t)
 612                         r);
 613 }
 614
 615
 616 size_t
 617 term_hspan(const struct roffsu *su)
 618 {
 619         double           r;
 620
 621         /* XXX: CM, IN, and PT are approximations. */
 622
 623         switch (su->unit) {
 624         case (SCALE_CM):
 625                 r = 4 * su->scale;
 626                 break;
 627         case (SCALE_IN):
 628                 /* XXX: this is an approximation. */
 629                 r = 10 * su->scale;
 630                 break;
 631         case (SCALE_PC):
 632                 r = (10 * su->scale) / 6;
 633                 break;
 634         case (SCALE_PT):
 635                 r = (10 * su->scale) / 72;
 636                 break;
 637         case (SCALE_MM):
 638                 r = su->scale / 1000; /* FIXME: double-check. */
 639                 break;
 640         case (SCALE_VS):
 641                 r = su->scale * 2 - 1; /* FIXME: double-check. */
 642                 break;
 643         default:
 644                 r = su->scale;
 645                 break;
 646         }
 647
 648         if (r < 0.0)
 649                 r = 0.0;
 650         return((size_t)/* LINTED */
 651                         r);
 652 }
 653
 654