html.c

   1 /*      $Id: html.c,v 1.202 2017/01/26 18:28:18 schwarze Exp $ */
   2 /*
   3  * Copyright (c) 2008-2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
   4  * Copyright (c) 2011-2015, 2017 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 AUTHORS DISCLAIM ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS 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 #include "config.h"
  19
  20 #include <sys/types.h>
  21
  22 #include <assert.h>
  23 #include <ctype.h>
  24 #include <stdarg.h>
  25 #include <stdio.h>
  26 #include <stdint.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <unistd.h>
  30
  31 #include "mandoc.h"
  32 #include "mandoc_aux.h"
  33 #include "out.h"
  34 #include "html.h"
  35 #include "manconf.h"
  36 #include "main.h"
  37
  38 struct  htmldata {
  39         const char       *name;
  40         int               flags;
  41 #define HTML_NOSTACK     (1 << 0)
  42 #define HTML_AUTOCLOSE   (1 << 1)
  43 #define HTML_NLBEFORE    (1 << 2)
  44 #define HTML_NLBEGIN     (1 << 3)
  45 #define HTML_NLEND       (1 << 4)
  46 #define HTML_NLAFTER     (1 << 5)
  47 #define HTML_NLAROUND    (HTML_NLBEFORE | HTML_NLAFTER)
  48 #define HTML_NLINSIDE    (HTML_NLBEGIN | HTML_NLEND)
  49 #define HTML_NLALL       (HTML_NLAROUND | HTML_NLINSIDE)
  50 #define HTML_INDENT      (1 << 6)
  51 #define HTML_NOINDENT    (1 << 7)
  52 };
  53
  54 static  const struct htmldata htmltags[TAG_MAX] = {
  55         {"html",        HTML_NLALL},
  56         {"head",        HTML_NLALL | HTML_INDENT},
  57         {"body",        HTML_NLALL},
  58         {"meta",        HTML_NOSTACK | HTML_AUTOCLOSE | HTML_NLALL},
  59         {"title",       HTML_NLAROUND},
  60         {"div",         HTML_NLAROUND},
  61         {"h1",          HTML_NLAROUND},
  62         {"h2",          HTML_NLAROUND},
  63         {"span",        0},
  64         {"link",        HTML_NOSTACK | HTML_AUTOCLOSE | HTML_NLALL},
  65         {"br",          HTML_NOSTACK | HTML_AUTOCLOSE | HTML_NLALL},
  66         {"a",           0},
  67         {"table",       HTML_NLALL | HTML_INDENT},
  68         {"tbody",       HTML_NLALL | HTML_INDENT},
  69         {"col",         HTML_NOSTACK | HTML_AUTOCLOSE | HTML_NLALL},
  70         {"tr",          HTML_NLALL | HTML_INDENT},
  71         {"td",          HTML_NLAROUND},
  72         {"li",          HTML_NLAROUND | HTML_INDENT},
  73         {"ul",          HTML_NLALL | HTML_INDENT},
  74         {"ol",          HTML_NLALL | HTML_INDENT},
  75         {"dl",          HTML_NLALL | HTML_INDENT},
  76         {"dt",          HTML_NLAROUND},
  77         {"dd",          HTML_NLAROUND | HTML_INDENT},
  78         {"pre",         HTML_NLALL | HTML_NOINDENT},
  79         {"b",           0},
  80         {"i",           0},
  81         {"code",        0},
  82         {"small",       0},
  83         {"style",       HTML_NLALL | HTML_INDENT},
  84         {"math",        HTML_NLALL | HTML_INDENT},
  85         {"mrow",        0},
  86         {"mi",          0},
  87         {"mo",          0},
  88         {"msup",        0},
  89         {"msub",        0},
  90         {"msubsup",     0},
  91         {"mfrac",       0},
  92         {"msqrt",       0},
  93         {"mfenced",     0},
  94         {"mtable",      0},
  95         {"mtr",         0},
  96         {"mtd",         0},
  97         {"munderover",  0},
  98         {"munder",      0},
  99         {"mover",       0},
 100 };
 101
 102 static  const char      *const roffscales[SCALE_MAX] = {
 103         "cm", /* SCALE_CM */
 104         "in", /* SCALE_IN */
 105         "pc", /* SCALE_PC */
 106         "pt", /* SCALE_PT */
 107         "em", /* SCALE_EM */
 108         "em", /* SCALE_MM */
 109         "ex", /* SCALE_EN */
 110         "ex", /* SCALE_BU */
 111         "em", /* SCALE_VS */
 112         "ex", /* SCALE_FS */
 113 };
 114
 115 static  void     a2width(const char *, struct roffsu *);
 116 static  void     print_byte(struct html *, char);
 117 static  void     print_endword(struct html *);
 118 static  void     print_indent(struct html *);
 119 static  void     print_word(struct html *, const char *);
 120
 121 static  void     print_ctag(struct html *, struct tag *);
 122 static  int      print_escape(struct html *, char);
 123 static  int      print_encode(struct html *, const char *, const char *, int);
 124 static  void     print_href(struct html *, const char *, const char *, int);
 125 static  void     print_metaf(struct html *, enum mandoc_esc);
 126
 127
 128 void *
 129 html_alloc(const struct manoutput *outopts)
 130 {
 131         struct html     *h;
 132
 133         h = mandoc_calloc(1, sizeof(struct html));
 134
 135         h->tags.head = NULL;
 136         h->style = outopts->style;
 137         h->base_man = outopts->man;
 138         h->base_includes = outopts->includes;
 139         if (outopts->fragment)
 140                 h->oflags |= HTML_FRAGMENT;
 141
 142         return h;
 143 }
 144
 145 void
 146 html_free(void *p)
 147 {
 148         struct tag      *tag;
 149         struct html     *h;
 150
 151         h = (struct html *)p;
 152
 153         while ((tag = h->tags.head) != NULL) {
 154                 h->tags.head = tag->next;
 155                 free(tag);
 156         }
 157
 158         free(h);
 159 }
 160
 161 void
 162 print_gen_head(struct html *h)
 163 {
 164         struct tag      *t;
 165
 166         print_otag(h, TAG_META, "?", "charset", "utf-8");
 167
 168         /*
 169          * Print a default style-sheet.
 170          */
 171
 172         t = print_otag(h, TAG_STYLE, "");
 173         print_text(h, "table.head, table.foot { width: 100%; }");
 174         print_endline(h);
 175         print_text(h, "td.head-rtitle, td.foot-os { text-align: right; }");
 176         print_endline(h);
 177         print_text(h, "td.head-vol { text-align: center; }");
 178         print_endline(h);
 179         print_text(h, "div.Pp { margin: 1ex 0ex; }");
 180         print_tagq(h, t);
 181
 182         if (h->style)
 183                 print_otag(h, TAG_LINK, "?h??", "rel", "stylesheet",
 184                     h->style, "type", "text/css", "media", "all");
 185 }
 186
 187 static void
 188 print_metaf(struct html *h, enum mandoc_esc deco)
 189 {
 190         enum htmlfont    font;
 191
 192         switch (deco) {
 193         case ESCAPE_FONTPREV:
 194                 font = h->metal;
 195                 break;
 196         case ESCAPE_FONTITALIC:
 197                 font = HTMLFONT_ITALIC;
 198                 break;
 199         case ESCAPE_FONTBOLD:
 200                 font = HTMLFONT_BOLD;
 201                 break;
 202         case ESCAPE_FONTBI:
 203                 font = HTMLFONT_BI;
 204                 break;
 205         case ESCAPE_FONT:
 206         case ESCAPE_FONTROMAN:
 207                 font = HTMLFONT_NONE;
 208                 break;
 209         default:
 210                 abort();
 211         }
 212
 213         if (h->metaf) {
 214                 print_tagq(h, h->metaf);
 215                 h->metaf = NULL;
 216         }
 217
 218         h->metal = h->metac;
 219         h->metac = font;
 220
 221         switch (font) {
 222         case HTMLFONT_ITALIC:
 223                 h->metaf = print_otag(h, TAG_I, "");
 224                 break;
 225         case HTMLFONT_BOLD:
 226                 h->metaf = print_otag(h, TAG_B, "");
 227                 break;
 228         case HTMLFONT_BI:
 229                 h->metaf = print_otag(h, TAG_B, "");
 230                 print_otag(h, TAG_I, "");
 231                 break;
 232         default:
 233                 break;
 234         }
 235 }
 236
 237 int
 238 html_strlen(const char *cp)
 239 {
 240         size_t           rsz;
 241         int              skip, sz;
 242
 243         /*
 244          * Account for escaped sequences within string length
 245          * calculations.  This follows the logic in term_strlen() as we
 246          * must calculate the width of produced strings.
 247          * Assume that characters are always width of "1".  This is
 248          * hacky, but it gets the job done for approximation of widths.
 249          */
 250
 251         sz = 0;
 252         skip = 0;
 253         while (1) {
 254                 rsz = strcspn(cp, "\\");
 255                 if (rsz) {
 256                         cp += rsz;
 257                         if (skip) {
 258                                 skip = 0;
 259                                 rsz--;
 260                         }
 261                         sz += rsz;
 262                 }
 263                 if ('\0' == *cp)
 264                         break;
 265                 cp++;
 266                 switch (mandoc_escape(&cp, NULL, NULL)) {
 267                 case ESCAPE_ERROR:
 268                         return sz;
 269                 case ESCAPE_UNICODE:
 270                 case ESCAPE_NUMBERED:
 271                 case ESCAPE_SPECIAL:
 272                 case ESCAPE_OVERSTRIKE:
 273                         if (skip)
 274                                 skip = 0;
 275                         else
 276                                 sz++;
 277                         break;
 278                 case ESCAPE_SKIPCHAR:
 279                         skip = 1;
 280                         break;
 281                 default:
 282                         break;
 283                 }
 284         }
 285         return sz;
 286 }
 287
 288 static int
 289 print_escape(struct html *h, char c)
 290 {
 291
 292         switch (c) {
 293         case '<':
 294                 print_word(h, "&lt;");
 295                 break;
 296         case '>':
 297                 print_word(h, "&gt;");
 298                 break;
 299         case '&':
 300                 print_word(h, "&amp;");
 301                 break;
 302         case '"':
 303                 print_word(h, "&quot;");
 304                 break;
 305         case ASCII_NBRSP:
 306                 print_word(h, "&nbsp;");
 307                 break;
 308         case ASCII_HYPH:
 309                 print_byte(h, '-');
 310                 break;
 311         case ASCII_BREAK:
 312                 break;
 313         default:
 314                 return 0;
 315         }
 316         return 1;
 317 }
 318
 319 static int
 320 print_encode(struct html *h, const char *p, const char *pend, int norecurse)
 321 {
 322         char             numbuf[16];
 323         size_t           sz;
 324         int              c, len, nospace;
 325         const char      *seq;
 326         enum mandoc_esc  esc;
 327         static const char rejs[9] = { '\\', '<', '>', '&', '"',
 328                 ASCII_NBRSP, ASCII_HYPH, ASCII_BREAK, '\0' };
 329
 330         if (pend == NULL)
 331                 pend = strchr(p, '\0');
 332
 333         nospace = 0;
 334
 335         while (p < pend) {
 336                 if (HTML_SKIPCHAR & h->flags && '\\' != *p) {
 337                         h->flags &= ~HTML_SKIPCHAR;
 338                         p++;
 339                         continue;
 340                 }
 341
 342                 for (sz = strcspn(p, rejs); sz-- && p < pend; p++)
 343                         if (*p == ' ')
 344                                 print_endword(h);
 345                         else
 346                                 print_byte(h, *p);
 347
 348                 if (p >= pend)
 349                         break;
 350
 351                 if (print_escape(h, *p++))
 352                         continue;
 353
 354                 esc = mandoc_escape(&p, &seq, &len);
 355                 if (ESCAPE_ERROR == esc)
 356                         break;
 357
 358                 switch (esc) {
 359                 case ESCAPE_FONT:
 360                 case ESCAPE_FONTPREV:
 361                 case ESCAPE_FONTBOLD:
 362                 case ESCAPE_FONTITALIC:
 363                 case ESCAPE_FONTBI:
 364                 case ESCAPE_FONTROMAN:
 365                         if (0 == norecurse)
 366                                 print_metaf(h, esc);
 367                         continue;
 368                 case ESCAPE_SKIPCHAR:
 369                         h->flags |= HTML_SKIPCHAR;
 370                         continue;
 371                 default:
 372                         break;
 373                 }
 374
 375                 if (h->flags & HTML_SKIPCHAR) {
 376                         h->flags &= ~HTML_SKIPCHAR;
 377                         continue;
 378                 }
 379
 380                 switch (esc) {
 381                 case ESCAPE_UNICODE:
 382                         /* Skip past "u" header. */
 383                         c = mchars_num2uc(seq + 1, len - 1);
 384                         break;
 385                 case ESCAPE_NUMBERED:
 386                         c = mchars_num2char(seq, len);
 387                         if (c < 0)
 388                                 continue;
 389                         break;
 390                 case ESCAPE_SPECIAL:
 391                         c = mchars_spec2cp(seq, len);
 392                         if (c <= 0)
 393                                 continue;
 394                         break;
 395                 case ESCAPE_NOSPACE:
 396                         if ('\0' == *p)
 397                                 nospace = 1;
 398                         continue;
 399                 case ESCAPE_OVERSTRIKE:
 400                         if (len == 0)
 401                                 continue;
 402                         c = seq[len - 1];
 403                         break;
 404                 default:
 405                         continue;
 406                 }
 407                 if ((c < 0x20 && c != 0x09) ||
 408                     (c > 0x7E && c < 0xA0))
 409                         c = 0xFFFD;
 410                 if (c > 0x7E) {
 411                         (void)snprintf(numbuf, sizeof(numbuf), "&#%d;", c);
 412                         print_word(h, numbuf);
 413                 } else if (print_escape(h, c) == 0)
 414                         print_byte(h, c);
 415         }
 416
 417         return nospace;
 418 }
 419
 420 static void
 421 print_href(struct html *h, const char *name, const char *sec, int man)
 422 {
 423         const char      *p, *pp;
 424
 425         pp = man ? h->base_man : h->base_includes;
 426         while ((p = strchr(pp, '%')) != NULL) {
 427                 print_encode(h, pp, p, 1);
 428                 if (man && p[1] == 'S') {
 429                         if (sec == NULL)
 430                                 print_byte(h, '1');
 431                         else
 432                                 print_encode(h, sec, NULL, 1);
 433                 } else if ((man && p[1] == 'N') ||
 434                     (man == 0 && p[1] == 'I'))
 435                         print_encode(h, name, NULL, 1);
 436                 else
 437                         print_encode(h, p, p + 2, 1);
 438                 pp = p + 2;
 439         }
 440         if (*pp != '\0')
 441                 print_encode(h, pp, NULL, 1);
 442 }
 443
 444 struct tag *
 445 print_otag(struct html *h, enum htmltag tag, const char *fmt, ...)
 446 {
 447         va_list          ap;
 448         struct roffsu    mysu, *su;
 449         char             numbuf[16];
 450         struct tag      *t;
 451         const char      *attr;
 452         char            *s;
 453         double           v;
 454         int              i, have_style, tflags;
 455
 456         tflags = htmltags[tag].flags;
 457
 458         /* Push this tags onto the stack of open scopes. */
 459
 460         if ((tflags & HTML_NOSTACK) == 0) {
 461                 t = mandoc_malloc(sizeof(struct tag));
 462                 t->tag = tag;
 463                 t->next = h->tags.head;
 464                 h->tags.head = t;
 465         } else
 466                 t = NULL;
 467
 468         if (tflags & HTML_NLBEFORE)
 469                 print_endline(h);
 470         if (h->col == 0)
 471                 print_indent(h);
 472         else if ((h->flags & HTML_NOSPACE) == 0) {
 473                 if (h->flags & HTML_KEEP)
 474                         print_word(h, "&#160;");
 475                 else {
 476                         if (h->flags & HTML_PREKEEP)
 477                                 h->flags |= HTML_KEEP;
 478                         print_endword(h);
 479                 }
 480         }
 481
 482         if ( ! (h->flags & HTML_NONOSPACE))
 483                 h->flags &= ~HTML_NOSPACE;
 484         else
 485                 h->flags |= HTML_NOSPACE;
 486
 487         /* Print out the tag name and attributes. */
 488
 489         print_byte(h, '<');
 490         print_word(h, htmltags[tag].name);
 491
 492         va_start(ap, fmt);
 493
 494         have_style = 0;
 495         while (*fmt != '\0') {
 496                 if (*fmt == 's') {
 497                         print_word(h, " style=\"");
 498                         have_style = 1;
 499                         fmt++;
 500                         break;
 501                 }
 502                 s = va_arg(ap, char *);
 503                 switch (*fmt++) {
 504                 case 'c':
 505                         attr = "class";
 506                         break;
 507                 case 'h':
 508                         attr = "href";
 509                         break;
 510                 case 'i':
 511                         attr = "id";
 512                         break;
 513                 case '?':
 514                         attr = s;
 515                         s = va_arg(ap, char *);
 516                         break;
 517                 default:
 518                         abort();
 519                 }
 520                 print_byte(h, ' ');
 521                 print_word(h, attr);
 522                 print_byte(h, '=');
 523                 print_byte(h, '"');
 524                 switch (*fmt) {
 525                 case 'M':
 526                         print_href(h, s, va_arg(ap, char *), 1);
 527                         fmt++;
 528                         break;
 529                 case 'I':
 530                         print_href(h, s, NULL, 0);
 531                         fmt++;
 532                         break;
 533                 case 'R':
 534                         print_byte(h, '#');
 535                         fmt++;
 536                         /* FALLTHROUGH */
 537                 default:
 538                         print_encode(h, s, NULL, 1);
 539                         break;
 540                 }
 541                 print_byte(h, '"');
 542         }
 543
 544         /* Print out styles. */
 545
 546         s = NULL;
 547         su = &mysu;
 548         while (*fmt != '\0') {
 549
 550                 /* First letter: input argument type. */
 551
 552                 switch (*fmt++) {
 553                 case 'h':
 554                         i = va_arg(ap, int);
 555                         SCALE_HS_INIT(su, i);
 556                         break;
 557                 case 's':
 558                         s = va_arg(ap, char *);
 559                         break;
 560                 case 'u':
 561                         su = va_arg(ap, struct roffsu *);
 562                         break;
 563                 case 'v':
 564                         i = va_arg(ap, int);
 565                         SCALE_VS_INIT(su, i);
 566                         break;
 567                 case 'w':
 568                 case 'W':
 569                         s = va_arg(ap, char *);
 570                         a2width(s, su);
 571                         if (fmt[-1] == 'W')
 572                                 su->scale *= -1.0;
 573                         break;
 574                 default:
 575                         abort();
 576                 }
 577
 578                 /* Second letter: style name. */
 579
 580                 switch (*fmt++) {
 581                 case 'b':
 582                         attr = "margin-bottom";
 583                         break;
 584                 case 'h':
 585                         attr = "height";
 586                         break;
 587                 case 'i':
 588                         attr = "text-indent";
 589                         break;
 590                 case 'l':
 591                         attr = "margin-left";
 592                         break;
 593                 case 't':
 594                         attr = "margin-top";
 595                         break;
 596                 case 'w':
 597                         attr = "width";
 598                         break;
 599                 case 'W':
 600                         attr = "min-width";
 601                         break;
 602                 case '?':
 603                         print_word(h, s);
 604                         print_byte(h, ':');
 605                         print_byte(h, ' ');
 606                         print_word(h, va_arg(ap, char *));
 607                         print_byte(h, ';');
 608                         if (*fmt != '\0')
 609                                 print_byte(h, ' ');
 610                         continue;
 611                 default:
 612                         abort();
 613                 }
 614                 v = su->scale;
 615                 if (su->unit == SCALE_MM && (v /= 100.0) == 0.0)
 616                         v = 1.0;
 617                 else if (su->unit == SCALE_BU)
 618                         v /= 24.0;
 619                 print_word(h, attr);
 620                 print_byte(h, ':');
 621                 print_byte(h, ' ');
 622                 (void)snprintf(numbuf, sizeof(numbuf), "%.2f", v);
 623                 print_word(h, numbuf);
 624                 print_word(h, roffscales[su->unit]);
 625                 print_byte(h, ';');
 626                 if (*fmt != '\0')
 627                         print_byte(h, ' ');
 628         }
 629         if (have_style)
 630                 print_byte(h, '"');
 631
 632         va_end(ap);
 633
 634         /* Accommodate for "well-formed" singleton escaping. */
 635
 636         if (HTML_AUTOCLOSE & htmltags[tag].flags)
 637                 print_byte(h, '/');
 638
 639         print_byte(h, '>');
 640
 641         if (tflags & HTML_NLBEGIN)
 642                 print_endline(h);
 643         else
 644                 h->flags |= HTML_NOSPACE;
 645
 646         if (tflags & HTML_INDENT)
 647                 h->indent++;
 648         if (tflags & HTML_NOINDENT)
 649                 h->noindent++;
 650
 651         return t;
 652 }
 653
 654 static void
 655 print_ctag(struct html *h, struct tag *tag)
 656 {
 657         int      tflags;
 658
 659         /*
 660          * Remember to close out and nullify the current
 661          * meta-font and table, if applicable.
 662          */
 663         if (tag == h->metaf)
 664                 h->metaf = NULL;
 665         if (tag == h->tblt)
 666                 h->tblt = NULL;
 667
 668         tflags = htmltags[tag->tag].flags;
 669
 670         if (tflags & HTML_INDENT)
 671                 h->indent--;
 672         if (tflags & HTML_NOINDENT)
 673                 h->noindent--;
 674         if (tflags & HTML_NLEND)
 675                 print_endline(h);
 676         print_indent(h);
 677         print_byte(h, '<');
 678         print_byte(h, '/');
 679         print_word(h, htmltags[tag->tag].name);
 680         print_byte(h, '>');
 681         if (tflags & HTML_NLAFTER)
 682                 print_endline(h);
 683
 684         h->tags.head = tag->next;
 685         free(tag);
 686 }
 687
 688 void
 689 print_gen_decls(struct html *h)
 690 {
 691         print_word(h, "<!DOCTYPE html>");
 692         print_endline(h);
 693 }
 694
 695 void
 696 print_text(struct html *h, const char *word)
 697 {
 698         if (h->col && (h->flags & HTML_NOSPACE) == 0) {
 699                 if ( ! (HTML_KEEP & h->flags)) {
 700                         if (HTML_PREKEEP & h->flags)
 701                                 h->flags |= HTML_KEEP;
 702                         print_endword(h);
 703                 } else
 704                         print_word(h, "&#160;");
 705         }
 706
 707         assert(NULL == h->metaf);
 708         switch (h->metac) {
 709         case HTMLFONT_ITALIC:
 710                 h->metaf = print_otag(h, TAG_I, "");
 711                 break;
 712         case HTMLFONT_BOLD:
 713                 h->metaf = print_otag(h, TAG_B, "");
 714                 break;
 715         case HTMLFONT_BI:
 716                 h->metaf = print_otag(h, TAG_B, "");
 717                 print_otag(h, TAG_I, "");
 718                 break;
 719         default:
 720                 print_indent(h);
 721                 break;
 722         }
 723
 724         assert(word);
 725         if ( ! print_encode(h, word, NULL, 0)) {
 726                 if ( ! (h->flags & HTML_NONOSPACE))
 727                         h->flags &= ~HTML_NOSPACE;
 728                 h->flags &= ~HTML_NONEWLINE;
 729         } else
 730                 h->flags |= HTML_NOSPACE | HTML_NONEWLINE;
 731
 732         if (h->metaf) {
 733                 print_tagq(h, h->metaf);
 734                 h->metaf = NULL;
 735         }
 736
 737         h->flags &= ~HTML_IGNDELIM;
 738 }
 739
 740 void
 741 print_tagq(struct html *h, const struct tag *until)
 742 {
 743         struct tag      *tag;
 744
 745         while ((tag = h->tags.head) != NULL) {
 746                 print_ctag(h, tag);
 747                 if (until && tag == until)
 748                         return;
 749         }
 750 }
 751
 752 void
 753 print_stagq(struct html *h, const struct tag *suntil)
 754 {
 755         struct tag      *tag;
 756
 757         while ((tag = h->tags.head) != NULL) {
 758                 if (suntil && tag == suntil)
 759                         return;
 760                 print_ctag(h, tag);
 761         }
 762 }
 763
 764 void
 765 print_paragraph(struct html *h)
 766 {
 767         struct tag      *t;
 768
 769         t = print_otag(h, TAG_DIV, "c", "Pp");
 770         print_tagq(h, t);
 771 }
 772
 773
 774 /***********************************************************************
 775  * Low level output functions.
 776  * They implement line breaking using a short static buffer.
 777  ***********************************************************************/
 778
 779 /*
 780  * Buffer one HTML output byte.
 781  * If the buffer is full, flush and deactivate it and start a new line.
 782  * If the buffer is inactive, print directly.
 783  */
 784 static void
 785 print_byte(struct html *h, char c)
 786 {
 787         if ((h->flags & HTML_BUFFER) == 0) {
 788                 putchar(c);
 789                 h->col++;
 790                 return;
 791         }
 792
 793         if (h->col + h->bufcol < sizeof(h->buf)) {
 794                 h->buf[h->bufcol++] = c;
 795                 return;
 796         }
 797
 798         putchar('\n');
 799         h->col = 0;
 800         print_indent(h);
 801         putchar(' ');
 802         putchar(' ');
 803         fwrite(h->buf, h->bufcol, 1, stdout);
 804         putchar(c);
 805         h->col = (h->indent + 1) * 2 + h->bufcol + 1;
 806         h->bufcol = 0;
 807         h->flags &= ~HTML_BUFFER;
 808 }
 809
 810 /*
 811  * If something was printed on the current output line, end it.
 812  * Not to be called right after print_indent().
 813  */
 814 void
 815 print_endline(struct html *h)
 816 {
 817         if (h->col == 0)
 818                 return;
 819
 820         if (h->bufcol) {
 821                 putchar(' ');
 822                 fwrite(h->buf, h->bufcol, 1, stdout);
 823                 h->bufcol = 0;
 824         }
 825         putchar('\n');
 826         h->col = 0;
 827         h->flags |= HTML_NOSPACE;
 828         h->flags &= ~HTML_BUFFER;
 829 }
 830
 831 /*
 832  * Flush the HTML output buffer.
 833  * If it is inactive, activate it.
 834  */
 835 static void
 836 print_endword(struct html *h)
 837 {
 838         if (h->noindent) {
 839                 print_byte(h, ' ');
 840                 return;
 841         }
 842
 843         if ((h->flags & HTML_BUFFER) == 0) {
 844                 h->col++;
 845                 h->flags |= HTML_BUFFER;
 846         } else if (h->bufcol) {
 847                 putchar(' ');
 848                 fwrite(h->buf, h->bufcol, 1, stdout);
 849                 h->col += h->bufcol + 1;
 850         }
 851         h->bufcol = 0;
 852 }
 853
 854 /*
 855  * If at the beginning of a new output line,
 856  * perform indentation and mark the line as containing output.
 857  * Make sure to really produce some output right afterwards,
 858  * but do not use print_otag() for producing it.
 859  */
 860 static void
 861 print_indent(struct html *h)
 862 {
 863         size_t   i;
 864
 865         if (h->col)
 866                 return;
 867
 868         if (h->noindent == 0) {
 869                 h->col = h->indent * 2;
 870                 for (i = 0; i < h->col; i++)
 871                         putchar(' ');
 872         }
 873         h->flags &= ~HTML_NOSPACE;
 874 }
 875
 876 /*
 877  * Print or buffer some characters
 878  * depending on the current HTML output buffer state.
 879  */
 880 static void
 881 print_word(struct html *h, const char *cp)
 882 {
 883         while (*cp != '\0')
 884                 print_byte(h, *cp++);
 885 }
 886
 887 /*
 888  * Calculate the scaling unit passed in a `-width' argument.  This uses
 889  * either a native scaling unit (e.g., 1i, 2m) or the string length of
 890  * the value.
 891  */
 892 static void
 893 a2width(const char *p, struct roffsu *su)
 894 {
 895         if (a2roffsu(p, su, SCALE_MAX) < 2) {
 896                 su->unit = SCALE_EN;
 897                 su->scale = html_strlen(p);
 898         } else if (su->scale < 0.0)
 899                 su->scale = 0.0;
 900 }