src/document/plain/renderer.c

   1 /* Plain text document renderer */
   2
   3 #ifdef HAVE_CONFIG_H
   4 #include "config.h"
   5 #endif
   6
   7 #include <ctype.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10
  11 #include "elinks.h"
  12
  13 #include "bookmarks/bookmarks.h"
  14 #include "cache/cache.h"
  15 #include "config/options.h"
  16 #include "document/docdata.h"
  17 #include "document/document.h"
  18 #include "document/format.h"
  19 #include "document/options.h"
  20 #include "document/plain/renderer.h"
  21 #include "document/renderer.h"
  22 #include "globhist/globhist.h"
  23 #include "intl/charsets.h"
  24 #include "protocol/protocol.h"
  25 #include "protocol/uri.h"
  26 #include "terminal/color.h"
  27 #include "terminal/draw.h"
  28 #include "util/color.h"
  29 #include "util/error.h"
  30 #include "util/memory.h"
  31 #include "util/string.h"
  32
  33
  34 struct plain_renderer {
  35         /* The document being renderered */
  36         struct document *document;
  37
  38         /* The data and data length of the defragmented cache entry */
  39         unsigned char *source;
  40         int length;
  41
  42         /* The convert table that should be used for converting line strings to
  43          * the rendered strings. */
  44         struct conv_table *convert_table;
  45
  46         /* The default template char data for text */
  47         struct screen_char template;
  48
  49         /* The maximum width any line can have (used for wrapping text) */
  50         int max_width;
  51
  52         /* The current line number */
  53         int lineno;
  54
  55         /* Are we doing line compression */
  56         unsigned int compress:1;
  57 };
  58
  59 #define realloc_document_links(doc, size) \
  60         ALIGN_LINK(&(doc)->links, (doc)->nlinks, size)
  61
  62 static struct screen_char *
  63 realloc_line(struct document *document, int x, int y)
  64 {
  65         struct line *line = realloc_lines(document, y);
  66
  67         if (!line) return NULL;
  68
  69         if (x != line->length) {
  70                 if (!ALIGN_LINE(&line->chars, line->length, x))
  71                         return NULL;
  72
  73                 line->length = x;
  74         }
  75
  76         return line->chars;
  77 }
  78
  79 static inline struct link *
  80 add_document_link(struct document *document, unsigned char *uri, int length,
  81                   int x, int y)
  82 {
  83         struct link *link;
  84         struct point *point;
  85
  86         if (!realloc_document_links(document, document->nlinks + 1))
  87                 return NULL;
  88
  89         link = &document->links[document->nlinks];
  90
  91         if (!realloc_points(link, length))
  92                 return NULL;
  93
  94         link->npoints = length;
  95         link->type = LINK_HYPERTEXT;
  96         link->where = uri;
  97         link->color.background = document->options.default_style.color.background;
  98         link->color.foreground = document->options.default_color.link;
  99         link->number = document->nlinks;
 100
 101         for (point = link->points; length > 0; length--, point++, x++) {
 102                 point->x = x;
 103                 point->y = y;
 104         }
 105
 106         document->nlinks++;
 107         document->links_sorted = 0;
 108         return link;
 109 }
 110
 111 /* Searches a word to find an email adress or an URI to add as a link. */
 112 static inline struct link *
 113 check_link_word(struct document *document, unsigned char *uri, int length,
 114                 int x, int y)
 115 {
 116         struct uri test;
 117         unsigned char *where = NULL;
 118         unsigned char *mailto = memchr(uri, '@', length);
 119         int keep = uri[length];
 120         struct link *new_link;
 121
 122         assert(document);
 123         if_assert_failed return NULL;
 124
 125         uri[length] = 0;
 126
 127         if (mailto && mailto > uri && mailto - uri < length - 1) {
 128                 where = straconcat("mailto:", uri, (unsigned char *) NULL);
 129
 130         } else if (parse_uri(&test, uri) == URI_ERRNO_OK
 131                    && test.protocol != PROTOCOL_UNKNOWN
 132                    && (test.datalen || test.hostlen)) {
 133                 where = memacpy(uri, length);
 134         }
 135
 136         uri[length] = keep;
 137
 138         if (!where) return NULL;
 139
 140         /* We need to reparse the URI and normalize it so that the protocol and
 141          * host part are converted to lowercase. */
 142         normalize_uri(NULL, where);
 143
 144         new_link = add_document_link(document, where, length, x, y);
 145
 146         if (!new_link) mem_free(where);
 147
 148         return new_link;
 149 }
 150
 151 #define url_char(c) (           \
 152                 (c) > ' '       \
 153                 && (c) != '<'   \
 154                 && (c) != '>'   \
 155                 && (c) != '('   \
 156                 && (c) != ')'   \
 157                 && !isquote(c))
 158
 159 static inline int
 160 get_uri_length(unsigned char *line, int length)
 161 {
 162         int uri_end = 0;
 163
 164         while (uri_end < length
 165                && url_char(line[uri_end]))
 166                 uri_end++;
 167
 168         for (; uri_end > 0; uri_end--) {
 169                 if (line[uri_end - 1] != '.'
 170                     && line[uri_end - 1] != ',')
 171                         break;
 172         }
 173
 174         return uri_end;
 175 }
 176
 177 static int
 178 print_document_link(struct plain_renderer *renderer, int lineno,
 179                     unsigned char *line, int line_pos, int width,
 180                     int expanded, struct screen_char *pos, int cells)
 181 {
 182         struct document *document = renderer->document;
 183         unsigned char *start = &line[line_pos];
 184         int len = get_uri_length(start, width - line_pos);
 185         int screen_column = cells + expanded;
 186         struct link *new_link;
 187         int link_end = line_pos + len;
 188         unsigned char saved_char;
 189         struct document_options *doc_opts = &document->options;
 190         struct screen_char template = renderer->template;
 191         int i;
 192
 193         if (!len) return 0;
 194
 195         new_link = check_link_word(document, start, len, screen_column,
 196                                    lineno);
 197
 198         if (!new_link) return 0;
 199
 200         saved_char = line[link_end];
 201         line[link_end] = '\0';
 202
 203         if (0)
 204                 ; /* Shut up compiler */
 205 #ifdef CONFIG_GLOBHIST
 206         else if (get_global_history_item(start))
 207                 new_link->color.foreground = doc_opts->default_color.vlink;
 208 #endif
 209 #ifdef CONFIG_BOOKMARKS
 210         else if (get_bookmark(start))
 211                 new_link->color.foreground = doc_opts->default_color.bookmark_link;
 212 #endif
 213         else
 214                 new_link->color.foreground = doc_opts->default_color.link;
 215
 216         line[link_end] = saved_char;
 217
 218         new_link->color.background = doc_opts->default_style.color.background;
 219
 220         set_term_color(&template, &new_link->color,
 221                        doc_opts->color_flags, doc_opts->color_mode);
 222
 223         for (i = len; i; i--) {
 224                 template.data = line[line_pos++];
 225                 copy_screen_chars(pos++, &template, 1);
 226         }
 227
 228         return len;
 229 }
 230
 231 static void
 232 decode_esc_color(unsigned char *text, int *line_pos, int width,
 233                  struct screen_char *template, enum color_mode mode,
 234                  int *was_reversed)
 235 {
 236         struct screen_char ch;
 237         struct color_pair color;
 238         char *buf, *tail, *begin, *end;
 239         int k, foreground, background, f1, b1; /* , intensity; */
 240
 241         ++(*line_pos);
 242         buf = (char *)&text[*line_pos];
 243
 244         if (*buf != '[') return;
 245         ++buf;
 246         ++(*line_pos);
 247
 248         k = strspn(buf, "0123456789;");
 249         *line_pos += k;
 250         if (!k || buf[k] != 'm')  return;
 251
 252         end = buf + k;
 253         begin = tail = buf;
 254
 255         get_screen_char_color(template, &color, 0, mode);
 256         set_term_color(&ch, &color, 0, COLOR_MODE_16);
 257         b1 = background = (ch.color[0] >> 4) & 7;
 258         f1 = foreground = ch.color[0] & 15;
 259
 260         while (tail < end) {
 261                 unsigned char kod = (unsigned char)strtol(begin, &tail, 10);
 262
 263                 begin = tail + 1;
 264                 switch (kod) {
 265                 case 0:
 266                         background = 0;
 267                         foreground = 7;
 268                         break;
 269                 case 7:
 270                         if (*was_reversed == 0) {
 271                                 background = f1 & 7;
 272                                 foreground = b1;
 273                                 *was_reversed = 1;
 274                         }
 275                         break;
 276                 case 27:
 277                         if (*was_reversed == 1) {
 278                                 background = f1 & 7;
 279                                 foreground = b1;
 280                                 *was_reversed = 0;
 281                         }
 282                         break;
 283                 case 30:
 284                 case 31:
 285                 case 32:
 286                 case 33:
 287                 case 34:
 288                 case 35:
 289                 case 36:
 290                 case 37:
 291                         foreground = kod - 30;
 292                         break;
 293                 case 40:
 294                 case 41:
 295                 case 42:
 296                 case 43:
 297                 case 44:
 298                 case 45:
 299                 case 46:
 300                 case 47:
 301                         background = kod - 40;
 302                         break;
 303                 default:
 304                         break;
 305                 }
 306         }
 307         color.background = get_term_color16(background);
 308         color.foreground = get_term_color16(foreground);
 309         set_term_color(template, &color, 0, mode);
 310 }
 311
 312 static inline int
 313 add_document_line(struct plain_renderer *renderer,
 314                   unsigned char *line, int line_width)
 315 {
 316         struct document *document = renderer->document;
 317         struct screen_char *template = &renderer->template;
 318         struct screen_char saved_renderer_template = *template;
 319         struct screen_char *pos, *startpos;
 320         struct document_options *doc_opts = &document->options;
 321         int was_reversed = 0;
 322
 323 #ifdef CONFIG_UTF8
 324         int utf8 = doc_opts->utf8;
 325 #endif /* CONFIG_UTF8 */
 326         int cells = 0;
 327         int lineno = renderer->lineno;
 328         int expanded = 0;
 329         int width = line_width;
 330         int line_pos;
 331
 332         line = convert_string(renderer->convert_table, line, width,
 333                               document->options.cp, CSM_NONE, &width,
 334                               NULL, NULL);
 335         if (!line) return 0;
 336
 337         /* Now expand tabs */
 338         for (line_pos = 0; line_pos < width;) {
 339                 unsigned char line_char = line[line_pos];
 340                 int charlen = 1;
 341                 int cell = 1;
 342 #ifdef CONFIG_UTF8
 343                 unicode_val_T data;
 344
 345                 if (utf8) {
 346                         unsigned char *line_char2 = &line[line_pos];
 347                         charlen = utf8charlen(&line_char);
 348                         data = utf8_to_unicode(&line_char2, &line[width]);
 349
 350                         if (data == UCS_NO_CHAR) {
 351                                 line_pos += charlen;
 352                                 continue;
 353                         }
 354
 355                         cell = unicode_to_cell(data);
 356                 }
 357 #endif /* CONFIG_UTF8 */
 358
 359                 if (line_char == ASCII_TAB
 360                     && (line_pos + charlen == width
 361                         || line[line_pos + charlen] != ASCII_BS)) {
 362                         int tab_width = 7 - ((cells + expanded) & 7);
 363
 364                         expanded += tab_width;
 365                 } else if (line_char == ASCII_BS) {
 366 #if 0
 367                 This does not work: Suppose we have seventeen spaces
 368                 followed by a back-space; that will call for sixteen
 369                 bytes of memory, but we will print seventeen spaces
 370                 before we hit the back-space -- overflow!
 371
 372                         /* Don't count the character
 373                          * that the back-space character will delete */
 374                         if (expanded + line_pos)
 375                                 expanded--;
 376 #endif
 377 #if 0
 378                         /* Don't count the back-space character */
 379                         if (expanded > 0)
 380                                 expanded--;
 381 #endif
 382                 }
 383                 line_pos += charlen;
 384                 cells += cell;
 385         }
 386
 387         assert(expanded >= 0);
 388
 389         startpos = pos = realloc_line(document, width + expanded, lineno);
 390         if (!pos) {
 391                 mem_free(line);
 392                 return 0;
 393         }
 394
 395         cells = 0;
 396         expanded = 0;
 397         for (line_pos = 0; line_pos < width;) {
 398                 unsigned char line_char = line[line_pos];
 399                 unsigned char next_char, prev_char;
 400                 int charlen = 1;
 401                 int cell = 1;
 402 #ifdef CONFIG_UTF8
 403                 unicode_val_T data = UCS_NO_CHAR;
 404
 405                 if (utf8) {
 406                         unsigned char *line_char2 = &line[line_pos];
 407                         charlen = utf8charlen(&line_char);
 408                         data = utf8_to_unicode(&line_char2, &line[width]);
 409
 410                         if (data == UCS_NO_CHAR) {
 411                                 line_pos += charlen;
 412                                 continue;
 413                         }
 414
 415                         cell = unicode_to_cell(data);
 416                 }
 417 #endif /* CONFIG_UTF8 */
 418
 419                 prev_char = line_pos > 0 ? line[line_pos - 1] : '\0';
 420                 next_char = (line_pos + charlen < width) ?
 421                                 line[line_pos + charlen] : '\0';
 422
 423                 /* Do not expand tabs that precede back-spaces; this saves the
 424                  * back-space code some trouble. */
 425                 if (line_char == ASCII_TAB && next_char != ASCII_BS) {
 426                         int tab_width = 7 - ((cells + expanded) & 7);
 427
 428                         expanded += tab_width;
 429
 430                         template->data = ' ';
 431                         do
 432                                 copy_screen_chars(pos++, template, 1);
 433                         while (tab_width--);
 434
 435                         *template = saved_renderer_template;
 436
 437                 } else if (line_char == ASCII_BS) {
 438                         if (!(expanded + cells)) {
 439                                 /* We've backspaced to the start of the line */
 440                                 goto next;
 441                         }
 442                         if (pos > startpos)
 443                                 pos--;  /* Backspace */
 444
 445                         /* Handle x^H_ as _^Hx, but prevent an infinite loop
 446                          * swapping two underscores. */
 447                         if (next_char == '_'  && prev_char != '_') {
 448                                 /* x^H_ becomes _^Hx */
 449                                 if (line_pos - 1 >= 0)
 450                                         line[line_pos - 1] = next_char;
 451                                 if (line_pos + charlen < width)
 452                                         line[line_pos + charlen] = prev_char;
 453
 454                                 /* Go back and reparse the swapped characters */
 455                                 if (line_pos - 2 >= 0) {
 456                                         cells--;
 457                                         line_pos--;
 458                                 }
 459                                 continue;
 460                         }
 461
 462                         if ((expanded + line_pos) - 2 >= 0) {
 463                                 /* Don't count the backspace character or the
 464                                  * deleted character when returning the line's
 465                                  * width or when expanding tabs. */
 466                                 expanded -= 2;
 467                         }
 468
 469                         if (pos->data == '_' && next_char == '_') {
 470                                 /* Is _^H_ an underlined underscore
 471                                  * or an emboldened underscore? */
 472
 473                                 if (expanded + line_pos >= 0
 474                                     && pos - 1 >= startpos
 475                                     && (pos - 1)->attr) {
 476                                         /* There is some preceding text,
 477                                          * and it has an attribute; copy it */
 478                                         template->attr |= (pos - 1)->attr;
 479                                 } else {
 480                                         /* Default to bold; seems more useful
 481                                          * than underlining the underscore */
 482                                         template->attr |= SCREEN_ATTR_BOLD;
 483                                 }
 484
 485                         } else if (pos->data == '_') {
 486                                 /* Underline _^Hx */
 487
 488                                 template->attr |= SCREEN_ATTR_UNDERLINE;
 489
 490                         } else if (pos->data == next_char) {
 491                                 /* Embolden x^Hx */
 492
 493                                 template->attr |= SCREEN_ATTR_BOLD;
 494                         }
 495
 496                         /* Handle _^Hx^Hx as both bold and underlined */
 497                         if (template->attr)
 498                                 template->attr |= pos->attr;
 499                 } else if (line_char == 27) {
 500                         decode_esc_color(line, &line_pos, width,
 501                                          &saved_renderer_template,
 502                                          doc_opts->color_mode, &was_reversed);
 503                         *template = saved_renderer_template;
 504                 } else {
 505                         int added_chars = 0;
 506
 507                         if (document->options.plain_display_links
 508                             && isalpha(line_char) && isalpha(next_char)) {
 509                                 /* We only want to check for a URI if there are
 510                                  * at least two consecutive alphabetic
 511                                  * characters, or if we are at the very start of
 512                                  * the line.  It improves performance a bit.
 513                                  * --Zas */
 514                                 added_chars = print_document_link(renderer,
 515                                                                   lineno, line,
 516                                                                   line_pos,
 517                                                                   width,
 518                                                                   expanded,
 519                                                                   pos, cells);
 520                         }
 521
 522                         if (added_chars) {
 523                                 line_pos += added_chars - 1;
 524                                 cells += added_chars - 1;
 525                                 pos += added_chars;
 526                         } else {
 527 #ifdef CONFIG_UTF8
 528                                 if (utf8) {
 529                                         if (data == UCS_NO_CHAR) {
 530                                                 line_pos += charlen;
 531                                                 continue;
 532                                         }
 533
 534                                         template->data = (unicode_val_T)data;
 535                                         copy_screen_chars(pos++, template, 1);
 536
 537                                         if (cell == 2) {
 538                                                 template->data = UCS_NO_CHAR;
 539                                                 copy_screen_chars(pos++,
 540                                                                   template, 1);
 541                                         }
 542                                 } else
 543 #endif /* CONFIG_UTF8 */
 544                                 {
 545                                         if (!isscreensafe(line_char))
 546                                                 line_char = '.';
 547                                         template->data = line_char;
 548                                         copy_screen_chars(pos++, template, 1);
 549
 550                                         /* Detect copy of nul chars to screen,
 551                                          * this should not occur. --Zas */
 552                                         assert(line_char);
 553                                 }
 554                         }
 555
 556                         *template = saved_renderer_template;
 557                 }
 558 next:
 559                 line_pos += charlen;
 560                 cells += cell;
 561         }
 562         mem_free(line);
 563
 564         realloc_line(document, pos - startpos, lineno);
 565
 566         return width + expanded;
 567 }
 568
 569 static void
 570 init_template(struct screen_char *template, struct document_options *options)
 571 {
 572         get_screen_char_template(template, options, options->default_style);
 573 }
 574
 575 static struct node *
 576 add_node(struct plain_renderer *renderer, int x, int width, int height)
 577 {
 578         struct node *node = mem_alloc(sizeof(*node));
 579
 580         if (node) {
 581                 struct document *document = renderer->document;
 582
 583                 set_box(&node->box, x, renderer->lineno, width, height);
 584
 585                 int_lower_bound(&document->width, width);
 586                 int_lower_bound(&document->height, height);
 587
 588                 add_to_list(document->nodes, node);
 589         }
 590
 591         return node;
 592 }
 593
 594 static void
 595 add_document_lines(struct plain_renderer *renderer)
 596 {
 597         unsigned char *source = renderer->source;
 598         int length = renderer->length;
 599         int was_empty_line = 0;
 600         int was_wrapped = 0;
 601 #ifdef CONFIG_UTF8
 602         int utf8 = is_cp_utf8(renderer->document->cp);
 603 #endif
 604         for (; length > 0; renderer->lineno++) {
 605                 unsigned char *xsource;
 606                 int width, added, only_spaces = 1, spaces = 0, was_spaces = 0;
 607                 int last_space = 0;
 608                 int tab_spaces = 0;
 609                 int step = 0;
 610                 int cells = 0;
 611
 612                 /* End of line detection: We handle \r, \r\n and \n types. */
 613                 for (width = 0; (width < length) &&
 614                                 (cells < renderer->max_width);) {
 615                         if (source[width] == ASCII_CR)
 616                                 step++;
 617                         if (source[width + step] == ASCII_LF)
 618                                 step++;
 619                         if (step) break;
 620
 621                         if (isspace(source[width])) {
 622                                 last_space = width;
 623                                 if (only_spaces)
 624                                         spaces++;
 625                                 else
 626                                         was_spaces++;
 627                                 if (source[width] == '\t')
 628                                         tab_spaces += 7 - ((width + tab_spaces) % 8);
 629                         } else {
 630                                 only_spaces = 0;
 631                                 was_spaces = 0;
 632                         }
 633 #ifdef CONFIG_UTF8
 634                         if (utf8) {
 635                                 unsigned char *text = &source[width];
 636                                 unicode_val_T data = utf8_to_unicode(&text,
 637                                                         &source[length]);
 638
 639                                 if (data == UCS_NO_CHAR) return;
 640
 641                                 cells += unicode_to_cell(data);
 642                                 width += utf8charlen(&source[width]);
 643                         } else
 644 #endif /* CONFIG_UTF8 */
 645                         {
 646                                 cells++;
 647                                 width++;
 648                         }
 649                 }
 650
 651                 if (only_spaces && step) {
 652                         if (was_wrapped || (renderer->compress && was_empty_line)) {
 653                                 /* Successive empty lines will appear as one. */
 654                                 length -= step + spaces;
 655                                 source += step + spaces;
 656                                 renderer->lineno--;
 657                                 assert(renderer->lineno >= 0);
 658                                 continue;
 659                         }
 660                         was_empty_line = 1;
 661
 662                         /* No need to keep whitespaces on an empty line. */
 663                         source += spaces;
 664                         length -= spaces;
 665                         width -= spaces;
 666
 667                 } else {
 668                         was_empty_line = 0;
 669                         was_wrapped = !step;
 670
 671                         if (was_spaces && step) {
 672                                 /* Drop trailing whitespaces. */
 673                                 width -= was_spaces;
 674                                 step += was_spaces;
 675                         }
 676
 677                         if (!step && (width < length) && last_space) {
 678                                 width = last_space;
 679                                 step = 1;
 680                         }
 681                 }
 682
 683                 assert(width >= 0);
 684
 685                 /* We will touch the supplied source, so better replicate it. */
 686                 xsource = memacpy(source, width);
 687                 if (!xsource) continue;
 688
 689                 added = add_document_line(renderer, xsource, width);
 690                 mem_free(xsource);
 691
 692                 if (added) {
 693                         /* Add (search) nodes on a line by line basis */
 694                         add_node(renderer, 0, added, 1);
 695                 }
 696
 697                 /* Skip end of line chars too. */
 698                 width += step;
 699                 length -= width;
 700                 source += width;
 701         }
 702
 703         assert(!length);
 704 }
 705
 706 void
 707 render_plain_document(struct cache_entry *cached, struct document *document,
 708                       struct string *buffer)
 709 {
 710         struct conv_table *convert_table;
 711         unsigned char *head = empty_string_or_(cached->head);
 712         struct plain_renderer renderer;
 713
 714         convert_table = get_convert_table(head, document->options.cp,
 715                                           document->options.assume_cp,
 716                                           &document->cp,
 717                                           &document->cp_status,
 718                                           document->options.hard_assume);
 719
 720         renderer.source = buffer->source;
 721         renderer.length = buffer->length;
 722
 723         renderer.document = document;
 724         renderer.lineno = 0;
 725         renderer.convert_table = convert_table;
 726         renderer.compress = document->options.plain_compress_empty_lines;
 727         renderer.max_width = document->options.wrap ? document->options.box.width
 728                                                     : INT_MAX;
 729
 730         document->color.background = document->options.default_style.color.background;
 731         document->width = 0;
 732 #ifdef CONFIG_UTF8
 733         document->options.utf8 = is_cp_utf8(document->options.cp);
 734 #endif /* CONFIG_UTF8 */
 735
 736         /* Setup the style */
 737         init_template(&renderer.template, &document->options);
 738
 739         add_document_lines(&renderer);
 740 }