apps/plugins/text_viewer/tv_text_processor.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2002 Gilles Roux
  11  *               2003 Garrett Derner
  12  *               2010 Yoshihisa Uchida
  13  *
  14  * This program is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU General Public License
  16  * as published by the Free Software Foundation; either version 2
  17  * of the License, or (at your option) any later version.
  18  *
  19  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  20  * KIND, either express or implied.
  21  *
  22  ****************************************************************************/
  23 #include "plugin.h"
  24 #include "ctype.h"
  25 #include "tv_preferences.h"
  26 #include "tv_text_processor.h"
  27
  28 enum{
  29     TV_TEXT_UNKNOWN,
  30     TV_TEXT_MAC,
  31     TV_TEXT_UNIX,
  32     TV_TEXT_WIN,
  33 };
  34
  35 /* the max characters of each blocks */
  36 #ifdef HAVE_LCD_BITMAP
  37 #define TV_MAX_CHARS_PER_BLOCK (LCD_WIDTH / 2 + 1)
  38 #else
  39 #define TV_MAX_CHARS_PER_BLOCK (LCD_WIDTH + 1)
  40 #endif
  41
  42 #define TV_MAX_BLOCKS 5
  43
  44 static unsigned text_type = TV_TEXT_UNKNOWN;
  45
  46 static const unsigned char *end_ptr;
  47
  48 static unsigned short ucsbuf[TV_MAX_BLOCKS][TV_MAX_CHARS_PER_BLOCK];
  49 static unsigned char  utf8buf[TV_MAX_CHARS_PER_BLOCK * (2 * 3)];
  50 static unsigned char  *outbuf;
  51
  52 static int block_count;
  53 static int block_width;
  54
  55 /* if this value is true, then  tv_create_line_text returns a blank line. */
  56 static bool expand_extra_line = false;
  57
  58 /* when a line is divided, this value sets true. */
  59 static bool is_break_line = false;
  60
  61 static unsigned short break_chars[] =
  62     {
  63         0,
  64         /* halfwidth characters */
  65         '\t', '\n', 0x0b, 0x0c, ' ', '!', ',', '-', '.', ':', ';', '?', 0xb7,
  66         /* fullwidth characters */
  67         0x2010, /* hyphen */
  68         0x3000, /* fullwidth space */
  69         0x3001, /* ideographic comma */
  70         0x3002, /* ideographic full stop */
  71         0x30fb, /* katakana middle dot */
  72         0x30fc, /* katakana-hiragana prolonged sound mark */
  73         0xff01, /* fullwidth exclamation mark */
  74         0xff0c, /* fullwidth comma */
  75         0xff0d, /* fullwidth hyphen-minus */
  76         0xff0e, /* fullwidth full stop */
  77         0xff1a, /* fullwidth colon */
  78         0xff1b, /* fullwidth semicolon */
  79         0xff1f, /* fullwidth question mark */
  80     };
  81
  82 /* the characters which is not judged as space with isspace() */
  83 static unsigned short extra_spaces[] = { 0, 0x3000 };
  84
  85 static int tv_glyph_width(int ch)
  86 {
  87     if (ch == '\n')
  88         return 0;
  89
  90     if (ch == 0)
  91         ch = ' ';
  92
  93 #ifdef HAVE_LCD_BITMAP
  94     /* the width of the diacritics charcter is 0 */
  95     if (rb->is_diacritic(ch, NULL))
  96         return 0;
  97
  98     return rb->font_get_width(preferences->font, ch);
  99 #else
 100     return 1;
 101 #endif
 102 }
 103
 104 static unsigned char *tv_get_ucs(const unsigned char *str, unsigned short *ch)
 105 {
 106     int count = 1;
 107     unsigned char utf8_tmp[3];
 108
 109     /* distinguish the text_type */
 110     if (*str == '\r')
 111     {
 112         if (text_type == TV_TEXT_WIN || text_type == TV_TEXT_UNKNOWN)
 113         {
 114             if (str + 1 < end_ptr && *(str+1) == '\n')
 115             {
 116                 if (text_type == TV_TEXT_UNKNOWN)
 117                     text_type = TV_TEXT_WIN;
 118
 119                 *ch = '\n';
 120                 return (unsigned char *)str + 2;
 121             }
 122
 123             if (text_type == TV_TEXT_UNKNOWN)
 124                 text_type = TV_TEXT_MAC;
 125         }
 126         *ch = (text_type == TV_TEXT_MAC)? '\n' : ' ';
 127         return (unsigned char *)str + 1;
 128     }
 129     else if (*str == '\n')
 130     {
 131         if (text_type == TV_TEXT_UNKNOWN)
 132             text_type = TV_TEXT_UNIX;
 133
 134         *ch = (text_type == TV_TEXT_UNIX)? '\n' : ' ';
 135         return (unsigned char *)str + 1;
 136     }
 137
 138     if (preferences->encoding == UTF_8)
 139         return (unsigned char*)rb->utf8decode(str, ch);
 140
 141 #ifdef HAVE_LCD_BITMAP
 142     if ((*str >= 0x80) &&
 143         ((preferences->encoding > SJIS) ||
 144          (preferences->encoding == SJIS && (*str <= 0xa0 || *str >= 0xe0))))
 145     {
 146         if (str + 1 >= end_ptr)
 147         {
 148             end_ptr = str;
 149             *ch = 0;
 150             return (unsigned char *)str;
 151         }
 152         count = 2;
 153     }
 154 #endif
 155     rb->iso_decode(str, utf8_tmp, preferences->encoding, count);
 156     rb->utf8decode(utf8_tmp, ch);
 157     return (unsigned char *)str + count;
 158 }
 159
 160 static void tv_decode2utf8(const unsigned short *ucs, int count)
 161 {
 162     int i;
 163
 164     for (i = 0; i < count; i++)
 165         outbuf = rb->utf8encode(ucs[i], outbuf);
 166
 167     *outbuf = '\0';
 168 }
 169
 170 static bool tv_is_line_break_char(unsigned short ch)
 171 {
 172     size_t i;
 173
 174     /* when the word mode is CHOP, all characters does not break line. */
 175     if (preferences->word_mode == WM_CHOP)
 176         return false;
 177
 178     for (i = 0; i < sizeof(break_chars); i++)
 179     {
 180         if (break_chars[i] == ch)
 181             return true;
 182     }
 183     return false;
 184 }
 185
 186 static bool tv_isspace(unsigned short ch)
 187 {
 188     size_t i;
 189
 190     if (ch < 128 && isspace(ch))
 191         return true;
 192
 193     for (i = 0; i < sizeof(extra_spaces); i++)
 194     {
 195         if (extra_spaces[i] == ch)
 196             return true;
 197     }
 198     return false;
 199 }
 200
 201 static bool tv_is_break_line_join_mode(const unsigned char *next_str)
 202 {
 203     unsigned short ch;
 204
 205     tv_get_ucs(next_str, &ch);
 206     return tv_isspace(ch);
 207 }
 208
 209 static int tv_form_reflow_line(unsigned short *ucs, int chars)
 210 {
 211     unsigned short new_ucs[TV_MAX_CHARS_PER_BLOCK];
 212     unsigned short *p = new_ucs;
 213     unsigned short ch;
 214     int i;
 215     int k;
 216     int expand_spaces;
 217     int indent_chars = 0;
 218     int nonspace_chars = 0;
 219     int nonspace_width = 0;
 220     int remain_spaces;
 221     int spaces = 0;
 222     int words_spaces;
 223
 224     if (preferences->alignment == AL_LEFT)
 225     {
 226         while (chars > 0 && ucs[chars-1] == ' ')
 227             chars--;
 228     }
 229
 230     if (chars == 0)
 231         return 0;
 232
 233     while (ucs[indent_chars] == ' ')
 234         indent_chars++;
 235
 236     for (i = indent_chars; i < chars; i++)
 237     {
 238         ch = ucs[i];
 239         if (ch == ' ')
 240             spaces++;
 241         else
 242         {
 243             nonspace_chars++;
 244             nonspace_width += tv_glyph_width(ch);
 245         }
 246     }
 247
 248     if (spaces == 0)
 249         return chars;
 250
 251     expand_spaces = (block_width - nonspace_width) / tv_glyph_width(' ') - indent_chars;
 252     if (indent_chars + nonspace_chars + expand_spaces > TV_MAX_CHARS_PER_BLOCK)
 253         expand_spaces = TV_MAX_CHARS_PER_BLOCK - indent_chars - nonspace_chars;
 254
 255     words_spaces  = expand_spaces / spaces;
 256     remain_spaces = expand_spaces - words_spaces * spaces;
 257
 258     for (i = 0; i < indent_chars; i++)
 259         *p++ = ' ';
 260
 261     for ( ; i < chars; i++)
 262     {
 263         ch = ucs[i];
 264         *p++ = ch;
 265         if (ch == ' ')
 266         {
 267             for (k = ((remain_spaces > 0)? 0 : 1); k < words_spaces; k++)
 268                 *p++ = ch;
 269
 270             remain_spaces--;
 271         }
 272     }
 273
 274     rb->memcpy(ucs, new_ucs, sizeof(unsigned short) * TV_MAX_CHARS_PER_BLOCK);
 275     return indent_chars + nonspace_chars + expand_spaces;
 276 }
 277
 278 static void tv_align_right(int *block_chars)
 279 {
 280     unsigned short *cur_text;
 281     unsigned short *prev_text;
 282     unsigned short ch;
 283     int cur_block = block_count - 1;
 284     int prev_block;
 285     int cur_chars;
 286     int prev_chars;
 287     int idx;
 288     int break_pos;
 289     int break_width = 0;
 290     int append_width;
 291     int width;
 292
 293     while (cur_block > 0)
 294     {
 295         cur_text  = ucsbuf[cur_block];
 296         cur_chars = block_chars[cur_block];
 297         idx = cur_chars;
 298         width = 0;
 299         while(--idx >= 0)
 300             width += tv_glyph_width(cur_text[idx]);
 301
 302         width = block_width - width;
 303         prev_block = cur_block - 1;
 304
 305         do {
 306             prev_text  = ucsbuf[prev_block];
 307             prev_chars = block_chars[prev_block];
 308
 309             idx = prev_chars;
 310             append_width = 0;
 311             break_pos = prev_chars;
 312             while (append_width < width && idx > 0)
 313             {
 314                 ch = prev_text[--idx];
 315                 if (tv_is_line_break_char(ch))
 316                 {
 317                     break_pos = idx + 1;
 318                     break_width = append_width;
 319                 }
 320                 append_width += tv_glyph_width(ch);
 321             }
 322             if (append_width > width)
 323                 idx++;
 324
 325             if (idx == 0)
 326             {
 327                 break_pos = 0;
 328                 break_width = append_width;
 329             }
 330
 331             if (break_pos < prev_chars)
 332                 append_width = break_width;
 333             /* the case of
 334              *   (1) when the first character of the cur_text concatenates
 335              *       the last character of the prev_text.
 336              *   (2) the length of ucsbuf[block] is short (< 0.75 * block width)
 337              */
 338             else if (((!tv_isspace(*cur_text) && !tv_isspace(prev_text[prev_chars - 1])) ||
 339                      (4 * width >= 3 * block_width)))
 340             {
 341                 break_pos = idx;
 342             }
 343
 344             if (break_pos < prev_chars)
 345             {
 346                 rb->memmove(cur_text + prev_chars - break_pos,
 347                             cur_text, block_chars[cur_block] * sizeof(unsigned short));
 348                 rb->memcpy(cur_text, prev_text + break_pos,
 349                            (prev_chars - break_pos) * sizeof(unsigned short));
 350
 351                 block_chars[prev_block]  = break_pos;
 352                 block_chars[cur_block ] += prev_chars - break_pos;
 353             }
 354         } while ((width -= append_width) > 0 && --prev_block >= 0);
 355         cur_block--;
 356     }
 357 }
 358
 359 static int tv_parse_text(const unsigned char *src, unsigned short *ucs,
 360                              int *ucs_chars, bool is_indent)
 361 {
 362     const unsigned char *cur  = src;
 363     const unsigned char *next = src;
 364     const unsigned char *line_break_ptr = NULL;
 365     const unsigned char *line_end_ptr   = NULL;
 366     unsigned short ch = 0;
 367     unsigned short prev_ch;
 368     int chars = 0;
 369     int gw;
 370     int line_break_width = 0;
 371     int line_end_chars   = 0;
 372     int width = 0;
 373     bool is_space = false;
 374
 375     while (true) {
 376         cur = next;
 377         if (cur >= end_ptr)
 378         {
 379             line_end_ptr   = cur;
 380             line_end_chars = chars;
 381             is_break_line  = true;
 382             break;
 383         }
 384
 385         prev_ch = ch;
 386         next = tv_get_ucs(cur, &ch);
 387         if (ch == '\n')
 388         {
 389             if (preferences->line_mode != LM_JOIN || tv_is_break_line_join_mode(next))
 390             {
 391                 line_end_ptr   = next;
 392                 line_end_chars = chars;
 393                 is_break_line  = false;
 394                 break;
 395             }
 396
 397             if (preferences->word_mode == WM_CHOP || tv_isspace(prev_ch))
 398                 continue;
 399
 400             /*
 401              * when the line mode is JOIN and the word mode is WRAP,
 402              * the next character does not concatenate with the
 403              * previous character.
 404              */
 405             ch = ' ';
 406         }
 407         else if ((is_space = tv_isspace(ch)) == true)
 408         {
 409             /*
 410              * when the line mode is REFLOW:
 411              *     (1) spacelike character convert to ' '
 412              *     (2) plural spaces are collected to one
 413              */
 414             if (preferences->line_mode == LM_REFLOW)
 415             {
 416                 ch = ' ';
 417                 if (prev_ch == ch)
 418                     continue;
 419             }
 420
 421             /* when the alignment is RIGHT, ignores indent spaces. */
 422             if (preferences->alignment == AL_RIGHT && is_indent)
 423                 continue;
 424         }
 425         else
 426             is_indent = false;
 427
 428         if (preferences->line_mode == LM_REFLOW && is_indent)
 429             gw = tv_glyph_width(ch) * preferences->indent_spaces;
 430         else
 431             gw = tv_glyph_width(ch);
 432
 433         width += gw;
 434         if (width > block_width)
 435         {
 436             width -= gw;
 437             if (is_space)
 438             {
 439                 line_end_ptr   = cur;
 440                 line_end_chars = chars;
 441             }
 442             is_break_line = true;
 443             break;
 444         }
 445
 446         if (preferences->line_mode != LM_REFLOW || !is_indent)
 447             ucs[chars++] = ch;
 448         else
 449         {
 450             unsigned char i;
 451             for (i = 0; i < preferences->indent_spaces; i++)
 452                 ucs[chars++] = ch;
 453         }
 454
 455         if (tv_is_line_break_char(ch))
 456         {
 457             line_break_ptr   = next;
 458             line_break_width = width;
 459             line_end_chars   = chars;
 460         }
 461         if (chars >= TV_MAX_CHARS_PER_BLOCK)
 462         {
 463             is_break_line = true;
 464             break;
 465         }
 466     }
 467
 468     /* set the end position and character count */
 469     if (line_end_ptr == NULL)
 470     {
 471         /*
 472          * when the last line break position is too short (line length < 0.75 * block width),
 473          * the line is cut off at the position where it is closest to the displayed width.
 474          */
 475         if ((preferences->line_mode == LM_REFLOW && line_break_ptr == NULL) ||
 476             (4 * line_break_width < 3 * block_width))
 477         {
 478             line_end_ptr   = cur;
 479             line_end_chars = chars;
 480         }
 481         else
 482             line_end_ptr = line_break_ptr;
 483     }
 484
 485     *ucs_chars = line_end_chars;
 486     return line_end_ptr - src;
 487 }
 488
 489 int tv_create_formed_text(const unsigned char *src, ssize_t bufsize,
 490                               int block, bool is_multi, const unsigned char **dst)
 491 {
 492     unsigned short ch;
 493     int chars[block_count];
 494     int i;
 495     int size = 0;
 496     bool is_indent;
 497
 498     outbuf = utf8buf;
 499     *outbuf = '\0';
 500
 501     for (i = 0; i < block_count; i++)
 502         chars[i] = 0;
 503
 504     if (dst != NULL)
 505         *dst = utf8buf;
 506
 507     if (preferences->line_mode == LM_EXPAND && (expand_extra_line = !expand_extra_line) == true)
 508         return 0;
 509
 510     end_ptr = src + bufsize;
 511
 512     tv_get_ucs(src, &ch);
 513     is_indent = (tv_isspace(ch) && !is_break_line);
 514
 515     if (is_indent && preferences->indent_spaces == 0 && (expand_extra_line = !expand_extra_line) == true)
 516         return 0;
 517
 518     for (i = 0; i < block_count; i++)
 519     {
 520         size += tv_parse_text(src + size, ucsbuf[i], &chars[i], is_indent);
 521         if (!is_break_line)
 522             break;
 523
 524         is_indent = false;
 525     }
 526
 527     if (dst != NULL)
 528     {
 529         if (preferences->alignment == AL_RIGHT)
 530             tv_align_right(chars);
 531
 532         for (i = 0; i < block_count; i++)
 533         {
 534             if (i == block || (is_multi && i == block + 1))
 535             {
 536                 if (is_break_line && preferences->line_mode == LM_REFLOW)
 537                     chars[i] = tv_form_reflow_line(ucsbuf[i], chars[i]);
 538
 539                 tv_decode2utf8(ucsbuf[i], chars[i]);
 540             }
 541         }
 542     }
 543
 544     return size;
 545 }
 546
 547 bool tv_init_text_processor(unsigned char **buf, size_t *size)
 548 {
 549     /* unused : no need for dynamic buffer yet */
 550     (void)buf;
 551     (void)size;
 552
 553     text_type = TV_TEXT_UNKNOWN;
 554     expand_extra_line = false;
 555     is_break_line = false;
 556     return true;
 557 }
 558
 559 void tv_set_creation_conditions(int blocks, int width)
 560 {
 561     block_count = blocks;
 562     block_width = width;
 563 }