src/vspace.C

   1 // -*- C++ -*-
   2 /* This file is part of
   3  * ======================================================
   4  *
   5  *           LyX, The Document Processor
   6  *
   7  *           Copyright 1995 Matthias Ettrich
   8  *           Copyright 1995-2000 The LyX Team.
   9  *
  10  * ====================================================== */
  11
  12 #include <config.h>
  13
  14 #ifdef __GNUG__
  15 #pragma implementation "vspace.h"
  16 #endif
  17
  18 #include "lyx_main.h"
  19 #include "buffer.h"
  20 #include "vspace.h"
  21 #include "lyxrc.h"
  22 #include "lyxtext.h"
  23 #include "BufferView.h"
  24 #include "support/lstrings.h"
  25
  26
  27 /*  length units
  28  */
  29
  30 static const int num_units = LyXLength::UNIT_NONE;
  31
  32 // I am not sure if "mu" should be possible to select (Lgb)
  33 static char const * unit_name[num_units] = { "sp", "pt", "bp", "dd",
  34                                              "mm", "pc", "cc", "cm",
  35                                              "in", "ex", "em", "mu" };
  36
  37
  38 LyXLength::UNIT unitFromString (string const & data)
  39 {
  40         int i = 0;
  41         while ((i < num_units) && (data != unit_name[i])) ++i;
  42         return static_cast<LyXLength::UNIT>(i);
  43 }
  44
  45 /*  The following static items form a simple scanner for
  46  *  length strings, used by isValid[Glue]Length.  See comments there.
  47  */
  48 static float           number[4] = { 0, 0, 0, 0 };
  49 static LyXLength::UNIT unit[4]   = { LyXLength::UNIT_NONE,
  50                                      LyXLength::UNIT_NONE,
  51                                      LyXLength::UNIT_NONE,
  52                                      LyXLength::UNIT_NONE };
  53 //static int number_index, unit_index;
  54 int number_index, unit_index;
  55
  56
  57 static inline
  58 void lyx_advance(string & data, unsigned int n)
  59 {
  60         data.erase(0, n);
  61 }
  62
  63
  64 static inline
  65 bool isEndOfData(string const & data)
  66 {
  67         return frontStrip(data).empty();
  68 }
  69
  70
  71 static
  72 char nextToken(string & data)
  73 {
  74         data = frontStrip(data);
  75         if (data.empty())
  76                 return '\0';
  77         else if (data[0] == '+') {
  78                 lyx_advance(data, 1);
  79                 return '+';
  80         } else if (prefixIs(data, "plus")) {
  81                 lyx_advance(data, 4);
  82                 return '+';
  83         } else if (data[0] == '-') {
  84                 lyx_advance(data, 1);
  85                 return '-';
  86         } else if (prefixIs(data, "minus")) {
  87                 lyx_advance(data, 5);
  88                 return '-';
  89         } else {
  90                 string::size_type i;
  91
  92                 // I really mean assignment ("=") below, not equality!
  93                 if ((i = data.find_last_of("0123456789.")) != string::npos) {
  94                         if (number_index > 3) return 'E';  // Error
  95                         string buffer = data.substr(0, i + 1);
  96                         if (isStrDbl(buffer)) {
  97                                 number[number_index] = strToDbl(buffer);
  98                                 lyx_advance(data, i + 1);
  99                                 ++number_index;
 100                                 return 'n';
 101                         } else
 102                                 return 'E';  // Error
 103                 } else if ((i = data.find_last_of("abcdefghijklmnopqrstuvwxyz"))
 104                            != string::npos) {
 105                         if (unit_index > 3) return 'E';  // Error
 106                         string buffer = data.substr(0, i + 1);
 107                         unit[unit_index] = unitFromString(buffer);
 108                         if (unit[unit_index] != LyXLength::UNIT_NONE) {
 109                                 lyx_advance(data, i + 1);
 110                                 ++unit_index;
 111                                 return 'u';
 112                         } else
 113                                 return 'E';  // Error
 114                 } else
 115                         return 'E';  // Error
 116         }
 117 }
 118
 119
 120 struct LaTeXLength {
 121         char const * pattern;
 122         int   plus_val_index, minus_val_index,
 123                 plus_uni_index, minus_uni_index;
 124 };
 125
 126
 127 static
 128 LaTeXLength table[] = {
 129         { "nu",       0, 0, 0, 0 },
 130         { "nu+nu",    2, 0, 2, 0 },
 131         { "nu+nu-nu", 2, 3, 2, 3 },
 132         { "nu+-nu",   2, 2, 2, 2 },
 133         { "nu-nu",    0, 2, 0, 2 },
 134         { "nu-nu+nu", 3, 2, 3, 2 },
 135         { "nu-+nu",   2, 2, 2, 2 },
 136         { "n+nu",     2, 0, 1, 0 },
 137         { "n+n-nu",   2, 3, 1, 1 },
 138         { "n+-nu",    2, 2, 1, 1 },
 139         { "n-nu",     0, 2, 0, 1 },
 140         { "n-n+nu",   3, 2, 1, 1 },
 141         { "n-+nu",    2, 2, 1, 1 },
 142         { "",         0, 0, 0, 0 }   // sentinel, must be empty
 143 };
 144
 145
 146 bool isValidGlueLength (string const & data, LyXGlueLength * result)
 147 {
 148         // This parser is table-driven.  First, it constructs a "pattern"
 149         // that describes the sequence of tokens in "data".  For example,
 150         // "n-nu" means: number, minus sign, number, unit.  As we go along,
 151         // numbers and units are stored into static arrays.  Then, "pattern"
 152         // is searched in the "table".  If it is found, the associated
 153         // table entries tell us which number and unit should go where
 154         // in the LyXLength structure.  Example: if "data" has the "pattern"
 155         // "nu+nu-nu", the associated table entries are "2, 3, 2, 3".
 156         // That means, "plus_val" is the second number that was seen
 157         // in the input, "minus_val" is the third number, and "plus_uni"
 158         // and "minus_uni" are the second and third units, respectively.
 159         // ("val" and "uni" are always the first items seen in "data".)
 160         //     This is the most elegant solution I could find -- a straight-
 161         // forward approach leads to very long, tedious code that would be
 162         // much harder to understand and maintain. (AS)
 163
 164         if (data.empty())
 165                 return true;
 166         string buffer = frontStrip(data);
 167
 168         // To make isValidGlueLength recognize negative values as
 169         // the first number this little hack is needed:
 170         short val_sign = 1; // positive as default
 171         switch(buffer[0]) {
 172         case '-':
 173                 lyx_advance(buffer, 1);
 174                 val_sign = -1;
 175                 break;
 176         case '+':
 177                 lyx_advance(buffer, 1);
 178                 // fall through
 179         default:
 180                 // no action
 181                 break;
 182         }
 183         // end of hack
 184
 185         int       pattern_index = 0, table_index = 0;
 186         char      pattern[20];
 187
 188         number_index = unit_index = 1;  // entries at index 0 are sentinels
 189
 190         // construct "pattern" from "data"
 191         while (!isEndOfData (buffer)) {
 192                 if (pattern_index > 20) return false;
 193                 pattern[pattern_index] = nextToken (buffer);
 194                 if (pattern[pattern_index] == 'E') return false;
 195                 ++pattern_index;
 196         }
 197         pattern[pattern_index] = '\0';
 198
 199         // search "pattern" in "table"
 200         table_index = 0;
 201         while (compare(pattern, table[table_index].pattern)) {
 202                 ++table_index;
 203                 if (!*table[table_index].pattern) return false;
 204         }
 205
 206         // Get the values from the appropriate places.  If an index
 207         // is zero, the corresponding array value is zero or UNIT_NONE,
 208         // so we needn't check this.
 209         if (result) {
 210                 result->val = number[1] * val_sign;
 211                 result->uni = unit[1];
 212                 result->plus_val  = number[table[table_index].plus_val_index];
 213                 result->minus_val = number[table[table_index].minus_val_index];
 214                 result->plus_uni  = unit  [table[table_index].plus_uni_index];
 215                 result->minus_uni = unit  [table[table_index].minus_uni_index];
 216         }
 217         return true;
 218 }
 219
 220
 221 bool isValidLength(string const & data, LyXLength * result)
 222 {
 223         /// This is a trimmed down version of isValidGlueLength.
 224         /// The parser may seem overkill for lengths without
 225         /// glue, but since we already have it, using it is
 226         /// easier than writing something from scratch.
 227
 228         string   buffer(data);
 229         int       pattern_index = 0;
 230         char      pattern[3];
 231
 232         // To make isValidLength recognize negative values
 233         // this little hack is needed:
 234         short val_sign = 1; // positive as default
 235         switch(buffer[0]) {
 236         case '-':
 237                 lyx_advance(buffer, 1);
 238                 val_sign = -1;
 239                 break;
 240         case '+':
 241                 lyx_advance(buffer, 1);
 242                 // fall through
 243         default:
 244                 // no action
 245                 break;
 246         }
 247         // end of hack
 248
 249         number_index = unit_index = 1;  // entries at index 0 are sentinels
 250
 251         // construct "pattern" from "data"
 252         while (!isEndOfData (buffer)) {
 253                 if (pattern_index > 2) return false;
 254                 pattern[pattern_index] = nextToken (buffer);
 255                 if (pattern[pattern_index] == 'E') return false;
 256                 ++pattern_index;
 257         }
 258         pattern[pattern_index] = '\0';
 259
 260         // only the most basic pattern is accepted here
 261         if (compare(pattern, "nu") != 0) return false;
 262
 263         // It _was_ a correct length string.
 264         // Store away the values we found.
 265         if (result) {
 266                 result->val = number[1] * val_sign;
 267                 result->uni = unit[1];
 268         }
 269         return true;
 270 }
 271
 272
 273 /// LyXLength class
 274
 275 LyXLength::LyXLength(string const & data)
 276 {
 277         LyXLength tmp;
 278
 279         if (!isValidLength (data, &tmp))
 280                 return; // should raise an exception
 281         else {
 282                 val = tmp.val;
 283                 uni = tmp.uni;
 284         }
 285 }
 286
 287
 288 string const LyXLength::asString() const
 289 {
 290         std::ostringstream buffer;
 291         buffer << val << unit_name[uni]; // setw?
 292         return buffer.str().c_str();
 293 }
 294
 295
 296 /*  LyXGlueLength class
 297  */
 298
 299 LyXGlueLength::LyXGlueLength (string const & data)
 300 {
 301         LyXGlueLength tmp(0.0, PT);
 302
 303         if (!isValidGlueLength (data, &tmp))
 304                 return; // should raise an exception
 305         else {
 306                 val = tmp.val;
 307                 uni = tmp.uni;
 308                 plus_val = tmp.plus_val;
 309                 plus_uni = tmp.plus_uni;
 310                 minus_val = tmp.minus_val;
 311                 minus_uni = tmp.minus_uni;
 312         }
 313 }
 314
 315
 316 string const LyXGlueLength::asString() const
 317 {
 318         std::ostringstream buffer;
 319
 320         if (plus_val != 0.0)
 321                 if (minus_val != 0.0)
 322                         if ((uni == plus_uni) && (uni == minus_uni))
 323                                 if (plus_val == minus_val)
 324                                         buffer << val << "+-"
 325                                                << plus_val << unit_name[uni];
 326                                 else
 327                                         buffer << val
 328                                                << '+' << plus_val
 329                                                << '-' << minus_val
 330                                                << unit_name[uni];
 331                         else
 332                                 if (plus_uni == minus_uni
 333                                     && plus_val == minus_val)
 334                                         buffer << val << unit_name[uni]
 335                                                << "+-" << plus_val
 336                                                << unit_name[plus_uni];
 337
 338                                 else
 339                                         buffer << val << unit_name[uni]
 340                                                << '+' << plus_val
 341                                                << unit_name[plus_uni]
 342                                                << '-' << minus_val
 343                                                << unit_name[minus_uni];
 344                 else
 345                         if (uni == plus_uni)
 346                                 buffer << val << '+' << plus_val
 347                                        << unit_name[uni];
 348                         else
 349                                 buffer << val << unit_name[uni]
 350                                        << '+' << plus_val
 351                                        << unit_name[plus_uni];
 352
 353         else
 354                 if (minus_val != 0.0)
 355                         if (uni == minus_uni)
 356                                 buffer << val << '-' << minus_val
 357                                        << unit_name[uni];
 358
 359                         else
 360                                 buffer << val << unit_name[uni]
 361                                        << '-' << minus_val
 362                                        << unit_name[minus_uni];
 363                 else
 364                         buffer << val << unit_name[uni];
 365
 366         return buffer.str().c_str();
 367 }
 368
 369
 370 string const LyXGlueLength::asLatexString() const
 371 {
 372         std::ostringstream buffer;
 373
 374         if (plus_val != 0.0)
 375                 if (minus_val != 0.0)
 376                         buffer << val << unit_name[uni]
 377                                << " plus "
 378                                << plus_val << unit_name[plus_uni]
 379                                << " minus "
 380                                << minus_val << unit_name[minus_uni];
 381                 else
 382                         buffer << val << unit_name[uni]
 383                                << " plus "
 384                                << plus_val << unit_name[plus_uni];
 385         else
 386                 if (minus_val != 0.0)
 387                         buffer << val << unit_name[uni]
 388                                << " minus "
 389                                << minus_val << unit_name[minus_uni];
 390                 else
 391                         buffer << val << unit_name[uni];
 392
 393         return buffer.str().c_str();
 394 }
 395
 396
 397 /*  VSpace class
 398  */
 399
 400 VSpace::VSpace (string const & data)
 401         : kin (NONE), len (0.0, LyXLength::PT)
 402 {
 403         kp = false;
 404         if (data.empty())
 405                 return;
 406         float   value;
 407         string input  = strip(data);
 408
 409         int length = input.length();
 410
 411         if (length > 1 && input[length-1] == '*') {
 412                 kp = true;
 413                 input.erase(length - 1);
 414         }
 415
 416         if      (prefixIs (input, "defskip"))   kin = DEFSKIP;
 417         else if (prefixIs (input, "smallskip")) kin = SMALLSKIP;
 418         else if (prefixIs (input, "medskip"))   kin = MEDSKIP;
 419         else if (prefixIs (input, "bigskip"))   kin = BIGSKIP;
 420         else if (prefixIs (input, "vfill"))     kin = VFILL;
 421         else if (isValidGlueLength (input, &len))
 422                 kin = LENGTH;
 423         else if (sscanf(input.c_str(), "%f", &value) == 1) {
 424                 // This last one is for reading old .lyx files
 425                 // without units in added_space_top/bottom.
 426                 // Let unit default to centimeters here.
 427                 kin = LENGTH;
 428                 len = LyXGlueLength (value, LyXLength::CM);
 429         }
 430 }
 431
 432
 433 bool VSpace::operator==(VSpace const & other) const
 434 {
 435         if (this->kin == other.kin)
 436                 if (this->kin == LENGTH)
 437                         if (this->len == other.len)
 438                                 return this->kp == other.kp;
 439                         else
 440                                 return false;
 441                 else
 442                         return this->kp == other.kp;
 443         else
 444                 return false;
 445 }
 446
 447
 448 string const VSpace::asLyXCommand() const
 449 {
 450         string result;
 451
 452         switch (kin) {
 453         case NONE:      break;
 454         case DEFSKIP:   result = "defskip";      break;
 455         case SMALLSKIP: result = "smallskip";    break;
 456         case MEDSKIP:   result = "medskip";      break;
 457         case BIGSKIP:   result = "bigskip";      break;
 458         case VFILL:     result = "vfill";        break;
 459         case LENGTH:    result = len.asString(); break;
 460         }
 461         if (kp && (kin != NONE) && (kin != DEFSKIP))
 462                 return result += '*';
 463         else
 464                 return result;
 465 }
 466
 467
 468 string const VSpace::asLatexCommand(BufferParams const & params) const
 469 {
 470         switch (kin) {
 471         case NONE:      return string();
 472         case DEFSKIP:
 473                 return params.getDefSkip().asLatexCommand(params);
 474         case SMALLSKIP: return kp ? "\\vspace*{\\smallskipamount}"
 475                                 : "\\smallskip{}";
 476         case MEDSKIP:   return kp ? "\\vspace*{\\medskipamount}"
 477                                 : "\\medskip{}";
 478         case BIGSKIP:   return kp ? "\\vspace*{\\bigskipamount}"
 479                                 : "\\bigskip{}";
 480         case VFILL:     return kp ? "\\vspace*{\\fill}"
 481                                 : "\\vfill{}";
 482         case LENGTH:    return kp ? "\\vspace*{" + len.asLatexString() + '}'
 483                                 : "\\vspace{" + len.asLatexString() + '}';
 484         }
 485         return string();  // should never be reached
 486 }
 487
 488
 489 int VSpace::inPixels(BufferView * bv) const
 490 {
 491         // Height of a normal line in pixels (zoom factor considered)
 492         int height = bv->text->DefaultHeight(); // [pixels]
 493         int skip = 0;
 494         if (kin == DEFSKIP)
 495             skip = bv->buffer()->params.getDefSkip().inPixels(bv);
 496
 497         return inPixels(height, skip);
 498 }
 499
 500 int VSpace::inPixels(int default_height, int default_skip) const
 501 {
 502         // Height of a normal line in pixels (zoom factor considered)
 503         int height = default_height; // [pixels]
 504
 505         // Zoom factor specified by user in percent
 506         float const zoom = lyxrc.zoom / 100.0; // [percent]
 507
 508         // DPI setting for monitor: pixels/inch
 509         float const dpi = lyxrc.dpi; // screen resolution [pixels/inch]
 510
 511         // We want the result in pixels
 512         float result, value;
 513
 514         switch (kin) {
 515         case NONE: return 0;
 516
 517         case DEFSKIP:
 518                 return default_skip;
 519
 520                 // This is how the skips are normally defined by
 521                 // LateX.  But there should be some way to change
 522                 // this per document.
 523         case SMALLSKIP: return height / 4;
 524         case MEDSKIP:   return height / 2;
 525         case BIGSKIP:   return height;
 526         case VFILL:     return 3 * height;
 527                 // leave space for the vfill symbol
 528         case LENGTH:
 529                 // Pixel values are scaled so that the ratio
 530                 // between lengths and font sizes on the screen
 531                 // is the same as on paper.
 532
 533                 // we don't care about sign of value, we
 534                 // can't display negative anyway
 535                 result = 0.0;
 536                 value = len.value();
 537                 short val_sign = value < 0.0 ? -1 : 1;
 538
 539                 switch (len.unit()) {
 540                 case LyXLength::SP:
 541                         // Scaled point: sp = 1/65536 pt
 542                         result = zoom * dpi * value
 543                                 / (72.27 * 65536); // 4736286.7
 544                         break;
 545                 case LyXLength::PT:
 546                         // Point: 1 pt = 1/72.27 inch
 547                         result = zoom * dpi * value
 548                                 / 72.27; // 72.27
 549                         break;
 550                 case LyXLength::BP:
 551                         // Big point: 1 bp = 1/72 inch
 552                         result = zoom * dpi * value
 553                                 / 72; // 72
 554                         break;
 555                 case LyXLength::DD:
 556                         // Didot: 1157dd = 1238 pt?
 557                         result = zoom * dpi * value
 558                                 / (72.27 / (0.376 * 2.845)); // 67.559735
 559                         break;
 560                 case LyXLength::MM:
 561                         // Millimeter: 1 mm = 1/25.4 inch
 562                         result = zoom * dpi * value
 563                                 / 25.4; // 25.4
 564                         break;
 565                 case LyXLength::PC:
 566                         // Pica: 1 pc = 12 pt
 567                         result = zoom * dpi * value
 568                                 / (72.27 / 12); // 6.0225
 569                         break;
 570                 case LyXLength::CC:
 571                         // Cicero: 1 cc = 12 dd
 572                         result = zoom * dpi * value
 573                                 / (72.27 / (12 * 0.376 * 2.845)); // 5.6299779
 574                         break;
 575                 case LyXLength::CM:
 576                         // Centimeter: 1 cm = 1/2.54 inch
 577                         result = zoom * dpi * value
 578                                 / 2.54; // 2.54
 579                         break;
 580                 case LyXLength::IN:
 581                         // Inch
 582                         result = zoom * dpi * value;
 583                         break;
 584                 case LyXLength::EX:
 585                         // Ex: The height of an "x"
 586                         result = zoom * value * height / 2; // what to / width?
 587                         break;
 588                 case LyXLength::EM: // what to / width?
 589                         // Em: The width of an "m"
 590                         result = zoom * value * height / 2; // Why 2?
 591                         break;
 592                 case LyXLength::MU: // This is probably only allowed in
 593                         // math mode
 594                         result = zoom * value * height;
 595                         break;
 596                 case LyXLength::UNIT_NONE:
 597                         result = 0;  // this cannot happen
 598                         break;
 599                 }
 600                 return int (result * val_sign + 0.5);
 601         }
 602         return 0; // never reached
 603 }