src/vspace.C

   1 /* This file is part of
   2  * ======================================================
   3  *
   4  *           LyX, The Document Processor
   5  *
   6  *           Copyright 1995 Matthias Ettrich
   7  *           Copyright 1995-2001 The LyX Team.
   8  *
   9  * ====================================================== */
  10
  11 #include <config.h>
  12
  13 #ifdef __GNUG__
  14 #pragma implementation "vspace.h"
  15 #endif
  16
  17 #include "vspace.h"
  18 #include "lyx_main.h"
  19 #include "buffer.h"
  20 #include "lyxrc.h"
  21 #include "lyxtext.h"
  22 #include "BufferView.h"
  23
  24 #include "support/lstrings.h"
  25
  26 #include <cstdio>
  27
  28
  29 namespace {
  30
  31 /*  length units
  32  */
  33
  34 int const num_units = LyXLength::UNIT_NONE;
  35
  36 // I am not sure if "mu" should be possible to select (Lgb)
  37 char const * unit_name[num_units] = { "sp", "pt", "bp", "dd",
  38                                       "mm", "pc", "cc", "cm",
  39                                       "in", "ex", "em", "mu",
  40                                       "%",  "c%", "p%", "l%" };
  41
  42
  43 /*  The following static items form a simple scanner for
  44  *  length strings, used by isValid[Glue]Length.  See comments there.
  45  */
  46 double           number[4] = { 0, 0, 0, 0 };
  47 LyXLength::UNIT unit[4]   = { LyXLength::UNIT_NONE,
  48                               LyXLength::UNIT_NONE,
  49                               LyXLength::UNIT_NONE,
  50                               LyXLength::UNIT_NONE };
  51 int number_index;
  52 int unit_index;
  53
  54
  55 inline
  56 void lyx_advance(string & data, string::size_type n)
  57 {
  58         data.erase(0, n);
  59 }
  60
  61
  62 inline
  63 bool isEndOfData(string const & data)
  64 {
  65         return frontStrip(data).empty();
  66 }
  67
  68
  69 char nextToken(string & data)
  70 {
  71         data = frontStrip(data);
  72         if (data.empty())
  73                 return '\0';
  74         else if (data[0] == '+') {
  75                 lyx_advance(data, 1);
  76                 return '+';
  77         } else if (prefixIs(data, "plus")) {
  78                 lyx_advance(data, 4);
  79                 return '+';
  80         } else if (data[0] == '-') {
  81                 lyx_advance(data, 1);
  82                 return '-';
  83         } else if (prefixIs(data, "minus")) {
  84                 lyx_advance(data, 5);
  85                 return '-';
  86         } else {
  87                 string::size_type i = data.find_first_not_of("0123456789.");
  88
  89                 if (i != 0) {
  90                         if (number_index > 3) return 'E';
  91
  92                         string buffer;
  93
  94                         // we have found some number
  95                         if (i == string::npos) {
  96                                 buffer = data;
  97                                 i = data.size() + 1;
  98                         } else
  99                                 buffer = data.substr(0, i);
 100
 101                         lyx_advance(data, i);
 102
 103                         if (isStrDbl(buffer)) {
 104                                 number[number_index] = strToDbl(buffer);
 105                                 ++number_index;
 106                                 return 'n';
 107                         } else return 'E';
 108                 }
 109
 110                 i = data.find_first_not_of("abcdefghijklmnopqrstuvwxyz%");
 111                 if (i != 0) {
 112                         if (unit_index > 3) return 'E';
 113
 114                         string buffer;
 115
 116                         // we have found some alphabetical string
 117                         if (i == string::npos) {
 118                                 buffer = data;
 119                                 i = data.size() + 1;
 120                         } else
 121                                 buffer = data.substr(0, i);
 122
 123                         // possibly we have "mmplus" string or similar
 124                         if (buffer.size() > 5 && (buffer.substr(2,4) == string("plus") || buffer.substr(2,5) == string("minus"))) {
 125                                 lyx_advance(data, 2);
 126                                 unit[unit_index] = unitFromString(buffer.substr(0, 2));
 127                         } else {
 128                                 lyx_advance(data, i);
 129                                 unit[unit_index] = unitFromString(buffer);
 130                         }
 131
 132                         if (unit[unit_index] != LyXLength::UNIT_NONE) {
 133                                 ++unit_index;
 134                                 return 'u';
 135                         } else return 'E';  // Error
 136                 }
 137                 return 'E';  // Error
 138         }
 139 }
 140
 141
 142 struct LaTeXLength {
 143         char const * pattern;
 144         int  plus_val_index;
 145         int  minus_val_index;
 146         int  plus_uni_index;
 147         int  minus_uni_index;
 148 };
 149
 150
 151 LaTeXLength table[] = {
 152         { "nu",       0, 0, 0, 0 },
 153         { "nu+nu",    2, 0, 2, 0 },
 154         { "nu+nu-nu", 2, 3, 2, 3 },
 155         { "nu+-nu",   2, 2, 2, 2 },
 156         { "nu-nu",    0, 2, 0, 2 },
 157         { "nu-nu+nu", 3, 2, 3, 2 },
 158         { "nu-+nu",   2, 2, 2, 2 },
 159         { "n+nu",     2, 0, 1, 0 },
 160         { "n+n-nu",   2, 3, 1, 1 },
 161         { "n+-nu",    2, 2, 1, 1 },
 162         { "n-nu",     0, 2, 0, 1 },
 163         { "n-n+nu",   3, 2, 1, 1 },
 164         { "n-+nu",    2, 2, 1, 1 },
 165         { "",         0, 0, 0, 0 }   // sentinel, must be empty
 166 };
 167
 168 } // namespace anon
 169
 170 const char * stringFromUnit(int unit)
 171 {
 172         if (unit < 0 || unit >= num_units)
 173                 return 0;
 174         return unit_name[unit];
 175 }
 176
 177
 178 bool isValidGlueLength(string const & data, LyXGlueLength * result)
 179 {
 180         // This parser is table-driven.  First, it constructs a "pattern"
 181         // that describes the sequence of tokens in "data".  For example,
 182         // "n-nu" means: number, minus sign, number, unit.  As we go along,
 183         // numbers and units are stored into static arrays.  Then, "pattern"
 184         // is searched in the "table".  If it is found, the associated
 185         // table entries tell us which number and unit should go where
 186         // in the LyXLength structure.  Example: if "data" has the "pattern"
 187         // "nu+nu-nu", the associated table entries are "2, 3, 2, 3".
 188         // That means, "plus_val" is the second number that was seen
 189         // in the input, "minus_val" is the third number, and "plus_uni"
 190         // and "minus_uni" are the second and third units, respectively.
 191         // ("val" and "uni" are always the first items seen in "data".)
 192         // This is the most elegant solution I could find -- a straight-
 193         // forward approach leads to very long, tedious code that would be
 194         // much harder to understand and maintain. (AS)
 195
 196         if (data.empty())
 197                 return true;
 198         string buffer = frontStrip(data);
 199
 200         // To make isValidGlueLength recognize negative values as
 201         // the first number this little hack is needed:
 202         int val_sign = 1; // positive as default
 203         switch (buffer[0]) {
 204         case '-':
 205                 lyx_advance(buffer, 1);
 206                 val_sign = -1;
 207                 break;
 208         case '+':
 209                 lyx_advance(buffer, 1);
 210                 // fall through
 211         default:
 212                 // no action
 213                 break;
 214         }
 215         // end of hack
 216
 217         int  pattern_index = 0;
 218         int  table_index = 0;
 219         char pattern[20];
 220
 221         number_index = 1;
 222         unit_index = 1;  // entries at index 0 are sentinels
 223
 224         // construct "pattern" from "data"
 225         while (!isEndOfData (buffer)) {
 226                 if (pattern_index > 20) return false;
 227                 pattern[pattern_index] = nextToken (buffer);
 228                 if (pattern[pattern_index] == 'E') return false;
 229                 ++pattern_index;
 230         }
 231         pattern[pattern_index] = '\0';
 232
 233         // search "pattern" in "table"
 234         table_index = 0;
 235         while (compare(pattern, table[table_index].pattern)) {
 236                 ++table_index;
 237                 if (!*table[table_index].pattern)
 238                         return false;
 239         }
 240
 241         // Get the values from the appropriate places.  If an index
 242         // is zero, the corresponding array value is zero or UNIT_NONE,
 243         // so we needn't check this.
 244         if (result) {
 245                 result->val_        = number[1] * val_sign;
 246                 result->unit_       = unit[1];
 247                 result->plus_val_   = number[table[table_index].plus_val_index];
 248                 result->minus_val_  = number[table[table_index].minus_val_index];
 249                 result->plus_unit_  = unit  [table[table_index].plus_uni_index];
 250                 result->minus_unit_ = unit  [table[table_index].minus_uni_index];
 251         }
 252         return true;
 253 }
 254
 255
 256 bool isValidLength(string const & data, LyXLength * result)
 257 {
 258         /// This is a trimmed down version of isValidGlueLength.
 259         /// The parser may seem overkill for lengths without
 260         /// glue, but since we already have it, using it is
 261         /// easier than writing something from scratch.
 262         if (data.empty())
 263                 return true;
 264
 265         string   buffer = data;
 266         int      pattern_index = 0;
 267         char     pattern[3];
 268
 269         // To make isValidLength recognize negative values
 270         // this little hack is needed:
 271         int val_sign = 1; // positive as default
 272         switch (buffer[0]) {
 273         case '-':
 274                 lyx_advance(buffer, 1);
 275                 val_sign = -1;
 276                 break;
 277         case '+':
 278                 lyx_advance(buffer, 1);
 279                 // fall through
 280         default:
 281                 // no action
 282                 break;
 283         }
 284         // end of hack
 285
 286         number_index = unit_index = 1;  // entries at index 0 are sentinels
 287
 288         // construct "pattern" from "data"
 289         while (!isEndOfData (buffer)) {
 290                 if (pattern_index > 2)
 291                         return false;
 292                 pattern[pattern_index] = nextToken (buffer);
 293                 if (pattern[pattern_index] == 'E')
 294                         return false;
 295                 ++pattern_index;
 296         }
 297         pattern[pattern_index] = '\0';
 298
 299         // only the most basic pattern is accepted here
 300         if (compare(pattern, "nu") != 0) return false;
 301
 302         // It _was_ a correct length string.
 303         // Store away the values we found.
 304         if (result) {
 305                 result->val_  = number[1] * val_sign;
 306                 result->unit_ = unit[1];
 307         }
 308         return true;
 309 }
 310
 311
 312
 313
 314 //
 315 // LyXLength
 316 //
 317
 318 LyXLength::LyXLength()
 319         : val_(0), unit_(LyXLength::PT)
 320 {}
 321
 322
 323 LyXLength::LyXLength(double v, LyXLength::UNIT u)
 324         : val_(v), unit_(u)
 325 {}
 326
 327
 328 LyXLength::LyXLength(string const & data)
 329 {
 330         LyXLength tmp;
 331
 332         if (!isValidLength (data, &tmp))
 333                 return; // should raise an exception
 334
 335         val_  = tmp.val_;
 336         unit_ = tmp.unit_;
 337 }
 338
 339
 340 string const LyXLength::asString() const
 341 {
 342         ostringstream buffer;
 343         buffer << val_ << unit_name[unit_]; // setw?
 344         return buffer.str().c_str();
 345 }
 346
 347
 348 string const LyXLength::asLatexString() const
 349 {
 350         ostringstream buffer;
 351         switch(unit_) {
 352         case PW:
 353         case PE:
 354             buffer << abs(static_cast<int>(val_/100)) << "."
 355                                 << abs(static_cast<int>(val_)%100) << "\\columnwidth";
 356             break;
 357         case PP:
 358             buffer << abs(static_cast<int>(val_/100)) << "."
 359                                 << abs(static_cast<int>(val_)%100) << "\\pagewidth";
 360             break;
 361         case PL:
 362             buffer << abs(static_cast<int>(val_/100)) << "."
 363                                 << abs(static_cast<int>(val_)%100) << "\\linewidth";
 364             break;
 365         default:
 366             buffer << val_ << unit_name[unit_]; // setw?
 367             break;
 368         }
 369         return buffer.str().c_str();
 370 }
 371
 372
 373 double LyXLength::value() const
 374 {
 375         return val_;
 376 }
 377
 378
 379 LyXLength::UNIT LyXLength::unit() const
 380 {
 381         return unit_;
 382 }
 383
 384
 385 bool operator==(LyXLength const & l1, LyXLength const & l2)
 386 {
 387         return l1.value() == l2.value() && l1.unit() == l2.unit();
 388 }
 389
 390
 391 LyXLength::UNIT unitFromString (string const & data)
 392 {
 393         int i = 0;
 394         while (i < num_units && data != unit_name[i])
 395                 ++i;
 396         return static_cast<LyXLength::UNIT>(i);
 397 }
 398
 399
 400
 401 //
 402 // LyXGlueLength
 403 //
 404
 405
 406 LyXGlueLength::LyXGlueLength(
 407                         double v,  LyXLength::UNIT u,
 408                         double pv, LyXLength::UNIT pu,
 409                         double mv, LyXLength::UNIT mu)
 410         : LyXLength(v, u),
 411           plus_val_(pv),  minus_val_(mv),
 412           plus_unit_(pu), minus_unit_(mu)
 413 {}
 414
 415
 416 LyXGlueLength::LyXGlueLength(string const & data)
 417 {
 418         LyXGlueLength tmp(0.0, PT);
 419
 420         // we should really raise exception here
 421         if (!isValidGlueLength(data, &tmp))
 422                 ;
 423
 424         val_        = tmp.val_;
 425         unit_       = tmp.unit_;
 426         plus_val_   = tmp.plus_val_;
 427         plus_unit_  = tmp.plus_unit_;
 428         minus_val_  = tmp.minus_val_;
 429         minus_unit_ = tmp.minus_unit_;
 430 }
 431
 432
 433 string const LyXGlueLength::asString() const
 434 {
 435         ostringstream buffer;
 436
 437         if (plus_val_ != 0.0)
 438                 if (minus_val_ != 0.0)
 439                         if (unit_ == plus_unit_ && unit_ == minus_unit_)
 440                                 if (plus_val_ == minus_val_)
 441                                         buffer << val_ << "+-"
 442                                                << plus_val_ << unit_name[unit_];
 443                                 else
 444                                         buffer << val_
 445                                                << '+' << plus_val_
 446                                                << '-' << minus_val_
 447                                                << unit_name[unit_];
 448                         else
 449                                 if (plus_unit_ == minus_unit_
 450                                     && plus_val_ == minus_val_)
 451                                         buffer << val_ << unit_name[unit_]
 452                                                << "+-" << plus_val_
 453                                                << unit_name[plus_unit_];
 454
 455                                 else
 456                                         buffer << val_ << unit_name[unit_]
 457                                                << '+' << plus_val_
 458                                                << unit_name[plus_unit_]
 459                                                << '-' << minus_val_
 460                                                << unit_name[minus_unit_];
 461                 else
 462                         if (unit_ == plus_unit_)
 463                                 buffer << val_ << '+' << plus_val_
 464                                        << unit_name[unit_];
 465                         else
 466                                 buffer << val_ << unit_name[unit_]
 467                                        << '+' << plus_val_
 468                                        << unit_name[plus_unit_];
 469
 470         else
 471                 if (minus_val_ != 0.0)
 472                         if (unit_ == minus_unit_)
 473                                 buffer << val_ << '-' << minus_val_
 474                                        << unit_name[unit_];
 475
 476                         else
 477                                 buffer << val_ << unit_name[unit_]
 478                                        << '-' << minus_val_
 479                                        << unit_name[minus_unit_];
 480                 else
 481                         buffer << val_ << unit_name[unit_];
 482
 483         return buffer.str().c_str();
 484 }
 485
 486
 487 string const LyXGlueLength::asLatexString() const
 488 {
 489         ostringstream buffer;
 490
 491         if (plus_val_ != 0.0)
 492                 if (minus_val_ != 0.0)
 493                         buffer << val_ << unit_name[unit_]
 494                                << " plus "
 495                                << plus_val_ << unit_name[plus_unit_]
 496                                << " minus "
 497                                << minus_val_ << unit_name[minus_unit_];
 498                 else
 499                         buffer << val_ << unit_name[unit_]
 500                                << " plus "
 501                                << plus_val_ << unit_name[plus_unit_];
 502         else
 503                 if (minus_val_ != 0.0)
 504                         buffer << val_ << unit_name[unit_]
 505                                << " minus "
 506                                << minus_val_ << unit_name[minus_unit_];
 507                 else
 508                         buffer << val_ << unit_name[unit_];
 509
 510         return buffer.str().c_str();
 511 }
 512
 513
 514 double LyXGlueLength::plusValue() const
 515 {
 516         return plus_val_;
 517 }
 518
 519
 520 LyXLength::UNIT LyXGlueLength::plusUnit() const
 521 {
 522         return plus_unit_;
 523 }
 524
 525
 526 double LyXGlueLength::minusValue() const
 527 {
 528         return minus_val_;
 529 }
 530
 531
 532 LyXLength::UNIT LyXGlueLength::minusUnit() const
 533 {
 534         return minus_unit_;
 535 }
 536
 537
 538 bool operator==(LyXGlueLength const & l1, LyXGlueLength const & l2)
 539 {
 540         return l1.value() == l2.value()
 541                 && l1.unit() == l2.unit()
 542                 && l1.plusValue() == l2.plusValue()
 543                 && l1.plusUnit() == l2.plusUnit()
 544                 && l1.minusValue() == l2.minusValue()
 545                 && l1.minusUnit() == l2.minusUnit();
 546 }
 547
 548
 549 bool operator!=(LyXGlueLength const & l1, LyXGlueLength const & l2)
 550 {
 551         return !(l1 == l2);
 552 }
 553
 554
 555
 556 //
 557 //  VSpace class
 558 //
 559
 560 VSpace::VSpace()
 561         : kind_(NONE), len_(0.0, LyXLength::PT), keep_(false)
 562 {}
 563
 564
 565 VSpace::VSpace(vspace_kind k)
 566         : kind_(k), len_(0.0, LyXLength::PT), keep_(false)
 567 {}
 568
 569
 570 VSpace::VSpace(LyXGlueLength l)
 571         : kind_(LENGTH), len_(l), keep_(false)
 572 {}
 573
 574
 575 VSpace::VSpace(double v, LyXLength::UNIT u)
 576         : kind_(LENGTH), len_(v, u), keep_(false)
 577 {}
 578
 579
 580 VSpace::VSpace(string const & data)
 581         : kind_(NONE), len_(0.0, LyXLength::PT), keep_(false)
 582 {
 583         if (data.empty())
 584                 return;
 585         double value;
 586         string input  = strip(data);
 587
 588         string::size_type const length = input.length();
 589
 590         if (length > 1 && input[length-1] == '*') {
 591                 keep_ = true;
 592                 input.erase(length - 1);
 593         }
 594
 595         if      (prefixIs (input, "defskip"))    kind_ = DEFSKIP;
 596         else if (prefixIs (input, "smallskip"))  kind_ = SMALLSKIP;
 597         else if (prefixIs (input, "medskip"))    kind_ = MEDSKIP;
 598         else if (prefixIs (input, "bigskip"))    kind_ = BIGSKIP;
 599         else if (prefixIs (input, "vfill"))      kind_ = VFILL;
 600         else if (isValidGlueLength(input, &len_)) kind_ = LENGTH;
 601         else if (sscanf(input.c_str(), "%lf", &value) == 1) {
 602                 // This last one is for reading old .lyx files
 603                 // without units in added_space_top/bottom.
 604                 // Let unit default to centimeters here.
 605                 kind_ = LENGTH;
 606                 len_  = LyXGlueLength(value, LyXLength::CM);
 607         }
 608 }
 609
 610
 611 VSpace::vspace_kind VSpace::kind() const
 612 {
 613         return kind_;
 614 }
 615
 616
 617 LyXGlueLength VSpace::length() const
 618 {
 619         return len_;
 620 }
 621
 622
 623 bool VSpace::keep() const
 624 {
 625         return keep_;
 626 }
 627
 628
 629 void VSpace::setKeep(bool val)
 630 {
 631         keep_ = val;
 632 }
 633
 634
 635 bool VSpace::operator==(VSpace const & other) const
 636 {
 637         if (kind_ != other.kind_)
 638                 return false;
 639
 640         if (kind_ != LENGTH)
 641                 return this->keep_ == other.keep_;
 642
 643         if (len_ != other.len_)
 644                 return false;
 645
 646         return keep_ == other.keep_;
 647 }
 648
 649
 650 string const VSpace::asLyXCommand() const
 651 {
 652         string result;
 653         switch (kind_) {
 654         case NONE:      break;
 655         case DEFSKIP:   result = "defskip";      break;
 656         case SMALLSKIP: result = "smallskip";    break;
 657         case MEDSKIP:   result = "medskip";      break;
 658         case BIGSKIP:   result = "bigskip";      break;
 659         case VFILL:     result = "vfill";        break;
 660         case LENGTH:    result = len_.asString(); break;
 661         }
 662         if (keep_ && kind_ != NONE && kind_ != DEFSKIP)
 663                 result += '*';
 664         return result;
 665 }
 666
 667
 668 string const VSpace::asLatexCommand(BufferParams const & params) const
 669 {
 670         switch (kind_) {
 671         case NONE:      return string();
 672         case DEFSKIP:
 673                 return params.getDefSkip().asLatexCommand(params);
 674         case SMALLSKIP: return keep_ ? "\\vspace*{\\smallskipamount}"
 675                                 : "\\smallskip{}";
 676         case MEDSKIP:   return keep_ ? "\\vspace*{\\medskipamount}"
 677                                 : "\\medskip{}";
 678         case BIGSKIP:   return keep_ ? "\\vspace*{\\bigskipamount}"
 679                                 : "\\bigskip{}";
 680         case VFILL:     return keep_ ? "\\vspace*{\\fill}"
 681                                 : "\\vfill{}";
 682         case LENGTH:    return keep_ ? "\\vspace*{" + len_.asLatexString() + '}'
 683                                 : "\\vspace{" + len_.asLatexString() + '}';
 684         }
 685         return string();  // should never be reached
 686 }
 687
 688
 689 int VSpace::inPixels(BufferView * bv) const
 690 {
 691         // Height of a normal line in pixels (zoom factor considered)
 692         int height = bv->text->defaultHeight(); // [pixels]
 693         int skip  = 0;
 694         int width = bv->workWidth();
 695
 696         if (kind_ == DEFSKIP)
 697                 skip = bv->buffer()->params.getDefSkip().inPixels(bv);
 698
 699         return inPixels(height, skip, width);
 700 }
 701
 702
 703 int VSpace::inPixels(int default_height, int default_skip, int default_width)
 704         const
 705 {
 706         // Height of a normal line in pixels (zoom factor considered)
 707         int height = default_height; // [pixels]
 708
 709         // Zoom factor specified by user in percent
 710         double const zoom = lyxrc.zoom / 100.0; // [percent]
 711
 712         // DPI setting for monitor: pixels/inch
 713         double const dpi = lyxrc.dpi; // screen resolution [pixels/inch]
 714
 715         // We want the result in pixels
 716         double result;
 717         double value;
 718
 719         switch (kind_) {
 720         case NONE:
 721                 return 0;
 722
 723         case DEFSKIP:
 724                 return default_skip;
 725
 726                 // This is how the skips are normally defined by
 727                 // LateX.  But there should be some way to change
 728                 // this per document.
 729         case SMALLSKIP: return height / 4;
 730         case MEDSKIP:   return height / 2;
 731         case BIGSKIP:   return height;
 732         case VFILL:     return 3 * height;
 733                 // leave space for the vfill symbol
 734         case LENGTH:
 735                 // Pixel values are scaled so that the ratio
 736                 // between lengths and font sizes on the screen
 737                 // is the same as on paper.
 738
 739                 // we don't care about sign of value, we
 740                 // display negative space with text too
 741                 result = 0.0;
 742                 value  = len_.value();
 743                 int val_sign = value < 0.0 ? -1 : 1;
 744
 745                 switch (len_.unit()) {
 746                 case LyXLength::SP:
 747                         // Scaled point: sp = 1/65536 pt
 748                         result = zoom * dpi * value
 749                                 / (72.27 * 65536); // 4736286.7
 750                         break;
 751                 case LyXLength::PT:
 752                         // Point: 1 pt = 1/72.27 inch
 753                         result = zoom * dpi * value
 754                                 / 72.27; // 72.27
 755                         break;
 756                 case LyXLength::BP:
 757                         // Big point: 1 bp = 1/72 inch
 758                         result = zoom * dpi * value
 759                                 / 72; // 72
 760                         break;
 761                 case LyXLength::DD:
 762                         // Didot: 1157dd = 1238 pt?
 763                         result = zoom * dpi * value
 764                                 / (72.27 / (0.376 * 2.845)); // 67.559735
 765                         break;
 766                 case LyXLength::MM:
 767                         // Millimeter: 1 mm = 1/25.4 inch
 768                         result = zoom * dpi * value
 769                                 / 25.4; // 25.4
 770                         break;
 771                 case LyXLength::PC:
 772                         // Pica: 1 pc = 12 pt
 773                         result = zoom * dpi * value
 774                                 / (72.27 / 12); // 6.0225
 775                         break;
 776                 case LyXLength::CC:
 777                         // Cicero: 1 cc = 12 dd
 778                         result = zoom * dpi * value
 779                                 / (72.27 / (12 * 0.376 * 2.845)); // 5.6299779
 780                         break;
 781                 case LyXLength::CM:
 782                         // Centimeter: 1 cm = 1/2.54 inch
 783                         result = zoom * dpi * value
 784                                 / 2.54; // 2.54
 785                         break;
 786                 case LyXLength::IN:
 787                         // Inch
 788                         result = zoom * dpi * value;
 789                         break;
 790                 case LyXLength::EX:
 791                         // Ex: The height of an "x"
 792                         result = zoom * value * height / 2; // what to / width?
 793                         break;
 794                 case LyXLength::EM: // what to / width?
 795                         // Em: The width of an "m"
 796                         result = zoom * value * height / 2; // Why 2?
 797                         break;
 798                 case LyXLength::MU: // This is probably only allowed in
 799                         // math mode
 800                         result = zoom * value * height;
 801                         break;
 802                 case LyXLength::PW: // Always % of workarea
 803                 case LyXLength::PE:
 804                 case LyXLength::PP:
 805                 case LyXLength::PL:
 806                         result = value * default_width / 100;
 807                         break;
 808                 case LyXLength::UNIT_NONE:
 809                         result = 0;  // this cannot happen
 810                         break;
 811                 }
 812                 return static_cast<int>(result * val_sign + 0.5);
 813         }
 814         return 0; // never reached
 815 }