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         }
  81         else if (prefixIs(data, "plus")) {
  82                 lyx_advance (data, 4);
  83                 return '+';
  84         }
  85         else if (data[0] == '-') {
  86                 lyx_advance (data, 1);
  87                 return '-';
  88         }
  89         else if (prefixIs(data, "minus")) {
  90                 lyx_advance (data, 5);
  91                 return '-';
  92         }
  93         else {
  94                 string::size_type i;
  95
  96                 // I really mean assignment ("=") below, not equality!
  97                 if ((i = data.find_last_of("0123456789.")) != string::npos) {
  98                         if (number_index > 3) return 'E';  // Error
  99                         string buffer = data.substr(0, i + 1);
 100                         if (sscanf (buffer.c_str(),
 101                                     "%f", &number[number_index]) == 1) {
 102                                 lyx_advance (data, i + 1);
 103                                 ++number_index;
 104                                 return 'n';
 105                         } else
 106                                 return 'E';  // Error
 107                 } else if ((i = data.find_last_of("abcdefghijklmnopqrstuvwxyz"))
 108                            != string::npos) {
 109                         if (unit_index > 3) return 'E';  // Error
 110                         string buffer = data.substr(0, i + 1);
 111                         unit[unit_index] = unitFromString (buffer);
 112                         if (unit[unit_index] != LyXLength::UNIT_NONE) {
 113                                 lyx_advance (data, i + 1);
 114                                 ++unit_index;
 115                                 return 'u';
 116                         } else
 117                                 return 'E';  // Error
 118                 } else
 119                         return 'E';  // Error
 120         }
 121 }
 122
 123
 124 struct LaTeXLength {
 125         char const * pattern;
 126         int   plus_val_index, minus_val_index,
 127                 plus_uni_index, minus_uni_index;
 128 };
 129
 130
 131 static
 132 LaTeXLength table[] = {
 133         { "nu",       0, 0, 0, 0 },
 134         { "nu+nu",    2, 0, 2, 0 },
 135         { "nu+nu-nu", 2, 3, 2, 3 },
 136         { "nu+-nu",   2, 2, 2, 2 },
 137         { "nu-nu",    0, 2, 0, 2 },
 138         { "nu-nu+nu", 3, 2, 3, 2 },
 139         { "nu-+nu",   2, 2, 2, 2 },
 140         { "n+nu",     2, 0, 1, 0 },
 141         { "n+n-nu",   2, 3, 1, 1 },
 142         { "n+-nu",    2, 2, 1, 1 },
 143         { "n-nu",     0, 2, 0, 1 },
 144         { "n-n+nu",   3, 2, 1, 1 },
 145         { "n-+nu",    2, 2, 1, 1 },
 146         { "",         0, 0, 0, 0 }   // sentinel, must be empty
 147 };
 148
 149
 150 bool isValidGlueLength (string const & data, LyXGlueLength * result)
 151 {
 152         // This parser is table-driven.  First, it constructs a "pattern"
 153         // that describes the sequence of tokens in "data".  For example,
 154         // "n-nu" means: number, minus sign, number, unit.  As we go along,
 155         // numbers and units are stored into static arrays.  Then, "pattern"
 156         // is searched in the "table".  If it is found, the associated
 157         // table entries tell us which number and unit should go where
 158         // in the LyXLength structure.  Example: if "data" has the "pattern"
 159         // "nu+nu-nu", the associated table entries are "2, 3, 2, 3".
 160         // That means, "plus_val" is the second number that was seen
 161         // in the input, "minus_val" is the third number, and "plus_uni"
 162         // and "minus_uni" are the second and third units, respectively.
 163         // ("val" and "uni" are always the first items seen in "data".)
 164         //     This is the most elegant solution I could find -- a straight-
 165         // forward approach leads to very long, tedious code that would be
 166         // much harder to understand and maintain. (AS)
 167
 168         if (data.empty())
 169                 return true;
 170         string buffer = frontStrip(data);
 171
 172         // To make isValidGlueLength recognize negative values as
 173         // the first number this little hack is needed:
 174         short val_sign = 1; // positive as default
 175         switch(buffer[0]) {
 176         case '-':
 177                 lyx_advance(buffer, 1);
 178                 val_sign = -1;
 179                 break;
 180         case '+':
 181                 lyx_advance(buffer, 1);
 182                 // fall through
 183         default:
 184                 // no action
 185                 break;
 186         }
 187         // end of hack
 188
 189         int       pattern_index = 0, table_index = 0;
 190         char      pattern[20];
 191
 192         number_index = unit_index = 1;  // entries at index 0 are sentinels
 193
 194         // construct "pattern" from "data"
 195         while (!isEndOfData (buffer)) {
 196                 if (pattern_index > 20) return false;
 197                 pattern[pattern_index] = nextToken (buffer);
 198                 if (pattern[pattern_index] == 'E') return false;
 199                 ++pattern_index;
 200         }
 201         pattern[pattern_index] = '\0';
 202
 203         // search "pattern" in "table"
 204         table_index = 0;
 205         while (compare(pattern, table[table_index].pattern)) {
 206                 ++table_index;
 207                 if (!*table[table_index].pattern) return false;
 208         }
 209
 210         // Get the values from the appropriate places.  If an index
 211         // is zero, the corresponding array value is zero or UNIT_NONE,
 212         // so we needn't check this.
 213         if (result) {
 214                 result->val = number[1] * val_sign;
 215                 result->uni = unit[1];
 216                 result->plus_val  = number[table[table_index].plus_val_index];
 217                 result->minus_val = number[table[table_index].minus_val_index];
 218                 result->plus_uni  = unit  [table[table_index].plus_uni_index];
 219                 result->minus_uni = unit  [table[table_index].minus_uni_index];
 220         }
 221         return true;
 222 }
 223
 224
 225 bool isValidLength(string const & data, LyXLength * result)
 226 {
 227         /// This is a trimmed down version of isValidGlueLength.
 228         /// The parser may seem overkill for lengths without
 229         /// glue, but since we already have it, using it is
 230         /// easier than writing something from scratch.
 231
 232         string   buffer = data;
 233         int       pattern_index = 0;
 234         char      pattern[3];
 235
 236         // To make isValidLength recognize negative values
 237         // this little hack is needed:
 238         short val_sign = 1; // positive as default
 239         switch(buffer[0]) {
 240         case '-':
 241                 lyx_advance(buffer, 1);
 242                 val_sign = -1;
 243                 break;
 244         case '+':
 245                 lyx_advance(buffer, 1);
 246                 // fall through
 247         default:
 248                 // no action
 249                 break;
 250         }
 251         // end of hack
 252
 253         number_index = unit_index = 1;  // entries at index 0 are sentinels
 254
 255         // construct "pattern" from "data"
 256         while (!isEndOfData (buffer)) {
 257                 if (pattern_index > 2) return false;
 258                 pattern[pattern_index] = nextToken (buffer);
 259                 if (pattern[pattern_index] == 'E') return false;
 260                 ++pattern_index;
 261         }
 262         pattern[pattern_index] = '\0';
 263
 264         // only the most basic pattern is accepted here
 265         if (compare(pattern, "nu") != 0) return false;
 266
 267         // It _was_ a correct length string.
 268         // Store away the values we found.
 269         if (result) {
 270                 result->val = number[1] * val_sign;
 271                 result->uni = unit[1];
 272         }
 273         return true;
 274 }
 275
 276
 277 /// LyXLength class
 278
 279 LyXLength::LyXLength(string const & data)
 280 {
 281         LyXLength tmp;
 282
 283         if (!isValidLength (data, &tmp))
 284                 return; // should raise an exception
 285         else {
 286                 val = tmp.val;
 287                 uni = tmp.uni;
 288         }
 289 }
 290
 291
 292 bool LyXLength::operator== (LyXLength const & other) const
 293 {
 294         return (val == other.val &&
 295                 uni == other.uni);
 296 }
 297
 298
 299 string LyXLength::asString() const
 300 {
 301 #ifdef HAVE_SSTREAM
 302         std::ostringstream buffer;
 303         buffer << val << unit_name[uni]; // setw?
 304         return buffer.str().c_str();
 305 #else
 306         char tbuf[20];
 307         ostrstream buffer(tbuf, 20);
 308         buffer << val << unit_name[uni] << '\0'; // setw?
 309         return buffer.str();
 310 #endif
 311 }
 312
 313
 314 /*  LyXGlueLength class
 315  */
 316
 317 LyXGlueLength::LyXGlueLength (string const & data)
 318 {
 319         LyXGlueLength tmp(0.0, PT);
 320
 321         if (!isValidGlueLength (data, &tmp))
 322                 return; // should raise an exception
 323         else {
 324                 val = tmp.val;
 325                 uni = tmp.uni;
 326                 plus_val = tmp.plus_val;
 327                 plus_uni = tmp.plus_uni;
 328                 minus_val = tmp.minus_val;
 329                 minus_uni = tmp.minus_uni;
 330         }
 331 }
 332
 333
 334 bool LyXGlueLength::operator== (LyXGlueLength const & other) const
 335 {
 336         return (val == other.val &&
 337                 uni == other.uni &&
 338                 plus_val  == other.plus_val &&
 339                 plus_uni  == other.plus_uni &&
 340                 minus_val == other.minus_val &&
 341                 minus_uni == other.minus_uni);
 342 }
 343
 344
 345 string LyXGlueLength::asString() const
 346 {
 347 #ifdef HAVE_SSTREAM
 348         std::ostringstream buffer;
 349 #else
 350         char tbuf[20];
 351         ostrstream buffer(tbuf, 20);
 352 #endif
 353         if (plus_val != 0.0)
 354                 if (minus_val != 0.0)
 355                         if ((uni == plus_uni) && (uni == minus_uni))
 356                                 if (plus_val == minus_val)
 357                                         buffer << val << "+-"
 358                                                << plus_val << unit_name[uni];
 359                                 else
 360                                         buffer << val
 361                                                << '+' << plus_val
 362                                                << '-' << minus_val
 363                                                << unit_name[uni];
 364                         else
 365                                 if (plus_uni == minus_uni
 366                                     && plus_val == minus_val)
 367                                         buffer << val << unit_name[uni]
 368                                                << "+-" << plus_val
 369                                                << unit_name[plus_uni];
 370
 371                                 else
 372                                         buffer << val << unit_name[uni]
 373                                                << '+' << plus_val
 374                                                << unit_name[plus_uni]
 375                                                << '-' << minus_val
 376                                                << unit_name[minus_uni];
 377                 else
 378                         if (uni == plus_uni)
 379                                 buffer << val << '+' << plus_val
 380                                        << unit_name[uni];
 381                         else
 382                                 buffer << val << unit_name[uni]
 383                                        << '+' << plus_val
 384                                        << unit_name[plus_uni];
 385
 386         else
 387                 if (minus_val != 0.0)
 388                         if (uni == minus_uni)
 389                                 buffer << val << '-' << minus_val
 390                                        << unit_name[uni];
 391
 392                         else
 393                                 buffer << val << unit_name[uni]
 394                                        << '-' << minus_val
 395                                        << unit_name[minus_uni];
 396                 else
 397                         buffer << val << unit_name[uni];
 398 #ifdef HAVE_SSTREAM
 399         return buffer.str().c_str();
 400 #else
 401         buffer << '\0';
 402         return buffer.str();
 403 #endif
 404 }
 405
 406
 407 string LyXGlueLength::asLatexString() const
 408 {
 409 #ifdef HAVE_SSTREAM
 410         std::ostringstream buffer;
 411 #else
 412         char tbuf[40];
 413         ostrstream buffer(tbuf, 40);
 414 #endif
 415
 416         if (plus_val != 0.0)
 417                 if (minus_val != 0.0)
 418                         buffer << val << unit_name[uni]
 419                                << " plus "
 420                                << plus_val << unit_name[plus_uni]
 421                                << " minus "
 422                                << minus_val << unit_name[minus_uni];
 423                 else
 424                         buffer << val << unit_name[uni]
 425                                << " plus "
 426                                << plus_val << unit_name[plus_uni];
 427         else
 428                 if (minus_val != 0.0)
 429                         buffer << val << unit_name[uni]
 430                                << " minus "
 431                                << minus_val << unit_name[minus_uni];
 432                 else
 433                         buffer << val << unit_name[uni];
 434 #ifdef HAVE_SSTREAM
 435         return buffer.str().c_str();
 436 #else
 437         buffer << '\0';
 438         return buffer.str();
 439 #endif
 440 }
 441
 442
 443 /*  VSpace class
 444  */
 445
 446 VSpace::VSpace (string const & data)
 447         : kin (NONE), len (0.0, LyXLength::PT)
 448 {
 449         kp = false;
 450         if (data.empty())
 451                 return;
 452         float   value;
 453         string input  = strip(data);
 454
 455         int length = input.length();
 456
 457         if (length > 1 && input[length-1] == '*') {
 458                 kp = true;
 459                 input.erase(length - 1);
 460         }
 461
 462         if      (prefixIs (input, "defskip"))   kin = DEFSKIP;
 463         else if (prefixIs (input, "smallskip")) kin = SMALLSKIP;
 464         else if (prefixIs (input, "medskip"))   kin = MEDSKIP;
 465         else if (prefixIs (input, "bigskip"))   kin = BIGSKIP;
 466         else if (prefixIs (input, "vfill"))     kin = VFILL;
 467         else if (isValidGlueLength (input, &len))
 468                 kin = LENGTH;
 469         else if (sscanf (input.c_str(), "%f", &value) == 1) {
 470                 // This last one is for reading old .lyx files
 471                 // without units in added_space_top/bottom.
 472                 // Let unit default to centimeters here.
 473                 kin = LENGTH;
 474                 len = LyXGlueLength (value, LyXLength::CM);
 475         }
 476 }
 477
 478
 479 bool VSpace::operator==(VSpace const & other) const
 480 {
 481         if (this->kin == other.kin)
 482                 if (this->kin == LENGTH)
 483                         if (this->len == other.len)
 484                                 return this->kp == other.kp;
 485                         else
 486                                 return false;
 487                 else
 488                         return this->kp == other.kp;
 489         else
 490                 return false;
 491 }
 492
 493
 494 string VSpace::asLyXCommand() const
 495 {
 496         string result;
 497
 498         switch (kin) {
 499         case NONE:      break;
 500         case DEFSKIP:   result = "defskip";      break;
 501         case SMALLSKIP: result = "smallskip";    break;
 502         case MEDSKIP:   result = "medskip";      break;
 503         case BIGSKIP:   result = "bigskip";      break;
 504         case VFILL:     result = "vfill";        break;
 505         case LENGTH:    result = len.asString(); break;
 506         }
 507         if (kp && (kin != NONE) && (kin != DEFSKIP))
 508                 return result += '*';
 509         else
 510                 return result;
 511 }
 512
 513
 514 string VSpace::asLatexCommand(BufferParams const & params) const
 515 {
 516         switch (kin) {
 517         case NONE:      return string();
 518         case DEFSKIP:
 519                 return params.getDefSkip().asLatexCommand(params);
 520         case SMALLSKIP: return kp ? "\\vspace*{\\smallskipamount}"
 521                                 : "\\smallskip{}";
 522         case MEDSKIP:   return kp ? "\\vspace*{\\medskipamount}"
 523                                 : "\\medskip{}";
 524         case BIGSKIP:   return kp ? "\\vspace*{\\bigskipamount}"
 525                                 : "\\bigskip{}";
 526         case VFILL:     return kp ? "\\vspace*{\\fill}"
 527                                 : "\\vfill{}";
 528         case LENGTH:    return kp ? "\\vspace*{" + len.asLatexString() + '}'
 529                                 : "\\vspace{" + len.asLatexString() + '}';
 530         }
 531         return string();  // should never be reached
 532 }
 533
 534
 535 int VSpace::inPixels(BufferView * bv) const
 536 {
 537         // Height of a normal line in pixels (zoom factor considered)
 538         int height = bv->text->DefaultHeight(); // [pixels]
 539
 540         // Zoom factor specified by user in percent
 541         float const zoom = lyxrc.zoom / 100.0; // [percent]
 542
 543         // DPI setting for monitor: pixels/inch
 544         float const dpi = lyxrc.dpi; // screen resolution [pixels/inch]
 545
 546         // We want the result in pixels
 547         float result, value;
 548
 549         switch (kin) {
 550         case NONE: return 0;
 551
 552         case DEFSKIP:
 553                 return bv->buffer()->params.getDefSkip().inPixels(bv);
 554
 555                 // This is how the skips are normally defined by
 556                 // LateX.  But there should be some way to change
 557                 // this per document.
 558         case SMALLSKIP: return height / 4;
 559         case MEDSKIP:   return height / 2;
 560         case BIGSKIP:   return height;
 561         case VFILL:     return 3 * height;
 562                 // leave space for the vfill symbol
 563         case LENGTH:
 564                 // Pixel values are scaled so that the ratio
 565                 // between lengths and font sizes on the screen
 566                 // is the same as on paper.
 567
 568                 // we don't care about sign of value, we
 569                 // can't display negative anyway
 570                 result = 0.0;
 571                 value = len.value();
 572                 short val_sign = value < 0.0 ? -1 : 1;
 573
 574                 switch (len.unit()) {
 575                 case LyXLength::SP:
 576                         // Scaled point: sp = 1/65536 pt
 577                         result = zoom * dpi * value
 578                                 / (72.27 * 65536); // 4736286.7
 579                         break;
 580                 case LyXLength::PT:
 581                         // Point: 1 pt = 1/72.27 inch
 582                         result = zoom * dpi * value
 583                                 / 72.27; // 72.27
 584                         break;
 585                 case LyXLength::BP:
 586                         // Big point: 1 bp = 1/72 inch
 587                         result = zoom * dpi * value
 588                                 / 72; // 72
 589                         break;
 590                 case LyXLength::DD:
 591                         // Didot: 1157dd = 1238 pt?
 592                         result = zoom * dpi * value
 593                                 / (72.27 / (0.376 * 2.845)); // 67.559735
 594                         break;
 595                 case LyXLength::MM:
 596                         // Millimeter: 1 mm = 1/25.4 inch
 597                         result = zoom * dpi * value
 598                                 / 25.4; // 25.4
 599                         break;
 600                 case LyXLength::PC:
 601                         // Pica: 1 pc = 12 pt
 602                         result = zoom * dpi * value
 603                                 / (72.27 / 12); // 6.0225
 604                         break;
 605                 case LyXLength::CC:
 606                         // Cicero: 1 cc = 12 dd
 607                         result = zoom * dpi * value
 608                                 / (72.27 / (12 * 0.376 * 2.845)); // 5.6299779
 609                         break;
 610                 case LyXLength::CM:
 611                         // Centimeter: 1 cm = 1/2.54 inch
 612                         result = zoom * dpi * value
 613                                 / 2.54; // 2.54
 614                         break;
 615                 case LyXLength::IN:
 616                         // Inch
 617                         result = zoom * dpi * value;
 618                         break;
 619                 case LyXLength::EX:
 620                         // Ex: The height of an "x"
 621                         result = zoom * value * height / 2; // what to / width?
 622                         break;
 623                 case LyXLength::EM: // what to / width?
 624                         // Em: The width of an "m"
 625                         result = zoom * value * height / 2; // Why 2?
 626                         break;
 627                 case LyXLength::MU: // This is probably only allowed in
 628                         // math mode
 629                         result = zoom * value * height;
 630                         break;
 631                 case LyXLength::UNIT_NONE:
 632                         result = 0;  // this cannot happen
 633                         break;
 634                 }
 635                 return int (result * val_sign + 0.5);
 636         }
 637         return 0; // never reached
 638 }