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 string LyXLength::asString() const
 293 {
 294 #ifdef HAVE_SSTREAM
 295         std::ostringstream buffer;
 296         buffer << val << unit_name[uni]; // setw?
 297         return buffer.str().c_str();
 298 #else
 299         char tbuf[20];
 300         ostrstream buffer(tbuf, 20);
 301         buffer << val << unit_name[uni] << '\0'; // setw?
 302         return buffer.str();
 303 #endif
 304 }
 305
 306
 307 /*  LyXGlueLength class
 308  */
 309
 310 LyXGlueLength::LyXGlueLength (string const & data)
 311 {
 312         LyXGlueLength tmp(0.0, PT);
 313
 314         if (!isValidGlueLength (data, &tmp))
 315                 return; // should raise an exception
 316         else {
 317                 val = tmp.val;
 318                 uni = tmp.uni;
 319                 plus_val = tmp.plus_val;
 320                 plus_uni = tmp.plus_uni;
 321                 minus_val = tmp.minus_val;
 322                 minus_uni = tmp.minus_uni;
 323         }
 324 }
 325
 326
 327 string LyXGlueLength::asString() const
 328 {
 329 #ifdef HAVE_SSTREAM
 330         std::ostringstream buffer;
 331 #else
 332         char tbuf[20];
 333         ostrstream buffer(tbuf, 20);
 334 #endif
 335         if (plus_val != 0.0)
 336                 if (minus_val != 0.0)
 337                         if ((uni == plus_uni) && (uni == minus_uni))
 338                                 if (plus_val == minus_val)
 339                                         buffer << val << "+-"
 340                                                << plus_val << unit_name[uni];
 341                                 else
 342                                         buffer << val
 343                                                << '+' << plus_val
 344                                                << '-' << minus_val
 345                                                << unit_name[uni];
 346                         else
 347                                 if (plus_uni == minus_uni
 348                                     && plus_val == minus_val)
 349                                         buffer << val << unit_name[uni]
 350                                                << "+-" << plus_val
 351                                                << unit_name[plus_uni];
 352
 353                                 else
 354                                         buffer << val << unit_name[uni]
 355                                                << '+' << plus_val
 356                                                << unit_name[plus_uni]
 357                                                << '-' << minus_val
 358                                                << unit_name[minus_uni];
 359                 else
 360                         if (uni == plus_uni)
 361                                 buffer << val << '+' << plus_val
 362                                        << unit_name[uni];
 363                         else
 364                                 buffer << val << unit_name[uni]
 365                                        << '+' << plus_val
 366                                        << unit_name[plus_uni];
 367
 368         else
 369                 if (minus_val != 0.0)
 370                         if (uni == minus_uni)
 371                                 buffer << val << '-' << minus_val
 372                                        << unit_name[uni];
 373
 374                         else
 375                                 buffer << val << unit_name[uni]
 376                                        << '-' << minus_val
 377                                        << unit_name[minus_uni];
 378                 else
 379                         buffer << val << unit_name[uni];
 380 #ifdef HAVE_SSTREAM
 381         return buffer.str().c_str();
 382 #else
 383         buffer << '\0';
 384         return buffer.str();
 385 #endif
 386 }
 387
 388
 389 string LyXGlueLength::asLatexString() const
 390 {
 391 #ifdef HAVE_SSTREAM
 392         std::ostringstream buffer;
 393 #else
 394         char tbuf[40];
 395         ostrstream buffer(tbuf, 40);
 396 #endif
 397
 398         if (plus_val != 0.0)
 399                 if (minus_val != 0.0)
 400                         buffer << val << unit_name[uni]
 401                                << " plus "
 402                                << plus_val << unit_name[plus_uni]
 403                                << " minus "
 404                                << minus_val << unit_name[minus_uni];
 405                 else
 406                         buffer << val << unit_name[uni]
 407                                << " plus "
 408                                << plus_val << unit_name[plus_uni];
 409         else
 410                 if (minus_val != 0.0)
 411                         buffer << val << unit_name[uni]
 412                                << " minus "
 413                                << minus_val << unit_name[minus_uni];
 414                 else
 415                         buffer << val << unit_name[uni];
 416 #ifdef HAVE_SSTREAM
 417         return buffer.str().c_str();
 418 #else
 419         buffer << '\0';
 420         return buffer.str();
 421 #endif
 422 }
 423
 424
 425 /*  VSpace class
 426  */
 427
 428 VSpace::VSpace (string const & data)
 429         : kin (NONE), len (0.0, LyXLength::PT)
 430 {
 431         kp = false;
 432         if (data.empty())
 433                 return;
 434         float   value;
 435         string input  = strip(data);
 436
 437         int length = input.length();
 438
 439         if (length > 1 && input[length-1] == '*') {
 440                 kp = true;
 441                 input.erase(length - 1);
 442         }
 443
 444         if      (prefixIs (input, "defskip"))   kin = DEFSKIP;
 445         else if (prefixIs (input, "smallskip")) kin = SMALLSKIP;
 446         else if (prefixIs (input, "medskip"))   kin = MEDSKIP;
 447         else if (prefixIs (input, "bigskip"))   kin = BIGSKIP;
 448         else if (prefixIs (input, "vfill"))     kin = VFILL;
 449         else if (isValidGlueLength (input, &len))
 450                 kin = LENGTH;
 451         else if (sscanf (input.c_str(), "%f", &value) == 1) {
 452                 // This last one is for reading old .lyx files
 453                 // without units in added_space_top/bottom.
 454                 // Let unit default to centimeters here.
 455                 kin = LENGTH;
 456                 len = LyXGlueLength (value, LyXLength::CM);
 457         }
 458 }
 459
 460
 461 bool VSpace::operator==(VSpace const & other) const
 462 {
 463         if (this->kin == other.kin)
 464                 if (this->kin == LENGTH)
 465                         if (this->len == other.len)
 466                                 return this->kp == other.kp;
 467                         else
 468                                 return false;
 469                 else
 470                         return this->kp == other.kp;
 471         else
 472                 return false;
 473 }
 474
 475
 476 string VSpace::asLyXCommand() const
 477 {
 478         string result;
 479
 480         switch (kin) {
 481         case NONE:      break;
 482         case DEFSKIP:   result = "defskip";      break;
 483         case SMALLSKIP: result = "smallskip";    break;
 484         case MEDSKIP:   result = "medskip";      break;
 485         case BIGSKIP:   result = "bigskip";      break;
 486         case VFILL:     result = "vfill";        break;
 487         case LENGTH:    result = len.asString(); break;
 488         }
 489         if (kp && (kin != NONE) && (kin != DEFSKIP))
 490                 return result += '*';
 491         else
 492                 return result;
 493 }
 494
 495
 496 string VSpace::asLatexCommand(BufferParams const & params) const
 497 {
 498         switch (kin) {
 499         case NONE:      return string();
 500         case DEFSKIP:
 501                 return params.getDefSkip().asLatexCommand(params);
 502         case SMALLSKIP: return kp ? "\\vspace*{\\smallskipamount}"
 503                                 : "\\smallskip{}";
 504         case MEDSKIP:   return kp ? "\\vspace*{\\medskipamount}"
 505                                 : "\\medskip{}";
 506         case BIGSKIP:   return kp ? "\\vspace*{\\bigskipamount}"
 507                                 : "\\bigskip{}";
 508         case VFILL:     return kp ? "\\vspace*{\\fill}"
 509                                 : "\\vfill{}";
 510         case LENGTH:    return kp ? "\\vspace*{" + len.asLatexString() + '}'
 511                                 : "\\vspace{" + len.asLatexString() + '}';
 512         }
 513         return string();  // should never be reached
 514 }
 515
 516
 517 int VSpace::inPixels(BufferView * bv) const
 518 {
 519         // Height of a normal line in pixels (zoom factor considered)
 520         int height = bv->text->DefaultHeight(); // [pixels]
 521         int skip = 0;
 522         if (kin == DEFSKIP)
 523             skip = bv->buffer()->params.getDefSkip().inPixels(bv);
 524
 525         return inPixels(height, skip);
 526 }
 527
 528 int VSpace::inPixels(int default_height, int default_skip) const
 529 {
 530         // Height of a normal line in pixels (zoom factor considered)
 531         int height = default_height; // [pixels]
 532
 533         // Zoom factor specified by user in percent
 534         float const zoom = lyxrc.zoom / 100.0; // [percent]
 535
 536         // DPI setting for monitor: pixels/inch
 537         float const dpi = lyxrc.dpi; // screen resolution [pixels/inch]
 538
 539         // We want the result in pixels
 540         float result, value;
 541
 542         switch (kin) {
 543         case NONE: return 0;
 544
 545         case DEFSKIP:
 546                 return default_skip;
 547
 548                 // This is how the skips are normally defined by
 549                 // LateX.  But there should be some way to change
 550                 // this per document.
 551         case SMALLSKIP: return height / 4;
 552         case MEDSKIP:   return height / 2;
 553         case BIGSKIP:   return height;
 554         case VFILL:     return 3 * height;
 555                 // leave space for the vfill symbol
 556         case LENGTH:
 557                 // Pixel values are scaled so that the ratio
 558                 // between lengths and font sizes on the screen
 559                 // is the same as on paper.
 560
 561                 // we don't care about sign of value, we
 562                 // can't display negative anyway
 563                 result = 0.0;
 564                 value = len.value();
 565                 short val_sign = value < 0.0 ? -1 : 1;
 566
 567                 switch (len.unit()) {
 568                 case LyXLength::SP:
 569                         // Scaled point: sp = 1/65536 pt
 570                         result = zoom * dpi * value
 571                                 / (72.27 * 65536); // 4736286.7
 572                         break;
 573                 case LyXLength::PT:
 574                         // Point: 1 pt = 1/72.27 inch
 575                         result = zoom * dpi * value
 576                                 / 72.27; // 72.27
 577                         break;
 578                 case LyXLength::BP:
 579                         // Big point: 1 bp = 1/72 inch
 580                         result = zoom * dpi * value
 581                                 / 72; // 72
 582                         break;
 583                 case LyXLength::DD:
 584                         // Didot: 1157dd = 1238 pt?
 585                         result = zoom * dpi * value
 586                                 / (72.27 / (0.376 * 2.845)); // 67.559735
 587                         break;
 588                 case LyXLength::MM:
 589                         // Millimeter: 1 mm = 1/25.4 inch
 590                         result = zoom * dpi * value
 591                                 / 25.4; // 25.4
 592                         break;
 593                 case LyXLength::PC:
 594                         // Pica: 1 pc = 12 pt
 595                         result = zoom * dpi * value
 596                                 / (72.27 / 12); // 6.0225
 597                         break;
 598                 case LyXLength::CC:
 599                         // Cicero: 1 cc = 12 dd
 600                         result = zoom * dpi * value
 601                                 / (72.27 / (12 * 0.376 * 2.845)); // 5.6299779
 602                         break;
 603                 case LyXLength::CM:
 604                         // Centimeter: 1 cm = 1/2.54 inch
 605                         result = zoom * dpi * value
 606                                 / 2.54; // 2.54
 607                         break;
 608                 case LyXLength::IN:
 609                         // Inch
 610                         result = zoom * dpi * value;
 611                         break;
 612                 case LyXLength::EX:
 613                         // Ex: The height of an "x"
 614                         result = zoom * value * height / 2; // what to / width?
 615                         break;
 616                 case LyXLength::EM: // what to / width?
 617                         // Em: The width of an "m"
 618                         result = zoom * value * height / 2; // Why 2?
 619                         break;
 620                 case LyXLength::MU: // This is probably only allowed in
 621                         // math mode
 622                         result = zoom * value * height;
 623                         break;
 624                 case LyXLength::UNIT_NONE:
 625                         result = 0;  // this cannot happen
 626                         break;
 627                 }
 628                 return int (result * val_sign + 0.5);
 629         }
 630         return 0; // never reached
 631 }