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 extern LyXRC * lyxrc;
  27
  28 /*  length units
  29  */
  30
  31 static const int num_units = LyXLength::UNIT_NONE;
  32
  33 // I am not sure if "mu" should be possible to select (Lgb)
  34 static char const * unit_name[num_units] = { "sp", "pt", "bp", "dd",
  35                                              "mm", "pc", "cc", "cm",
  36                                              "in", "ex", "em", "mu" };
  37
  38
  39 LyXLength::UNIT unitFromString (string const & data)
  40 {
  41         int i = 0;
  42         while ((i < num_units) && (data != unit_name[i])) ++i;
  43         return static_cast<LyXLength::UNIT>(i);
  44 }
  45
  46 /*  The following static items form a simple scanner for
  47  *  length strings, used by isValid[Glue]Length.  See comments there.
  48  */
  49 static float           number[4] = { 0, 0, 0, 0 };
  50 static LyXLength::UNIT unit[4]   = { LyXLength::UNIT_NONE,
  51                                      LyXLength::UNIT_NONE,
  52                                      LyXLength::UNIT_NONE,
  53                                      LyXLength::UNIT_NONE };
  54 //static int number_index, unit_index;
  55 int number_index, unit_index;
  56
  57
  58 static inline
  59 void lyx_advance (string & data, unsigned int n)
  60 {
  61         data.erase(0, n);
  62 }
  63
  64
  65 static inline
  66 bool isEndOfData (string const & data)
  67 {
  68         return frontStrip (data).empty();
  69 }
  70
  71
  72 static
  73 char nextToken (string & data)
  74 {
  75         data = frontStrip(data);
  76         if (data.empty())
  77                 return '\0';
  78         else if (data[0] == '+') {
  79                 lyx_advance (data, 1);
  80                 return '+';
  81         }
  82         else if (prefixIs(data, "plus")) {
  83                 lyx_advance (data, 4);
  84                 return '+';
  85         }
  86         else if (data[0] == '-') {
  87                 lyx_advance (data, 1);
  88                 return '-';
  89         }
  90         else if (prefixIs(data, "minus")) {
  91                 lyx_advance (data, 5);
  92                 return '-';
  93         }
  94         else {
  95                 string::size_type i;
  96
  97                 // I really mean assignment ("=") below, not equality!
  98                 if ((i = data.find_last_of("0123456789.")) != string::npos) {
  99                         if (number_index > 3) return 'E';  // Error
 100                         string buffer = data.substr(0, i + 1);
 101                         if (sscanf (buffer.c_str(),
 102                                     "%f", &number[number_index]) == 1) {
 103                                 lyx_advance (data, i + 1);
 104                                 ++number_index;
 105                                 return 'n';
 106                         } else
 107                                 return 'E';  // Error
 108                 } else if ((i = data.find_last_of("abcdefghijklmnopqrstuvwxyz"))
 109                            != string::npos) {
 110                         if (unit_index > 3) return 'E';  // Error
 111                         string buffer = data.substr(0, i + 1);
 112                         unit[unit_index] = unitFromString (buffer);
 113                         if (unit[unit_index] != LyXLength::UNIT_NONE) {
 114                                 lyx_advance (data, i + 1);
 115                                 ++unit_index;
 116                                 return 'u';
 117                         } else
 118                                 return 'E';  // Error
 119                 } else
 120                         return 'E';  // Error
 121         }
 122 }
 123
 124
 125 struct LaTeXLength {
 126         char const * pattern;
 127         int   plus_val_index, minus_val_index,
 128                 plus_uni_index, minus_uni_index;
 129 };
 130
 131
 132 static
 133 LaTeXLength table[] = {
 134         { "nu",       0, 0, 0, 0 },
 135         { "nu+nu",    2, 0, 2, 0 },
 136         { "nu+nu-nu", 2, 3, 2, 3 },
 137         { "nu+-nu",   2, 2, 2, 2 },
 138         { "nu-nu",    0, 2, 0, 2 },
 139         { "nu-nu+nu", 3, 2, 3, 2 },
 140         { "nu-+nu",   2, 2, 2, 2 },
 141         { "n+nu",     2, 0, 1, 0 },
 142         { "n+n-nu",   2, 3, 1, 1 },
 143         { "n+-nu",    2, 2, 1, 1 },
 144         { "n-nu",     0, 2, 0, 1 },
 145         { "n-n+nu",   3, 2, 1, 1 },
 146         { "n-+nu",    2, 2, 1, 1 },
 147         { "",         0, 0, 0, 0 }   // sentinel, must be empty
 148 };
 149
 150
 151 bool isValidGlueLength (string const & data, LyXGlueLength * result)
 152 {
 153         // This parser is table-driven.  First, it constructs a "pattern"
 154         // that describes the sequence of tokens in "data".  For example,
 155         // "n-nu" means: number, minus sign, number, unit.  As we go along,
 156         // numbers and units are stored into static arrays.  Then, "pattern"
 157         // is searched in the "table".  If it is found, the associated
 158         // table entries tell us which number and unit should go where
 159         // in the LyXLength structure.  Example: if "data" has the "pattern"
 160         // "nu+nu-nu", the associated table entries are "2, 3, 2, 3".
 161         // That means, "plus_val" is the second number that was seen
 162         // in the input, "minus_val" is the third number, and "plus_uni"
 163         // and "minus_uni" are the second and third units, respectively.
 164         // ("val" and "uni" are always the first items seen in "data".)
 165         //     This is the most elegant solution I could find -- a straight-
 166         // forward approach leads to very long, tedious code that would be
 167         // much harder to understand and maintain. (AS)
 168
 169         if (data.empty())
 170                 return true;
 171         string buffer = frontStrip(data);
 172
 173         // To make isValidGlueLength recognize negative values as
 174         // the first number this little hack is needed:
 175         short val_sign = 1; // positive as default
 176         switch(buffer[0]) {
 177         case '-':
 178                 lyx_advance(buffer, 1);
 179                 val_sign = -1;
 180                 break;
 181         case '+':
 182                 lyx_advance(buffer, 1);
 183                 // fall through
 184         default:
 185                 // no action
 186                 break;
 187         }
 188         // end of hack
 189
 190         int       pattern_index = 0, table_index = 0;
 191         char      pattern[20];
 192
 193         number_index = unit_index = 1;  // entries at index 0 are sentinels
 194
 195         // construct "pattern" from "data"
 196         while (!isEndOfData (buffer)) {
 197                 if (pattern_index > 20) return false;
 198                 pattern[pattern_index] = nextToken (buffer);
 199                 if (pattern[pattern_index] == 'E') return false;
 200                 ++pattern_index;
 201         }
 202         pattern[pattern_index] = '\0';
 203
 204         // search "pattern" in "table"
 205         table_index = 0;
 206         while (compare(pattern, table[table_index].pattern)) {
 207                 ++table_index;
 208                 if (!*table[table_index].pattern) return false;
 209         }
 210
 211         // Get the values from the appropriate places.  If an index
 212         // is zero, the corresponding array value is zero or UNIT_NONE,
 213         // so we needn't check this.
 214         if (result) {
 215                 result->val = number[1] * val_sign;
 216                 result->uni = unit[1];
 217                 result->plus_val  = number[table[table_index].plus_val_index];
 218                 result->minus_val = number[table[table_index].minus_val_index];
 219                 result->plus_uni  = unit  [table[table_index].plus_uni_index];
 220                 result->minus_uni = unit  [table[table_index].minus_uni_index];
 221         }
 222         return true;
 223 }
 224
 225
 226 bool isValidLength(string const & data, LyXLength * result)
 227 {
 228         /// This is a trimmed down version of isValidGlueLength.
 229         /// The parser may seem overkill for lengths without
 230         /// glue, but since we already have it, using it is
 231         /// easier than writing something from scratch.
 232
 233         string   buffer = data;
 234         int       pattern_index = 0;
 235         char      pattern[3];
 236
 237         // To make isValidLength recognize negative values
 238         // this little hack is needed:
 239         short val_sign = 1; // positive as default
 240         switch(buffer[0]) {
 241         case '-':
 242                 lyx_advance(buffer, 1);
 243                 val_sign = -1;
 244                 break;
 245         case '+':
 246                 lyx_advance(buffer, 1);
 247                 // fall through
 248         default:
 249                 // no action
 250                 break;
 251         }
 252         // end of hack
 253
 254         number_index = unit_index = 1;  // entries at index 0 are sentinels
 255
 256         // construct "pattern" from "data"
 257         while (!isEndOfData (buffer)) {
 258                 if (pattern_index > 2) return false;
 259                 pattern[pattern_index] = nextToken (buffer);
 260                 if (pattern[pattern_index] == 'E') return false;
 261                 ++pattern_index;
 262         }
 263         pattern[pattern_index] = '\0';
 264
 265         // only the most basic pattern is accepted here
 266         if (compare(pattern, "nu") != 0) return false;
 267
 268         // It _was_ a correct length string.
 269         // Store away the values we found.
 270         if (result) {
 271                 result->val = number[1] * val_sign;
 272                 result->uni = unit[1];
 273         }
 274         return true;
 275 }
 276
 277
 278 /// LyXLength class
 279
 280 LyXLength::LyXLength(string const & data)
 281 {
 282         LyXLength tmp;
 283
 284         if (!isValidLength (data, &tmp))
 285                 return; // should raise an exception
 286         else {
 287                 val = tmp.val;
 288                 uni = tmp.uni;
 289         }
 290 }
 291
 292
 293 bool LyXLength::operator== (LyXLength const & other) const
 294 {
 295         return (val == other.val &&
 296                 uni == other.uni);
 297 }
 298
 299
 300 string LyXLength::asString() const
 301 {
 302 #ifdef HAVE_SSTREAM
 303         ostringstream buffer;
 304         buffer << val << unit_name[uni]; // setw?
 305         return buffer.str().c_str();
 306 #else
 307         char tbuf[20];
 308         ostrstream buffer(tbuf, 20);
 309         buffer << val << unit_name[uni] << '\0'; // setw?
 310         return buffer.str();
 311 #endif
 312 }
 313
 314
 315 /*  LyXGlueLength class
 316  */
 317
 318 LyXGlueLength::LyXGlueLength (string const & data)
 319 {
 320         LyXGlueLength tmp(0.0, PT);
 321
 322         if (!isValidGlueLength (data, &tmp))
 323                 return; // should raise an exception
 324         else {
 325                 val = tmp.val;
 326                 uni = tmp.uni;
 327                 plus_val = tmp.plus_val;
 328                 plus_uni = tmp.plus_uni;
 329                 minus_val = tmp.minus_val;
 330                 minus_uni = tmp.minus_uni;
 331         }
 332 }
 333
 334
 335 bool LyXGlueLength::operator== (LyXGlueLength const & other) const
 336 {
 337         return (val == other.val &&
 338                 uni == other.uni &&
 339                 plus_val  == other.plus_val &&
 340                 plus_uni  == other.plus_uni &&
 341                 minus_val == other.minus_val &&
 342                 minus_uni == other.minus_uni);
 343 }
 344
 345
 346 string LyXGlueLength::asString() const
 347 {
 348 #ifdef HAVE_SSTREAM
 349         ostringstream buffer;
 350 #else
 351         char tbuf[20];
 352         ostrstream buffer(tbuf, 20);
 353 #endif
 354         if (plus_val != 0.0)
 355                 if (minus_val != 0.0)
 356                         if ((uni == plus_uni) && (uni == minus_uni))
 357                                 if (plus_val == minus_val)
 358                                         buffer << val << "+-"
 359                                                << plus_val << unit_name[uni];
 360                                 else
 361                                         buffer << val
 362                                                << '+' << plus_val
 363                                                << '-' << minus_val
 364                                                << unit_name[uni];
 365                         else
 366                                 if (plus_uni == minus_uni
 367                                     && plus_val == minus_val)
 368                                         buffer << val << unit_name[uni]
 369                                                << "+-" << plus_val
 370                                                << unit_name[plus_uni];
 371
 372                                 else
 373                                         buffer << val << unit_name[uni]
 374                                                << '+' << plus_val
 375                                                << unit_name[plus_uni]
 376                                                << '-' << minus_val
 377                                                << unit_name[minus_uni];
 378                 else
 379                         if (uni == plus_uni)
 380                                 buffer << val << '+' << plus_val
 381                                        << unit_name[uni];
 382                         else
 383                                 buffer << val << unit_name[uni]
 384                                        << '+' << plus_val
 385                                        << unit_name[plus_uni];
 386
 387         else
 388                 if (minus_val != 0.0)
 389                         if (uni == minus_uni)
 390                                 buffer << val << '-' << minus_val
 391                                        << unit_name[uni];
 392
 393                         else
 394                                 buffer << val << unit_name[uni]
 395                                        << '-' << minus_val
 396                                        << unit_name[minus_uni];
 397                 else
 398                         buffer << val << unit_name[uni];
 399 #ifdef HAVE_SSTREAM
 400         return buffer.str().c_str();
 401 #else
 402         buffer << '\0';
 403         return buffer.str();
 404 #endif
 405 }
 406
 407
 408 string LyXGlueLength::asLatexString() const
 409 {
 410 #ifdef HAVE_SSTREAM
 411         ostringstream buffer;
 412 #else
 413         char tbuf[40];
 414         ostrstream buffer(tbuf, 40);
 415 #endif
 416
 417         if (plus_val != 0.0)
 418                 if (minus_val != 0.0)
 419                         buffer << val << unit_name[uni]
 420                                << " plus "
 421                                << plus_val << unit_name[plus_uni]
 422                                << " minus "
 423                                << minus_val << unit_name[minus_uni];
 424                 else
 425                         buffer << val << unit_name[uni]
 426                                << " plus "
 427                                << plus_val << unit_name[plus_uni];
 428         else
 429                 if (minus_val != 0.0)
 430                         buffer << val << unit_name[uni]
 431                                << " minus "
 432                                << minus_val << unit_name[minus_uni];
 433                 else
 434                         buffer << val << unit_name[uni];
 435 #ifdef HAVE_SSTREAM
 436         return buffer.str().c_str();
 437 #else
 438         buffer << '\0';
 439         return buffer.str();
 440 #endif
 441 }
 442
 443
 444 /*  VSpace class
 445  */
 446
 447 VSpace::VSpace (string const & data)
 448         : kin (NONE), len (0.0, LyXLength::PT)
 449 {
 450         kp = false;
 451         if (data.empty())
 452                 return;
 453         float   value;
 454         string input  = strip(data);
 455
 456         int length = input.length();
 457
 458         if (length > 1 && input[length-1] == '*') {
 459                 kp = true;
 460                 input.erase(length - 1);
 461         }
 462
 463         if      (prefixIs (input, "defskip"))   kin = DEFSKIP;
 464         else if (prefixIs (input, "smallskip")) kin = SMALLSKIP;
 465         else if (prefixIs (input, "medskip"))   kin = MEDSKIP;
 466         else if (prefixIs (input, "bigskip"))   kin = BIGSKIP;
 467         else if (prefixIs (input, "vfill"))     kin = VFILL;
 468         else if (isValidGlueLength (input, &len))
 469                 kin = LENGTH;
 470         else if (sscanf (input.c_str(), "%f", &value) == 1) {
 471                 // This last one is for reading old .lyx files
 472                 // without units in added_space_top/bottom.
 473                 // Let unit default to centimeters here.
 474                 kin = LENGTH;
 475                 len = LyXGlueLength (value, LyXLength::CM);
 476         }
 477 }
 478
 479
 480 bool VSpace::operator==(VSpace const & other) const
 481 {
 482         if (this->kin == other.kin)
 483                 if (this->kin == LENGTH)
 484                         if (this->len == other.len)
 485                                 return this->kp == other.kp;
 486                         else
 487                                 return false;
 488                 else
 489                         return this->kp == other.kp;
 490         else
 491                 return false;
 492 }
 493
 494
 495 string VSpace::asLyXCommand() const
 496 {
 497         string result;
 498
 499         switch (kin) {
 500         case NONE:      break;
 501         case DEFSKIP:   result = "defskip";      break;
 502         case SMALLSKIP: result = "smallskip";    break;
 503         case MEDSKIP:   result = "medskip";      break;
 504         case BIGSKIP:   result = "bigskip";      break;
 505         case VFILL:     result = "vfill";        break;
 506         case LENGTH:    result = len.asString(); break;
 507         }
 508         if (kp && (kin != NONE) && (kin != DEFSKIP))
 509                 return result += '*';
 510         else
 511                 return result;
 512 }
 513
 514
 515 string VSpace::asLatexCommand(BufferParams const & params) const
 516 {
 517         switch (kin) {
 518         case NONE:      return string();
 519         case DEFSKIP:
 520                 return params.getDefSkip().asLatexCommand(params);
 521         case SMALLSKIP: return kp ? "\\vspace*{\\smallskipamount}"
 522                                 : "\\smallskip{}";
 523         case MEDSKIP:   return kp ? "\\vspace*{\\medskipamount}"
 524                                 : "\\medskip{}";
 525         case BIGSKIP:   return kp ? "\\vspace*{\\bigskipamount}"
 526                                 : "\\bigskip{}";
 527         case VFILL:     return kp ? "\\vspace*{\\fill}"
 528                                 : "\\vfill{}";
 529         case LENGTH:    return kp ? "\\vspace*{" + len.asLatexString() + '}'
 530                                 : "\\vspace{" + len.asLatexString() + '}';
 531         }
 532         return string();  // should never be reached
 533 }
 534
 535
 536 int VSpace::inPixels(BufferView * bv) const
 537 {
 538         // Height of a normal line in pixels (zoom factor considered)
 539         int height = bv->text->DefaultHeight(); // [pixels]
 540
 541         // Zoom factor specified by user in percent
 542         float const zoom = lyxrc->zoom / 100.0; // [percent]
 543
 544         // DPI setting for monitor: pixels/inch
 545         float const dpi = lyxrc->dpi; // screen resolution [pixels/inch]
 546
 547         // We want the result in pixels
 548         float result, value;
 549
 550         switch (kin) {
 551         case NONE: return 0;
 552
 553         case DEFSKIP:
 554                 return bv->buffer()->params.getDefSkip().inPixels(bv);
 555
 556                 // This is how the skips are normally defined by
 557                 // LateX.  But there should be some way to change
 558                 // this per document.
 559         case SMALLSKIP: return height/4;
 560         case MEDSKIP:   return height/2;
 561         case BIGSKIP:   return height;
 562         case VFILL:     return 3*height;
 563                 // leave space for the vfill symbol
 564         case LENGTH:
 565                 // Pixel values are scaled so that the ratio
 566                 // between lengths and font sizes on the screen
 567                 // is the same as on paper.
 568
 569                 // we don't care about sign of value, we
 570                 // can't display negative anyway
 571                 result = 0.0;
 572                 value = len.value();
 573                 short val_sign = value < 0.0 ? -1 : 1;
 574
 575                 switch (len.unit()) {
 576                 case LyXLength::SP:
 577                         // Scaled point: sp = 1/65536 pt
 578                         result = zoom * dpi * value
 579                                 / (72.27 * 65536); // 4736286.7
 580                         break;
 581                 case LyXLength::PT:
 582                         // Point: 1 pt = 1/72.27 inch
 583                         result = zoom * dpi * value
 584                                 / 72.27; // 72.27
 585                         break;
 586                 case LyXLength::BP:
 587                         // Big point: 1 bp = 1/72 inch
 588                         result = zoom * dpi * value
 589                                 / 72; // 72
 590                         break;
 591                 case LyXLength::DD:
 592                         // Didot: 1157dd = 1238 pt?
 593                         result = zoom * dpi * value
 594                                 / (72.27 / (0.376 * 2.845)); // 67.559735
 595                         break;
 596                 case LyXLength::MM:
 597                         // Millimeter: 1 mm = 1/25.4 inch
 598                         result = zoom * dpi * value
 599                                 / 25.4; // 25.4
 600                         break;
 601                 case LyXLength::PC:
 602                         // Pica: 1 pc = 12 pt
 603                         result = zoom * dpi * value
 604                                 / (72.27 / 12); // 6.0225
 605                         break;
 606                 case LyXLength::CC:
 607                         // Cicero: 1 cc = 12 dd
 608                         result = zoom * dpi * value
 609                                 / (72.27 / (12 * 0.376 * 2.845)); // 5.6299779
 610                         break;
 611                 case LyXLength::CM:
 612                         // Centimeter: 1 cm = 1/2.54 inch
 613                         result = zoom * dpi * value
 614                                 / 2.54; // 2.54
 615                         break;
 616                 case LyXLength::IN:
 617                         // Inch
 618                         result = zoom * dpi * value;
 619                         break;
 620                 case LyXLength::EX:
 621                         // Ex: The height of an "x"
 622                         result = zoom * value * height / 2; // what to / width?
 623                         break;
 624                 case LyXLength::EM: // what to / width?
 625                         // Em: The width of an "m"
 626                         result = zoom * value * height / 2; // Why 2?
 627                         break;
 628                 case LyXLength::MU: // This is probably only allowed in
 629                         // math mode
 630                         result = zoom * value * height;
 631                         break;
 632                 case LyXLength::UNIT_NONE:
 633                         result = 0;  // this cannot happen
 634                         break;
 635                 }
 636                 return int (result * val_sign + 0.5);
 637         }
 638         return 0; // never reached
 639 }