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 1995-1999 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 <cstring>
  24 #include "BufferView.h"
  25 #include "support/lstrings.h"
  26
  27 extern LyXRC * lyxrc;
  28
  29 /*  length units
  30  */
  31
  32 static const int num_units = LyXLength::UNIT_NONE;
  33
  34 // I am not sure if "mu" should be possible to select (Lgb)
  35 static char const * unit_name[num_units] = { "sp", "pt", "bp", "dd",
  36                                              "mm", "pc", "cc", "cm",
  37                                              "in", "ex", "em", "mu" };
  38
  39
  40 LyXLength::UNIT unitFromString (string const & data)
  41 {
  42         int i = 0;
  43         while ((i < num_units) && (data != unit_name[i])) ++i;
  44         return static_cast<LyXLength::UNIT>(i);
  45 }
  46
  47 /*  The following static items form a simple scanner for
  48  *  length strings, used by isValid[Glue]Length.  See comments there.
  49  */
  50 static float           number[4] = { 0, 0, 0, 0 };
  51 static LyXLength::UNIT unit[4]   = { LyXLength::UNIT_NONE,
  52                                      LyXLength::UNIT_NONE,
  53                                      LyXLength::UNIT_NONE,
  54                                      LyXLength::UNIT_NONE };
  55 //static int number_index, unit_index;
  56 int number_index, unit_index;
  57
  58 static inline void lyx_advance (string & data, unsigned int n)
  59 {
  60         data.erase(0, n);
  61 }
  62
  63 static inline bool isEndOfData (string const & data)
  64 {
  65         return frontStrip (data).empty();
  66 }
  67
  68 static char nextToken (string & data)
  69 {
  70         data = frontStrip(data);
  71         if (data.empty())
  72                 return '\0';
  73         else if (data[0] == '+') {
  74                 lyx_advance (data, 1);
  75                 return '+';
  76         }
  77         else if (prefixIs(data, "plus")) {
  78                 lyx_advance (data, 4);
  79                 return '+';
  80         }
  81         else if (data[0] == '-') {
  82                 lyx_advance (data, 1);
  83                 return '-';
  84         }
  85         else if (prefixIs(data, "minus")) {
  86                 lyx_advance (data, 5);
  87                 return '-';
  88         }
  89         else {
  90                 string::size_type i;
  91
  92                 // I really mean assignment ("=") below, not equality!
  93                 if ((i = data.find_last_of("0123456789.")) != string::npos) {
  94                         if (number_index > 3) return 'E';  // Error
  95                         string buffer = data.substr(0, i + 1);
  96                         if (sscanf (buffer.c_str(),
  97                                     "%f", &number[number_index]) == 1) {
  98                                 lyx_advance (data, i + 1);
  99                                 ++number_index;
 100                                 return 'n';
 101                         } else
 102                                 return 'E';  // Error
 103                 } else if ((i = data.find_last_of("abcdefghijklmnopqrstuvwxyz"))
 104                            != string::npos) {
 105                         if (unit_index > 3) return 'E';  // Error
 106                         string buffer = data.substr(0, i + 1);
 107                         unit[unit_index] = unitFromString (buffer);
 108                         if (unit[unit_index] != LyXLength::UNIT_NONE) {
 109                                 lyx_advance (data, i + 1);
 110                                 ++unit_index;
 111                                 return 'u';
 112                         } else
 113                                 return 'E';  // Error
 114                 } else
 115                         return 'E';  // Error
 116         }
 117 }
 118
 119 static struct {
 120         char const * pattern;
 121         int   plus_val_index, minus_val_index,
 122                 plus_uni_index, minus_uni_index;
 123 } table[] = { { "nu",       0, 0, 0, 0 },
 124               { "nu+nu",    2, 0, 2, 0 },
 125               { "nu+nu-nu", 2, 3, 2, 3 },
 126               { "nu+-nu",   2, 2, 2, 2 },
 127               { "nu-nu",    0, 2, 0, 2 },
 128               { "nu-nu+nu", 3, 2, 3, 2 },
 129               { "nu-+nu",   2, 2, 2, 2 },
 130               { "n+nu",     2, 0, 1, 0 },
 131               { "n+n-nu",   2, 3, 1, 1 },
 132               { "n+-nu",    2, 2, 1, 1 },
 133               { "n-nu",     0, 2, 0, 1 },
 134               { "n-n+nu",   3, 2, 1, 1 },
 135               { "n-+nu",    2, 2, 1, 1 },
 136               { "",         0, 0, 0, 0 }   // sentinel, must be empty
 137 };
 138
 139 bool isValidGlueLength (string const & data, LyXGlueLength * result)
 140 {
 141         // This parser is table-driven.  First, it constructs a "pattern"
 142         // that describes the sequence of tokens in "data".  For example,
 143         // "n-nu" means: number, minus sign, number, unit.  As we go along,
 144         // numbers and units are stored into static arrays.  Then, "pattern"
 145         // is searched in the "table".  If it is found, the associated
 146         // table entries tell us which number and unit should go where
 147         // in the LyXLength structure.  Example: if "data" has the "pattern"
 148         // "nu+nu-nu", the associated table entries are "2, 3, 2, 3".
 149         // That means, "plus_val" is the second number that was seen
 150         // in the input, "minus_val" is the third number, and "plus_uni"
 151         // and "minus_uni" are the second and third units, respectively.
 152         // ("val" and "uni" are always the first items seen in "data".)
 153         //     This is the most elegant solution I could find -- a straight-
 154         // forward approach leads to very long, tedious code that would be
 155         // much harder to understand and maintain. (AS)
 156
 157         if (data.empty())
 158                 return true;
 159         string buffer = frontStrip(data);
 160
 161         // To make isValidGlueLength recognize negative values as
 162         // the first number this little hack is needed:
 163         short val_sign = 1; // positive as default
 164         switch(buffer[0]) {
 165         case '-':
 166                 lyx_advance(buffer, 1);
 167                 val_sign = -1;
 168                 break;
 169         case '+':
 170                 lyx_advance(buffer, 1);
 171                 // fall through
 172         default:
 173                 // no action
 174                 break;
 175         }
 176         // end of hack
 177
 178         int       pattern_index = 0, table_index = 0;
 179         char      pattern[20];
 180
 181         number_index = unit_index = 1;  // entries at index 0 are sentinels
 182
 183         // construct "pattern" from "data"
 184         while (!isEndOfData (buffer)) {
 185                 if (pattern_index > 20) return false;
 186                 pattern[pattern_index] = nextToken (buffer);
 187                 if (pattern[pattern_index] == 'E') return false;
 188                 ++pattern_index;
 189         }
 190         pattern[pattern_index] = '\0';
 191
 192         // search "pattern" in "table"
 193         table_index = 0;
 194         while (compare(pattern, table[table_index].pattern)) {
 195                 ++table_index;
 196                 if (!*table[table_index].pattern) return false;
 197         }
 198
 199         // Get the values from the appropriate places.  If an index
 200         // is zero, the corresponding array value is zero or UNIT_NONE,
 201         // so we needn't check this.
 202         if (result) {
 203                 result->val = number[1] * val_sign;
 204                 result->uni = unit[1];
 205                 result->plus_val  = number[table[table_index].plus_val_index];
 206                 result->minus_val = number[table[table_index].minus_val_index];
 207                 result->plus_uni  = unit  [table[table_index].plus_uni_index];
 208                 result->minus_uni = unit  [table[table_index].minus_uni_index];
 209         }
 210         return true;
 211 }
 212
 213
 214 bool isValidLength(string const & data, LyXLength * result)
 215 {
 216         /// This is a trimmed down version of isValidGlueLength.
 217         /// The parser may seem overkill for lengths without
 218         /// glue, but since we already have it, using it is
 219         /// easier than writing something from scratch.
 220
 221         string   buffer = data;
 222         int       pattern_index = 0;
 223         char      pattern[3];
 224
 225         // To make isValidLength recognize negative values
 226         // this little hack is needed:
 227         short val_sign = 1; // positive as default
 228         switch(buffer[0]) {
 229         case '-':
 230                 lyx_advance(buffer, 1);
 231                 val_sign = -1;
 232                 break;
 233         case '+':
 234                 lyx_advance(buffer, 1);
 235                 // fall through
 236         default:
 237                 // no action
 238                 break;
 239         }
 240         // end of hack
 241
 242         number_index = unit_index = 1;  // entries at index 0 are sentinels
 243
 244         // construct "pattern" from "data"
 245         while (!isEndOfData (buffer)) {
 246                 if (pattern_index > 2) return false;
 247                 pattern[pattern_index] = nextToken (buffer);
 248                 if (pattern[pattern_index] == 'E') return false;
 249                 ++pattern_index;
 250         }
 251         pattern[pattern_index] = '\0';
 252
 253         // only the most basic pattern is accepted here
 254         if (compare(pattern, "nu") != 0) return false;
 255
 256         // It _was_ a correct length string.
 257         // Store away the values we found.
 258         if (result) {
 259                 result->val = number[1] * val_sign;
 260                 result->uni = unit[1];
 261         }
 262         return true;
 263 }
 264
 265 /// LyXLength class
 266
 267 LyXLength::LyXLength(string const & data)
 268 {
 269         LyXLength tmp;
 270
 271         if (!isValidLength (data, &tmp))
 272                 return; // should raise an exception
 273         else {
 274                 val = tmp.val;
 275                 uni = tmp.uni;
 276         }
 277 }
 278
 279 bool LyXLength::operator== (LyXLength const & other) const
 280 {
 281         return (val == other.val &&
 282                 uni == other.uni);
 283 }
 284
 285 string LyXLength::asString() const
 286 {
 287         char buffer[20];
 288
 289         sprintf (buffer, "%g%s", val, unit_name[uni]);
 290         return string (buffer);
 291 }
 292
 293
 294 /*  LyXGlueLength class
 295  */
 296
 297 LyXGlueLength::LyXGlueLength (string const & data)
 298 {
 299         LyXGlueLength tmp(0.0, PT);
 300
 301         if (!isValidGlueLength (data, &tmp))
 302                 return; // should raise an exception
 303         else {
 304                 val = tmp.val;
 305                 uni = tmp.uni;
 306                 plus_val = tmp.plus_val;
 307                 plus_uni = tmp.plus_uni;
 308                 minus_val = tmp.minus_val;
 309                 minus_uni = tmp.minus_uni;
 310         }
 311 }
 312
 313
 314 bool LyXGlueLength::operator== (LyXGlueLength const & other) const
 315 {
 316         return (val == other.val &&
 317                 uni == other.uni &&
 318                 plus_val  == other.plus_val &&
 319                 plus_uni  == other.plus_uni &&
 320                 minus_val == other.minus_val &&
 321                 minus_uni == other.minus_uni);
 322 }
 323
 324
 325 string LyXGlueLength::asString() const
 326 {
 327         char buffer[20];
 328
 329         if (plus_val != 0.0)
 330                 if (minus_val != 0.0)
 331                         if ((uni == plus_uni) && (uni == minus_uni))
 332                                 if (plus_val == minus_val)
 333                                         sprintf (buffer, "%g+-%g%s",
 334                                                  val, plus_val, unit_name[uni]);
 335                                 else
 336                                         sprintf (buffer, "%g+%g-%g%s",
 337                                                  val, plus_val, minus_val,
 338                                                  unit_name[uni]);
 339                         else
 340                                 if ((plus_uni == minus_uni) && (plus_val == minus_val))
 341                                         sprintf (buffer, "%g%s+-%g%s",
 342                                                  val, unit_name[uni],
 343                                                  plus_val, unit_name[plus_uni]);
 344                                 else
 345                                         sprintf (buffer, "%g%s+%g%s-%g%s",
 346                                                  val,       unit_name[uni],
 347                                                  plus_val,  unit_name[plus_uni],
 348                                                  minus_val, unit_name[minus_uni]);
 349                 else
 350                         if (uni == plus_uni)
 351                                 sprintf (buffer, "%g+%g%s",
 352                                          val, plus_val, unit_name[uni]);
 353                         else
 354                                 sprintf (buffer, "%g%s+%g%s",
 355                                          val,      unit_name[uni],
 356                                          plus_val, unit_name[plus_uni]);
 357         else
 358                 if (minus_val != 0.0)
 359                         if (uni == minus_uni)
 360                                 sprintf (buffer, "%g-%g%s",
 361                                          val, minus_val, unit_name[uni]);
 362                         else
 363                                 sprintf (buffer, "%g%s-%g%s",
 364                                          val,       unit_name[uni],
 365                                          minus_val, unit_name[minus_uni]);
 366                 else
 367                         sprintf (buffer, "%g%s", val, unit_name[uni]);
 368         return string (buffer);
 369 }
 370
 371
 372 string LyXGlueLength::asLatexString() const
 373 {
 374         char buffer[40];
 375
 376         if (plus_val != 0.0)
 377                 if (minus_val != 0.0)
 378                         sprintf (buffer, "%g%s plus %g%s minus %g%s",
 379                                  val, unit_name[uni],
 380                                  plus_val,  unit_name[plus_uni],
 381                                  minus_val, unit_name[minus_uni]);
 382                 else
 383                         sprintf (buffer, "%g%s plus %g%s",
 384                                  val,      unit_name[uni],
 385                                  plus_val, unit_name[plus_uni]);
 386         else
 387                 if (minus_val != 0.0)
 388                         sprintf (buffer, "%g%s minus %g%s",
 389                                  val,       unit_name[uni],
 390                                  minus_val, unit_name[minus_uni]);
 391                 else
 392                         sprintf (buffer, "%g%s",
 393                                  val, unit_name[uni]);
 394         return string (buffer);
 395 }
 396
 397
 398 /*  VSpace class
 399  */
 400
 401 VSpace::VSpace (string const & data)
 402         : kin (NONE), len (0.0, LyXLength::PT)
 403 {
 404         kp = false;
 405         if (data.empty())
 406                 return;
 407         float   value;
 408         string input  = strip(data);
 409
 410         int length = input.length();
 411
 412         if (length > 1 && input[length-1] == '*') {
 413                 kp = true;
 414                 input.erase(length - 1);
 415         }
 416
 417         if      (prefixIs (input, "defskip"))   kin = DEFSKIP;
 418         else if (prefixIs (input, "smallskip")) kin = SMALLSKIP;
 419         else if (prefixIs (input, "medskip"))   kin = MEDSKIP;
 420         else if (prefixIs (input, "bigskip"))   kin = BIGSKIP;
 421         else if (prefixIs (input, "vfill"))     kin = VFILL;
 422         else if (isValidGlueLength (input, &len))
 423                 kin = LENGTH;
 424         else if (sscanf (input.c_str(), "%f", &value) == 1) {
 425                 // This last one is for reading old .lyx files
 426                 // without units in added_space_top/bottom.
 427                 // Let unit default to centimeters here.
 428                 kin = LENGTH;
 429                 len = LyXGlueLength (value, LyXLength::CM);
 430         }
 431 }
 432
 433
 434 bool VSpace::operator==(VSpace const & other) const
 435 {
 436         if (this->kin == other.kin)
 437                 if (this->kin == LENGTH)
 438                         if (this->len == other.len)
 439                                 return this->kp == other.kp;
 440                         else
 441                                 return false;
 442                 else
 443                         return this->kp == other.kp;
 444         else
 445                 return false;
 446 }
 447
 448
 449 string VSpace::asLyXCommand() const
 450 {
 451         string result;
 452
 453         switch (kin) {
 454         case NONE:      break;
 455         case DEFSKIP:   result = "defskip";      break;
 456         case SMALLSKIP: result = "smallskip";    break;
 457         case MEDSKIP:   result = "medskip";      break;
 458         case BIGSKIP:   result = "bigskip";      break;
 459         case VFILL:     result = "vfill";        break;
 460         case LENGTH:    result = len.asString(); break;
 461         }
 462         if (kp && (kin != NONE) && (kin != DEFSKIP))
 463                 return result += '*';
 464         else
 465                 return result;
 466 }
 467
 468
 469 string VSpace::asLatexCommand(BufferParams const & params) const
 470 {
 471         switch (kin) {
 472         case NONE:      return string();
 473         case DEFSKIP:
 474                 return params.getDefSkip().asLatexCommand(params);
 475         case SMALLSKIP: return kp ? "\\vspace*{\\smallskipamount}"
 476                                 : "\\smallskip{}";
 477         case MEDSKIP:   return kp ? "\\vspace*{\\medskipamount}"
 478                                 : "\\medskip{}";
 479         case BIGSKIP:   return kp ? "\\vspace*{\\bigskipamount}"
 480                                 : "\\bigskip{}";
 481         case VFILL:     return kp ? "\\vspace*{\\fill}"
 482                                 : "\\vfill{}";
 483         case LENGTH:    return kp ? "\\vspace*{" + len.asLatexString() + '}'
 484                                 : "\\vspace{" + len.asLatexString() + '}';
 485         }
 486         return string();  // should never be reached
 487 }
 488
 489
 490 int VSpace::inPixels(BufferView * bv) const
 491 {
 492         // Height of a normal line in pixels (zoom factor considered)
 493         int height = bv->text->DefaultHeight(); // [pixels]
 494
 495         // Zoom factor specified by user in percent
 496         float const zoom = lyxrc->zoom / 100.0; // [percent]
 497
 498         // DPI setting for monitor: pixels/inch
 499         float const dpi = lyxrc->dpi; // screen resolution [pixels/inch]
 500
 501         // We want the result in pixels
 502         float result, value;
 503
 504         switch (kin) {
 505         case NONE: return 0;
 506
 507         case DEFSKIP:
 508                 return bv->buffer()->params.getDefSkip().inPixels(bv);
 509
 510                 // This is how the skips are normally defined by
 511                 // LateX.  But there should be some way to change
 512                 // this per document.
 513         case SMALLSKIP: return height/4;
 514         case MEDSKIP:   return height/2;
 515         case BIGSKIP:   return height;
 516         case VFILL:     return 3*height;
 517                 // leave space for the vfill symbol
 518         case LENGTH:
 519                 // Pixel values are scaled so that the ratio
 520                 // between lengths and font sizes on the screen
 521                 // is the same as on paper.
 522
 523                 // we don't care about sign of value, we
 524                 // can't display negative anyway
 525                 result = 0.0;
 526                 value = len.value();
 527                 short val_sign = value < 0.0 ? -1 : 1;
 528
 529                 switch (len.unit()) {
 530                 case LyXLength::SP:
 531                         // Scaled point: sp = 1/65536 pt
 532                         result = zoom * dpi * value
 533                                 / (72.27 * 65536); // 4736286.7
 534                         break;
 535                 case LyXLength::PT:
 536                         // Point: 1 pt = 1/72.27 inch
 537                         result = zoom * dpi * value
 538                                 / 72.27; // 72.27
 539                         break;
 540                 case LyXLength::BP:
 541                         // Big point: 1 bp = 1/72 inch
 542                         result = zoom * dpi * value
 543                                 / 72; // 72
 544                         break;
 545                 case LyXLength::DD:
 546                         // Didot: 1157dd = 1238 pt?
 547                         result = zoom * dpi * value
 548                                 / (72.27 / (0.376 * 2.845)); // 67.559735
 549                         break;
 550                 case LyXLength::MM:
 551                         // Millimeter: 1 mm = 1/25.4 inch
 552                         result = zoom * dpi * value
 553                                 / 25.4; // 25.4
 554                         break;
 555                 case LyXLength::PC:
 556                         // Pica: 1 pc = 12 pt
 557                         result = zoom * dpi * value
 558                                 / (72.27 / 12); // 6.0225
 559                         break;
 560                 case LyXLength::CC:
 561                         // Cicero: 1 cc = 12 dd
 562                         result = zoom * dpi * value
 563                                 / (72.27 / (12 * 0.376 * 2.845)); // 5.6299779
 564                         break;
 565                 case LyXLength::CM:
 566                         // Centimeter: 1 cm = 1/2.54 inch
 567                         result = zoom * dpi * value
 568                                 / 2.54; // 2.54
 569                         break;
 570                 case LyXLength::IN:
 571                         // Inch
 572                         result = zoom * dpi * value;
 573                         break;
 574                 case LyXLength::EX:
 575                         // Ex: The height of an "x"
 576                         result = zoom * value * height / 2; // what to / width?
 577                         break;
 578                 case LyXLength::EM: // what to / width?
 579                         // Em: The width of an "m"
 580                         result = zoom * value * height / 2; // Why 2?
 581                         break;
 582                 case LyXLength::MU: // This is probably only allowed in
 583                         // math mode
 584                         result = zoom * value * height;
 585                         break;
 586                 case LyXLength::UNIT_NONE:
 587                         result = 0;  // this cannot happen
 588                         break;
 589                 }
 590                 return int (result * val_sign + 0.5);
 591         }
 592         return 0; // never reached
 593 }