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