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