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