src/lyxlength.C

   1 /**
   2  * \file lyxlength.C
   3  * This file is part of LyX, the document processor.
   4  * Licence details can be found in the file COPYING.
   5  *
   6  * \author Matthias Ettrich
   7  * \author Lars Gullik Bjønnes
   8  * \author Jean-Marc Lasgouttes
   9  * \author Angus Leeming
  10  * \author John Levon
  11  * \author Dekel Tsur
  12  *
  13  * Full author contact details are available in file CREDITS.
  14  */
  15
  16 #include <config.h>
  17
  18 #include "lyxlength.h"
  19 #include "lengthcommon.h"
  20 #include "lyxrc.h"
  21
  22
  23 #include "support/std_sstream.h"
  24
  25 using std::abs;
  26 using std::ostringstream;
  27 using std::string;
  28
  29
  30 LyXLength::LyXLength()
  31         : val_(0), unit_(LyXLength::UNIT_NONE)
  32 {}
  33
  34
  35 LyXLength::LyXLength(double v, LyXLength::UNIT u)
  36         : val_(v), unit_(u)
  37 {}
  38
  39
  40 LyXLength::LyXLength(string const & data)
  41         : val_(0), unit_(LyXLength::PT)
  42 {
  43         LyXLength tmp;
  44
  45         if (!isValidLength(data, &tmp))
  46                 return; // should raise an exception
  47
  48         val_  = tmp.val_;
  49         unit_ = tmp.unit_;
  50 }
  51
  52
  53 string const LyXLength::asString() const
  54 {
  55         ostringstream os;
  56         os << val_ << unit_name[unit_]; // setw?
  57         return os.str();
  58 }
  59
  60
  61 string const LyXLength::asLatexString() const
  62 {
  63         char buffer[80];
  64         switch (unit_) {
  65         case PTW:
  66                 snprintf(buffer, 78, "%.2f\\textwidth", val_/100.0);
  67                 break;
  68         case PCW:
  69                 snprintf(buffer, 78, "%.2f\\columnwidth", val_/100.0);
  70                 break;
  71         case PPW:
  72                 snprintf(buffer, 78, "%.2f\\paperwidth", val_/100.0);
  73                 break;
  74         case PLW:
  75                 snprintf(buffer, 78, "%.2f\\linewidth", val_/100.0);
  76                 break;
  77         case PPH:
  78                 snprintf(buffer, 78, "%.2f\\paperheight", val_/100.0);
  79                 break;
  80         case PTH:
  81                 snprintf(buffer, 78, "%.2f\\textheight", val_/100.0);
  82                 break;
  83         default:
  84                 snprintf(buffer, 78, "%f%s", val_, unit_name[unit_]);
  85           break;
  86         }
  87         // paranoia
  88         buffer[79] = 0;
  89         return buffer;
  90 }
  91
  92
  93 double LyXLength::value() const
  94 {
  95         return val_;
  96 }
  97
  98
  99 LyXLength::UNIT LyXLength::unit() const
 100 {
 101         return unit_;
 102 }
 103
 104
 105 void LyXLength::value(double v)
 106 {
 107         val_ = v;
 108 }
 109
 110
 111 void LyXLength::unit(LyXLength::UNIT u)
 112 {
 113         unit_ = u;
 114 }
 115
 116
 117 bool LyXLength::zero() const
 118 {
 119         return val_ == 0.0;
 120 }
 121
 122
 123 bool LyXLength::empty() const
 124 {
 125         return unit_ == LyXLength::UNIT_NONE;
 126 }
 127
 128
 129 int LyXLength::inPixels(int text_width, int em_width_base) const
 130 {
 131         // Zoom factor specified by user in percent
 132         double const zoom = lyxrc.zoom / 100.0; // [percent]
 133
 134         // DPI setting for monitor: pixels/inch
 135         double const dpi = lyxrc.dpi; // screen resolution [pixels/inch]
 136
 137         double const em_width = (em_width_base > 0)
 138                 ? em_width_base
 139                 : 10*(dpi/72.27)*zoom;
 140         // A different estimate for em_width is
 141         // font_metrics::width('M', LyXFont(LyXFont::ALL_SANE))
 142         // but this estimate might not be more accurate as the screen font
 143         // is different then the latex font.
 144
 145         // Pixel values are scaled so that the ratio
 146         // between lengths and font sizes on the screen
 147         // is the same as on paper.
 148
 149 #ifdef WITH_WARNINGS
 150 #warning if you don't care than either call this function differently or let it return negative values and call abs() explicitly when needed (Andre')
 151 #endif
 152
 153         double result = 0.0;
 154
 155         switch (unit_) {
 156         case LyXLength::SP:
 157                 // Scaled point: sp = 1/65536 pt
 158                 result = zoom * dpi * val_
 159                         / (72.27 * 65536); // 4736286.7
 160                 break;
 161         case LyXLength::PT:
 162                 // Point: 1 pt = 1/72.27 inch
 163                 result = zoom * dpi * val_
 164                         / 72.27; // 72.27
 165                 break;
 166         case LyXLength::BP:
 167                 // Big point: 1 bp = 1/72 inch
 168                 result = zoom * dpi * val_
 169                         / 72; // 72
 170                 break;
 171         case LyXLength::DD:
 172                 // Didot: 1157dd = 1238 pt?
 173                 result = zoom * dpi * val_
 174                         / (72.27 / (0.376 * 2.845)); // 67.559735
 175                 break;
 176         case LyXLength::MM:
 177                 // Millimeter: 1 mm = 1/25.4 inch
 178                 result = zoom * dpi * val_
 179                         / 25.4; // 25.4
 180                 break;
 181         case LyXLength::PC:
 182                 // Pica: 1 pc = 12 pt
 183                 result = zoom * dpi * val_
 184                         / (72.27 / 12); // 6.0225
 185                 break;
 186         case LyXLength::CC:
 187                 // Cicero: 1 cc = 12 dd
 188                 result = zoom * dpi * val_
 189                         / (72.27 / (12 * 0.376 * 2.845)); // 5.6299779
 190                 break;
 191         case LyXLength::CM:
 192                 // Centimeter: 1 cm = 1/2.54 inch
 193                 result = zoom * dpi * val_
 194                         / 2.54; // 2.54
 195                 break;
 196         case LyXLength::IN:
 197                 // Inch
 198                 result = zoom * dpi * val_;
 199                 break;
 200         case LyXLength::EX:
 201                 // Ex: The height of an "x"
 202                 // 0.4305 is the ration between 1ex and 1em in cmr10
 203                 result = val_ * em_width * 0.4305;
 204                 break;
 205         case LyXLength::EM:
 206                 // Em: The width of an "m"
 207                 result = val_ * em_width;
 208                 break;
 209         case LyXLength::MU:
 210                 // math unit = 1/18em
 211                 result = val_ * em_width / 18;
 212                 break;
 213         case LyXLength::PCW: // Always % of workarea
 214         case LyXLength::PTW:
 215         case LyXLength::PLW:
 216                 result = val_ * text_width / 100;
 217                 break;
 218         case LyXLength::PPW:
 219                 // paperwidth/textwidth is 1.7 for A4 paper with default margins
 220                 result = val_ * text_width * 1.7 / 100;
 221                 break;
 222         case LyXLength::PTH:
 223                 result = val_ * text_width * 1.787 / 100;
 224                 break;
 225         case LyXLength::PPH:
 226                 result = val_ * text_width * 2.2 / 100;
 227                 break;
 228         case LyXLength::UNIT_NONE:
 229                 result = 0;  // this cannot happen
 230                 break;
 231         }
 232         return static_cast<int>(result + ((result >= 0) ? 0.5 : -0.5));
 233 }
 234
 235
 236 int LyXLength::inBP() const
 237 {
 238         // return any LyXLength value as a one with
 239         // the PostScript point, called bp (big points)
 240         double result = 0.0;
 241         switch (unit_) {
 242         case LyXLength::CM:
 243                 // 1bp = 0.2835cm
 244                 result = val_ * 28.346;
 245                 break;
 246         case LyXLength::MM:
 247                 // 1bp = 0.02835mm
 248                 result = val_ * 2.8346;
 249                 break;
 250         case LyXLength::IN:
 251                 // 1pt = 1/72in
 252                 result = val_ * 72.0;
 253                 break;
 254         default:
 255                 // no other than bp possible
 256                 result = val_;
 257                 break;
 258         }
 259         return static_cast<int>(result + 0.5);
 260 }
 261
 262
 263 bool operator==(LyXLength const & l1, LyXLength const & l2)
 264 {
 265         return l1.value() == l2.value() && l1.unit() == l2.unit();
 266 }
 267
 268
 269 bool operator!=(LyXLength const & l1, LyXLength const & l2)
 270 {
 271         return !(l1 == l2);
 272 }