src/Length.h

   1 // -*- C++ -*-
   2 /**
   3  * \file Length.h
   4  * This file is part of LyX, the document processor.
   5  * Licence details can be found in the file COPYING.
   6  *
   7  * \author Matthias Ettrich
   8  * \author Lars Gullik Bjønnes
   9  * \author Jean-Marc Lasgouttes
  10  * \author John Levon
  11  *
  12  * Full author contact details are available in file CREDITS.
  13  */
  14
  15 #ifndef LENGTH_H
  16 #define LENGTH_H
  17
  18 #include "support/strfwd.h"
  19
  20
  21 namespace lyx {
  22
  23 // Solaris/x86 version 9 and earlier define these
  24 #undef PC
  25 #undef SP
  26
  27 /////////////////////////////////////////////////////////////////////
  28 //
  29 // Length
  30 //
  31 /////////////////////////////////////////////////////////////////////
  32
  33
  34 /**
  35  * Length - Represents latex length measurement
  36  */
  37 class Length {
  38 public:
  39         /// length units
  40         enum UNIT {
  41                 SP, ///< Scaled point (65536sp = 1pt) TeX's smallest unit.
  42                 PT, ///< Point = 1/72.27in = 0.351mm
  43                 BP, ///< Big point (72bp = 1in), also PostScript point
  44                 DD, ///< Didot point = 1/72 of a French inch, = 0.376mm
  45                 MM, ///< Millimeter = 2.845pt
  46                 PC, ///< Pica = 12pt = 4.218mm
  47                 CC, ///< Cicero = 12dd = 4.531mm
  48                 CM, ///< Centimeter = 10mm = 2.371pc
  49                 IN, ///< Inch = 25.4mm = 72.27pt = 6.022pc
  50                 EX, ///< Height of a small "x" for the current font.
  51                 EM, ///< Width of capital "M" in current font.
  52                 MU, ///< Math unit (18mu = 1em) for positioning in math mode
  53                 PTW, //< Percent of TextWidth
  54                 PCW, //< Percent of ColumnWidth
  55                 PPW, //< Percent of PageWidth
  56                 PLW, //< Percent of LineWidth
  57                 PTH, //< Percent of TextHeight          // Herbert 2002-05-16
  58                 PPH, //< Percent of PaperHeight         // Herbert 2002-05-16
  59                 UNIT_NONE ///< no unit
  60         };
  61
  62         ///
  63         Length();
  64         ///
  65         Length(double v, Length::UNIT u);
  66
  67         /// "data" must be a decimal number, followed by a unit
  68         explicit Length(std::string const & data);
  69
  70         ///
  71         void swap(Length & rhs);
  72         ///
  73         double value() const;
  74         ///
  75         Length::UNIT unit() const;
  76         ///
  77         void value(double);
  78         ///
  79         void unit(Length::UNIT unit);
  80         ///
  81         bool zero() const;
  82         ///
  83         bool empty() const;
  84         /// return string representation
  85         std::string const asString() const;
  86         /// return string representation
  87         docstring const asDocstring() const;
  88         /// return string representation for LaTeX
  89         std::string const asLatexString() const;
  90         /// return the on-screen size of this length
  91         int inPixels(int text_width, int em_width = 0) const;
  92         /// return the on-screen size of this length of an image
  93         int inBP() const;
  94
  95         friend bool isValidLength(std::string const & data, Length * result);
  96
  97 private:
  98         ///
  99         double val_;
 100         ///
 101         Length::UNIT unit_;
 102 };
 103
 104 ///
 105 bool operator==(Length const & l1, Length const & l2);
 106 ///
 107 bool operator!=(Length const & l1, Length const & l2);
 108 /** Test whether \p data represents a valid length.
 109  *
 110  * \returns whether \p data is a valid length
 111  * \param data Length in LyX format. Since the only difference between LyX
 112  * and LaTeX format is the representation of length variables as units (e.g.
 113  * \c text% vs. \c \\textwidth) you can actually use this function as well
 114  * for testing LaTeX lengths as long as they only contain real units like pt.
 115  * \param result Pointer to a Length variable. If \p result is not 0 and
 116  * \p data is valid, the length represented by it is stored into \p result.
 117  */
 118 bool isValidLength(std::string const & data, Length * result = 0);
 119 /// return the LyX name of the given unit number
 120 char const * stringFromUnit(int unit);
 121
 122
 123 /////////////////////////////////////////////////////////////////////
 124 //
 125 // GlueLength
 126 //
 127 /////////////////////////////////////////////////////////////////////
 128
 129 class GlueLength {
 130 public:
 131         ///
 132         GlueLength() {}
 133         ///
 134         explicit GlueLength(Length const & len);
 135         ///
 136         GlueLength(Length const & len,
 137                       Length const & plus,
 138                       Length const & minus);
 139
 140         /** "data" must be a decimal number, followed by a unit, and
 141           optional "glue" indicated by "+" and "-".  You may abbreviate
 142           reasonably.  Examples:
 143           1.2 cm  //  4mm +2pt  //  2cm -4mm +2mm  //  4+0.1-0.2cm
 144           The traditional Latex format is also accepted, like
 145           4cm plus 10pt minus 10pt */
 146         explicit GlueLength(std::string const & data);
 147
 148         ///
 149         Length const & len() const;
 150         ///
 151         Length const & plus() const;
 152         ///
 153         Length const & minus() const;
 154
 155
 156         /// conversion
 157         std::string const asString() const;
 158         ///
 159         std::string const asLatexString() const;
 160
 161         friend bool isValidGlueLength(std::string const & data,
 162                                       GlueLength* result);
 163
 164 private:
 165         /// the normal vlaue
 166         Length len_;
 167         /// extra stretch
 168         Length plus_;
 169         /// extra shrink
 170         Length minus_;
 171 };
 172
 173 ///
 174 bool operator==(GlueLength const & l1, GlueLength const & l2);
 175 ///
 176 bool operator!=(GlueLength const & l1, GlueLength const & l2);
 177 /** If "data" is valid, the length represented by it is
 178     stored into "result", if that is not 0. */
 179 bool isValidGlueLength(std::string const & data, GlueLength * result = 0);
 180
 181 /// the number of units possible
 182 extern int const num_units;
 183
 184 /**
 185  * array of unit names
 186  *
 187  * FIXME: I am not sure if "mu" should be possible to select (Lgb)
 188  */
 189 extern char const * const unit_name[];
 190 extern char const * const unit_name_gui[];
 191
 192 /// return the unit given a string representation such as "cm"
 193 Length::UNIT unitFromString(std::string const & data);
 194
 195
 196 } // namespace lyx
 197
 198 #endif // LENGTH_H