lyx_mirror/src/Length.h

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// -*- C++ -*-
/**
* \file Length.h
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author Matthias Ettrich
* \author Lars Gullik Bjønnes
* \author Jean-Marc Lasgouttes
* \author John Levon
*
* Full author contact details are available in file CREDITS.
*/
#ifndef LENGTH_H
#define LENGTH_H
#include "support/strfwd.h"
namespace lyx {
// Solaris/x86 version 9 and earlier define these
#undef PC
#undef SP
/////////////////////////////////////////////////////////////////////
//
// Length
//
/////////////////////////////////////////////////////////////////////
/**
* Length - Represents latex length measurement
*/
class Length {
public:
/// length units
enum UNIT {
SP, ///< Scaled point (65536sp = 1pt) TeX's smallest unit.
PT, ///< Point = 1/72.27in = 0.351mm
BP, ///< Big point (72bp = 1in), also PostScript point
DD, ///< Didot point = 1/72 of a French inch, = 0.376mm
MM, ///< Millimeter = 2.845pt
PC, ///< Pica = 12pt = 4.218mm
CC, ///< Cicero = 12dd = 4.531mm
CM, ///< Centimeter = 10mm = 2.371pc
IN, ///< Inch = 25.4mm = 72.27pt = 6.022pc
EX, ///< Height of a small "x" for the current font.
EM, ///< Width of capital "M" in current font.
MU, ///< Math unit (18mu = 1em) for positioning in math mode
PTW, //< Percent of TextWidth
PCW, //< Percent of ColumnWidth
PPW, //< Percent of PageWidth
PLW, //< Percent of LineWidth
PTH, //< Percent of TextHeight // Herbert 2002-05-16
PPH, //< Percent of PaperHeight // Herbert 2002-05-16
UNIT_NONE ///< no unit
};
///
Length();
///
Length(double v, Length::UNIT u);
/// "data" must be a decimal number, followed by a unit
explicit Length(std::string const & data);
///
void swap(Length & rhs);
///
double value() const;
///
Length::UNIT unit() const;
///
void value(double);
///
void unit(Length::UNIT unit);
///
bool zero() const;
///
bool empty() const;
/// return string representation
std::string const asString() const;
/// return string representation
docstring const asDocstring() const;
/// return string representation for LaTeX
std::string const asLatexString() const;
/// return the on-screen size of this length
int inPixels(int text_width, int em_width = 0) const;
/// return the value in Big Postscript points.
int inBP() const;
/// return the default unit (centimeter or inch)
static UNIT defaultUnit();
friend bool isValidLength(std::string const & data, Length * result);
private:
///
double val_;
///
Length::UNIT unit_;
};
///
bool operator==(Length const & l1, Length const & l2);
///
bool operator!=(Length const & l1, Length const & l2);
/** Test whether \p data represents a valid length.
*
* \returns whether \p data is a valid length
* \param data Length in LyX format. Since the only difference between LyX
* and LaTeX format is the representation of length variables as units (e.g.
* \c text% vs. \c \\textwidth) you can actually use this function as well
* for testing LaTeX lengths as long as they only contain real units like pt.
* \param result Pointer to a Length variable. If \p result is not 0 and
* \p data is valid, the length represented by it is stored into \p result.
*/
bool isValidLength(std::string const & data, Length * result = 0);
/// return the LyX name of the given unit number
char const * stringFromUnit(int unit);
/////////////////////////////////////////////////////////////////////
//
// GlueLength
//
/////////////////////////////////////////////////////////////////////
class GlueLength {
public:
///
GlueLength() {}
///
explicit GlueLength(Length const & len);
///
GlueLength(Length const & len,
Length const & plus,
Length const & minus);
/** "data" must be a decimal number, followed by a unit, and
optional "glue" indicated by "+" and "-". You may abbreviate
reasonably. Examples:
1.2 cm // 4mm +2pt // 2cm -4mm +2mm // 4+0.1-0.2cm
The traditional Latex format is also accepted, like
4cm plus 10pt minus 10pt */
explicit GlueLength(std::string const & data);
///
Length const & len() const;
///
Length const & plus() const;
///
Length const & minus() const;
/// conversion
std::string const asString() const;
///
std::string const asLatexString() const;
friend bool isValidGlueLength(std::string const & data,
GlueLength* result);
private:
/// the normal vlaue
Length len_;
/// extra stretch
Length plus_;
/// extra shrink
Length minus_;
};
///
bool operator==(GlueLength const & l1, GlueLength const & l2);
///
bool operator!=(GlueLength const & l1, GlueLength const & l2);
/** If "data" is valid, the length represented by it is
stored into "result", if that is not 0. */
bool isValidGlueLength(std::string const & data, GlueLength * result = 0);
/// the number of units possible
extern int const num_units;
/**
* array of unit names
*
* FIXME: I am not sure if "mu" should be possible to select (Lgb)
*/
extern char const * const unit_name[];
extern char const * const unit_name_gui[];
/// return the unit given a string representation such as "cm"
Length::UNIT unitFromString(std::string const & data);
} // namespace lyx
#endif // LENGTH_H