lyx_mirror/src/frontends/font_metrics.h
André Pönitz 4588bb075a lots of small stuff
git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@7995 a592a061-630c-0410-9148-cb99ea01b6c8
2003-10-28 11:18:40 +00:00

100 lines
2.9 KiB
C++

// -*- C++ -*-
/**
* \file font_metrics.h
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author unknown
* \author John Levon
*
* Full author contact details are available in file CREDITS.
*/
#ifndef FONT_METRICS_H
#define FONT_METRICS_H
#include <string>
class LyXFont;
/**
* A namespace holding helper functions for determining
* the screen dimensions of fonts.
*
* The geometry is the standard typographical geometry,
* as follows :
*
* --------------+------------------<maxAscent
* | |
* <-------> (right bearing)
* <-> (left bearing)
* char ascent>___ |
* ^ oooo | oooo
* origin>____ | oo oo | oo oo
* \| oo oo | oo oo
* --------------+---ooooo--|--oooo-<baseline
* | oo |
* char | oo oo |
* descent>______| oooo |
* <- width ->
* --------------+----------+-------<maxDescent
*
*/
namespace font_metrics {
/// return the maximum ascent of the font
int maxAscent(LyXFont const & f);
/// return the maximum descent of the font
int maxDescent(LyXFont const & f);
/// return the maximum descent of the font
inline int maxHeight(LyXFont const & f) {
return maxAscent(f) + maxDescent(f);
}
/// return the ascent of the char in the font
int ascent(char c, LyXFont const & f);
/// return the descent of the char in the font
int descent(char c, LyXFont const & f);
/// return the descent of the char in the font
inline int height(char c, LyXFont const & f) {
return ascent(c, f) + descent(c, f);
}
/// return the left bearing of the char in the font
int lbearing(char c, LyXFont const & f);
/// return the right bearing of the char in the font
int rbearing(char c, LyXFont const & f);
/// return the inner width of the char in the font
inline int center(char c, LyXFont const & f) {
return (rbearing(c, f) - lbearing(c, f)) / 2;
}
/// return the width of the string in the font
int width(char const * s, size_t n, LyXFont const & f);
/// return the width of the char in the font
inline int width(char c, LyXFont const & f) {
return width(&c, 1, f);
}
/// return the width of the string in the font
inline int width(std::string const & s, LyXFont const & f) {
return s.empty() ? 0 : width(s.data(), s.length(), f);
}
/// FIXME ??
int signedWidth(std::string const & s, LyXFont const & f);
/**
* fill in width,ascent,descent with the values for the
* given string in the font.
*/
void rectText(std::string const & str, LyXFont const & font,
int & width,
int & ascent,
int & descent);
/**
* fill in width,ascent,descent with the values for the
* given string in the font for a button.
*/
void buttonText(std::string const & str, LyXFont const & font,
int & width,
int & ascent,
int & descent);
}
#endif // FONT_METRICS_H