lyx_mirror/src/frontends/qt4/GuiFontMetrics.h
Abdelrazak Younes 5f4e6d9a7c * GuiFontMetrics
- add constants instead of hard-coded values.
  - add assertions and comments for out of range values.


git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@16126 a592a061-630c-0410-9148-cb99ea01b6c8
2006-12-01 17:23:58 +00:00

101 lines
2.3 KiB
C++

// -*- C++ -*-
/**
* \file FontMetrics.h
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author Abdelrazak Younes
*
* Full author contact details are available in file CREDITS.
*/
#ifndef QT4_FONT_METRICS_H
#define QT4_FONT_METRICS_H
#include "frontends/FontMetrics.h"
#include "support/docstring.h"
#include <QFontMetrics>
// Starting with version 3.1.0, Qt/X11 does its own caching of
// character width, so it is not necessary to provide ours.
#if defined(Q_WS_MACX) || defined(Q_WS_WIN32)
#define USE_LYX_FONTCACHE
#endif
namespace lyx {
namespace frontend {
size_t const MaxCharType = 65536;
struct CharMetrics
{
int width;
int ascent;
int descent;
};
class GuiFontMetrics: public FontMetrics
{
public:
GuiFontMetrics(QFont const & font);
GuiFontMetrics(QFont const & font, QFont const & smallcaps_font);
virtual ~GuiFontMetrics() {}
virtual int maxAscent() const;
virtual int maxDescent() const;
#ifndef USE_LYX_FONTCACHE
virtual int width(char_type c) const {
return metrics_.width(QChar(static_cast<short int>(c)));
}
#else
virtual int width(char_type c) const;
#endif
virtual int ascent(char_type c) const;
virtual int descent(char_type c) const;
virtual int lbearing(char_type c) const;
virtual int rbearing(char_type c) const;
virtual int width(char_type const * s, size_t n) const;
virtual int signedWidth(docstring const & s) const;
virtual void rectText(docstring const & str,
int & width,
int & ascent,
int & descent) const;
virtual void buttonText(docstring const & str,
int & width,
int & ascent,
int & descent) const;
///
int width(QString const & str) const;
private:
int smallcapsWidth(QString const & s) const;
/// Metrics on the font
QFontMetrics metrics_;
QFontMetrics smallcaps_metrics_;
bool smallcaps_shape_;
#ifdef USE_LYX_FONTCACHE
/// fill in \c metrics_cache_ at specified value.
void fillCache(unsigned short val) const;
/// Cache of char widths
/** This cache adds 20Mo of memory to the LyX executable when
* loading UserGuide.lyx which contains a good number of fonts. If
* this turns out to be too much, we can switch to a \c QHash based
* solution.
**/
mutable CharMetrics metrics_cache_[MaxCharType];
#endif // USE_LYX_FONTCACHE
};
} // namespace frontend
} // namespace lyx
#endif // QT4_FONT_METRICS_H