lyx_mirror/src/frontends/qt4/GuiFontMetrics.h
Jean-Marc Lasgouttes 2ff639a0e6 Fix positionning of cursor
The old implementation of Row::Element::pos2x and x2pos did not work
correctly with Arabic text, because characters can have shapes that
depend on context.

This new implementation leverages QTextLayout in a simplified way,
since only one word is added to the layout.

This allows to make Row::Element::x2pos more readable.

Fixes: #9115.
2014-07-08 21:30:05 +02:00

91 lines
2.1 KiB
C++

// -*- C++ -*-
/**
* \file GuiFontMetrics.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 GUI_FONT_METRICS_H
#define GUI_FONT_METRICS_H
#include "frontends/FontMetrics.h"
#include "support/docstring.h"
#include <map>
#include <QFont>
#include <QFontMetrics>
#include <QHash>
namespace lyx {
namespace frontend {
class GuiFontMetrics : public FontMetrics
{
public:
GuiFontMetrics(QFont const & font);
virtual ~GuiFontMetrics() {}
virtual int maxAscent() const;
virtual int maxDescent() const;
virtual Dimension const defaultDimension() const;
virtual int width(char_type c) const;
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(docstring const & s) const;
virtual int signedWidth(docstring const & s) const;
virtual int pos2x(docstring const & s, int pos, bool rtl) const;
virtual int x2pos(docstring const & s, int & x, bool rtl) const;
virtual Dimension const dimension(char_type c) 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:
/// The font
QFont font_;
/// Metrics on the font
QFontMetrics metrics_;
/// Cache of char widths
mutable QHash<char_type, int> width_cache_;
/// Cache of string widths
/// FIXME Try to use a QHash (this requires to define qHash(docstring))
mutable std::map<docstring, int> strwidth_cache_;
struct AscendDescend {
int ascent;
int descent;
};
/// Cache of char ascends and descends
mutable QHash<char_type, AscendDescend> metrics_cache_;
/// fill in \c metrics_cache_ at specified value.
AscendDescend const fillMetricsCache(char_type) const;
/// Cache of char right bearings
mutable QHash<char_type, int> rbearing_cache_;
};
} // namespace frontend
} // namespace lyx
#endif // GUI_FONT_METRICS_H