lyx_mirror/src/frontends/qt4/GuiFontMetrics.cpp
Pavel Sanda c1173eb11c Coding style
git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@26335 a592a061-630c-0410-9148-cb99ea01b6c8
2008-09-08 01:18:33 +00:00

277 lines
6.1 KiB
C++

/**
* \file GuiFontMetrics.cpp
* 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.
*/
#include <config.h>
#include "GuiFontMetrics.h"
#include "qt_helpers.h"
#include "Language.h"
#include "Dimension.h"
#include "insets/Inset.h"
#include "support/lassert.h"
using namespace std;
namespace lyx {
namespace frontend {
/**
* Convert a UCS4 character into a QChar.
* This is a hack (it does only make sense for the common part of the UCS4
* and UTF16 encodings) and should not be used.
* This does only exist because of performance reasons (a real conversion
* using iconv is too slow on windows).
*/
static inline QChar const ucs4_to_qchar(char_type const ucs4)
{
LASSERT(is_utf16(ucs4), /**/);
return QChar(static_cast<unsigned short>(ucs4));
}
// Caution: When using ucs4_to_qchar() in these methods, this is no
// real conversion but a simple cast in reality. This is the reason
// why this works well for symbol fonts used in mathed too, even though
// these are not real ucs4 characters. These are codepoints in the
// modern fonts used, nothing unicode related.
// See comment in QLPainter::text() for more explanation.
GuiFontMetrics::GuiFontMetrics(QFont const & font)
: metrics_(font), smallcaps_metrics_(font), smallcaps_shape_(false)
{
}
GuiFontMetrics::GuiFontMetrics(QFont const & font, QFont const & smallcaps_font)
: metrics_(font), smallcaps_metrics_(smallcaps_font), smallcaps_shape_(true)
{
}
int GuiFontMetrics::maxAscent() const
{
return metrics_.ascent();
}
int GuiFontMetrics::maxDescent() const
{
// We add 1 as the value returned by QT is different than X
// See http://doc.trolltech.com/2.3/qfontmetrics.html#200b74
return metrics_.descent() + 1;
}
int GuiFontMetrics::lbearing(char_type c) const
{
if (!is_utf16(c))
// FIXME: QFontMetrics::leftBearingdoes not support the
// full unicode range. Once it does, we could use:
//return metrics_.leftBearing(toqstr(docstring(1, c)));
return 0;
return metrics_.leftBearing(ucs4_to_qchar(c));
}
namespace {
int const outOfLimitMetric = -10000;
}
int GuiFontMetrics::rbearing(char_type c) const
{
int value = rbearing_cache_.value(c, outOfLimitMetric);
if (value != outOfLimitMetric)
return value;
// Qt rbearing is from the right edge of the char's width().
if (is_utf16(c)) {
QChar sc = ucs4_to_qchar(c);
value = width(c) - metrics_.rightBearing(sc);
} else {
// FIXME: QFontMetrics::leftBearing does not support the
// full unicode range. Once it does, we could use:
// metrics_.rightBearing(toqstr(docstring(1, c)));
value = width(c);
}
rbearing_cache_.insert(c, value);
return value;
}
int GuiFontMetrics::smallcapsWidth(char_type c) const
{
// FIXME: Optimisation probably needed: we don't use the width cache.
if (is_utf16(c)) {
QChar const qc = ucs4_to_qchar(c);
QChar const uc = qc.toUpper();
if (qc != uc)
return smallcaps_metrics_.width(uc);
else
return metrics_.width(qc);
} else {
QString const s = toqstr(docstring(1, c));
QString const us = s.toUpper();
if (s != us)
return smallcaps_metrics_.width(us);
else
return metrics_.width(s);
}
}
int GuiFontMetrics::width(docstring const & s) const
{
size_t ls = s.size();
int w = 0;
for (unsigned int i = 0; i < ls; ++i) {
//FIXME: we need to detect surrogate pairs and act accordingly
/**
if isSurrogateBase(s[i]) {
docstring c = s[i];
if (smallcaps_shape_)
w += metrics_.width(toqstr(c + s[i + 1]));
else
w += smallcaps_metrics_.width(toqstr(c + s[i + 1]));
++i;
}
else
*/
w += width(s[i]);
}
return w;
}
int GuiFontMetrics::width(QString const & ucs2) const
{
return width(qstring_to_ucs4(ucs2));
}
int GuiFontMetrics::signedWidth(docstring const & s) const
{
if (s.empty())
return 0;
if (s[0] == '-')
return -width(s.substr(1, s.size() - 1));
else
return width(s);
}
void GuiFontMetrics::rectText(docstring const & str,
int & w, int & ascent, int & descent) const
{
static int const d = Inset::TEXT_TO_INSET_OFFSET / 2;
w = width(str) + Inset::TEXT_TO_INSET_OFFSET;
ascent = metrics_.ascent() + d;
descent = metrics_.descent() + d;
}
void GuiFontMetrics::buttonText(docstring const & str,
int & w, int & ascent, int & descent) const
{
rectText(str, w, ascent, descent);
w += Inset::TEXT_TO_INSET_OFFSET;
}
Dimension const GuiFontMetrics::defaultDimension() const
{
return Dimension(0, maxAscent(), maxDescent());
}
Dimension const GuiFontMetrics::dimension(char_type c) const
{
return Dimension(width(c), ascent(c), descent(c));
}
GuiFontMetrics::AscendDescend const GuiFontMetrics::fillMetricsCache(
char_type c) const
{
QRect r;
if (is_utf16(c))
r = metrics_.boundingRect(ucs4_to_qchar(c));
else
r = metrics_.boundingRect(toqstr(docstring(1, c)));
AscendDescend ad = { -r.top(), r.bottom() + 1};
// We could as well compute the width but this is not really
// needed for now as it is done directly in width() below.
metrics_cache_.insert(c, ad);
return ad;
}
int GuiFontMetrics::width(char_type c) const
{
if (smallcaps_shape_)
return smallcapsWidth(c);
int value = width_cache_.value(c, outOfLimitMetric);
if (value != outOfLimitMetric)
return value;
if (is_utf16(c))
value = metrics_.width(ucs4_to_qchar(c));
else
value = metrics_.width(toqstr(docstring(1, c)));
width_cache_.insert(c, value);
return value;
}
int GuiFontMetrics::ascent(char_type c) const
{
static AscendDescend const outOfLimitAD =
{outOfLimitMetric, outOfLimitMetric};
AscendDescend value = metrics_cache_.value(c, outOfLimitAD);
if (value.ascent != outOfLimitMetric)
return value.ascent;
value = fillMetricsCache(c);
return value.ascent;
}
int GuiFontMetrics::descent(char_type c) const
{
static AscendDescend const outOfLimitAD =
{outOfLimitMetric, outOfLimitMetric};
AscendDescend value = metrics_cache_.value(c, outOfLimitAD);
if (value.descent != outOfLimitMetric)
return value.descent;
value = fillMetricsCache(c);
return value.descent;
}
} // namespace frontend
} // namespace lyx