This commit fixes the following bug:

http://bugzilla.lyx.org/show_bug.cgi?id=2900

The only drawback is that it requires about 20Mo extra-memory when loading the UserGuide. If it turns out to be too much, we can switch to a QHash based solution instead of a table.

* dimension.[Ch]:
  - Dimension(LyXFont const, char_typec): new ctor
  - set(LyXFont const & font, char_type c): new method.

* frontends/FontMetrics.h:
  - width(char_type): is now a pure virtual method.

* GuiFontMetrics:
  - CharMetrics: new structure;
  - the metrics cache now also cache ascent and descent. This is especially useful for mathed.

* MathSupport.[Ch]:
  - mathed_char_dim(): deleted. We now use Dimension::set() directly instead.

* rowpainter.C: fixe empty space.



git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@16124 a592a061-630c-0410-9148-cb99ea01b6c8

src/dimension.C

@@ -36,4 +36,12 @@ void Dimension::clear(LyXFont const & font)
 }
 
 
+void Dimension::set(LyXFont const & font, char_type c)
+{
+	frontend::FontMetrics const & fm = theFontMetrics(font);
+	des = fm.descent(c);
+	asc = fm.ascent(c);
+	wid = fm.width(c);
+}
+
 } // namespace lyx

src/dimension.h

@@ -12,6 +12,7 @@
 #ifndef DIMENSION_H
 #define DIMENSION_H
 
+#include "support/types.h"
 
 namespace lyx {
 
@@ -25,6 +26,8 @@ public:
 	/// initialize data
 	Dimension(int w, int a, int d) : wid(w), asc(a), des(d) {}
 
+	Dimension(LyXFont const & font, char_type c) { set(font, c); }
+
 	Dimension & operator=(Dimension const & dim) {
 		wid = dim.wid;
 		asc = dim.asc;
@@ -35,8 +38,11 @@ public:
 	void operator+=(Dimension const & dim);
 	/// set to empty box
 	void clear() { wid = asc = des = 0; }
-	/// set to empty box suitble for given font
+	/// set to empty box suitble for given font.
 	void clear(LyXFont const & font);
+	/// set to a char dimensions for a given font.
+	void set(LyXFont const & font, char_type c);
+
 	/// get height
 	int height() const { return asc + des; }
 	/// get ascent

src/frontends/FontMetrics.h

@@ -58,6 +58,8 @@ public:
 	virtual int maxAscent() const = 0;
 	/// return the maximum descent of the font
 	virtual int maxDescent() const = 0;
+	/// return the width of the char in the font
+	virtual int width(char_type c) const = 0;
 	/// return the ascent of the char in the font
 	virtual int ascent(char_type c) const = 0;
 	/// return the descent of the char in the font
@@ -103,13 +105,6 @@ public:
 		return (rbearing(c) - lbearing(c)) / 2;
 	}
 
-	/// return the width of the char in the font
-	inline int width(char_type c) const
-	{
-		char_type tmp[2] = { c, L'\0'};
-		return width(tmp, 1);
-	}
-
 	/// return the width of the string in the font
 	inline int width(docstring const & s) const
 	{

src/frontends/NoGuiFontMetrics.h

@@ -31,6 +31,8 @@ public:
 
 	virtual int maxDescent() const { return 1; }
 	
+	virtual int width(char_type) const { return 1; }
+
 	virtual int ascent(char_type) const { return 1; }
 	
 	int descent(char_type) const { return 1; }

src/frontends/qt4/GuiFontMetrics.C

@@ -19,9 +19,6 @@
 
 #include "support/unicode.h"
 
-using lyx::char_type;
-using lyx::docstring;
-
 using std::string;
 
 namespace lyx {
@@ -32,8 +29,11 @@ GuiFontMetrics::GuiFontMetrics(QFont const & font)
 : metrics_(font), smallcaps_metrics_(font), smallcaps_shape_(false)
 {
 #ifdef USE_LYX_FONTCACHE
-  for (int i = 0; i != 65536; ++i)
-    widthcache_[i] = -1;
+ for (int i = 0; i != 65536; ++i) {
+	 metrics_cache_[i].width = -1000;
+	 metrics_cache_[i].ascent = -1000;
+	 metrics_cache_[i].descent = -1000;
+ }
 #endif
 }
 
@@ -58,20 +58,6 @@ int GuiFontMetrics::maxDescent() const
 }
 
 
-int GuiFontMetrics::ascent(char_type c) const
-{
-	QRect const & r = metrics_.boundingRect(ucs4_to_qchar(c));
-	return -r.top();
-}
-
-
-int GuiFontMetrics::descent(char_type c) const
-{
-	QRect const & r = metrics_.boundingRect(ucs4_to_qchar(c));
-	return r.bottom() + 1;
-}
-
-
 int GuiFontMetrics::lbearing(char_type c) const
 {
 	return metrics_.leftBearing(ucs4_to_qchar(c));
@@ -110,19 +96,18 @@ int GuiFontMetrics::width(char_type const * s, size_t ls) const
 	// casts in reality.
 
 	if (ls == 1 && !smallcaps_shape_) {
-		QChar const c = ucs4_to_qchar(s[0]);
-		return width(c.unicode());
+		return width(s[0]);
 	}
 
-	QString ucs2;
-	ucs4_to_qstring(s, ls, ucs2);
-
-	if (smallcaps_shape_)
+	if (smallcaps_shape_) {
+		QString ucs2;
+		ucs4_to_qstring(s, ls, ucs2);
 		return smallcapsWidth(ucs2);
+	}
 
 	int w = 0;
 	for (unsigned int i = 0; i < ls; ++i)
-		w += width(ucs2[i].unicode());
+		w += width(s[i]);
 
 	return w;
 }
@@ -178,14 +163,64 @@ void GuiFontMetrics::buttonText(docstring const & str,
 	descent = metrics_.descent() + d;
 }
 
-#ifdef USE_LYX_FONTCACHE
-int GuiFontMetrics::width(unsigned short val) const
+#ifndef USE_LYX_FONTCACHE
+
+int GuiFontMetrics::ascent(char_type c) const
 {
-	if (widthcache_[val] == -1)
-		widthcache_[val] = metrics_.width(QChar(val));
-	return widthcache_[val];
+	QRect const & r = metrics_.boundingRect(ucs4_to_qchar(c));
+	return -r.top();
 }
+
+
+int GuiFontMetrics::descent(char_type c) const
+{
+	QRect const & r = metrics_.boundingRect(ucs4_to_qchar(c));
+	return r.bottom() + 1;
+}
+
+#else
+
+void GuiFontMetrics::fillCache(unsigned short val) const
+{
+	QRect const & r = metrics_.boundingRect(QChar(val));
+	metrics_cache_[val].descent = r.bottom() + 1;
+	metrics_cache_[val].ascent = -r.top();
+	// 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_[val].width = metrics_.width(QChar(val));
+}
+
+
+int GuiFontMetrics::width(char_type c) const
+{
+	unsigned short val = static_cast<unsigned short>(c);
+	if (metrics_cache_[val].width == -1000)
+		metrics_cache_[val].width = metrics_.width(QChar(val));
+
+	return metrics_cache_[val].width;
+}
+
+
+int GuiFontMetrics::ascent(char_type c) const
+{
+	unsigned short val = static_cast<unsigned short>(c);
+	if (metrics_cache_[val].ascent == -1000)
+		fillCache(val);
+
+	return metrics_cache_[val].ascent;
+}
+
+
+int GuiFontMetrics::descent(char_type c) const
+{
+	unsigned short val = static_cast<unsigned short>(c);
+	if (metrics_cache_[val].descent == -1000)
+		fillCache(val);
+
+	return metrics_cache_[val].descent;
+}
+
 #endif
 
-}
-}
+} // frontend
+} // lyx

src/frontends/qt4/GuiFontMetrics.h

@@ -27,6 +27,14 @@
 namespace lyx {
 namespace frontend {
 
+struct CharMetrics
+{
+	int width;
+	int ascent;
+	int descent;
+};
+
+
 class GuiFontMetrics: public FontMetrics
 {
 public:
@@ -38,17 +46,24 @@ public:
 
 	virtual int maxAscent() const;
 	virtual int maxDescent() const;
-	virtual int ascent(lyx::char_type c) const;
-	int descent(lyx::char_type c) const;
-	virtual int lbearing(lyx::char_type c) const;
-	virtual int rbearing(lyx::char_type c) const;
-	virtual int width(lyx::char_type const * s, size_t n) const;
-	virtual int signedWidth(lyx::docstring const & s) const;
-	virtual void rectText(lyx::docstring const & str,
+#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(lyx::docstring const & str,
+	virtual void buttonText(docstring const & str,
 		int & width,
 		int & ascent,
 		int & descent) const;
@@ -64,16 +79,16 @@ private:
 
 	bool smallcaps_shape_;
 
-#ifndef USE_LYX_FONTCACHE
-	/// Return pixel width for the given unicode char
-	int width(unsigned short val) const { return metrics_.width(QChar(val)); }
-
-#else
-	/// Return pixel width for the given unicode char
-	int width(unsigned short val) const;
-
+#ifdef USE_LYX_FONTCACHE
+	/// fill in \c metrics_cache_ at specified value.
+	void fillCache(unsigned short val) const;
 	/// Cache of char widths
-	mutable int widthcache_[65536];
+	/** 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_[65536];
 #endif // USE_LYX_FONTCACHE
 };
 

src/mathed/InsetMathBrace.C

@@ -46,8 +46,7 @@ auto_ptr<InsetBase> InsetMathBrace::doClone() const
 bool InsetMathBrace::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(0).metrics(mi);
-	Dimension t;
-	mathed_char_dim(mi.base.font, '{', t);
+	Dimension t(mi.base.font, '{');
 	dim.asc = max(cell(0).ascent(), t.asc);
 	dim.des = max(cell(0).descent(), t.des);
 	dim.wid = cell(0).width() + 2 * t.wid;
@@ -63,8 +62,7 @@ void InsetMathBrace::draw(PainterInfo & pi, int x, int y) const
 {
 	LyXFont font = pi.base.font;
 	font.setColor(LColor::latex);
-	Dimension t;
-	mathed_char_dim(font, '{', t);
+	Dimension t(font, '{');
 	pi.pain.text(x, y, '{', font);
 	cell(0).draw(pi, x + t.wid, y);
 	pi.pain.text(x + t.wid + cell(0).width(), y, '}', font);

src/mathed/InsetMathChar.C

@@ -62,15 +62,15 @@ bool InsetMathChar::metrics(MetricsInfo & mi, Dimension & dim) const
 #if 1
 	if (char_ == '=' && has_math_fonts) {
 		FontSetChanger dummy(mi.base, "cmr");
-		mathed_char_dim(mi.base.font, char_, dim);
+		dim.set(mi.base.font, char_);
 	} else if ((char_ == '>' || char_ == '<') && has_math_fonts) {
 		FontSetChanger dummy(mi.base, "cmm");
-		mathed_char_dim(mi.base.font, char_, dim);
+		dim.set(mi.base.font, char_);
 	} else if (!slanted(char_) && mi.base.fontname == "mathnormal") {
 		ShapeChanger dummy(mi.base.font, LyXFont::UP_SHAPE);
-		mathed_char_dim(mi.base.font, char_, dim);
+		dim.set(mi.base.font, char_);
 	} else {
-		mathed_char_dim(mi.base.font, char_, dim);
+		dim.set(mi.base.font, char_);
 	}
 	int const em = mathed_char_width(mi.base.font, 'M');
 	if (isBinaryOp(char_))
@@ -79,7 +79,7 @@ bool InsetMathChar::metrics(MetricsInfo & mi, Dimension & dim) const
 		dim.wid += static_cast<int>(0.1667*em+0.5);
 #else
 	whichFont(font_, code_, mi);
-	mathed_char_dim(font_, char_, dim);
+	dim.set(font_, char_);
 	if (isBinaryOp(char_, code_))
 		width_ += 2 * theFontMetrics(font_).width(' ');
 	lyxerr << "InsetMathChar::metrics: " << dim << endl;

src/mathed/InsetMathDelim.C

@@ -75,7 +75,7 @@ bool InsetMathDelim::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(0).metrics(mi);
 	Dimension t;
-	mathed_char_dim(mi.base.font, 'I', t);
+	t.set(mi.base.font, 'I');
 	int h0 = (t.asc + t.des) / 2;
 	int a0 = max(cell(0).ascent(), t.asc)   - h0;
 	int d0 = max(cell(0).descent(), t.des)  + h0;

src/mathed/InsetMathDots.C

@@ -37,7 +37,7 @@ auto_ptr<InsetBase> InsetMathDots::doClone() const
 
 bool InsetMathDots::metrics(MetricsInfo & mi, Dimension & dim) const
 {
-	mathed_char_dim(mi.base.font, 'M', dim);
+	dim.set(mi.base.font, 'M');
 	dh_ = 0;
 	if (key_->name == "cdots" || key_->name == "dotsb"
 			|| key_->name == "dotsm" || key_->name == "dotsi")

src/mathed/MathData.C

@@ -241,7 +241,7 @@ bool isInside(DocIterator const & it, MathArray const & ar,
 
 void MathArray::metrics(MetricsInfo & mi) const
 {
-	mathed_char_dim(mi.base.font, 'I', dim_);
+	dim_.set(mi.base.font, 'I');
 
 	if (empty())
 		return;

src/mathed/MathSupport.C

@@ -367,15 +367,6 @@ deco_struct const * search_deco(docstring const & name)
 } // namespace anon
 
 
-void mathed_char_dim(LyXFont const & font, char_type c, Dimension & dim)
-{
-	frontend::FontMetrics const & fm = theFontMetrics(font);
-	dim.des = fm.descent(c);
-	dim.asc = fm.ascent(c);
-	dim.wid = fm.width(c);
-}
-
-
 int mathed_char_width(LyXFont const & font, char_type c)
 {
 	return theFontMetrics(font).width(c);

src/mathed/MathSupport.h

@@ -28,7 +28,6 @@ class MathAtom;
 class InsetMath;
 
 
-void mathed_char_dim(LyXFont const &, char_type c, Dimension & dim);
 int mathed_char_width(LyXFont const &, char_type c);
 
 void mathed_draw_deco(PainterInfo & pi, int x, int y, int w, int h,

src/rowpainter.C

@@ -949,7 +949,7 @@ void paintPar
 			rp.paintChangeBar();
 			if (rit == rb)
 				rp.paintFirst();
-			rp.paintText();
+ 			rp.paintText();
 			if (rit + 1 == re)
 				rp.paintLast();
 		}