Account for real width of nucleus when positioning superscripts in mathed

* src/mathed/MathSupport.[Ch]
	(mathed_char_kerning): New. Compute right kerning for the given
	font and character as the difference between right bearing and
	logical width.

	* src/mathed/InsetMathScript.[Ch]
	(InsetMathScript::dx1, InsetMathScript::metrics): Account for
	nucleus right kerning.
	(InsetMathScript::nker): New. Return the nucleus right kerning
	if positive, zero otherwise.

	* src/mathed/MathData.[Ch]
	(MathArray::metrics): Cache the nucleus right kerning value.
	(MathArray::kerning): New. Return cached right kerning.

	* src/mathed/InsetMathChar.[Ch]
	(InsetMathChar::metrics): Cache the character right kerning.
	(InsetMathChar::kerning): New. Return cached right kerning.

	* src/mathed/InsetMath.h
	(InsetMath::kerning): New virtual method.

	* src/mathed/InsetMathSymbol.[Ch]
	(InsetMathSymbol::metrics): Cache the symbol right kerning.
	(InsetMathSymbol::kerning): New. Return cached right kerning.

	* src/mathed/InsetMathFont.[Ch]
	(InsetMathFont::kerning): New. Return cached right kerning.



git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@17497 a592a061-630c-0410-9148-cb99ea01b6c8

src/mathed/InsetMath.h

@@ -200,6 +200,9 @@ public:
 
 	/// math stuff usually isn't allowed in text mode
 	virtual bool allowedIn(mode_type mode) const { return mode == MATH_MODE; }
+
+	/// superscript kerning
+	virtual int kerning() const { return 0; }
 };
 
 ///

src/mathed/InsetMathChar.C

@@ -46,7 +46,7 @@ namespace {
 
 
 InsetMathChar::InsetMathChar(char_type c)
-	: char_(c)
+	: char_(c), kerning_(0)
 {}
 
 
@@ -70,7 +70,9 @@ bool InsetMathChar::metrics(MetricsInfo & mi, Dimension & dim) const
 		ShapeChanger dummy(mi.base.font, LyXFont::UP_SHAPE);
 		dim = theFontMetrics(mi.base.font).dimension(char_);
 	} else {
-		dim = theFontMetrics(mi.base.font).dimension(char_);
+		frontend::FontMetrics const & fm = theFontMetrics(mi.base.font);
+		dim = fm.dimension(char_);
+		kerning_ = fm.rbearing(char_) - dim.wid;
 	}
 	int const em = mathed_char_width(mi.base.font, 'M');
 	if (isBinaryOp(char_))

src/mathed/InsetMathChar.h

@@ -32,6 +32,8 @@ public:
 	void drawT(TextPainter &, int x, int y) const;
 	///
 	int width() const { return width_; }
+	///
+	int kerning() const { return kerning_; }
 
 	///
 	void write(WriteStream & os) const;
@@ -54,6 +56,8 @@ private:
 	char_type char_;
 	/// cached width
 	mutable int width_;
+	/// cached kerning for superscript
+	mutable int kerning_;
 };
 
 } // namespace lyx

src/mathed/InsetMathFont.h

@@ -45,6 +45,8 @@ public:
 	void validate(LaTeXFeatures & features) const;
 	///
 	void infoize(odocstream & os) const;
+	///
+	int kerning() const { return cell(0).kerning(); }
 
 private:
 	virtual std::auto_ptr<InsetBase> doClone() const;

src/mathed/InsetMathScript.C

@@ -225,7 +225,7 @@ int InsetMathScript::dx0() const
 int InsetMathScript::dx1() const
 {
 	BOOST_ASSERT(hasUp());
-	return hasLimits() ? (dim_.wid - up().width()) / 2 : nwid();
+	return hasLimits() ? (dim_.wid - up().width()) / 2 : nwid() + nker();
 }
 
 
@@ -253,6 +253,16 @@ int InsetMathScript::ndes() const
 }
 
 
+int InsetMathScript::nker() const
+{
+	if (nuc().size()) {
+		int kerning = nuc().kerning();
+		return kerning > 0 ? kerning : 0;
+	}
+	return 0;
+}
+
+
 bool InsetMathScript::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(0).metrics(mi);
@@ -270,7 +280,7 @@ bool InsetMathScript::metrics(MetricsInfo & mi, Dimension & dim) const
 			dim.wid = max(dim.wid, down().width());
 	} else {
 		if (hasUp())
-			dim.wid = max(dim.wid, up().width());
+			dim.wid = max(dim.wid, nker() + up().width());
 		if (hasDown())
 			dim.wid = max(dim.wid, down().width());
 		dim.wid += nwid();

src/mathed/InsetMathScript.h

@@ -124,6 +124,8 @@ private:
 	int nasc() const;
 	/// returns descent of nucleus if any
 	int ndes() const;
+	/// returns superscript kerning of nucleus if any
+	int nker() const;
 	/// where do we have to draw the scripts?
 	bool hasLimits() const;
 	/// clean up empty cells and return true if a cell has been deleted.

src/mathed/InsetMathSymbol.C

@@ -64,6 +64,8 @@ bool InsetMathSymbol::metrics(MetricsInfo & mi, Dimension & dim) const
 	int const em = mathed_char_width(mi.base.font, 'M');
 	FontSetChanger dummy(mi.base, sym_->inset);
 	mathed_string_dim(mi.base.font, sym_->draw, dim);
+	docstring::const_reverse_iterator rit = sym_->draw.rbegin();
+	kerning_ = mathed_char_kerning(mi.base.font, *rit);
 	// correct height for broken cmex and wasy font
 	if (sym_->inset == "cmex" || sym_->inset == "wasy") {
 		h_ = 4 * dim.des / 5;

src/mathed/InsetMathSymbol.h

@@ -37,6 +37,8 @@ public:
 	void draw(PainterInfo &, int x, int y) const;
 	///
 	int width() const { return width_; }
+	///
+	int kerning() const { return kerning_; }
 
 	///
 	bool isRelOp() const;
@@ -76,6 +78,8 @@ private:
 	mutable int h_;
 	/// cached width
 	mutable int width_;
+	/// cached superscript kerning
+	mutable int kerning_;
 	///
 	mutable bool scriptable_;
 };

src/mathed/MathData.C

@@ -282,6 +282,8 @@ void MathArray::metrics(MetricsInfo & mi) const
 #endif
 		at->metrics(mi, d);
 		dim_ += d;
+		if (i == n - 1)
+			kerning_ = at->kerning();
 	}
 }
 

src/mathed/MathData.h

@@ -158,6 +158,8 @@ public:
 	int slevel() const { return slevel_; }
 	/// additional super/subscript shift
 	int sshift() const { return sshift_; }
+	/// superscript kerning
+	int kerning() const { return kerning_; }
 
 protected:
 	/// cached dimensions of cell
@@ -167,6 +169,7 @@ protected:
 	mutable int mindes_;
 	mutable int slevel_;
 	mutable int sshift_;
+	mutable int kerning_;
 
 private:
 	/// is this an exact match at this position?

src/mathed/MathSupport.C

@@ -373,6 +373,13 @@ int mathed_char_width(LyXFont const & font, char_type c)
 }
 
 
+int mathed_char_kerning(LyXFont const & font, char_type c)
+{
+	frontend::FontMetrics const & fm = theFontMetrics(font);
+	return fm.rbearing(c) - fm.width(c);
+}
+
+
 void mathed_string_dim(LyXFont const & font,
 		       docstring const & s,
 		       Dimension & dim)

src/mathed/MathSupport.h

@@ -30,6 +30,8 @@ class InsetMath;
 
 int mathed_char_width(LyXFont const &, char_type c);
 
+int mathed_char_kerning(LyXFont const &, char_type c);
+
 void mathed_draw_deco(PainterInfo & pi, int x, int y, int w, int h,
 	docstring const & name);