support for \cfrac in mathed, fixes bug 2473 and can also go to LyX 1.6.3

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@28639 a592a061-630c-0410-9148-cb99ea01b6c8

src/mathed/InsetMathFrac.cpp

@@ -5,6 +5,7 @@
  *
  * \author Alejandro Aguilar Sierra
  * \author André Pönitz
+ * \author Uwe Stöhr
  *
  * Full author contact details are available in file CREDITS.
  */
@@ -466,6 +467,62 @@ void InsetMathTFrac::validate(LaTeXFeatures & features) const
 }
 
 
+/////////////////////////////////////////////////////////////////////
+//
+// InsetMathCFrac
+//
+/////////////////////////////////////////////////////////////////////
+
+
+Inset * InsetMathCFrac::clone() const
+{
+	return new InsetMathCFrac(*this);
+}
+
+
+void InsetMathCFrac::metrics(MetricsInfo & mi, Dimension & dim) const
+{
+	Dimension dim0, dim1;
+	cell(0).metrics(mi, dim0);
+	cell(1).metrics(mi, dim1);
+	dim.wid = max(dim0.wid, dim1.wid) + 2;
+	dim.asc = dim0.height() + 2 + 5;
+	dim.des = dim1.height() + 2 - 5;
+}
+
+
+void InsetMathCFrac::draw(PainterInfo & pi, int x, int y) const
+{
+	Dimension const dim = dimension(*pi.base.bv);
+	Dimension const & dim0 = cell(0).dimension(*pi.base.bv);
+	Dimension const & dim1 = cell(1).dimension(*pi.base.bv);
+	int m = x + dim.wid / 2;
+	cell(0).draw(pi, m - dim0.wid / 2, y - dim0.des - 2 - 5);
+	cell(1).draw(pi, m - dim1.wid / 2, y + dim1.asc  + 2 - 5);
+	pi.pain.line(x + 1, y - 5, x + dim.wid - 2, y - 5, Color_math);
+	setPosCache(pi, x, y);
+}
+
+
+docstring InsetMathCFrac::name() const
+{
+	return from_ascii("cfrac");
+}
+
+
+void InsetMathCFrac::mathmlize(MathStream & os) const
+{
+	os << MTag("mcfrac") << cell(0) << cell(1) << ETag("mcfrac");
+}
+
+
+void InsetMathCFrac::validate(LaTeXFeatures & features) const
+{
+	features.require("amsmath");
+	InsetMathNest::validate(features);
+}
+
+
 /////////////////////////////////////////////////////////////////////
 //
 // InsetMathBinom

src/mathed/InsetMathFrac.h

@@ -128,6 +128,26 @@ private:
 };
 
 
+/// \cfrac support
+class InsetMathCFrac : public InsetMathFrac {
+public:
+	///
+	InsetMathCFrac() {}
+	///
+	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	///
+	void draw(PainterInfo &, int x, int y) const;
+	///
+	docstring name() const;
+	///
+	void mathmlize(MathStream &) const;
+	///
+	void validate(LaTeXFeatures & features) const;
+private:
+	Inset * clone() const;
+};
+
+
 /// Binom like objects
 class InsetMathBinom : public InsetMathFracBase {
 public:

src/mathed/InsetMathNest.cpp

@@ -1928,6 +1928,7 @@ MathCompletionList::MathCompletionList(Cursor const & cur)
 	globals.push_back(from_ascii("\\color"));
 	globals.push_back(from_ascii("\\normalcolor"));
 	globals.push_back(from_ascii("\\textcolor"));
+	globals.push_back(from_ascii("\\cfrac"));
 	globals.push_back(from_ascii("\\dfrac"));
 	globals.push_back(from_ascii("\\tfrac"));
 	globals.push_back(from_ascii("\\dbinom"));

src/mathed/MathFactory.cpp

@@ -447,6 +447,8 @@ MathAtom createInsetMath(docstring const & s)
 		return MathAtom(new InsetMathColor(true));
 	if (s == "textcolor")
 		return MathAtom(new InsetMathColor(false));
+	if (s == "cfrac")
+		return MathAtom(new InsetMathCFrac);
 	if (s == "dfrac")
 		return MathAtom(new InsetMathDFrac);
 	if (s == "tfrac")