Fix vertical alignment of fractions

Fractions and binoms are vartically aligned with -

Nicefracs are ascent-aligned with the surrounding text

diff --git a/src/mathed/InsetMathFrac.cpp b/src/mathed/InsetMathFrac.cpp
index 140205fa67b1e218e28cf7323e42fcbb2d86a92b..6b768c91c2e159dfc1204730535b2a405102811d 100644 (file)
--- a/src/mathed/InsetMathFrac.cpp
+++ b/src/mathed/InsetMathFrac.cpp
@@ -22,6 +22,7 @@
 #include "MetricsInfo.h"
 #include "TextPainter.h"
 
+#include "frontends/FontMetrics.h"
 #include "frontends/Painter.h"
 
 #include "support/lassert.h"
@@ -148,6 +149,31 @@ MathClass InsetMathFrac::mathClass() const
 }
 
 
+
+namespace {
+
+// align frac to minus character
+int dy_for_frac(MetricsBase & mb)
+{
+       Changer dummy = mb.changeFontSet("mathnormal");
+       return theFontMetrics(mb.font).ascent('-') - 1;
+}
+
+
+// align the top of M in the cell with the top of M in the surrounding font
+int dy_for_nicefrac(MetricsBase & mb)
+{
+       // this is according to nicefrac.sty
+       int big_m = theFontMetrics(mb.font).ascent('M');
+       Changer dummy = mb.changeScript();
+       int small_m = theFontMetrics(mb.font).ascent('M');
+       return big_m - small_m;
+}
+
+} // anon namespace
+
+
+
 void InsetMathFrac::metrics(MetricsInfo & mi, Dimension & dim) const
 {
        Dimension dim0, dim1, dim2;
@@ -176,6 +202,7 @@ void InsetMathFrac::metrics(MetricsInfo & mi, Dimension & dim) const
        case NICEFRAC: {
                // \unitfrac, \unitfracthree, \nicefrac
                dim.wid = 0;
+               int const dy = dy_for_nicefrac(mi.base);
                // is there an extra cell holding the value being given a dimension?
                // (this is \unitfracthree)
                if (kind_ == UNITFRAC && nargs() == 3) {
@@ -188,8 +215,8 @@ void InsetMathFrac::metrics(MetricsInfo & mi, Dimension & dim) const
                cell(0).metrics(mi, dim0);
                cell(1).metrics(mi, dim1);
                dim.wid += dim0.wid + dim1.wid + 5;
-               dim.asc = max(dim2.asc, dim0.height() + 5);
-               dim.des = max(dim2.des, dim1.height() - 5);
+               dim.asc = max(max(dim2.asc, dim0.asc + dy), dim1.asc);
+               dim.des = max(max(dim2.des, dim0.des - dy), dim1.des);
        }
                break;
 
@@ -201,6 +228,7 @@ void InsetMathFrac::metrics(MetricsInfo & mi, Dimension & dim) const
        case TFRAC:
        case OVER:
        case ATOP: {
+               int const dy = dy_for_frac(mi.base);
                Changer dummy =
                        // \tfrac is always in text size
                        (kind_ == TFRAC) ? mi.base.font.changeStyle(LM_ST_SCRIPT) :
@@ -214,8 +242,8 @@ void InsetMathFrac::metrics(MetricsInfo & mi, Dimension & dim) const
                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;
+               dim.asc = dim0.height() + 2 + dy;
+               dim.des = max(0, dim1.height() + 2 - dy);
        }
        } //switch (kind_)
        metricsMarkers(mi, dim);
@@ -248,6 +276,7 @@ void InsetMathFrac::draw(PainterInfo & pi, int x, int y) const
        case NICEFRAC: {
                // \unitfrac, \unitfracthree, \nicefrac
                int xx = x;
+               int const dy = dy_for_nicefrac(pi.base);
                // is there an extra cell holding the value being given a dimension?
                // (this is \unitfracthree)
                if (kind_ == UNITFRAC && nargs() == 3) {
@@ -259,13 +288,9 @@ void InsetMathFrac::draw(PainterInfo & pi, int x, int y) const
                // nice fraction
                // FIXME:
                // * the solidus should be \kern-2mu/\kern-1mu.
-               // * the vertical offset of the first cell should be such that the
-               //   top of M in the first cell matches the one of the
-               //   surrounding text.
                Changer dummy2 = pi.base.changeScript();
-               cell(0).draw(pi, xx + 2, y - dim0.des - 5);
-               Dimension const dim1 = cell(1).dimension(*pi.base.bv);
-               cell(1).draw(pi, xx + dim0.wid + 5, y + dim1.asc / 2);
+               cell(0).draw(pi, xx + 2, y - dy);
+               cell(1).draw(pi, xx + dim0.wid + 5, y);
                // Diag line:
                pi.pain.line(xx + dim0.wid + 1, y + dim.des - 2,
                             xx + dim0.wid + 6, y - dim.asc + 2,
@@ -281,6 +306,7 @@ void InsetMathFrac::draw(PainterInfo & pi, int x, int y) const
        case TFRAC:
        case OVER:
        case ATOP: {
+               int const dy = dy_for_frac(pi.base);
                Changer dummy =
                        // \tfrac is always in text size
                        (kind_ == TFRAC) ? pi.base.font.changeStyle(LM_ST_SCRIPT) :
@@ -300,15 +326,13 @@ void InsetMathFrac::draw(PainterInfo & pi, int x, int y) const
                        (kind_ == CFRACRIGHT) ? x + dim.wid - dim0.wid - 2 :
                        // center
                                                m - dim0.wid / 2;
-               // FIXME: vertical offset should be based on ex
-               //int dy = theFontMetrics(pi.base.font).ex() / 2;
-               cell(0).draw(pi, xx, y - dim0.des - 2 - 5);
+               cell(0).draw(pi, xx, y - dim0.des - 2 - dy);
                // center
-               cell(1).draw(pi, m - dim1.wid / 2, y + dim1.asc + 2 - 5);
+               cell(1).draw(pi, m - dim1.wid / 2, y + dim1.asc + 2 - dy);
                // horizontal line
                if (kind_ != ATOP)
-                       pi.pain.line(x + 1, y - 5,
-                                    x + dim.wid - 2, y - 5, pi.base.font.color());
+                       pi.pain.line(x + 1, y - dy,
+                                    x + dim.wid - 2, y - dy, pi.base.font.color());
        }
        } //switch (kind_)
        drawMarkers(pi, x, y);
@@ -601,14 +625,15 @@ int InsetMathBinom::dw(int height) const
 void InsetMathBinom::metrics(MetricsInfo & mi, Dimension & dim) const
 {
        Dimension dim0, dim1;
+       int const dy = dy_for_frac(mi.base);
        Changer dummy =
                (kind_ == DBINOM) ? mi.base.font.changeStyle(LM_ST_DISPLAY) :
                (kind_ == TBINOM) ? mi.base.font.changeStyle(LM_ST_SCRIPT) :
                                    mi.base.changeFrac();
        cell(0).metrics(mi, dim0);
        cell(1).metrics(mi, dim1);
-       dim.asc = dim0.height() + 4 + 5;
-       dim.des = dim1.height() + 4 - 5;
+       dim.asc = dim0.height() + 4 + dy;
+       dim.des = max(0, dim1.height() + 4 - dy);
        dim.wid = max(dim0.wid, dim1.wid) + 2 * dw(dim.height()) + 4;
        metricsMarkers2(mi, dim);
 }
@@ -619,6 +644,7 @@ void InsetMathBinom::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 const dy = dy_for_frac(pi.base);
        // define the binom brackets
        docstring const bra = kind_ == BRACE ? from_ascii("{") :
                kind_ == BRACK ? from_ascii("[") : from_ascii("(");
@@ -631,8 +657,8 @@ void InsetMathBinom::draw(PainterInfo & pi, int x, int y) const
                        (kind_ == DBINOM) ? pi.base.font.changeStyle(LM_ST_DISPLAY) :
                        (kind_ == TBINOM) ? pi.base.font.changeStyle(LM_ST_SCRIPT) :
                                            pi.base.changeFrac();
-               cell(0).draw(pi, m - dim0.wid / 2, y - dim0.des - 3 - 5);
-               cell(1).draw(pi, m - dim1.wid / 2, y + dim1.asc + 3 - 5);
+               cell(0).draw(pi, m - dim0.wid / 2, y - dim0.des - 3 - dy);
+               cell(1).draw(pi, m - dim1.wid / 2, y + dim1.asc + 3 - dy);
        }
        // draw the brackets and the marker
        mathed_draw_deco(pi, x, y - dim.ascent(), dw(dim.height()),

diff --git a/src/mathed/InsetMathFrac.h b/src/mathed/InsetMathFrac.h
index 96b62930ba1ef1b3d845d24dab80f16a8d80f3cd..9d5484487687932368f8bd45dc2be588cd4f47c1 100644 (file)
--- a/src/mathed/InsetMathFrac.h
+++ b/src/mathed/InsetMathFrac.h
@@ -93,7 +93,10 @@ public:
        void htmlize(HtmlStream &) const;
        ///
        void validate(LaTeXFeatures & features) const;
-public:
+private:
+       /// vertical displacement
+       int dy(FontInfo & fi) const;
+       ///
        Inset * clone() const;
        ///
        Kind kind_;