From 66fa801e74e1775b31008df548332436ce79e2e1 Mon Sep 17 00:00:00 2001 From: Jean-Marc Lasgouttes Date: Thu, 26 Mar 2015 16:55:19 +0100 Subject: [PATCH] Improve support for on screen length calculation The computation of length on screen depend in particular of the computation of the size of an em. Many places of the code used to rely on the width of the M character, which is not really correct: http://en.wikipedia.org/wiki/Em_%28typography%29 In digital typography, the best value to use is the point size of the font. * Implement FontMetrics::em(), which returns the value in pixels of the EM unit. Convert code to use it. * Introduce Length::inPixel(MetricsBase const &), which takes the textwidth and em information from the MetricsBase object. Convert code to use it. * Fix several places where Length::inPixel is used without a proper em value. * add mathed_font_em() helper function. It should eventually be removed like some other functions in MathSupport. * Add dummy implementation of FontMetrics to tex2lyx for linking purposes. --- src/BufferView.cpp | 2 +- src/Length.cpp | 11 ++++++++++- src/Length.h | 14 +++++++++++++- src/TextMetrics.cpp | 2 +- src/frontends/FontMetrics.h | 3 +++ src/frontends/qt4/GuiFontMetrics.cpp | 6 ++++++ src/frontends/qt4/GuiFontMetrics.h | 1 + src/insets/InsetBox.cpp | 2 +- src/insets/InsetLine.cpp | 6 +++--- src/insets/InsetSpace.cpp | 16 ++++++++-------- src/insets/InsetSpecialChar.cpp | 6 ++---- src/insets/InsetTabular.cpp | 6 +++--- src/mathed/InsetMathChar.cpp | 4 ++-- src/mathed/InsetMathGrid.cpp | 5 +---- src/mathed/InsetMathKern.cpp | 2 +- src/mathed/InsetMathSpace.cpp | 4 +--- src/mathed/InsetMathSymbol.cpp | 4 ++-- src/mathed/MathSupport.cpp | 6 ++++++ src/mathed/MathSupport.h | 2 ++ src/tex2lyx/dummy_impl.cpp | 16 ++++++++++++++++ 20 files changed, 83 insertions(+), 35 deletions(-) diff --git a/src/BufferView.cpp b/src/BufferView.cpp index 77750d87e3..8948b73d2d 100644 --- a/src/BufferView.cpp +++ b/src/BufferView.cpp @@ -3000,7 +3000,7 @@ void BufferView::checkCursorScrollOffset(PainterInfo & pi) // Horizontal scroll offset of the cursor row in pixels int offset = d->horiz_scroll_offset_; - int const MARGIN = Length(2, Length::EM).inPixels(workWidth()); + int const MARGIN = Length(2, Length::EM).inPixels(pi.base); if (cur_x < offset + MARGIN) { // scroll right offset = cur_x - MARGIN; diff --git a/src/Length.cpp b/src/Length.cpp index 0deed7481c..2463be8f66 100644 --- a/src/Length.cpp +++ b/src/Length.cpp @@ -17,6 +17,9 @@ #include "Length.h" #include "LyXRC.h" +#include "MetricsInfo.h" + +#include "frontends/FontMetrics.h" #include "support/docstream.h" @@ -197,7 +200,7 @@ int Length::inPixels(int text_width, int em_width_base) const ? em_width_base : 10*(dpi/72.27)*zoom; // A different estimate for em_width is - // theFontMetrics(FontInfo(sane_font)).width('M') + // theFontMetrics(FontInfo(sane_font)).em() // but this estimate might not be more accurate as the screen font // is different then the latex font. @@ -288,6 +291,12 @@ int Length::inPixels(int text_width, int em_width_base) const } +int Length::inPixels(MetricsBase const & base) const +{ + return inPixels(base.textwidth, theFontMetrics(base.font).em()); +} + + int Length::inBP() const { // return any Length value as a one with diff --git a/src/Length.h b/src/Length.h index 435eea0535..ef17bac760 100644 --- a/src/Length.h +++ b/src/Length.h @@ -20,6 +20,8 @@ namespace lyx { +class MetricsBase; + // Solaris/x86 version 9 and earlier define these #undef PC #undef SP @@ -87,8 +89,18 @@ public: std::string const asLatexString() const; /// return string representation for HTML std::string const asHTMLString() const; - /// return the on-screen size of this length + /** return the on-screen size of this length. + * + * If the second argument is not provided, then the unit EM will + * only be approximated. It is better if possible to use + * FontMetrics::em() to get this value. + */ int inPixels(int text_width, int em_width = 0) const; + /** return the on-screen size of this length + * + * This version of the function uses the right EM definition. + */ + int inPixels(MetricsBase const &) const; /// return the value in Big Postscript points. int inBP() const; diff --git a/src/TextMetrics.cpp b/src/TextMetrics.cpp index afc7f4ebdc..33baa8cafd 100644 --- a/src/TextMetrics.cpp +++ b/src/TextMetrics.cpp @@ -1736,7 +1736,7 @@ int TextMetrics::leftMargin(int max_width, } if (!par.params().leftIndent().zero()) - l_margin += par.params().leftIndent().inPixels(max_width); + l_margin += par.params().leftIndent().inPixels(max_width, labelfont_metrics.em()); LyXAlignment align; diff --git a/src/frontends/FontMetrics.h b/src/frontends/FontMetrics.h index 56e47eaeab..53f57a2880 100644 --- a/src/frontends/FontMetrics.h +++ b/src/frontends/FontMetrics.h @@ -63,6 +63,9 @@ public: /// return default dimension of the font. /// \warning \c width is set to zero. virtual Dimension const defaultDimension() const = 0; + /// return the em size + virtual int em() 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 diff --git a/src/frontends/qt4/GuiFontMetrics.cpp b/src/frontends/qt4/GuiFontMetrics.cpp index f3a4c0fab7..b488b684eb 100644 --- a/src/frontends/qt4/GuiFontMetrics.cpp +++ b/src/frontends/qt4/GuiFontMetrics.cpp @@ -72,6 +72,12 @@ int GuiFontMetrics::maxDescent() const } +int GuiFontMetrics::em() const +{ + return QFontInfo(font_).pixelSize(); +} + + int GuiFontMetrics::lbearing(char_type c) const { if (!is_utf16(c)) diff --git a/src/frontends/qt4/GuiFontMetrics.h b/src/frontends/qt4/GuiFontMetrics.h index ac1e71419d..7555929c9b 100644 --- a/src/frontends/qt4/GuiFontMetrics.h +++ b/src/frontends/qt4/GuiFontMetrics.h @@ -35,6 +35,7 @@ public: virtual int maxAscent() const; virtual int maxDescent() const; virtual Dimension const defaultDimension() const; + virtual int em() const; virtual int width(char_type c) const; virtual int ascent(char_type c) const; virtual int descent(char_type c) const; diff --git a/src/insets/InsetBox.cpp b/src/insets/InsetBox.cpp index c96a7c9e7d..de1c7fd582 100644 --- a/src/insets/InsetBox.cpp +++ b/src/insets/InsetBox.cpp @@ -171,7 +171,7 @@ void InsetBox::metrics(MetricsInfo & m, Dimension & dim) const // back up textwidth. int textwidth_backup = m.base.textwidth; if (hasFixedWidth()) - m.base.textwidth = params_.width.inPixels(m.base.textwidth); + m.base.textwidth = params_.width.inPixels(m.base); InsetCollapsable::metrics(m, dim); // retore textwidth. m.base.textwidth = textwidth_backup; diff --git a/src/insets/InsetLine.cpp b/src/insets/InsetLine.cpp index 82960b262e..8b80f0d3ec 100644 --- a/src/insets/InsetLine.cpp +++ b/src/insets/InsetLine.cpp @@ -111,7 +111,7 @@ void InsetLine::metrics(MetricsInfo & mi, Dimension & dim) const int const max_width = mi.base.textwidth; Length const width(to_ascii(getParam("width"))); - dim.wid = width.inPixels(max_width, fm.width(char_type('M'))); + dim.wid = width.inPixels(mi.base); // assure that the line inset is not outside of the window // check that it doesn't exceed the outer boundary @@ -123,11 +123,11 @@ void InsetLine::metrics(MetricsInfo & mi, Dimension & dim) const dim.wid = max(minw, abs(dim.wid)); Length height = Length(to_ascii(getParam("height"))); - height_ = height.inPixels(max_width, fm.width(char_type('M'))); + height_ = height.inPixels(mi.base); // get the length of the parameters in pixels Length offset = Length(to_ascii(getParam("offset"))); - offset_ = offset.inPixels(max_width, fm.width(char_type('M'))); + offset_ = offset.inPixels(mi.base); dim.asc = max(fm.maxAscent(), offset_ + height_); dim.des = max(fm.maxDescent(), - offset_); diff --git a/src/insets/InsetSpace.cpp b/src/insets/InsetSpace.cpp index 8f746f5e31..839ccc917b 100644 --- a/src/insets/InsetSpace.cpp +++ b/src/insets/InsetSpace.cpp @@ -209,19 +209,20 @@ void InsetSpace::metrics(MetricsInfo & mi, Dimension & dim) const frontend::FontMetrics const & fm = theFontMetrics(mi.base.font); dim.asc = fm.maxAscent(); dim.des = fm.maxDescent(); + int const em = fm.em(); switch (params_.kind) { case InsetSpaceParams::THIN: case InsetSpaceParams::NEGTHIN: - dim.wid = fm.width(char_type('M')) / 6; + dim.wid = em / 6; break; case InsetSpaceParams::MEDIUM: case InsetSpaceParams::NEGMEDIUM: - dim.wid = fm.width(char_type('M')) / 4; + dim.wid = em / 4; break; case InsetSpaceParams::THICK: case InsetSpaceParams::NEGTHICK: - dim.wid = fm.width(char_type('M')) / 2; + dim.wid = em / 2; break; case InsetSpaceParams::PROTECTED: case InsetSpaceParams::VISIBLE: @@ -229,20 +230,19 @@ void InsetSpace::metrics(MetricsInfo & mi, Dimension & dim) const dim.wid = fm.width(char_type(' ')); break; case InsetSpaceParams::QUAD: - dim.wid = fm.width(char_type('M')); + dim.wid = em; break; case InsetSpaceParams::QQUAD: - dim.wid = 2 * fm.width(char_type('M')); + dim.wid = 2 * em; break; case InsetSpaceParams::ENSPACE: case InsetSpaceParams::ENSKIP: - dim.wid = int(0.5 * fm.width(char_type('M'))); + dim.wid = int(0.5 * em); break; case InsetSpaceParams::CUSTOM: case InsetSpaceParams::CUSTOM_PROTECTED: { int const w = - params_.length.len().inPixels(mi.base.textwidth, - fm.width(char_type('M'))); + params_.length.len().inPixels(mi.base); int const minw = (w < 0) ? 3 * arrow_size : 4; dim.wid = max(minw, abs(w)); break; diff --git a/src/insets/InsetSpecialChar.cpp b/src/insets/InsetSpecialChar.cpp index 8a52f166fc..99ac836916 100644 --- a/src/insets/InsetSpecialChar.cpp +++ b/src/insets/InsetSpecialChar.cpp @@ -47,7 +47,7 @@ namespace { int logoWidth(FontInfo const & font, InsetSpecialChar::Kind kind) { frontend::FontMetrics const & fm = theFontMetrics(font); - int const em = fm.width('M'); + int const em = fm.em(); int width = 0; // See drawlogo() below to understand what this does. switch (kind) { @@ -137,9 +137,7 @@ namespace { void drawLogo(PainterInfo & pi, InsetSpecialChar::Kind kind, int & x, int & y) { FontInfo const & font = pi.base.font; - // FIXME: this definition of em is bogus, but there is a need - // for a big refactoring of the code around this issue anyway. - int const em = theFontMetrics(font).width('M'); + int const em = theFontMetrics(font).em(); switch (kind) { case InsetSpecialChar::PHRASE_LYX: /** Reference macro: diff --git a/src/insets/InsetTabular.cpp b/src/insets/InsetTabular.cpp index d39cf7f263..1566836770 100644 --- a/src/insets/InsetTabular.cpp +++ b/src/insets/InsetTabular.cpp @@ -3591,7 +3591,7 @@ void InsetTabular::metrics(MetricsInfo & mi, Dimension & dim) const MetricsInfo m = mi; Length const p_width = tabular.getPWidth(cell); if (!p_width.zero()) - m.base.textwidth = p_width.inPixels(mi.base.textwidth); + m.base.textwidth = p_width.inPixels(mi.base); tabular.cellInset(cell)->metrics(m, dim); if (!p_width.zero()) dim.wid = m.base.textwidth; @@ -3652,11 +3652,11 @@ void InsetTabular::metrics(MetricsInfo & mi, Dimension & dim) const } int const top_space = tabular.row_info[r].top_space_default ? default_line_space : - tabular.row_info[r].top_space.inPixels(mi.base.textwidth); + tabular.row_info[r].top_space.inPixels(mi.base); tabular.setRowAscent(r, maxasc + ADD_TO_HEIGHT + top_space); int const bottom_space = tabular.row_info[r].bottom_space_default ? default_line_space : - tabular.row_info[r].bottom_space.inPixels(mi.base.textwidth); + tabular.row_info[r].bottom_space.inPixels(mi.base); tabular.setRowDescent(r, maxdes + ADD_TO_HEIGHT + bottom_space); } diff --git a/src/mathed/InsetMathChar.cpp b/src/mathed/InsetMathChar.cpp index 03bda07cf6..724bad43fd 100644 --- a/src/mathed/InsetMathChar.cpp +++ b/src/mathed/InsetMathChar.cpp @@ -75,7 +75,7 @@ void InsetMathChar::metrics(MetricsInfo & mi, Dimension & dim) const dim = fm.dimension(char_); kerning_ = fm.rbearing(char_) - dim.wid; } - int const em = mathed_char_width(mi.base.font, 'M'); + int const em = mathed_font_em(mi.base.font); if (isBinaryOp(char_)) dim.wid += static_cast(0.5*em+0.5); else if (char_ == '\'') @@ -93,7 +93,7 @@ void InsetMathChar::metrics(MetricsInfo & mi, Dimension & dim) const void InsetMathChar::draw(PainterInfo & pi, int x, int y) const { //lyxerr << "drawing '" << char_ << "' font: " << pi.base.fontname << endl; - int const em = mathed_char_width(pi.base.font, 'M'); + int const em = mathed_font_em(pi.base.font); if (isBinaryOp(char_)) x += static_cast(0.25*em+0.5); else if (char_ == '\'') diff --git a/src/mathed/InsetMathGrid.cpp b/src/mathed/InsetMathGrid.cpp index 07f0b2ce79..d3eb677197 100644 --- a/src/mathed/InsetMathGrid.cpp +++ b/src/mathed/InsetMathGrid.cpp @@ -28,7 +28,6 @@ #include "FuncRequest.h" #include "frontends/Clipboard.h" -#include "frontends/FontMetrics.h" #include "frontends/Painter.h" #include "support/debug.h" @@ -98,9 +97,7 @@ InsetMathGrid::RowInfo::RowInfo() int InsetMathGrid::RowInfo::skipPixels(MetricsInfo const & mi) const { - frontend::FontMetrics const & fm = theFontMetrics(mi.base.font); - return crskip_.inPixels(mi.base.textwidth, - fm.width(char_type('M'))); + return crskip_.inPixels(mi.base); } diff --git a/src/mathed/InsetMathKern.cpp b/src/mathed/InsetMathKern.cpp index 7f990f9968..80e3243ae6 100644 --- a/src/mathed/InsetMathKern.cpp +++ b/src/mathed/InsetMathKern.cpp @@ -47,7 +47,7 @@ void InsetMathKern::metrics(MetricsInfo & mi, Dimension & dim) const { dim.asc = 0; dim.des = 0; - dim.wid = wid_.inPixels(0, mathed_char_width(mi.base.font, 'M')); + dim.wid = wid_.inPixels(mi.base); } diff --git a/src/mathed/InsetMathSpace.cpp b/src/mathed/InsetMathSpace.cpp index 2a3b6f45cb..c84bc771d8 100644 --- a/src/mathed/InsetMathSpace.cpp +++ b/src/mathed/InsetMathSpace.cpp @@ -123,9 +123,7 @@ void InsetMathSpace::metrics(MetricsInfo & mi, Dimension & dim) const dim.asc = 4; dim.des = 0; if (space_info[space_].custom) - dim.wid = abs(length_.inPixels( - mi.base.textwidth, - mathed_char_width(mi.base.font, 'M'))); + dim.wid = abs(length_.inPixels(mi.base)); else dim.wid = space_info[space_].width; } diff --git a/src/mathed/InsetMathSymbol.cpp b/src/mathed/InsetMathSymbol.cpp index 8b2d1a2f72..352352bdd6 100644 --- a/src/mathed/InsetMathSymbol.cpp +++ b/src/mathed/InsetMathSymbol.cpp @@ -67,7 +67,7 @@ void InsetMathSymbol::metrics(MetricsInfo & mi, Dimension & dim) const sym_->extra == "mathalpha" && mi.base.fontname == "mathit"; std::string const font = italic_upcase_greek ? "cmm" : sym_->inset; - int const em = mathed_char_width(mi.base.font, 'M'); + int const em = mathed_font_em(mi.base.font); FontSetChanger dummy(mi.base, from_ascii(font)); mathed_string_dim(mi.base.font, sym_->draw, dim); docstring::const_reverse_iterator rit = sym_->draw.rbegin(); @@ -104,7 +104,7 @@ void InsetMathSymbol::draw(PainterInfo & pi, int x, int y) const sym_->extra == "mathalpha" && pi.base.fontname == "mathit"; std::string const font = italic_upcase_greek ? "cmm" : sym_->inset; - int const em = mathed_char_width(pi.base.font, 'M'); + int const em = mathed_font_em(pi.base.font); if (isRelOp()) x += static_cast(0.25*em+0.5); else diff --git a/src/mathed/MathSupport.cpp b/src/mathed/MathSupport.cpp index 7d15c42672..1f90873fec 100644 --- a/src/mathed/MathSupport.cpp +++ b/src/mathed/MathSupport.cpp @@ -501,6 +501,12 @@ deco_struct const * search_deco(docstring const & name) } // namespace anon +int mathed_font_em(FontInfo const & font) +{ + return theFontMetrics(font).em(); +} + + int mathed_char_width(FontInfo const & font, char_type c) { return theFontMetrics(font).width(c); diff --git a/src/mathed/MathSupport.h b/src/mathed/MathSupport.h index dc0087f915..aa5ef2adc2 100644 --- a/src/mathed/MathSupport.h +++ b/src/mathed/MathSupport.h @@ -27,6 +27,8 @@ class MathAtom; class InsetMath; +int mathed_font_em(FontInfo const &); + int mathed_char_width(FontInfo const &, char_type c); int mathed_char_kerning(FontInfo const &, char_type c); diff --git a/src/tex2lyx/dummy_impl.cpp b/src/tex2lyx/dummy_impl.cpp index 6fb1a84b76..9e9c310729 100644 --- a/src/tex2lyx/dummy_impl.cpp +++ b/src/tex2lyx/dummy_impl.cpp @@ -121,6 +121,22 @@ string alignmentToCSS(LyXAlignment) return string(); } +// +// Dummy FontMetrics (needed by Length) +// + + +class FontMetrics { + int em() const { return 0; }; +}; + +class FontInfo; + +FontMetrics const & theFontMetrics(FontInfo const &) { + static FontMetrics dummy; + return dummy; +} + // // Keep the linker happy on Windows // -- 2.39.2