NEW: JKQTMathText: added functions to set the font-size in pixels (as alternative to the existing functions that set them in points), implements request #76

doc/dox/whatsnew.dox

@@ -54,6 +54,7 @@ Changes, compared to  \ref page_whatsnew_V4_0_0 "v4.0.0" include:
     <li>NEW: \limits and \nolimits works as in LaTeX now (before it was simply removed and the functionality implemented for a fixed list of symbols)</li>
     <li>NEW: added top-corner (\ulcorner/\urcorner) and bottom-corner brackets (\llcorner/\lrcorner)</li>
     <li>NEW: added \overbracket and \underbracket</li>
+    <li>NEW: added functions to set the font-size in pixels (as alternative to the existing functions that set them in points), implements request <a href="https://github.com/jkriege2/JKQtPlotter/issues/76">#76</a> from <a href="https://github.com/igormironchik">user:igormironchik</a> </li>
   </ul>
 </ul>
 

examples/jkqtmathtext_test/testform.cpp

@@ -258,6 +258,7 @@ TestForm::TestForm(QWidget *parent) :
     connect(ui->cmbLastAlign, SIGNAL(currentIndexChanged(int)), this, SLOT(updateMath()));
     connect(ui->cmbFont, SIGNAL(currentIndexChanged(int)), this, SLOT(updateMath()));
     connect(ui->cmbScript, SIGNAL(currentIndexChanged(int)), this, SLOT(updateMath()));
+    connect(ui->cmbSizeUnit, SIGNAL(currentIndexChanged(int)), this, SLOT(updateMath()));
     connect(ui->cmbTestset, SIGNAL(currentIndexChanged(int)), this, SLOT(updateMath()));
     connect(ui->cmbCaligraphic, SIGNAL(currentIndexChanged(int)), this, SLOT(updateMath()));
     connect(ui->cmbUnicodeSans, SIGNAL(currentIndexChanged(int)), this, SLOT(updateMath()));
@@ -573,9 +574,11 @@ void TestForm::updateMath()
         bool ok=true;
         int size=sl[i].trimmed().toUInt(&ok);
         if (!ok) size=10+i*5;
-        mt.setFontSize(size);
+        QString unit="";
+        if (ui->cmbSizeUnit->currentIndex()==0) { unit="pt"; mt.setFontSize(size); }
+        else {unit="px"; mt.setFontSizePixels(size); }
         double durationSizingMS=0, durationTimingMS=0;
-        Y+=draw(painter, X1, Y, mt, QString("%1, %2, %3pt").arg(ui->cmbTestset->currentText()).arg(ui->cmbFont->currentText()).arg(size), durationSizingMS, durationTimingMS);
+        Y+=draw(painter, X1, Y, mt, QString("%1, %2, %3"+unit).arg(ui->cmbTestset->currentText()).arg(ui->cmbFont->currentText()).arg(size), durationSizingMS, durationTimingMS);
 
         if (i==0) {
             ui->labError->clear();
@@ -600,8 +603,10 @@ void TestForm::updateMath()
         bool ok=true;
         int size=sl.last().trimmed().toUInt(&ok);
         if (!ok) size=font().pointSizeF();
-        mt.setFontSize(size);
+        QString unit;
-        Y+=drawAligned(painter, X1, Y, mt, QString("%1, %2pt, align: %3").arg(ui->cmbTestset->currentText()).arg(size).arg(ui->cmbLastAlign->currentText()));
+        if (ui->cmbSizeUnit->currentIndex()==0) { unit="pt"; mt.setFontSize(size); }
+        else { unit="px"; mt.setFontSizePixels(size); }
+        Y+=drawAligned(painter, X1, Y, mt, QString("%1, %2"+unit+", align: %3").arg(ui->cmbTestset->currentText()).arg(size).arg(ui->cmbLastAlign->currentText()));
     }
 
     painter.end();

examples/jkqtmathtext_test/testform.ui

@@ -588,7 +588,7 @@
     </widget>
    </item>
    <item row="0" column="0" colspan="2">
-    <layout class="QHBoxLayout" name="horizontalLayout_2" stretch="0,2,0,2,0,0,1,0,0,0,0,0,0">
+    <layout class="QHBoxLayout" name="horizontalLayout_2" stretch="0,2,0,2,0,0,0,1,0,0,0,0,0,0">
      <item>
       <widget class="QLabel" name="label_3">
        <property name="text">
@@ -675,6 +675,26 @@
        </item>
       </widget>
      </item>
+     <item>
+      <widget class="QComboBox" name="cmbSizeUnit">
+       <property name="sizePolicy">
+        <sizepolicy hsizetype="Minimum" vsizetype="Fixed">
+         <horstretch>0</horstretch>
+         <verstretch>0</verstretch>
+        </sizepolicy>
+       </property>
+       <item>
+        <property name="text">
+         <string>pt</string>
+        </property>
+       </item>
+       <item>
+        <property name="text">
+         <string>px</string>
+        </property>
+       </item>
+      </widget>
+     </item>
      <item>
       <widget class="QLabel" name="label_2">
        <property name="text">

lib/jkqtmathtext/jkqtmathtext.cpp

@@ -61,6 +61,7 @@ JKQTMathText::JKQTMathText(QObject* parent):
     //qDebug()<<"init_resoucre: "<<std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::high_resolution_clock::now()-t0).count()/1000.0<<"ms"; t0=std::chrono::high_resolution_clock::now();
 
     fontSize=10;
+    fontSizeUnits=JKQTMathTextEnvironment::POINTS;
     fontColor=QColor("black");
     italic_correction_factor=0.4;
     brace_factor=1.04;
@@ -121,30 +122,6 @@ JKQTMathText::JKQTMathText(QObject* parent):
 #else
         const auto fonts=QFontDatabase::families();
 #endif
-        //qDebug()<<"fonts:\n"<<fonts;
-
-        /*if (SCAN_FONTS_ON_STARTUP) {
-            for (const QString& f: fonts) {
-                QFont fnt(f);
-                QFontInfo fi(fnt);
-                if (typewriterFont=="typewriter" && fi.styleHint()==QFont::TypeWriter) {
-                    typewriterFont=f;
-                }
-                if (decorativeFont=="decorative" && fi.styleHint()==QFont::Decorative) {
-                    decorativeFont=f;
-                }
-                if (serifFont=="serif" && fi.styleHint()==QFont::Serif) {
-                    serifFont=f;
-                }
-                if (sansFont=="sans" && fi.styleHint()==QFont::SansSerif) {
-                    sansFont=f;
-                }
-                if (scriptFont=="script" && fi.styleHint()==QFont::Cursive) {
-                    scriptFont=f;
-                }
-            }
-        }*/
-        //qDebug()<<"iterate "<<fonts.size()<<" fonts: "<<std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::high_resolution_clock::now()-t0).count()/1000.0<<"ms"; t0=std::chrono::high_resolution_clock::now();
 
 
         auto checkForFonts=[&fonts](QString& targetfont, const QStringList& fontoptions) {
@@ -220,6 +197,7 @@ JKQTMathText::~JKQTMathText() {
 
 void JKQTMathText::loadSettings(const QSettings& settings, const QString& group){
     fontSize=settings.value(group+"font_size", fontSize).toDouble();
+    fontSizeUnits=JKQTMathTextEnvironment::String2FontSizeUnit(settings.value(group+"font_size_units", JKQTMathTextEnvironment::FontSizeUnit2String(fontSizeUnits)).toString());
     fontColor=jkqtp_String2QColor(settings.value(group+"font_color", jkqtp_QColor2String(fontColor)).toString());
     brace_factor=settings.value(group+"brace_factor", brace_factor).toDouble();
     brace_shrink_factor=settings.value(group+"brace_shrink_factor", brace_shrink_factor).toDouble();
@@ -261,6 +239,7 @@ void JKQTMathText::loadSettings(const QSettings& settings, const QString& group)
 
 void JKQTMathText::saveSettings(QSettings& settings, const QString& group) const{
     settings.setValue(group+"font_size", fontSize);
+    settings.setValue(group+"font_size_units", JKQTMathTextEnvironment::FontSizeUnit2String(fontSizeUnits));
     settings.setValue(group+"font_color", jkqtp_QColor2String(fontColor));
     settings.setValue(group+ "brace_factor", brace_factor);
     settings.setValue(group+ "brace_shrink_factor", brace_shrink_factor);
@@ -363,6 +342,24 @@ bool JKQTMathText::useASANA(bool mathModeOnly)
 }
 
 void JKQTMathText::useAnyUnicode(QString timesFont, const QString &sansFont, JKQTMathTextFontEncoding encodingTimes, JKQTMathTextFontEncoding encodingSans)
+{
+    if (!timesFont.isEmpty()) {
+        setFontRoman(timesFont, encodingTimes);
+        setFontMathRoman(timesFont, encodingTimes);
+    }
+    if (!sansFont.isEmpty()) {
+        setFontSans(sansFont, encodingSans);
+        setFontMathSans(sansFont, encodingSans);
+    }
+}
+
+void JKQTMathText::useAnyUnicodeForMathOnly(QString timesFont, const QString &sansFont, JKQTMathTextFontEncoding encodingTimes, JKQTMathTextFontEncoding encodingSans)
+{
+    if (!timesFont.isEmpty()) { setFontMathRoman(timesFont, encodingTimes); }
+    if (!sansFont.isEmpty()) { setFontMathSans(sansFont, encodingSans); }
+}
+
+void JKQTMathText::useAnyUnicodeForTextOnly(QString timesFont, const QString &sansFont, JKQTMathTextFontEncoding encodingTimes, JKQTMathTextFontEncoding encodingSans)
 {
     if (!timesFont.isEmpty()) { setFontRoman(timesFont, encodingTimes); }
     if (!sansFont.isEmpty()) { setFontSans(sansFont, encodingSans); }
@@ -376,9 +373,11 @@ QString JKQTMathText::toHtml(bool *ok, double fontPointSize) {
         JKQTMathTextEnvironment ev;
         ev.color=fontColor;
         ev.fontSize=fontPointSize;
+        ev.fontSizeUnit=JKQTMathTextEnvironment::POINTS;
 
         JKQTMathTextEnvironment defaultev;
         defaultev.fontSize=fontPointSize;
+        defaultev.fontSizeUnit=JKQTMathTextEnvironment::POINTS;
 
         okk=getNodeTree()->toHtml(s, ev, defaultev);
     }
@@ -399,12 +398,36 @@ QColor JKQTMathText::getFontColor() const
 
 void JKQTMathText::setFontSize(double __value)
 {
-    this->fontSize = __value;
+    setFontPointSize(__value);
+}
+
+void JKQTMathText::setFontPointSize(double __value)
+{
+    fontSize = __value;
+    fontSizeUnits=JKQTMathTextEnvironment::POINTS;
+}
+
+void JKQTMathText::setFontSizePixels(double __value)
+{
+    fontSize = __value;
+    fontSizeUnits=JKQTMathTextEnvironment::PIXELS;
 }
 
 double JKQTMathText::getFontSize() const
 {
-    return this->fontSize;
+    return getFontPointSize();
+}
+
+double JKQTMathText::getFontPointSize() const
+{
+    if (fontSizeUnits==JKQTMathTextEnvironment::POINTS) return fontSize;
+    else return -1;
+}
+
+double JKQTMathText::getFontSizePixels() const
+{
+    if (fontSizeUnits==JKQTMathTextEnvironment::PIXELS) return fontSize;
+    else return -1;
 }
 
 void JKQTMathText::addReplacementFont(const QString &nonUseFont, const QString &useFont, JKQTMathTextFontEncoding useFontEncoding) {
@@ -1638,6 +1661,7 @@ void JKQTMathText::getSizeDetail(QPainter& painter, double& width, double& ascen
         JKQTMathTextEnvironment ev;
         ev.color=fontColor;
         ev.fontSize=fontSize;
+        ev.fontSizeUnit=fontSizeUnits;
 
         double overallHeight=0;        
         getNodeTree()->getSize(painter, ev, width, ascent, overallHeight, strikeoutPos);
@@ -1658,6 +1682,7 @@ void JKQTMathText::draw(QPainter& painter, double x, double y, bool drawBoxes){
         JKQTMathTextEnvironment ev;
         ev.color=fontColor;
         ev.fontSize=fontSize;
+        ev.fontSizeUnit=fontSizeUnits;
         QPen pp=painter.pen();
         QPen p=pp;
         p.setStyle(Qt::SolidLine);
@@ -1678,6 +1703,7 @@ void JKQTMathText::draw(QPainter& painter, unsigned int flags, QRectF rect, bool
         JKQTMathTextEnvironment ev;
         ev.color=fontColor;
         ev.fontSize=fontSize;
+        ev.fontSizeUnit=fontSizeUnits;
         getNodeTree()->setDrawBoxes(drawBoxes);
         painter.setPen(p);
 

lib/jkqtmathtext/jkqtmathtext.h

@@ -294,10 +294,22 @@ class JKQTMATHTEXT_LIB_EXPORT JKQTMathText : public QObject {
         void setFontColor(const QColor & __value);
         /** \copydoc fontColor */ 
         QColor getFontColor() const;
-        /** \copydoc fontSize */ 
+        /** \copydoc setFontPointSize() */
         void setFontSize(double __value);
-        /** \copydoc fontSize */ 
+        /** \brief set the default font size in points
+         *  \see getFontSize(), fontSize, fontSizeUnits */
+        void setFontPointSize(double __value);
+        /** \brief set the default font soze in pixels
+         *  \see getFontSizePixels(), fontSize, fontSizeUnits */
+        void setFontSizePixels(double __value);
+        /** \brief returns the currently set default font size in points, if it was defined in points using setFontSize(), or -1 if it was set in pixels with setFontSizePixels()
+         *  \see setFontSize(), fontSize, fontSizeUnits */
+        double getFontPointSize() const;
+        /** \copydoc getFontPointSize() */
         double getFontSize() const;
+        /** \brief returns the currently set default font size in pixels, if it was defined in points using setFontSizePixels(), or -1 if it was set in points with setFontSize()
+         *  \see setFontSizePixels(), fontSize, fontSizeUnits */
+        double getFontSizePixels() const;
         /** \brief add a font pair to the table with font replacements
          *
          * e.g. if it is known that a certain font is not good for rendering, you can add an alternative with this function.
@@ -440,8 +452,9 @@ class JKQTMATHTEXT_LIB_EXPORT JKQTMathText : public QObject {
 
         /** \brief sets \a timesFont (with its encoding \a encodingTimes ) for serif-text and \a sansFont (with its encoding \a encodingSans ) for both mathmode and textmode fonts
          *
-         * use generic Unicode fonts, e.g. "Arial" and "Times New Roman" in math-mode.
+         * \note use generic Unicode fonts, e.g. "Arial" and "Times New Roman" in math-mode.
-         * You should use fonts that contain as many of the mathematical symbols as possible to ensure good rendering results.
+         *       You should use fonts that contain as many of the mathematical symbols as possible
+         *       to ensure good rendering results.
          *
          * <code>useAnyUnicode("Times New Roman", "Times New Roman")</code>:<br>\image html jkqtmathtext/jkqtmathparser_timesnewroman.png  <br><br>
          * <code>useAnyUnicode("Arial", "Arial")</code>:<br>\image html jkqtmathtext/jkqtmathparser_arial.png  <br><br>
@@ -449,7 +462,20 @@ class JKQTMATHTEXT_LIB_EXPORT JKQTMathText : public QObject {
          * <code>useAnyUnicode("Comic Sans MS", "Comic Sans MS")</code>:<br>\image html jkqtmathtext/jkqtmathparser_comicsans.png  <br><br>
          *
          */
-        void useAnyUnicode(QString timesFont=QString(""), const QString& sansFont=QString(""), JKQTMathTextFontEncoding encodingTimes=JKQTMathTextFontEncoding::MTFEUnicode, JKQTMathTextFontEncoding encodingSans=JKQTMathTextFontEncoding::MTFEUnicode);
+        void useAnyUnicode(QString timesFont, const QString& sansFont, JKQTMathTextFontEncoding encodingTimes=JKQTMathTextFontEncoding::MTFEUnicode, JKQTMathTextFontEncoding encodingSans=JKQTMathTextFontEncoding::MTFEUnicode);
+        /** \brief sets \a timesFont (with its encoding \a encodingTimes ) for serif-text and \a sansFont (with its encoding \a encodingSans ) for mathmode fonts only
+         *
+         * \note use generic Unicode fonts, e.g. "Arial" and "Times New Roman" in math-mode.
+         *       You should use fonts that contain as many of the mathematical symbols as possible to ensure good rendering results.
+         *
+         * \see useAnyUnicodeForTextOnly(), useAnyUnicode()
+         */
+        void useAnyUnicodeForMathOnly(QString timesFont, const QString& sansFont, JKQTMathTextFontEncoding encodingTimes=JKQTMathTextFontEncoding::MTFEUnicode, JKQTMathTextFontEncoding encodingSans=JKQTMathTextFontEncoding::MTFEUnicode);
+        /** \brief sets \a timesFont (with its encoding \a encodingTimes ) for serif-text and \a sansFont (with its encoding \a encodingSans ) for both mathmode fonts only
+         *
+         *  \see useAnyUnicodeForMathOnly(), useAnyUnicode()
+         */
+        void useAnyUnicodeForTextOnly(QString timesFont, const QString& sansFont, JKQTMathTextFontEncoding encodingTimes=JKQTMathTextFontEncoding::MTFEUnicode, JKQTMathTextFontEncoding encodingSans=JKQTMathTextFontEncoding::MTFEUnicode);
 
 
 
@@ -601,8 +627,10 @@ class JKQTMATHTEXT_LIB_EXPORT JKQTMathText : public QObject {
 
         /** \brief font color */
         QColor fontColor;
-        /** \brief base font size in points */
+        /** \brief base font size in the units defined in fontSizeUnits \see fontSizeUnits */
         double fontSize;
+        /** \brief unit of fontSize */
+        JKQTMathTextEnvironment::FontSizeUnit fontSizeUnits;
 
 
         /** \brief stores information about the different fonts used by LaTeX markup */

lib/jkqtmathtext/jkqtmathtexttools.cpp

@@ -415,10 +415,28 @@ bool InstructionNameMatchesJKQTMathTextBraceType(const QString &token, JKQTMathT
     return (bt==type);
 }
 
+QString JKQTMathTextEnvironment::FontSizeUnit2String(FontSizeUnit unit)
+{
+    switch(unit) {
+    case PIXELS: return "pix";
+    default:
+    case POINTS: return "pt";
+    }
+}
+
+JKQTMathTextEnvironment::FontSizeUnit JKQTMathTextEnvironment::String2FontSizeUnit(QString unit)
+{
+    unit=unit.toLower().trimmed();
+    if (unit=="pt" || unit=="points" || unit=="point") return POINTS;
+    if (unit=="pix" || unit=="pixel" || unit=="pixels" || unit=="px") return PIXELS;
+    return POINTS;
+}
+
 JKQTMathTextEnvironment::JKQTMathTextEnvironment() {
     color=QColor("black");
     font=MTEroman;
     fontSize=10;
+    fontSizeUnit=POINTS;
     bold=false;
     italic=false;
     smallCaps=false;
@@ -489,14 +507,17 @@ QFont JKQTMathTextEnvironment::getFont(JKQTMathText* parent) const {
     f.setStrikeOut(strike);
     f.setCapitalization(QFont::MixedCase);
     if (smallCaps) f.setCapitalization(QFont::SmallCaps);
-    f.setPointSizeF(fontSize);
+    if (fontSizeUnit==POINTS) f.setPointSizeF(fontSize);
+    else if (fontSizeUnit==PIXELS) f.setPixelSize(static_cast<int>(fontSize));
     f.setStyleStrategy(QFont::NoFontMerging);
     return f;
 }
 
 QString JKQTMathTextEnvironment::toHtmlStart(JKQTMathTextEnvironment defaultEv) const {
     QString s;
-    s=s+"font-size: "+QLocale::c().toString(fontSize)+"pt; ";
+    if (fontSizeUnit==POINTS) s=s+"font-size: "+QLocale::c().toString(fontSize)+"pt; ";
+    else if (fontSizeUnit==PIXELS) s=s+"font-size: "+QLocale::c().toString(fontSize)+"px; ";
+
     if (insideMath) {
         if (defaultEv.italic) {
             if (!italic) s=s+"font-style: italic; ";

lib/jkqtmathtext/jkqtmathtexttools.h

@@ -232,6 +232,16 @@ enum JKQTMathTextEnvironmentFont {
  *  \ingroup jkqtmathtext_tools
  */
 struct JKQTMATHTEXT_LIB_EXPORT JKQTMathTextEnvironment {
+    /** \brief units for the property JKQTMathTextEnvironment::fontSize (Points/PT or Pixels) */
+    enum FontSizeUnit {
+        POINTS,
+        PIXELS
+    };
+    /** \brief convert a FontSizeUnit to a string \see FontSizeUnit,String2FontSizeUnit() */
+    static QString FontSizeUnit2String(FontSizeUnit unit);
+    /** \brief convert a string into a FontSizeUnit \see FontSizeUnit,FontSizeUnit2String()  */
+    static FontSizeUnit String2FontSizeUnit(QString unit);
+
     JKQTMathTextEnvironment();
     /** \brief current font color */
     QColor color;
@@ -239,8 +249,11 @@ struct JKQTMATHTEXT_LIB_EXPORT JKQTMathTextEnvironment {
     JKQTMathTextEnvironmentFont font;
     /** \brief custom font, when font==MTECustomFont */
     QString customFontName;
-    /** \brief current font size [pt] */
+    /** \brief current font size the unit is determined by fontSizeUnit */
     double fontSize;
+    /** \brief the unit of the font size fontSize */
+    FontSizeUnit fontSizeUnit;
+
     /** \brief is the text currently bold? */
     bool bold;
     /** \brief is the text currently italic? */

lib/jkqtmathtext/nodes/jkqtmathtextbracenode.cpp

@@ -93,9 +93,9 @@ double JKQTMathTextBraceNode::draw(QPainter& painter, double x, double y, JKQTMa
     double nodeOverallHeight=0, nodeStrikeoutPos=0;
     double bracewidth=0, braceheight=0;
     getSizeInternalAndBrace(painter, currentEv, nodeWidth, nodeBaselineHeight, nodeOverallHeight, nodeStrikeoutPos, bracewidth, braceheight);
+    const QFontMetricsF fm(currentEv.getFont(parentMathText));
 
-
+    const double lw=qMax(0.25,fm.lineWidth());
-    const double lw=qMax(0.25,ceil(currentEv.fontSize/16.0));//fm.lineWidth();
 
     double xnew=x;
 
@@ -425,7 +425,8 @@ JKQTMathTextBraceType JKQTMathTextBraceNode::getClosebrace() const {
 
 void JKQTMathTextBraceNode::getBraceSize(QPainter &/*painter*/, JKQTMathTextEnvironment ev, double /*baselineHeight*/, double overallHeight, double &bracewidth, double &braceheight) const
 {
-    const double lw=qMax(0.25,ceil(ev.fontSize/12.0));
+    const QFontMetricsF fm(ev.getFont(parentMathText));
+    const double lw=qMax(0.25,fm.lineWidth());
     braceheight=overallHeight*parentMathText->getBraceFactor();
     bracewidth=0.6*pow(braceheight, 0.6);
     if (openbrace==MTBTCurlyBracket || closebrace==MTBTCurlyBracket)  bracewidth=qMax(bracewidth, lw*3.5);

lib/jkqtmathtext/nodes/jkqtmathtextwhitespacenode.cpp

@@ -111,8 +111,7 @@ double JKQTMathTextWhitespaceNode::draw(QPainter &painter, double x, double y, J
 
 void JKQTMathTextWhitespaceNode::getSizeInternal(QPainter &painter, JKQTMathTextEnvironment currentEv, double &width, double &baselineHeight, double &overallHeight, double &strikeoutPos, const JKQTMathTextNodeSize *prevNodeSize)
 {
-    const double singelWidthPT=Type2PointWidth(whitespace.type, currentEv);
+    const double singelWidthPIX=Type2PixelWidth(whitespace.type, currentEv, painter.device());
-    const double singelWidthPIX=singelWidthPT/72.0*painter.device()->logicalDpiX();
     const QFontMetricsF fm(currentEv.getFont(parentMathText));
     width=singelWidthPIX*static_cast<double>(whitespace.count);
     baselineHeight=0;
@@ -127,7 +126,7 @@ void JKQTMathTextWhitespaceNode::fillSupportedInstructions()
     if (supportedInstructions.size()==0) {
         supportedInstructions[" "]=WhitespaceProps(WSTthicker, 1);
         supportedInstructions["nbsp"]=WhitespaceProps(WSTNonbreaking, 1);
-        supportedInstructions["enspace"]=WhitespaceProps(WST1en, 1);
+        supportedInstructions["enspace"]=supportedInstructions["enskip"]=WhitespaceProps(WST1en, 1);
         supportedInstructions["quad"]=supportedInstructions["emspace"]=WhitespaceProps(WSTQuad, 1);
         supportedInstructions["qquad"]=WhitespaceProps(WSTQuad, 2);
         supportedInstructions[","]=supportedInstructions["thinspace"]=WhitespaceProps(WSTthin, 1);
@@ -159,13 +158,18 @@ QString JKQTMathTextWhitespaceNode::Type2String(Types type)
     return "???";
 }
 
-double JKQTMathTextWhitespaceNode::Type2PointWidth(Types type, JKQTMathTextEnvironment currentEv) const
+double JKQTMathTextWhitespaceNode::Type2PixelWidth(Types type, JKQTMathTextEnvironment currentEv, QPaintDevice* pd) const
 {
-    const double em=currentEv.fontSize;
+    const QFontMetricsF fm(currentEv.getFont(parentMathText), pd);
+#if QT_VERSION >= QT_VERSION_CHECK(5,11,0)
+    const double em=fm.horizontalAdvance(QChar(0x2003));//currentEv.fontSize;
+#else
+    const double em=fm.width(QChar(0x2003));//currentEv.fontSize;
+#endif
     const double en=em/2.0;
     switch (type) {
-        case WSTNormal: return QFontMetricsF(currentEv.getFont(parentMathText)).width(' ');
+        case WSTNormal: return fm.width(' ');
-        case WSTNonbreaking: return QFontMetricsF(currentEv.getFont(parentMathText)).width(' ');
+        case WSTNonbreaking: return fm.width(' ');
         case WST1en: return en;
         case WST1em: return em;
         case WSThair: return em/12.0;

lib/jkqtmathtext/nodes/jkqtmathtextwhitespacenode.h

@@ -57,8 +57,8 @@ class JKQTMATHTEXT_LIB_EXPORT JKQTMathTextWhitespaceNode: public JKQTMathTextNod
         };
         /** \brief converts Types \a type into a string */
         static QString Type2String(Types type);
-        /** \brief converts Types \a type into its width in points (pt), based on \a currentEv */
+        /** \brief converts Types \a type into its width in pixels, based on \a currentEv and \a pd */
-        double Type2PointWidth(Types type, JKQTMathTextEnvironment currentEv) const;
+        double Type2PixelWidth(Types type, JKQTMathTextEnvironment currentEv, QPaintDevice *pd) const;
         /** \brief checks whether a given LaTeX instruction name is supported by this node class type */
         static bool supportsInstructionName(const QString& instruction);
         /** \brief constructs a node with count=1 and type=WSTNormal */