Add QgsFontUtils methods for saving/loading font from XML (fix #12644)

Fixes loss of font styles when restoring projects. Credit to @nirvn
for the initial implementation.

python/core/qgsfontutils.sip

@@ -61,4 +61,37 @@ class QgsFontUtils
      * @note Added in QGIS 2.1
      */
     static QFont getStandardTestFont( const QString& style = "Roman", int pointsize = 12 );
+
+    /**Returns a DOM element containing the properties of the font.
+     * @param document DOM document
+     * @param elementName name for DOM element
+     * @returns DOM element containing font settings
+     * @note added in QGIS 2.10
+     * @see setFromXmlElement
+     */
+    static QDomElement toXmlElement( const QFont& font, QDomDocument &document, const QString &elementName );
+
+    /**Sets the properties of a font to match the properties stored in an XML element. Calling
+     * this will overwrite the current properties of the font.
+     * @param font font to update
+     * @param element DOM element
+     * @returns true if properties were successfully read from element
+     * @note added in QGIS 2.10
+     * @see toXmlElement
+     * @see setFromXmlChildNode
+     */
+    static bool setFromXmlElement( QFont& font, const QDomElement& element );
+
+    /**Sets the properties of a font to match the properties stored in an XML child node. Calling
+     * this will overwrite the current properties of the font.
+     * @param font font to update
+     * @param element DOM element
+     * @param childNode name of child node
+     * @returns true if child node exists and properties were successfully read from node
+     * @note added in QGIS 2.10
+     * @see setFromXmlElement
+     * @see toXmlElement
+     */
+    static bool setFromXmlChildNode( QFont& font, const QDomElement& element, const QString& childNode );
+
 };

src/core/composer/qgscomposerlabel.cpp

@@ -24,6 +24,7 @@
 #include "qgsvectorlayer.h"
 #include "qgsproject.h"
 #include "qgsdistancearea.h"
+#include "qgsfontutils.h"
 
 #include "qgswebview.h"
 #include "qgswebframe.h"
@@ -379,8 +380,7 @@ bool QgsComposerLabel::writeXML( QDomElement& elem, QDomDocument & doc ) const
   composerLabelElem.setAttribute( "valign", mVAlignment );
 
   //font
-  QDomElement labelFontElem = doc.createElement( "LabelFont" );
-  labelFontElem.setAttribute( "description", mFont.toString() );
+  QDomElement labelFontElem = QgsFontUtils::toXmlElement( mFont, doc, "LabelFont" );
   composerLabelElem.appendChild( labelFontElem );
 
   //font color
@@ -431,12 +431,7 @@ bool QgsComposerLabel::readXML( const QDomElement& itemElem, const QDomDocument&
   mVAlignment = ( Qt::AlignmentFlag )( itemElem.attribute( "valign" ).toInt() );
 
   //font
-  QDomNodeList labelFontList = itemElem.elementsByTagName( "LabelFont" );
-  if ( labelFontList.size() > 0 )
-  {
-    QDomElement labelFontElem = labelFontList.at( 0 ).toElement();
-    mFont.fromString( labelFontElem.attribute( "description" ) );
-  }
+  QgsFontUtils::setFromXmlChildNode( mFont, itemElem, "LabelFont" );
 
   //font color
   QDomNodeList fontColorList = itemElem.elementsByTagName( "FontColor" );

src/core/composer/qgscomposerlegendstyle.cpp

@@ -17,6 +17,7 @@
 
 #include "qgscomposerlegendstyle.h"
 #include "qgscomposition.h"
+#include "qgsfontutils.h"
 #include <QFont>
 #include <QMap>
 #include <QSettings>
@@ -61,7 +62,7 @@ void QgsComposerLegendStyle::writeXML( QString name, QDomElement& elem, QDomDocu
   if ( mMarginMap[Left] != 0 ) styleElem.setAttribute( "marginLeft", QString::number( mMarginMap[Left] ) );
   if ( mMarginMap[Right] != 0 ) styleElem.setAttribute( "marginRight", QString::number( mMarginMap[Right] ) );
 
-  styleElem.setAttribute( "font", mFont.toString() );
+  styleElem.appendChild( QgsFontUtils::toXmlElement( mFont, doc, "styleFont" ) );
 
   elem.appendChild( styleElem );
 }
@@ -71,7 +72,10 @@ void QgsComposerLegendStyle::readXML( const QDomElement& elem, const QDomDocumen
   Q_UNUSED( doc );
   if ( elem.isNull() ) return;
 
-  mFont.fromString( elem.attribute( "font" ) );
+  if ( !QgsFontUtils::setFromXmlChildNode( mFont, elem, "styleFont" ) )
+  {
+    mFont.fromString( elem.attribute( "font" ) );
+  }
 
   mMarginMap[Top] = elem.attribute( "marginTop", "0" ).toDouble();
   mMarginMap[Bottom] = elem.attribute( "marginBottom", "0" ).toDouble();

src/core/composer/qgscomposermapgrid.cpp

@@ -27,6 +27,7 @@
 #include "qgssymbolv2.h"
 #include "qgscoordinatereferencesystem.h"
 #include "qgslogger.h"
+#include "qgsfontutils.h"
 
 #include <QPainter>
 #include <QPen>
@@ -308,7 +309,7 @@ bool QgsComposerMapGrid::writeXML( QDomElement& elem, QDomDocument& doc ) const
   mapGridElem.setAttribute( "topAnnotationDirection", mTopGridAnnotationDirection );
   mapGridElem.setAttribute( "bottomAnnotationDirection", mBottomGridAnnotationDirection );
   mapGridElem.setAttribute( "frameAnnotationDistance", QString::number( mAnnotationFrameDistance ) );
-  mapGridElem.setAttribute( "annotationFont", mGridAnnotationFont.toString() );
+  mapGridElem.appendChild( QgsFontUtils::toXmlElement( mGridAnnotationFont, doc, "annotationFontProperties" ) );
   mapGridElem.setAttribute( "annotationFontColor", QgsSymbolLayerV2Utils::encodeColor( mGridAnnotationFontColor ) );
   mapGridElem.setAttribute( "annotationPrecision", mGridAnnotationPrecision );
   mapGridElem.setAttribute( "unit", mGridUnit );
@@ -429,7 +430,10 @@ bool QgsComposerMapGrid::readXML( const QDomElement& itemElem, const QDomDocumen
   mTopGridAnnotationDirection = QgsComposerMapGrid::AnnotationDirection( itemElem.attribute( "topAnnotationDirection", "0" ).toInt() );
   mBottomGridAnnotationDirection = QgsComposerMapGrid::AnnotationDirection( itemElem.attribute( "bottomAnnotationDirection", "0" ).toInt() );
   mAnnotationFrameDistance = itemElem.attribute( "frameAnnotationDistance", "0" ).toDouble();
-  mGridAnnotationFont.fromString( itemElem.attribute( "annotationFont", "" ) );
+  if ( !QgsFontUtils::setFromXmlChildNode( mGridAnnotationFont, itemElem, "annotationFontProperties" ) )
+  {
+    mGridAnnotationFont.fromString( itemElem.attribute( "annotationFont", "" ) );
+  }
   mGridAnnotationFontColor = QgsSymbolLayerV2Utils::decodeColor( itemElem.attribute( "annotationFontColor", "0,0,0,255" ) );
   mGridAnnotationPrecision = itemElem.attribute( "annotationPrecision", "3" ).toInt();
   int gridUnitInt =  itemElem.attribute( "unit", QString::number( MapUnit ) ).toInt();

src/core/composer/qgscomposerscalebar.cpp

@@ -28,6 +28,7 @@
 #include "qgsrectangle.h"
 #include "qgsproject.h"
 #include "qgssymbollayerv2utils.h"
+#include "qgsfontutils.h"
 #include <QDomDocument>
 #include <QDomElement>
 #include <QFontMetricsF>
@@ -668,7 +669,7 @@ bool QgsComposerScaleBar::writeXML( QDomElement& elem, QDomDocument & doc ) cons
   composerScaleBarElem.setAttribute( "maxBarWidth", mMaxBarWidth );
   composerScaleBarElem.setAttribute( "segmentMillimeters", QString::number( mSegmentMillimeters ) );
   composerScaleBarElem.setAttribute( "numMapUnitsPerScaleBarUnit", QString::number( mNumMapUnitsPerScaleBarUnit ) );
-  composerScaleBarElem.setAttribute( "font", mFont.toString() );
+  composerScaleBarElem.appendChild( QgsFontUtils::toXmlElement( mFont, doc, "scaleBarFont" ) );
   composerScaleBarElem.setAttribute( "outlineWidth", QString::number( mPen.widthF() ) );
   composerScaleBarElem.setAttribute( "unitLabel", mUnitLabeling );
   composerScaleBarElem.setAttribute( "units", mUnits );
@@ -755,10 +756,9 @@ bool QgsComposerScaleBar::readXML( const QDomElement& itemElem, const QDomDocume
   mPen.setJoinStyle( mLineJoinStyle );
   mLineCapStyle = QgsSymbolLayerV2Utils::decodePenCapStyle( itemElem.attribute( "lineCapStyle", "square" ) );
   mPen.setCapStyle( mLineCapStyle );
-  QString fontString = itemElem.attribute( "font", "" );
-  if ( !fontString.isEmpty() )
+  if ( !QgsFontUtils::setFromXmlChildNode( mFont, itemElem, "scaleBarFont" ) )
   {
-    mFont.fromString( fontString );
+    mFont.fromString( itemElem.attribute( "font", "" ) );
   }
 
   //colors

src/core/composer/qgscomposertable.cpp

@@ -19,6 +19,7 @@
 #include "qgscomposertablecolumn.h"
 #include "qgssymbollayerv2utils.h"
 #include "qgscomposerutils.h"
+#include "qgsfontutils.h"
 #include <QPainter>
 #include <QSettings>
 
@@ -267,10 +268,10 @@ void QgsComposerTable::setColumns( QList<QgsComposerTableColumn*> columns )
 bool QgsComposerTable::tableWriteXML( QDomElement& elem, QDomDocument & doc ) const
 {
   elem.setAttribute( "lineTextDist", QString::number( mLineTextDistance ) );
-  elem.setAttribute( "headerFont", mHeaderFont.toString() );
+  elem.appendChild( QgsFontUtils::toXmlElement( mHeaderFont, doc, "headerFontProperties" ) );
   elem.setAttribute( "headerFontColor", QgsSymbolLayerV2Utils::encodeColor( mHeaderFontColor ) );
   elem.setAttribute( "headerHAlignment", QString::number(( int )mHeaderHAlignment ) );
-  elem.setAttribute( "contentFont", mContentFont.toString() );
+  elem.appendChild( QgsFontUtils::toXmlElement( mContentFont, doc, "contentFontProperties" ) );
   elem.setAttribute( "contentFontColor", QgsSymbolLayerV2Utils::encodeColor( mContentFontColor ) );
   elem.setAttribute( "gridStrokeWidth", QString::number( mGridStrokeWidth ) );
   elem.setAttribute( "gridColor", QgsSymbolLayerV2Utils::encodeColor( mGridColor ) );
@@ -297,10 +298,16 @@ bool QgsComposerTable::tableReadXML( const QDomElement& itemElem, const QDomDocu
     return false;
   }
 
-  mHeaderFont.fromString( itemElem.attribute( "headerFont", "" ) );
+  if ( !QgsFontUtils::setFromXmlChildNode( mHeaderFont, itemElem, "headerFontProperties" ) )
+  {
+    mHeaderFont.fromString( itemElem.attribute( "headerFont", "" ) );
+  }
   mHeaderFontColor = QgsSymbolLayerV2Utils::decodeColor( itemElem.attribute( "headerFontColor", "0,0,0,255" ) );
   mHeaderHAlignment = QgsComposerTable::HeaderHAlignment( itemElem.attribute( "headerHAlignment", "0" ).toInt() );
-  mContentFont.fromString( itemElem.attribute( "contentFont", "" ) );
+  if ( !QgsFontUtils::setFromXmlChildNode( mContentFont, itemElem, "contentFontProperties" ) )
+  {
+    mContentFont.fromString( itemElem.attribute( "contentFont", "" ) );
+  }
   mContentFontColor = QgsSymbolLayerV2Utils::decodeColor( itemElem.attribute( "contentFontColor", "0,0,0,255" ) );
   mLineTextDistance = itemElem.attribute( "lineTextDist", "1.0" ).toDouble();
   mGridStrokeWidth = itemElem.attribute( "gridStrokeWidth", "0.5" ).toDouble();

src/core/composer/qgscomposertablev2.cpp

@@ -20,6 +20,7 @@
 #include "qgscomposertablecolumn.h"
 #include "qgssymbollayerv2utils.h"
 #include "qgscomposerframe.h"
+#include "qgsfontutils.h"
 
 QgsComposerTableV2::QgsComposerTableV2( QgsComposition *composition, bool createUndoCommands )
     : QgsComposerMultiFrame( composition, createUndoCommands )
@@ -80,11 +81,11 @@ bool QgsComposerTableV2::writeXML( QDomElement& elem, QDomDocument & doc, bool i
   elem.setAttribute( "emptyTableMode", QString::number(( int )mEmptyTableMode ) );
   elem.setAttribute( "emptyTableMessage", mEmptyTableMessage );
   elem.setAttribute( "showEmptyRows", mShowEmptyRows );
-  elem.setAttribute( "headerFont", mHeaderFont.toString() );
+  elem.appendChild( QgsFontUtils::toXmlElement( mHeaderFont, doc, "headerFontProperties" ) );
   elem.setAttribute( "headerFontColor", QgsSymbolLayerV2Utils::encodeColor( mHeaderFontColor ) );
   elem.setAttribute( "headerHAlignment", QString::number(( int )mHeaderHAlignment ) );
   elem.setAttribute( "headerMode", QString::number(( int )mHeaderMode ) );
-  elem.setAttribute( "contentFont", mContentFont.toString() );
+  elem.appendChild( QgsFontUtils::toXmlElement( mContentFont, doc, "contentFontProperties" ) );
   elem.setAttribute( "contentFontColor", QgsSymbolLayerV2Utils::encodeColor( mContentFontColor ) );
   elem.setAttribute( "gridStrokeWidth", QString::number( mGridStrokeWidth ) );
   elem.setAttribute( "gridColor", QgsSymbolLayerV2Utils::encodeColor( mGridColor ) );
@@ -124,11 +125,17 @@ bool QgsComposerTableV2::readXML( const QDomElement &itemElem, const QDomDocumen
   mEmptyTableMode = QgsComposerTableV2::EmptyTableMode( itemElem.attribute( "emptyTableMode", "0" ).toInt() );
   mEmptyTableMessage = itemElem.attribute( "emptyTableMessage", tr( "No matching records" ) );
   mShowEmptyRows = itemElem.attribute( "showEmptyRows", "0" ).toInt();
-  mHeaderFont.fromString( itemElem.attribute( "headerFont", "" ) );
+  if ( !QgsFontUtils::setFromXmlChildNode( mHeaderFont, itemElem, "headerFontProperties" ) )
+  {
+    mHeaderFont.fromString( itemElem.attribute( "headerFont", "" ) );
+  }
   mHeaderFontColor = QgsSymbolLayerV2Utils::decodeColor( itemElem.attribute( "headerFontColor", "0,0,0,255" ) );
   mHeaderHAlignment = QgsComposerTableV2::HeaderHAlignment( itemElem.attribute( "headerHAlignment", "0" ).toInt() );
   mHeaderMode = QgsComposerTableV2::HeaderMode( itemElem.attribute( "headerMode", "0" ).toInt() );
-  mContentFont.fromString( itemElem.attribute( "contentFont", "" ) );
+  if ( !QgsFontUtils::setFromXmlChildNode( mContentFont, itemElem, "contentFontProperties" ) )
+  {
+    mContentFont.fromString( itemElem.attribute( "contentFont", "" ) );
+  }
   mContentFontColor = QgsSymbolLayerV2Utils::decodeColor( itemElem.attribute( "contentFontColor", "0,0,0,255" ) );
   mCellMargin = itemElem.attribute( "cellMargin", "1.0" ).toDouble();
   mGridStrokeWidth = itemElem.attribute( "gridStrokeWidth", "0.5" ).toDouble();

src/core/qgsdiagramrendererv2.cpp

@@ -19,6 +19,7 @@
 #include "diagram/qgshistogramdiagram.h"
 #include "qgsrendercontext.h"
 #include "qgslayertreemodellegendnode.h"
+#include "qgsfontutils.h"
 
 #include <QDomElement>
 #include <QPainter>
@@ -79,7 +80,10 @@ void QgsDiagramSettings::readXML( const QDomElement& elem, const QgsVectorLayer*
   Q_UNUSED( layer );
 
   enabled = ( elem.attribute( "enabled", "1" ) != "0" );
-  font.fromString( elem.attribute( "font" ) );
+  if ( !QgsFontUtils::setFromXmlChildNode( font, elem, "fontProperties" ) )
+  {
+    font.fromString( elem.attribute( "font" ) );
+  }
   backgroundColor.setNamedColor( elem.attribute( "backgroundColor" ) );
   backgroundColor.setAlpha( elem.attribute( "backgroundAlpha" ).toInt() );
   size.setWidth( elem.attribute( "width" ).toDouble() );
@@ -206,7 +210,7 @@ void QgsDiagramSettings::writeXML( QDomElement& rendererElem, QDomDocument& doc,
 
   QDomElement categoryElem = doc.createElement( "DiagramCategory" );
   categoryElem.setAttribute( "enabled", enabled );
-  categoryElem.setAttribute( "font", font.toString() );
+  categoryElem.appendChild( QgsFontUtils::toXmlElement( font, doc, "fontProperties" ) );
   categoryElem.setAttribute( "backgroundColor", backgroundColor.name() );
   categoryElem.setAttribute( "backgroundAlpha", backgroundColor.alpha() );
   categoryElem.setAttribute( "width", QString::number( size.width() ) );

src/core/qgsfontutils.cpp

@@ -277,3 +277,46 @@ QFont QgsFontUtils::getStandardTestFont( const QString& style, int pointsize )
 
   return f;
 }
+
+QDomElement QgsFontUtils::toXmlElement( const QFont& font, QDomDocument& document, const QString& elementName )
+{
+  QDomElement fontElem = document.createElement( elementName );
+  fontElem.setAttribute( "description", font.toString() );
+  fontElem.setAttribute( "style", font.styleName() );
+  return fontElem;
+}
+
+bool QgsFontUtils::setFromXmlElement( QFont& font, const QDomElement& element )
+{
+  if ( element.isNull() )
+  {
+    return false;
+  }
+
+  font.fromString( element.attribute( "description" ) );
+  if ( element.hasAttribute( "style" ) )
+  {
+    ( void )updateFontViaStyle( font, element.attribute( "style" ) );
+  }
+
+  return true;
+}
+
+bool QgsFontUtils::setFromXmlChildNode( QFont& font, const QDomElement& element, const QString& childNode )
+{
+  if ( element.isNull() )
+  {
+    return false;
+  }
+
+  QDomNodeList nodeList = element.elementsByTagName( childNode );
+  if ( nodeList.size() > 0 )
+  {
+    QDomElement fontElem = nodeList.at( 0 ).toElement();
+    return setFromXmlElement( font, fontElem );
+  }
+  else
+  {
+    return false;
+  }
+}

src/core/qgsfontutils.h

@@ -18,6 +18,7 @@
 
 #include <QFont>
 #include <QString>
+#include <QDomElement>
 
 class CORE_EXPORT QgsFontUtils
 {
@@ -79,6 +80,38 @@ class CORE_EXPORT QgsFontUtils
      * @note Added in QGIS 2.1
      */
     static QFont getStandardTestFont( const QString& style = "Roman", int pointsize = 12 );
+
+    /**Returns a DOM element containing the properties of the font.
+     * @param document DOM document
+     * @param elementName name for DOM element
+     * @returns DOM element containing font settings
+     * @note added in QGIS 2.10
+     * @see setFromXmlElement
+     */
+    static QDomElement toXmlElement( const QFont& font, QDomDocument &document, const QString &elementName );
+
+    /**Sets the properties of a font to match the properties stored in an XML element. Calling
+     * this will overwrite the current properties of the font.
+     * @param font font to update
+     * @param element DOM element
+     * @returns true if properties were successfully read from element
+     * @note added in QGIS 2.10
+     * @see toXmlElement
+     * @see setFromXmlChildNode
+     */
+    static bool setFromXmlElement( QFont& font, const QDomElement& element );
+
+    /**Sets the properties of a font to match the properties stored in an XML child node. Calling
+     * this will overwrite the current properties of the font.
+     * @param font font to update
+     * @param element DOM element
+     * @param childNode name of child node
+     * @returns true if child node exists and properties were successfully read from node
+     * @note added in QGIS 2.10
+     * @see setFromXmlElement
+     * @see toXmlElement
+     */
+    static bool setFromXmlChildNode( QFont& font, const QDomElement& element, const QString& childNode );
 };
 
 #endif // QGSFONTUTILS_H

src/core/qgspallabeling.cpp

@@ -4183,7 +4183,7 @@ void QgsPalLabeling::drawLabeling( QgsRenderContext& context )
 
     //font
     QFont dFont = palGeometry->definedFont();
-    QgsDebugMsgLevel( QString( "PAL font tmpLyr: %1, Style: %2" ).arg( tmpLyr.textFont.toString() ).arg( QFontInfo( tmpLyr.textFont ).styleName() ), 4 );
+    QgsDebugMsgLevel( QString( "PAL font tmpLyr: %1, Style: %2" ).arg( tmpLyr.textFont.toString() ).arg( tmpLyr.textFont.styleName() ), 4 );
     QgsDebugMsgLevel( QString( "PAL font definedFont: %1, Style: %2" ).arg( dFont.toString() ).arg( dFont.styleName() ), 4 );
     tmpLyr.textFont = dFont;