Fix grid annotations, port tests

python/core/layout/qgslayoututils.sip

@@ -9,6 +9,7 @@
 
 
 
+
 class QgsLayoutUtils
 {
 %Docstring
@@ -87,6 +88,103 @@ class QgsLayoutUtils
  :rtype: float
 %End
 
+    static QFont scaledFontPixelSize( const QFont &font );
+%Docstring
+ Returns a ``font`` where size is set in points and the size has been upscaled with FONT_WORKAROUND_SCALE
+ to workaround QT font rendering bugs.
+ Returns a font with size set in pixels.
+ :rtype: QFont
+%End
+
+    static double fontAscentMM( const QFont &font );
+%Docstring
+ Calculates a ``font`` ascent in millimeters, including workarounds for QT font rendering issues.
+.. seealso:: fontDescentMM()
+.. seealso:: fontHeightMM()
+.. seealso:: fontHeightCharacterMM()
+.. seealso:: textWidthMM()
+ :rtype: float
+%End
+
+    static double fontDescentMM( const QFont &font );
+%Docstring
+ Calculate a ``font`` descent in millimeters, including workarounds for QT font rendering issues.
+.. seealso:: fontAscentMM()
+.. seealso:: fontHeightMM()
+.. seealso:: fontHeightCharacterMM()
+.. seealso:: textWidthMM()
+ :rtype: float
+%End
+
+    static double fontHeightMM( const QFont &font );
+%Docstring
+ Calculate a ``font`` height in millimeters, including workarounds for QT font rendering issues.
+ The font height is the font ascent + descent + 1 (for the baseline).
+.. seealso:: fontAscentMM()
+.. seealso:: fontDescentMM()
+.. seealso:: fontHeightCharacterMM()
+.. seealso:: textWidthMM()
+ :rtype: float
+%End
+
+    static double fontHeightCharacterMM( const QFont &font, QChar character );
+%Docstring
+ Calculate a ``font`` height in millimeters of a single ``character``, including workarounds for QT font
+ rendering issues.
+.. seealso:: fontAscentMM()
+.. seealso:: fontDescentMM()
+.. seealso:: fontHeightMM()
+.. seealso:: textWidthMM()
+ :rtype: float
+%End
+
+    static double textWidthMM( const QFont &font, const QString &text );
+%Docstring
+ Calculate a ``font`` width in millimeters for a ``text`` string, including workarounds for QT font
+ rendering issues.
+.. seealso:: fontAscentMM()
+.. seealso:: fontDescentMM()
+.. seealso:: fontHeightMM()
+.. seealso:: fontHeightCharacterMM()
+.. seealso:: textHeightMM()
+ :rtype: float
+%End
+
+    static double textHeightMM( const QFont &font, const QString &text, double multiLineHeight = 1.0 );
+%Docstring
+ Calculate a ``font`` height in millimeters for a ``text`` string, including workarounds for QT font
+ rendering issues. Note that this method uses a non-standard measure of text height,
+ where only the font ascent is considered for the first line of text.
+
+ The ``multiLineHeight`` parameter specifies the line spacing factor.
+
+.. seealso:: textWidthMM()
+ :rtype: float
+%End
+
+    static void drawText( QPainter *painter, QPointF position, const QString &text, const QFont &font, const QColor &color = QColor() );
+%Docstring
+ Draws ``text`` on a ``painter`` at a specific ``position``, taking care of layout specific issues (calculation to pixel,
+ scaling of font and painter to work around Qt font bugs).
+
+ If ``color`` is specified, text will be rendered in that color. If not specified, the current painter pen
+ color will be used instead.
+%End
+
+    static void drawText( QPainter *painter, const QRectF &rectangle, const QString &text, const QFont &font, const QColor &color = QColor(), const Qt::AlignmentFlag halignment = Qt::AlignLeft, const Qt::AlignmentFlag valignment = Qt::AlignTop, const int flags = Qt::TextWordWrap );
+%Docstring
+ Draws ``text`` on a ``painter`` within a ``rectangle``, taking care of layout specific issues (calculation to pixel,
+ scaling of font and painter to work around Qt font bugs).
+
+ If ``color`` is specified, text will be rendered in that color. If not specified, the current painter pen
+ color will be used instead.
+
+ The text alignment within ``rectangle`` can be set via the ``halignment`` and ``valignment``
+ arguments.
+
+ The ``flags`` parameter allows for passing Qt.TextFlags to control appearance of rendered text.
+%End
+
 };
 
 /************************************************************************

src/core/layout/qgslayoutitemmapgrid.cpp

@@ -1013,13 +1013,11 @@ void QgsLayoutItemMapGrid::drawCoordinateAnnotation( QPainter *p, QPointF pos, c
     return;
   }
 
-  QFontMetricsF fontMetrics( mGridAnnotationFont );
-
   QgsLayoutItemMapGrid::BorderSide frameBorder = borderForLineCoord( pos, coordinateType );
-  double textWidth = fontMetrics.width( annotationString );
+  double textWidth = QgsLayoutUtils::textWidthMM( mGridAnnotationFont, annotationString );
   //relevant for annotations is the height of digits
-  double textHeight = extension ? fontMetrics.ascent()
-                      : fontMetrics.boundingRect( QChar( '0' ) ).height();
+  double textHeight = extension ? QgsLayoutUtils::fontAscentMM( mGridAnnotationFont )
+                      : QgsLayoutUtils::fontHeightCharacterMM( mGridAnnotationFont, QChar( '0' ) );
   double xpos = pos.x();
   double ypos = pos.y();
   int rotation = 0;
@@ -1339,9 +1337,7 @@ void QgsLayoutItemMapGrid::drawAnnotation( QPainter *p, QPointF pos, int rotatio
   p->save();
   p->translate( pos );
   p->rotate( rotation );
-  p->setFont( mGridAnnotationFont );
-  p->setPen( mGridAnnotationFontColor );
-  p->drawText( QPointF( 0, 0 ), annotationText );
+  QgsLayoutUtils::drawText( p, QPointF( 0, 0 ), annotationText, mGridAnnotationFont, mGridAnnotationFontColor );
   p->restore();
 }
 

src/core/layout/qgslayoututils.cpp

@@ -159,3 +159,136 @@ double QgsLayoutUtils::relativePosition( const double position, const double bef
   //return linearly scaled position
   return m * position + c;
 }
+QFont QgsLayoutUtils::scaledFontPixelSize( const QFont &font )
+{
+  //upscale using FONT_WORKAROUND_SCALE
+  //ref: http://osgeo-org.1560.x6.nabble.com/Multi-line-labels-and-font-bug-td4157152.html
+  QFont scaledFont = font;
+  double pixelSize = pointsToMM( scaledFont.pointSizeF() ) * FONT_WORKAROUND_SCALE + 0.5;
+  scaledFont.setPixelSize( pixelSize );
+  return scaledFont;
+}
+
+double QgsLayoutUtils::fontAscentMM( const QFont &font )
+{
+  //upscale using FONT_WORKAROUND_SCALE
+  //ref: http://osgeo-org.1560.x6.nabble.com/Multi-line-labels-and-font-bug-td4157152.html
+  QFont metricsFont = scaledFontPixelSize( font );
+  QFontMetricsF fontMetrics( metricsFont );
+  return ( fontMetrics.ascent() / FONT_WORKAROUND_SCALE );
+}
+
+double QgsLayoutUtils::fontDescentMM( const QFont &font )
+{
+  //upscale using FONT_WORKAROUND_SCALE
+  //ref: http://osgeo-org.1560.x6.nabble.com/Multi-line-labels-and-font-bug-td4157152.html
+  QFont metricsFont = scaledFontPixelSize( font );
+  QFontMetricsF fontMetrics( metricsFont );
+  return ( fontMetrics.descent() / FONT_WORKAROUND_SCALE );
+
+}
+
+double QgsLayoutUtils::fontHeightMM( const QFont &font )
+{
+  //upscale using FONT_WORKAROUND_SCALE
+  //ref: http://osgeo-org.1560.x6.nabble.com/Multi-line-labels-and-font-bug-td4157152.html
+  QFont metricsFont = scaledFontPixelSize( font );
+  QFontMetricsF fontMetrics( metricsFont );
+  return ( fontMetrics.height() / FONT_WORKAROUND_SCALE );
+
+}
+
+double QgsLayoutUtils::fontHeightCharacterMM( const QFont &font, QChar character )
+{
+  //upscale using FONT_WORKAROUND_SCALE
+  //ref: http://osgeo-org.1560.x6.nabble.com/Multi-line-labels-and-font-bug-td4157152.html
+  QFont metricsFont = scaledFontPixelSize( font );
+  QFontMetricsF fontMetrics( metricsFont );
+  return ( fontMetrics.boundingRect( character ).height() / FONT_WORKAROUND_SCALE );
+}
+
+double QgsLayoutUtils::textWidthMM( const QFont &font, const QString &text )
+{
+  //upscale using FONT_WORKAROUND_SCALE
+  //ref: http://osgeo-org.1560.x6.nabble.com/Multi-line-labels-and-font-bug-td4157152.html
+  QFont metricsFont = scaledFontPixelSize( font );
+  QFontMetricsF fontMetrics( metricsFont );
+  return ( fontMetrics.width( text ) / FONT_WORKAROUND_SCALE );
+}
+
+double QgsLayoutUtils::textHeightMM( const QFont &font, const QString &text, double multiLineHeight )
+{
+  QStringList multiLineSplit = text.split( '\n' );
+  int lines = multiLineSplit.size();
+
+  //upscale using FONT_WORKAROUND_SCALE
+  //ref: http://osgeo-org.1560.x6.nabble.com/Multi-line-labels-and-font-bug-td4157152.html
+  QFont metricsFont = scaledFontPixelSize( font );
+  QFontMetricsF fontMetrics( metricsFont );
+
+  double fontHeight = fontMetrics.ascent() + fontMetrics.descent(); // ignore +1 for baseline
+  double textHeight = fontMetrics.ascent() + static_cast< double >( ( lines - 1 ) * fontHeight * multiLineHeight );
+
+  return textHeight / FONT_WORKAROUND_SCALE;
+}
+
+void QgsLayoutUtils::drawText( QPainter *painter, QPointF position, const QString &text, const QFont &font, const QColor &color )
+{
+  if ( !painter )
+  {
+    return;
+  }
+
+  //upscale using FONT_WORKAROUND_SCALE
+  //ref: http://osgeo-org.1560.x6.nabble.com/Multi-line-labels-and-font-bug-td4157152.html
+  QFont textFont = scaledFontPixelSize( font );
+
+  painter->save();
+  painter->setFont( textFont );
+  if ( color.isValid() )
+  {
+    painter->setPen( color );
+  }
+  double scaleFactor = 1.0 / FONT_WORKAROUND_SCALE;
+  painter->scale( scaleFactor, scaleFactor );
+  painter->drawText( position * FONT_WORKAROUND_SCALE, text );
+  painter->restore();
+}
+
+void QgsLayoutUtils::drawText( QPainter *painter, const QRectF &rect, const QString &text, const QFont &font, const QColor &color, const Qt::AlignmentFlag halignment, const Qt::AlignmentFlag valignment, const int flags )
+{
+  if ( !painter )
+  {
+    return;
+  }
+
+  //upscale using FONT_WORKAROUND_SCALE
+  //ref: http://osgeo-org.1560.x6.nabble.com/Multi-line-labels-and-font-bug-td4157152.html
+  QFont textFont = scaledFontPixelSize( font );
+
+  QRectF scaledRect( rect.x() * FONT_WORKAROUND_SCALE, rect.y() * FONT_WORKAROUND_SCALE,
+                     rect.width() * FONT_WORKAROUND_SCALE, rect.height() * FONT_WORKAROUND_SCALE );
+
+  painter->save();
+  painter->setFont( textFont );
+  if ( color.isValid() )
+  {
+    painter->setPen( color );
+  }
+  double scaleFactor = 1.0 / FONT_WORKAROUND_SCALE;
+  painter->scale( scaleFactor, scaleFactor );
+  painter->drawText( scaledRect, halignment | valignment | flags, text );
+  painter->restore();
+}
+
+double QgsLayoutUtils::pointsToMM( const double pointSize )
+{
+  //conversion to mm based on 1 point = 1/72 inch
+  return ( pointSize * 0.3527 );
+}
+
+double QgsLayoutUtils::mmToPoints( const double mmSize )
+{
+  //conversion to points based on 1 point = 1/72 inch
+  return ( mmSize / 0.3527 );
+}