Add support for super and subscript HTML formatting in text renderer

This allows for either: - <sup>superscript</sup> / <sub>subscript</sub> components in text, where the text will be vertically super or subscript aligned and automatically sized to 2/3rd of the parent font size. Users can also set a fixed font size for the super/sub script by including css rules, e.g. <sup style="font-size:33pt">super</sup> - "vertical-align: super" or "vertical-align: sub" CSS formatting rules in any other HTML element Sponsored by OSGEO UK
qgis · Nov 14, 2022 · a7c39ff · a7c39ff
1 parent 79b809a
commit a7c39ff
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Showing 13 changed files with 340 additions and 15 deletions.
diff --git a/python/core/auto_generated/textrenderer/qgstextdocumentmetrics.sip.in b/python/core/auto_generated/textrenderer/qgstextdocumentmetrics.sip.in
@@ -49,6 +49,19 @@ Returns ``True`` if the metrics could not be calculated because the text format
     QSizeF documentSize( Qgis::TextLayoutMode mode, Qgis::TextOrientation orientation ) const;
 %Docstring
 Returns the overall size of the document.
+%End
+
+    QRectF outerBounds( Qgis::TextLayoutMode mode, Qgis::TextOrientation orientation ) const;
+%Docstring
+Returns the outer bounds of the document, which is the :py:func:`~QgsTextDocumentMetrics.documentSize` adjusted to account
+for any text elements which fall outside of the usual document margins (such as super or
+sub script elements)
+
+.. warning::
+
+   Currently this is only supported for the Qgis.TextLayoutMode.Labeling mode.
+
+.. versionadded:: 3.30
 %End
 
     double blockWidth( int blockIndex ) const;
@@ -70,6 +83,14 @@ Returns the offset from the top of the document to the text baseline for the giv
 %Docstring
 Returns the horizontal advance of the fragment at the specified block and fragment index.
 
+.. versionadded:: 3.30
+%End
+
+    double fragmentVerticalOffset( int blockIndex, int fragmentIndex, Qgis::TextLayoutMode mode ) const;
+%Docstring
+Returns the vertical offset from a text block's baseline which should be applied
+to the fragment at the specified index within that block.
+
 .. versionadded:: 3.30
 %End
 

diff --git a/src/core/labeling/qgspallabeling.cpp b/src/core/labeling/qgspallabeling.cpp
@@ -1460,7 +1460,7 @@ bool QgsPalLayerSettings::checkMinimumSizeMM( const QgsRenderContext &ct, const
   return QgsPalLabeling::checkMinimumSizeMM( ct, geom, minSize );
 }
 
-void QgsPalLayerSettings::calculateLabelSize( const QFontMetricsF *fm, const QString &text, double &labelX, double &labelY, const QgsFeature *f, QgsRenderContext *context, double *rotatedLabelX, double *rotatedLabelY, QgsTextDocument *document, QgsTextDocumentMetrics *documentMetrics )
+void QgsPalLayerSettings::calculateLabelSize( const QFontMetricsF *fm, const QString &text, double &labelX, double &labelY, const QgsFeature *f, QgsRenderContext *context, double *rotatedLabelX, double *rotatedLabelY, QgsTextDocument *document, QgsTextDocumentMetrics *documentMetrics, QRectF *outerBounds )
 {
   if ( !fm || !f )
   {
@@ -1714,6 +1714,16 @@ void QgsPalLayerSettings::calculateLabelSize( const QFontMetricsF *fm, const QSt
     *rotatedLabelY = rh * uPP;
   }
 #endif
+
+  if ( outerBounds && documentMetrics )
+  {
+    const QRectF outerBoundsPixels = documentMetrics->outerBounds( Qgis::TextLayoutMode::Labeling, orientation );
+
+    *outerBounds = QRectF( outerBoundsPixels.left() * uPP,
+                           outerBoundsPixels.top() * uPP,
+                           outerBoundsPixels.width() * uPP,
+                           outerBoundsPixels.height() * uPP );
+  }
 }
 
 void QgsPalLayerSettings::registerFeature( const QgsFeature &f, QgsRenderContext &context )
@@ -2018,15 +2028,16 @@ std::unique_ptr<QgsLabelFeature> QgsPalLayerSettings::registerFeatureWithDetails
 
   QgsTextDocument doc;
   QgsTextDocumentMetrics documentMetrics;
+  QRectF outerBounds;
   if ( format().allowHtmlFormatting() && !labelText.isEmpty() )
   {
     doc = QgsTextDocument::fromHtml( QStringList() << labelText );
     // also applies the line split to doc and calculates document metrics!
-    calculateLabelSize( labelFontMetrics.get(), labelText, labelWidth, labelHeight, mCurFeat, &context, &rotatedLabelX, &rotatedLabelY, &doc, &documentMetrics );
+    calculateLabelSize( labelFontMetrics.get(), labelText, labelWidth, labelHeight, mCurFeat, &context, &rotatedLabelX, &rotatedLabelY, &doc, &documentMetrics, &outerBounds );
   }
   else
   {
-    calculateLabelSize( labelFontMetrics.get(), labelText, labelWidth, labelHeight, mCurFeat, &context, &rotatedLabelX, &rotatedLabelY, nullptr, nullptr );
+    calculateLabelSize( labelFontMetrics.get(), labelText, labelWidth, labelHeight, mCurFeat, &context, &rotatedLabelX, &rotatedLabelY, nullptr, nullptr, &outerBounds );
   }
 
   // maximum angle between curved label characters (hardcoded defaults used in QGIS <2.0)
@@ -2668,6 +2679,11 @@ std::unique_ptr<QgsLabelFeature> QgsPalLayerSettings::registerFeatureWithDetails
                                          obstacleGeometry.boundingBox().height() ) );
   }
 
+  if ( outerBounds.left() != 0 || outerBounds.top() != 0 || !qgsDoubleNear( outerBounds.width(), labelWidth ) || !qgsDoubleNear( outerBounds.height(), labelHeight ) )
+  {
+    labelFeature->setOuterBounds( outerBounds );
+  }
+
   //set label's visual margin so that top visual margin is the leading, and bottom margin is the font's descent
   //this makes labels align to the font's baseline or highest character
   double topMargin = std::max( 0.25 * labelFontMetrics->ascent(), 0.0 );

diff --git a/src/core/labeling/qgspallabeling.h b/src/core/labeling/qgspallabeling.h
@@ -758,7 +758,7 @@ class CORE_EXPORT QgsPalLayerSettings
      */
 #ifndef SIP_RUN
     void calculateLabelSize( const QFontMetricsF *fm, const QString &text, double &labelX, double &labelY, const QgsFeature *f = nullptr, QgsRenderContext *context = nullptr, double *rotatedLabelX SIP_OUT = nullptr, double *rotatedLabelY SIP_OUT = nullptr,
-                             QgsTextDocument *document = nullptr, QgsTextDocumentMetrics *documentMetrics = nullptr );
+                             QgsTextDocument *document = nullptr, QgsTextDocumentMetrics *documentMetrics = nullptr, QRectF *outerBounds = nullptr );
 #else
     void calculateLabelSize( const QFontMetricsF *fm, const QString &text, double &labelX, double &labelY, const QgsFeature *f = nullptr, QgsRenderContext *context = nullptr, double *rotatedLabelX SIP_OUT = nullptr, double *rotatedLabelY SIP_OUT = nullptr );
 #endif

diff --git a/src/core/labeling/qgsvectorlayerlabelprovider.cpp b/src/core/labeling/qgsvectorlayerlabelprovider.cpp
@@ -556,7 +556,7 @@ void QgsVectorLayerLabelProvider::drawLabelPrivate( pal::LabelPosition *label, Q
     painter->drawRect( rect );
 
 
-    painter->setPen( QColor( 0, 0, 0, 120 ) );
+    painter->setPen( QColor( 0, 0, 0, 60 ) );
     const QgsMargins &margins = label->getFeaturePart()->feature()->visualMargin();
     if ( margins.top() > 0 )
     {
@@ -584,7 +584,10 @@ void QgsVectorLayerLabelProvider::drawLabelPrivate( pal::LabelPosition *label, Q
                                      outerBoundsPt2.x() - outerBoundsPt1.x(),
                                      outerBoundsPt2.y() - outerBoundsPt1.y() );
 
-      painter->setPen( QColor( 255, 0, 255, 140 ) );
+      QPen pen( QColor( 255, 0, 255, 140 ) );
+      pen.setCosmetic( true );
+      pen.setWidth( 1 );
+      painter->setPen( pen );
       painter->drawRect( outerBoundsPixel );
     }
 
@@ -594,13 +597,39 @@ void QgsVectorLayerLabelProvider::drawLabelPrivate( pal::LabelPosition *label, Q
       const QgsTextDocument &document = textFeature->document();
       const int blockCount = document.size();
 
+      double prevBlockBaseline = rect.bottom() - rect.top();
+
       // draw block baselines
-      painter->setPen( QColor( 0, 0, 255, 220 ) );
       for ( int blockIndex = 0; blockIndex < blockCount; ++blockIndex )
       {
         const double blockBaseLine = metrics.baselineOffset( blockIndex, Qgis::TextLayoutMode::Labeling );
-        painter->drawLine( QPointF( rect.left(), rect.top()  + blockBaseLine ),
-                           QPointF( rect.right(), rect.top() + blockBaseLine ) );
+
+        const QgsTextBlock &block = document.at( blockIndex );
+        const int fragmentCount = block.size();
+        double left = 0;
+        for ( int fragmentIndex = 0; fragmentIndex < fragmentCount; ++fragmentIndex )
+        {
+          const double fragmentVerticalOffset = metrics.fragmentVerticalOffset( blockIndex, fragmentIndex, Qgis::TextLayoutMode::Labeling );
+          const double right = left + metrics.fragmentHorizontalAdvance( blockIndex, fragmentIndex, Qgis::TextLayoutMode::Labeling );
+
+          if ( fragmentIndex > 0 )
+          {
+            QPen pen( QColor( 0, 0, 255, 220 ) );
+            pen.setStyle( Qt::PenStyle::DashLine );
+
+            painter->setPen( pen );
+
+            painter->drawLine( QPointF( rect.left() + left, rect.top() + blockBaseLine + fragmentVerticalOffset ),
+                               QPointF( rect.left() + left, rect.top() + prevBlockBaseline ) );
+
+          }
+
+          painter->setPen( QColor( 0, 0, 255, 220 ) );
+          painter->drawLine( QPointF( rect.left() + left, rect.top()  + blockBaseLine + fragmentVerticalOffset ),
+                             QPointF( rect.left() + right, rect.top() + blockBaseLine + fragmentVerticalOffset ) );
+          left = right;
+        }
+        prevBlockBaseline = blockBaseLine;
       }
     }