Update QgsTextRenderer::textWidth/textHeight to handle HTML formatting

nyalldawson · nyalldawson · commit 5092939ef98c · 2020-05-12T11:26:42.000+10:00
diff --git a/src/app/decorations/qgsdecorationcopyright.cpp b/src/app/decorations/qgsdecorationcopyright.cpp
@@ -121,11 +121,10 @@ void QgsDecorationCopyright::render( const QgsMapSettings &mapSettings, QgsRende
   QString displayString = QgsExpression::replaceExpressionText( mLabelText, &context.expressionContext() );
   QStringList displayStringList = displayString.split( '\n' );
 
-  QFontMetricsF fm( mTextFormat.scaledFont( context ) );
   QFontMetricsF textMetrics = QgsTextRenderer::fontMetrics( context, mTextFormat );
   double textDescent = textMetrics.descent();
-  double textWidth = QgsTextRenderer::textWidth( context, mTextFormat, displayStringList, &fm );
-  double textHeight = QgsTextRenderer::textHeight( context, mTextFormat, displayStringList, QgsTextRenderer::Point, &fm );
+  double textWidth = QgsTextRenderer::textWidth( context, mTextFormat, displayStringList );
+  double textHeight = QgsTextRenderer::textHeight( context, mTextFormat, displayStringList, QgsTextRenderer::Point );
 
   QPaintDevice *device = context.painter()->device();
   int deviceHeight = device->height() / device->devicePixelRatioF();
diff --git a/src/app/decorations/qgsdecorationtitle.cpp b/src/app/decorations/qgsdecorationtitle.cpp
@@ -110,11 +110,10 @@ void QgsDecorationTitle::render( const QgsMapSettings &mapSettings, QgsRenderCon
   QString displayString = QgsExpression::replaceExpressionText( mLabelText, &context.expressionContext() );
   QStringList displayStringList = displayString.split( '\n' );
 
-  QFontMetricsF fm( mTextFormat.scaledFont( context ) );
   QFontMetricsF textMetrics = QgsTextRenderer::fontMetrics( context, mTextFormat );
   double textDescent = textMetrics.descent();
-  double textWidth = QgsTextRenderer::textWidth( context, mTextFormat, displayStringList, &fm );
-  double textHeight = QgsTextRenderer::textHeight( context, mTextFormat, displayStringList, QgsTextRenderer::Point, &fm );
+  double textWidth = QgsTextRenderer::textWidth( context, mTextFormat, displayStringList );
+  double textHeight = QgsTextRenderer::textHeight( context, mTextFormat, displayStringList, QgsTextRenderer::Point );
 
   QPaintDevice *device = context.painter()->device();
   int deviceHeight = device->height() / device->devicePixelRatioF();
diff --git a/src/core/labeling/qgsvectorlayerlabelprovider.cpp b/src/core/labeling/qgsvectorlayerlabelprovider.cpp
@@ -520,8 +520,6 @@ void QgsVectorLayerLabelProvider::drawLabelPrivate( pal::LabelPosition *label, Q
   component.origin = outPt;
   component.rotation = label->getAlpha();
 
-
-
   if ( drawType == QgsTextRenderer::Background )
   {
     // get rotated label's center point
@@ -547,7 +545,7 @@ void QgsVectorLayerLabelProvider::drawLabelPrivate( pal::LabelPosition *label, Q
 
     component.size = QSizeF( labelWidthPx, labelHeightPx );
 
-    QgsTextRenderer::drawBackground( context, component, tmpLyr.format(), QStringList(), QgsTextRenderer::Label );
+    QgsTextRenderer::drawBackground( context, component, tmpLyr.format(), QgsTextDocument(), QgsTextRenderer::Label );
   }
 
   else if ( drawType == QgsTextRenderer::Buffer
diff --git a/src/core/textrenderer/qgstextrenderer.cpp b/src/core/textrenderer/qgstextrenderer.cpp
@@ -154,8 +154,7 @@ void QgsTextRenderer::drawPart( const QRectF &rect, double rotation, QgsTextRend
         component.center = rect.center();
       }
 
-      const QStringList lines = document.toPlainText();
-      QgsTextRenderer::drawBackground( context, component, format, lines, Rect );
+      QgsTextRenderer::drawBackground( context, component, format, document, Rect );
 
       break;
     }
@@ -205,8 +204,7 @@ void QgsTextRenderer::drawPart( QPointF origin, double rotation, QgsTextRenderer
       if ( !format.background().enabled() )
         return;
 
-      const QStringList lines = document.toPlainText();
-      QgsTextRenderer::drawBackground( context, component, format, lines, Point );
+      QgsTextRenderer::drawBackground( context, component, format, document, Point );
       break;
     }
 
@@ -447,35 +445,60 @@ void QgsTextRenderer::drawMask( QgsRenderContext &context, const QgsTextRenderer
   p->restore();
 }
 
-double QgsTextRenderer::textWidth( const QgsRenderContext &context, const QgsTextFormat &format, const QStringList &textLines, QFontMetricsF *fontMetrics )
+double QgsTextRenderer::textWidth( const QgsRenderContext &context, const QgsTextFormat &format, const QStringList &textLines, QFontMetricsF * )
 {
-  //calculate max width of text lines
-  std::unique_ptr< QFontMetricsF > newFm;
-  if ( !fontMetrics )
+  if ( !format.allowHtmlFormatting() )
   {
-    newFm.reset( new QFontMetricsF( format.scaledFont( context ) ) );
-    fontMetrics = newFm.get();
+    return textWidth( context, format, QgsTextDocument::fromPlainText( textLines ) );
   }
+  else
+  {
+    return textWidth( context, format, QgsTextDocument::fromHtml( textLines ) );
+  }
+}
+
+double QgsTextRenderer::textWidth( const QgsRenderContext &context, const QgsTextFormat &format, const QgsTextDocument &document )
+{
+  //calculate max width of text lines
+  const QFont baseFont = format.scaledFont( context );
 
   double width = 0;
   switch ( format.orientation() )
   {
     case QgsTextFormat::HorizontalOrientation:
     {
       double maxLineWidth = 0;
-      const auto constTextLines = textLines;
-      for ( const QString &line : constTextLines )
+      for ( const QgsTextBlock &block : document )
       {
-        maxLineWidth = std::max( maxLineWidth, fontMetrics->width( line ) );
+        double blockWidth = 0;
+        for ( const QgsTextFragment &fragment : block )
+        {
+          blockWidth += fragment.horizontalAdvance( baseFont );
+        }
+        maxLineWidth = std::max( maxLineWidth, blockWidth );
       }
       width = maxLineWidth;
       break;
     }
 
     case QgsTextFormat::VerticalOrientation:
     {
-      double labelWidth = fontMetrics->maxWidth();
-      width = labelWidth + ( textLines.size() - 1 ) * labelWidth * format.lineHeight();
+      double totalLineWidth = 0;
+      int blockIndex = 0;
+      for ( const QgsTextBlock &block : document )
+      {
+        double blockWidth = 0;
+        for ( const QgsTextFragment &fragment : block )
+        {
+          QFont fragmentFont = baseFont;
+          fragment.characterFormat().updateFontForFormat( fragmentFont );
+          blockWidth = std::max( QFontMetricsF( fragmentFont ).maxWidth(), blockWidth );
+        }
+
+        totalLineWidth += blockIndex == 0 ? blockWidth : blockWidth * format.lineHeight();
+        blockIndex++;
+      }
+      width = totalLineWidth;
       break;
     }
 
@@ -489,49 +512,92 @@ double QgsTextRenderer::textWidth( const QgsRenderContext &context, const QgsTex
   return width;
 }
 
-double QgsTextRenderer::textHeight( const QgsRenderContext &context, const QgsTextFormat &format, const QStringList &textLines, DrawMode mode, QFontMetricsF *fontMetrics )
+double QgsTextRenderer::textHeight( const QgsRenderContext &context, const QgsTextFormat &format, const QStringList &textLines, DrawMode mode, QFontMetricsF * )
 {
-  //calculate max width of text lines
-  std::unique_ptr< QFontMetricsF > newFm;
-  if ( !fontMetrics )
+  if ( !format.allowHtmlFormatting() )
   {
-    newFm.reset( new QFontMetricsF( format.scaledFont( context ) ) );
-    fontMetrics = newFm.get();
+    return textHeight( context, format, QgsTextDocument::fromPlainText( textLines ), mode );
   }
+  else
+  {
+    return textHeight( context, format, QgsTextDocument::fromHtml( textLines ), mode );
+  }
+}
+
+double QgsTextRenderer::textHeight( const QgsRenderContext &context, const QgsTextFormat &format, const QgsTextDocument &document, DrawMode mode )
+{
+  //calculate max height of text lines
+
+  const QFont baseFont = format.scaledFont( context );
 
   switch ( format.orientation() )
   {
     case QgsTextFormat::HorizontalOrientation:
     {
-      double labelHeight = fontMetrics->ascent() + fontMetrics->descent(); // ignore +1 for baseline
-      switch ( mode )
+      int blockIndex = 0;
+      double totalHeight = 0;
+      for ( const QgsTextBlock &block : document )
       {
-        case Label:
-          // rendering labels needs special handling - in this case text should be
-          // drawn with the bottom left corner coinciding with origin, vs top left
-          // for standard text rendering. Line height is also slightly different.
-          return labelHeight + ( textLines.size() - 1 ) * labelHeight * format.lineHeight();
+        double maxBlockHeight = 0;
+        double maxBlockLineSpacing = 0;
+        for ( const QgsTextFragment &fragment : block )
+        {
+          QFont fragmentFont = baseFont;
+          fragment.characterFormat().updateFontForFormat( fragmentFont );
+          const QFontMetricsF fm( fragmentFont );
 
-        case Rect:
-        case Point:
-          // standard rendering - designed to exactly replicate QPainter's drawText method
-          return labelHeight + ( textLines.size() - 1 ) * fontMetrics->lineSpacing() * format.lineHeight();
+          const double fragmentHeight = fm.ascent() + fm.descent(); // ignore +1 for baseline
+
+          maxBlockHeight = std::max( maxBlockHeight, fragmentHeight );
+          maxBlockLineSpacing = std::max( maxBlockLineSpacing, fm.lineSpacing() );
+        }
+
+        switch ( mode )
+        {
+          case Label:
+            // rendering labels needs special handling - in this case text should be
+            // drawn with the bottom left corner coinciding with origin, vs top left
+            // for standard text rendering. Line height is also slightly different.
+            totalHeight += blockIndex == 0 ? maxBlockHeight : maxBlockHeight * format.lineHeight();
+            break;
+
+          case Rect:
+          case Point:
+            // standard rendering - designed to exactly replicate QPainter's drawText method
+            totalHeight += blockIndex == 0 ? maxBlockHeight : maxBlockLineSpacing * format.lineHeight();
+            break;
+        }
+
+        blockIndex++;
       }
-      break;
+
+      return totalHeight;
     }
 
     case QgsTextFormat::VerticalOrientation:
     {
-      double labelHeight = fontMetrics->ascent();
-      double letterSpacing = format.scaledFont( context ).letterSpacing();
-      int maxLineLength = 0;
-      for ( const auto &line : textLines )
+      double maxBlockHeight = 0;
+      for ( const QgsTextBlock &block : document )
       {
-        if ( line.length() > maxLineLength )
-          maxLineLength = line.length();
+        double blockHeight = 0;
+        int fragmentIndex = 0;
+        for ( const QgsTextFragment &fragment : block )
+        {
+          QFont fragmentFont = baseFont;
+          fragment.characterFormat().updateFontForFormat( fragmentFont );
+          const QFontMetricsF fm( fragmentFont );
+
+          const double labelHeight = fm.ascent();
+          const double letterSpacing = fragmentFont.letterSpacing();
+
+          blockHeight += fragmentIndex = 0 ? labelHeight * fragment.text().size() + ( fragment.text().size() - 1 ) * letterSpacing
+                                         : fragment.text().size() * ( labelHeight + letterSpacing );
+          fragmentIndex++;
+        }
+        maxBlockHeight = std::max( maxBlockHeight, blockHeight );
       }
-      return labelHeight * maxLineLength + ( maxLineLength - 1 ) * letterSpacing;
-      break;
+
+      return maxBlockHeight;
     }
 
     case QgsTextFormat::RotationBasedOrientation:
@@ -544,8 +610,7 @@ double QgsTextRenderer::textHeight( const QgsRenderContext &context, const QgsTe
   return 0;
 }
 
-void QgsTextRenderer::drawBackground( QgsRenderContext &context, QgsTextRenderer::Component component, const QgsTextFormat &format,
-                                      const QStringList &textLines, DrawMode mode )
+void QgsTextRenderer::drawBackground( QgsRenderContext &context, QgsTextRenderer::Component component, const QgsTextFormat &format, const QgsTextDocument &document, QgsTextRenderer::DrawMode mode )
 {
   QgsTextBackgroundSettings background = format.background();
 
@@ -578,8 +643,8 @@ void QgsTextRenderer::drawBackground( QgsRenderContext &context, QgsTextRenderer
   {
     // need to calculate size of text
     QFontMetricsF fm( format.scaledFont( context ) );
-    double width = textWidth( context, format, textLines, &fm );
-    double height = textHeight( context, format, textLines, mode, &fm );
+    double width = textWidth( context, format, document );
+    double height = textHeight( context, format, document, mode );
 
     switch ( mode )
     {
diff --git a/src/core/textrenderer/qgstextrenderer.h b/src/core/textrenderer/qgstextrenderer.h
@@ -215,6 +215,9 @@ class CORE_EXPORT QgsTextRenderer
       HAlignment hAlign = AlignLeft;
     };
 
+    static double textWidth( const QgsRenderContext &context, const QgsTextFormat &format, const QgsTextDocument &document );
+    static double textHeight( const QgsRenderContext &context, const QgsTextFormat &format, const QgsTextDocument &document, DrawMode mode );
+
     /**
      * Draws a single component of rendered text using the specified settings.
      * \param rect destination rectangle for text
@@ -258,7 +261,7 @@ class CORE_EXPORT QgsTextRenderer
     static void drawBackground( QgsRenderContext &context,
                                 Component component,
                                 const QgsTextFormat &format,
-                                const QStringList &textLines,
+                                const QgsTextDocument &document,
                                 DrawMode mode = Rect );
 
     static void drawShadow( QgsRenderContext &context,

Original file line number	Diff line number	Diff line change
`@@ -520,8 +520,6 @@ void QgsVectorLayerLabelProvider::drawLabelPrivate( pal::LabelPosition *label, Q`
`520`	`520`	`component.origin = outPt;`
`521`	`521`	`component.rotation = label->getAlpha();`
`522`	`522`
`523`		`-`
`524`		`-`
`525`	`523`	`if ( drawType == QgsTextRenderer::Background )`
`526`	`524`	`{`
`527`	`525`	`// get rotated label's center point`
`@@ -547,7 +545,7 @@ void QgsVectorLayerLabelProvider::drawLabelPrivate( pal::LabelPosition *label, Q`
`547`	`545`
`548`	`546`	`component.size = QSizeF( labelWidthPx, labelHeightPx );`
`549`	`547`
`550`		`- QgsTextRenderer::drawBackground( context, component, tmpLyr.format(), QStringList(), QgsTextRenderer::Label );`
	`548`	`+ QgsTextRenderer::drawBackground( context, component, tmpLyr.format(), QgsTextDocument(), QgsTextRenderer::Label );`
`551`	`549`	`}`
`552`	`550`
`553`	`551`	`else if ( drawType == QgsTextRenderer::Buffer`