Support background-color CSS styling on <hr/>

[ChangeLog][QtGui][CSS] The background-color style can now be applied to
<hr/> to set the rule color.

Task-number: QTBUG-74342
Change-Id: Ib960ce4d38caa225f258b6d228fb794cef43e1b7
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

3 files changed, 19 insertions, 4 deletions

diff --git a/src/gui/text/qtextdocument.cpp b/src/gui/text/qtextdocument.cpp
index d3bec57bd4..68cdbc092e 100644
--- a/src/gui/text/qtextdocument.cpp
+++ b/src/gui/text/qtextdocument.cpp
@@ -2359,6 +2359,7 @@ QString QTextHtmlExporter::toHtml(ExportMode mode)
         html += QString::fromLatin1("<title>") + title + QString::fromLatin1("</title>");
     html += QLatin1String("<style type=\"text/css\">\n");
     html += QLatin1String("p, li { white-space: pre-wrap; }\n");
+    html += QLatin1String("hr { height: 1px; border-width: 0; }\n");
     html += QLatin1String("</style>");
     html += QLatin1String("</head><body");
 
@@ -3047,8 +3048,15 @@ void QTextHtmlExporter::emitBlock(const QTextBlock &block)
         QTextLength width = blockFormat.lengthProperty(QTextFormat::BlockTrailingHorizontalRulerWidth);
         if (width.type() != QTextLength::VariableLength)
             emitTextLength("width", width);
-        else
-            html += QLatin1Char(' ');
+        html += QLatin1Char(' ');
+
+        if (blockFormat.hasProperty(QTextFormat::BackgroundBrush)) {
+            html += QLatin1String("style=\"");
+            html += QLatin1String("background-color:");
+            html += colorValue(qvariant_cast<QBrush>(blockFormat.property(QTextFormat::BackgroundBrush)).color());
+            html += QLatin1Char(';');
+            html += QLatin1Char('\"');
+        }
 
         html += QLatin1String("/>");
         return;
diff --git a/src/gui/text/qtextdocumentlayout.cpp b/src/gui/text/qtextdocumentlayout.cpp
index abc062bc91..77361d4608 100644
--- a/src/gui/text/qtextdocumentlayout.cpp
+++ b/src/gui/text/qtextdocumentlayout.cpp
@@ -2044,7 +2044,9 @@ void QTextDocumentLayoutPrivate::drawBlock(const QPointF &offset, QPainter *pain
             rect.setRight((fd->size.width - fd->rightMargin).toReal());
         }
 
-        fillBackground(painter, rect, bg, r.topLeft());
+        // in the case of <hr>, the background-color CSS style fills only the rule's thickness instead of the whole line
+        if (!blockFormat.hasProperty(QTextFormat::BlockTrailingHorizontalRulerWidth))
+            fillBackground(painter, rect, bg, r.topLeft());
     }
 
     QList<QTextLayout::FormatRange> selections;
@@ -2104,7 +2106,10 @@ void QTextDocumentLayoutPrivate::drawBlock(const QPointF &offset, QPainter *pain
 
     if (blockFormat.hasProperty(QTextFormat::BlockTrailingHorizontalRulerWidth)) {
         const qreal width = blockFormat.lengthProperty(QTextFormat::BlockTrailingHorizontalRulerWidth).value(r.width());
-        painter->setPen(context.palette.color(QPalette::Dark));
+        const auto color = blockFormat.hasProperty(QTextFormat::BackgroundBrush)
+                         ? qvariant_cast<QBrush>(blockFormat.property(QTextFormat::BackgroundBrush)).color()
+                         : context.palette.color(QPalette::Dark);
+        painter->setPen(color);
         qreal y = r.bottom();
         if (bl.length() == 1)
             y = r.top() + r.height() / 2;
diff --git a/src/gui/text/qtexthtmlparser.cpp b/src/gui/text/qtexthtmlparser.cpp
index 6a9f7d3a96..ae2550b69e 100644
--- a/src/gui/text/qtexthtmlparser.cpp
+++ b/src/gui/text/qtexthtmlparser.cpp
@@ -1453,6 +1453,8 @@ void QTextHtmlParserNode::applyCssDeclarations(const QList<QCss::Declaration> &d
             applyBackgroundImage(bgImage, resourceProvider);
         } else if (bgBrush.style() != Qt::NoBrush) {
             charFormat.setBackground(bgBrush);
+            if (id == Html_hr)
+                blockFormat.setProperty(QTextFormat::BackgroundBrush, bgBrush);
         }
     }
 }