Implement support for stroke color and width in CSS parser

CSS does not have text outline properties, instead different
browsers have custom properties for this. That currently means
that you can have a QTextDocument where you applied a stroke to
text and textEdit.setHtml(textEdit.toHtml()) will remove it.

Since a primary goal of the HTML support in QTextDocument is that
it can be used to save and faithfully restore its contents, we
implement qt specific properties for stroke.

Task-number: QTBUG-123357
Change-Id: Id9cf63abfabe2109ffb6fd74f9cb013304763ccb
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

5 files changed, 59 insertions, 0 deletions

diff --git a/src/gui/text/qcssparser.cpp b/src/gui/text/qcssparser.cpp
index 2082263d7c..5861003de6 100644
--- a/src/gui/text/qcssparser.cpp
+++ b/src/gui/text/qcssparser.cpp
@@ -44,6 +44,8 @@ static const QCssKnownValue properties[NumProperties - 1] = {
     { "-qt-list-number-prefix", QtListNumberPrefix },
     { "-qt-list-number-suffix", QtListNumberSuffix },
     { "-qt-paragraph-type", QtParagraphType },
+    { "-qt-stroke-color", QtStrokeColor },
+    { "-qt-stroke-width", QtStrokeWidth },
     { "-qt-style-features", QtStyleFeatures },
     { "-qt-table-type", QtTableType },
     { "-qt-user-state", QtUserState },
diff --git a/src/gui/text/qcssparser_p.h b/src/gui/text/qcssparser_p.h
index 1369bdf162..a2d3622c7d 100644
--- a/src/gui/text/qcssparser_p.h
+++ b/src/gui/text/qcssparser_p.h
@@ -167,6 +167,8 @@ enum Property {
     TextDecorationColor,
     QtPlaceHolderTextColor,
     QtAccent,
+    QtStrokeWidth,
+    QtStrokeColor,
     NumProperties
 };
 
diff --git a/src/gui/text/qtextdocument.cpp b/src/gui/text/qtextdocument.cpp
index b5dd8c2b83..dc94643e8a 100644
--- a/src/gui/text/qtextdocument.cpp
+++ b/src/gui/text/qtextdocument.cpp
@@ -2701,6 +2701,18 @@ bool QTextHtmlExporter::emitCharFormatStyle(const QTextCharFormat &format)
         attributesEmitted = true;
     }
 
+    if (format.hasProperty(QTextFormat::TextOutline)) {
+        QPen outlinePen = format.textOutline();
+        html += " -qt-stroke-color:"_L1;
+        html += colorValue(outlinePen.color());
+        html += u';';
+
+        html += " -qt-stroke-width:"_L1;
+        html += QString::number(outlinePen.widthF());
+        html += "px;"_L1;
+        attributesEmitted = true;
+    }
+
     return attributesEmitted;
 }
 
diff --git a/src/gui/text/qtexthtmlparser.cpp b/src/gui/text/qtexthtmlparser.cpp
index 1168c6d5cd..df6e678827 100644
--- a/src/gui/text/qtexthtmlparser.cpp
+++ b/src/gui/text/qtexthtmlparser.cpp
@@ -1387,6 +1387,24 @@ void QTextHtmlParserNode::applyCssDeclarations(const QList<QCss::Declaration> &d
             }
             break;
         }
+        case QCss::QtStrokeColor:
+        {
+            QPen pen = charFormat.textOutline();
+            pen.setStyle(Qt::SolidLine);
+            pen.setColor(decl.colorValue());
+            charFormat.setTextOutline(pen);
+            break;
+        }
+        case QCss::QtStrokeWidth:
+        {
+            qreal width;
+            if (decl.realValue(&width, "px")) {
+                QPen pen = charFormat.textOutline();
+                pen.setWidthF(width);
+                charFormat.setTextOutline(pen);
+            }
+            break;
+        }
         default: break;
         }
     }
diff --git a/tests/auto/gui/text/qtextdocument/tst_qtextdocument.cpp b/tests/auto/gui/text/qtextdocument/tst_qtextdocument.cpp
index d233f6be18..ae6b0b28df 100644
--- a/tests/auto/gui/text/qtextdocument/tst_qtextdocument.cpp
+++ b/tests/auto/gui/text/qtextdocument/tst_qtextdocument.cpp
@@ -183,6 +183,8 @@ private slots:
     void delayedLayout();
     void undoContentChangeIndices();
 
+    void restoreStrokeFromHtml();
+
 private:
     void backgroundImage_checkExpectedHtml(const QTextDocument &doc);
     void buildRegExpData();
@@ -4045,5 +4047,28 @@ void tst_QTextDocument::undoContentChangeIndices() // QTBUG-113865
     QVERIFY(documentLength >= changeEnd);
 }
 
+void tst_QTextDocument::restoreStrokeFromHtml()
+{
+    QTextDocument document;
+    QTextCursor textCursor(&document);
+    QTextCharFormat textOutline;
+    textOutline.setTextOutline(QPen(Qt::red, 2.3));
+    textCursor.insertText("Outlined text", textOutline);
+
+    {
+        QTextDocument otherDocument;
+        otherDocument.setHtml(document.toHtml());
+        QCOMPARE(otherDocument.blockCount(), 1);
+        QTextBlock block = otherDocument.firstBlock();
+        QTextFragment fragment = block.begin().fragment();
+        QCOMPARE(fragment.text(), QStringLiteral("Outlined text"));
+        QTextCharFormat fmt = fragment.charFormat();
+        QVERIFY(fmt.hasProperty(QTextCharFormat::TextOutline));
+        QPen pen = fmt.textOutline();
+        QCOMPARE(pen.color(), QColor(Qt::red));
+        QCOMPARE(pen.widthF(), 2.3);
+    }
+}
+
 QTEST_MAIN(tst_QTextDocument)
 #include "tst_qtextdocument.moc"