QFont: Extend the string description to include the missing elements

This extends to/fromString to include style strategy, capitalization,
letter and word spacing and stretch. QFont::fromString() keeps
compatibility with strings from earlier versions as well.

Fixes: QTBUG-67687
Change-Id: I5e95a58f1cd850214af2a7d8906a214facd4e661
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

3 files changed, 50 insertions, 6 deletions

diff --git a/src/gui/text/qfont.cpp b/src/gui/text/qfont.cpp
index b5eab1cdb5..b4e33b4270 100644
--- a/src/gui/text/qfont.cpp
+++ b/src/gui/text/qfont.cpp
@@ -1988,7 +1988,13 @@ QString QFont::toString() const
         QString::number((int) underline()) + comma +
         QString::number((int) strikeOut()) + comma +
         QString::number((int)fixedPitch()) + comma +
-        QString::number((int)   false);
+        QString::number((int)   false) + comma +
+        QString::number((int)capitalization()) + comma +
+        QString::number((int)letterSpacingType()) + comma +
+        QString::number(letterSpacing()) + comma +
+        QString::number(wordSpacing()) + comma +
+        QString::number(stretch()) + comma +
+        QString::number((int)styleStrategy());
 
     QString fontStyle = styleName();
     if (!fontStyle.isEmpty())
@@ -2022,7 +2028,7 @@ bool QFont::fromString(const QString &descrip)
     const auto sr = QStringView(descrip).trimmed();
     const auto l = sr.split(QLatin1Char(','));
     const int count = l.count();
-    if (!count || (count > 2 && count < 9) || count > 11 ||
+    if (!count || (count > 2 && count < 9) || count == 9 || count > 17 ||
         l.first().isEmpty()) {
         qWarning("QFont::fromString: Invalid description '%s'",
                  descrip.isEmpty() ? "(empty)" : descrip.toLatin1().data());
@@ -2048,8 +2054,15 @@ bool QFont::fromString(const QString &descrip)
         setUnderline(l[6].toInt());
         setStrikeOut(l[7].toInt());
         setFixedPitch(l[8].toInt());
-        if (count == 11)
-            d->request.styleName = l[10].toString();
+        if (count >= 16) {
+            setCapitalization((Capitalization)l[10].toInt());
+            setLetterSpacing((SpacingType)l[11].toInt(), l[12].toDouble());
+            setWordSpacing(l[13].toDouble());
+            setStretch(l[14].toInt());
+            setStyleStrategy((StyleStrategy)l[15].toInt());
+        }
+        if (count == 11 || count == 17)
+            d->request.styleName = l[count - 1].toString();
         else
             d->request.styleName.clear();
     }
diff --git a/tests/auto/gui/kernel/qguivariant/test/tst_qguivariant.cpp b/tests/auto/gui/kernel/qguivariant/test/tst_qguivariant.cpp
index 840317347a..1e9e1f40d6 100644
--- a/tests/auto/gui/kernel/qguivariant/test/tst_qguivariant.cpp
+++ b/tests/auto/gui/kernel/qguivariant/test/tst_qguivariant.cpp
@@ -384,7 +384,7 @@ void tst_QGuiVariant::toString_data()
 #endif
 
     QFont font( "times", 12 );
-    QTest::newRow( "qfont" ) << QVariant::fromValue( font ) << QString("times,12,-1,5,50,0,0,0,0,0");
+    QTest::newRow("qfont") << QVariant::fromValue(font) << QString("times,12,-1,5,50,0,0,0,0,0,0,0,0,0,0,1");
     QTest::newRow( "qcolor" ) << QVariant::fromValue( QColor( 10, 10, 10 ) ) << QString( "#0a0a0a" );
 }
 
diff --git a/tests/auto/gui/text/qfont/tst_qfont.cpp b/tests/auto/gui/text/qfont/tst_qfont.cpp
index eb9d83c525..83d8d01062 100644
--- a/tests/auto/gui/text/qfont/tst_qfont.cpp
+++ b/tests/auto/gui/text/qfont/tst_qfont.cpp
@@ -588,6 +588,30 @@ void tst_QFont::toAndFromString()
 
         QCOMPARE(result, initial);
     }
+
+    // Since Qt 6.0 it was changed to include more information in the description, so
+    // this checks for compatibility
+    const QString fontStringFrom515(QLatin1String("Times New Roman,18,-1,5,75,1,0,0,1,0,Regular"));
+    QFont fontFrom515("Times New Roman", 18);
+    fontFrom515.setBold(true);
+    fontFrom515.setItalic(true);
+    fontFrom515.setFixedPitch(true);
+    fontFrom515.setStyleName("Regular");
+    QFont from515String;
+    from515String.fromString(fontStringFrom515);
+    QCOMPARE(from515String, fontFrom515);
+
+    const QString fontStringFrom60(QLatin1String("Times New Roman,18,-1,5,75,1,0,0,1,0,1,0,150.5,2.5,50,2,Regular"));
+    QFont fontFrom60 = fontFrom515;
+    fontFrom60.setStyleStrategy(QFont::PreferBitmap);
+    fontFrom60.setCapitalization(QFont::AllUppercase);
+    fontFrom60.setLetterSpacing(QFont::PercentageSpacing, 150.5);
+    fontFrom60.setWordSpacing(2.5);
+    fontFrom60.setStretch(50);
+    QFont from60String;
+    from60String.fromString(fontStringFrom60);
+    QCOMPARE(fontFrom60.toString(), fontStringFrom60);
+    QCOMPARE(from60String, fontFrom60);
 }
 
 void tst_QFont::fromStringWithoutStyleName()
@@ -596,10 +620,17 @@ void tst_QFont::fromStringWithoutStyleName()
     font1.fromString("Noto Sans,12,-1,5,50,0,0,0,0,0,Regular");
 
     QFont font2 = font1;
-    const QString str = "Times,16,-1,5,50,0,0,0,0,0";
+    const QString str = "Times,16,-1,5,50,0,0,0,0,0,0,0,0,0,0,1";
     font2.fromString(str);
 
     QCOMPARE(font2.toString(), str);
+
+    const QString fontStringFrom60(QLatin1String("Times New Roman,18,-1,5,75,1,0,0,1,0,1,0,150.5,2.5,50,2"));
+    QFont font3;
+    font3.fromString("Noto Sans,12,-1,5,50,0,0,0,0,0,Regular");
+    QFont font4 = font3;
+    font4.fromString(fontStringFrom60);
+    QCOMPARE(font4.toString(), fontStringFrom60);
 }
 
 void tst_QFont::fromDegenerateString_data()