Implement color role AccentColor in QStyleSheetStyle and QCssParser

The color role AccentColor has been added to QPalette.

This patch implements the new color role in QCssParser and subsequently
in QStyleSheetStyle.
The QBrush variable names used to populate brushes, have been changed
into speaking names for better code readability.

tst_QCssParser has been adapted accordingly.
The test function accentColor() has been added in tst_QStyleSheetStyle.

Documentation has been updated.

Change-Id: Ib09ddc1b61868f2bb8f70f654e83ea1c35276d30
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

6 files changed, 76 insertions, 23 deletions

diff --git a/src/gui/text/qcssparser.cpp b/src/gui/text/qcssparser.cpp
index f79369a36b..02d99a82ed 100644
--- a/src/gui/text/qcssparser.cpp
+++ b/src/gui/text/qcssparser.cpp
@@ -47,6 +47,7 @@ static const QCssKnownValue properties[NumProperties - 1] = {
     { "-qt-style-features", QtStyleFeatures },
     { "-qt-table-type", QtTableType },
     { "-qt-user-state", QtUserState },
+    { "accent-color", QtAccentColor },
     { "alternate-background-color", QtAlternateBackground },
     { "background", Background },
     { "background-attachment", BackgroundAttachment },
@@ -1341,17 +1342,23 @@ bool ValueExtractor::extractFont(QFont *font, int *fontSizeAdjustment)
     return hit;
 }
 
-bool ValueExtractor::extractPalette(QBrush *fg, QBrush *sfg, QBrush *sbg, QBrush *abg, QBrush *pfg)
+bool ValueExtractor::extractPalette(QBrush *foreground,
+                                    QBrush *selectedForeground,
+                                    QBrush *selectedBackground,
+                                    QBrush *alternateBackground,
+                                    QBrush *placeHolderTextForeground,
+                                    QBrush *accentColor)
 {
     bool hit = false;
     for (int i = 0; i < declarations.size(); ++i) {
         const Declaration &decl = declarations.at(i);
         switch (decl.d->propertyId) {
-        case Color: *fg = decl.brushValue(pal); break;
-        case QtSelectionForeground: *sfg = decl.brushValue(pal); break;
-        case QtSelectionBackground: *sbg = decl.brushValue(pal); break;
-        case QtAlternateBackground: *abg = decl.brushValue(pal); break;
-        case QtPlaceHolderTextColor: *pfg = decl.brushValue(pal); break;
+        case Color: *foreground = decl.brushValue(pal); break;
+        case QtSelectionForeground: *selectedForeground = decl.brushValue(pal); break;
+        case QtSelectionBackground: *selectedBackground = decl.brushValue(pal); break;
+        case QtAlternateBackground: *alternateBackground = decl.brushValue(pal); break;
+        case QtPlaceHolderTextColor: *placeHolderTextForeground = decl.brushValue(pal); break;
+        case QtAccentColor: *accentColor = decl.brushValue(pal); break;
         default: continue;
         }
         hit = true;
diff --git a/src/gui/text/qcssparser_p.h b/src/gui/text/qcssparser_p.h
index 8e4c7ce62d..20177312af 100644
--- a/src/gui/text/qcssparser_p.h
+++ b/src/gui/text/qcssparser_p.h
@@ -166,6 +166,7 @@ enum Property {
     WordSpacing,
     TextDecorationColor,
     QtPlaceHolderTextColor,
+    QtAccentColor,
     NumProperties
 };
 
@@ -823,7 +824,9 @@ struct Q_GUI_EXPORT ValueExtractor
     bool extractBox(int *margins, int *paddings, int *spacing = nullptr);
     bool extractBorder(int *borders, QBrush *colors, BorderStyle *Styles, QSize *radii);
     bool extractOutline(int *borders, QBrush *colors, BorderStyle *Styles, QSize *radii, int *offsets);
-    bool extractPalette(QBrush *fg, QBrush *sfg, QBrush *sbg, QBrush *abg, QBrush *pfg);
+    bool extractPalette(QBrush *foreground, QBrush *selectedForeground, QBrush *selectedBackground,
+                        QBrush *alternateBackground, QBrush *placeHolderTextForeground,
+                        QBrush *accentColor);
     int  extractStyleFeatures();
     bool extractImage(QIcon *icon, Qt::Alignment *a, QSize *size);
     bool extractIcon(QIcon *icon, QSize *size);
diff --git a/src/widgets/doc/src/widgets-and-layouts/stylesheet.qdoc b/src/widgets/doc/src/widgets-and-layouts/stylesheet.qdoc
index 0115285454..5315fe85d4 100644
--- a/src/widgets/doc/src/widgets-and-layouts/stylesheet.qdoc
+++ b/src/widgets/doc/src/widgets-and-layouts/stylesheet.qdoc
@@ -1358,6 +1358,13 @@
         \li Description
 
     \row
+        \li \b{\c accent-color}
+        \li \l{#Brush}{Brush} \br
+        \li The property sets the \c AccentColor, which is used to emphasize
+           interactive UI elements.
+           If this property is not set, it defaults to the \c highlight color.
+
+    \row
         \li \b{\c alternate-background-color} \target alternate-background-color-prop
         \li \l{#Brush}{Brush} \br
         \li The \l{QAbstractItemView::alternatingRowColors}
@@ -3064,6 +3071,7 @@
     \row
         \li \b{PaletteRole} \target PaletteRole
         \li \c alternate-base \br
+              | \c accentColor \br
               | \c base \br
               | \c bright-text \br
               | \c button \br
diff --git a/src/widgets/styles/qstylesheetstyle.cpp b/src/widgets/styles/qstylesheetstyle.cpp
index c2a720c433..5d0432d2e0 100644
--- a/src/widgets/styles/qstylesheetstyle.cpp
+++ b/src/widgets/styles/qstylesheetstyle.cpp
@@ -434,16 +434,26 @@ struct QStyleSheetBoxData : public QSharedData
 
 struct QStyleSheetPaletteData : public QSharedData
 {
-    QStyleSheetPaletteData(const QBrush &fg, const QBrush &sfg, const QBrush &sbg,
-                           const QBrush &abg, const QBrush &pfg)
-        : foreground(fg), selectionForeground(sfg), selectionBackground(sbg),
-          alternateBackground(abg), placeholderForeground(pfg) { }
+     QStyleSheetPaletteData(const QBrush &foreground,
+                            const QBrush &selectedForeground,
+                            const QBrush &selectedBackground,
+                            const QBrush &alternateBackground,
+                            const QBrush &placeHolderTextForeground,
+                            const QBrush &accentColor)
+        : foreground(foreground)
+        , selectionForeground(selectedForeground)
+        , selectionBackground(selectedBackground)
+        , alternateBackground(alternateBackground)
+        , placeholderForeground(placeHolderTextForeground)
+        , accentColor(accentColor)
+     { }
 
     QBrush foreground;
     QBrush selectionForeground;
     QBrush selectionBackground;
     QBrush alternateBackground;
     QBrush placeholderForeground;
+    QBrush accentColor;
 };
 
 struct QStyleSheetGeometryData : public QSharedData
@@ -955,10 +965,17 @@ QRenderRule::QRenderRule(const QList<Declaration> &declarations, const QObject *
         bg = new QStyleSheetBackgroundData(brush, pixmap, repeat, alignment, origin, attachment, clip);
     }
 
-    QBrush sfg, fg, pfg;
-    QBrush sbg, abg;
-    if (v.extractPalette(&fg, &sfg, &sbg, &abg, &pfg))
-        pal = new QStyleSheetPaletteData(fg, sfg, sbg, abg, pfg);
+    QBrush foreground;
+    QBrush selectedForeground;
+    QBrush selectedBackground;
+    QBrush alternateBackground;
+    QBrush placeHolderTextForeground;
+    QBrush accentColor;
+    if (v.extractPalette(&foreground, &selectedForeground, &selectedBackground,
+                         &alternateBackground, &placeHolderTextForeground, &accentColor)) {
+        pal = new QStyleSheetPaletteData(foreground, selectedForeground, selectedBackground,
+                                         alternateBackground, placeHolderTextForeground, accentColor);
+    }
 
     QIcon imgIcon;
     alignment = Qt::AlignCenter;
@@ -1487,6 +1504,8 @@ void QRenderRule::configurePalette(QPalette *p, QPalette::ColorGroup cg, const Q
         p->setBrush(cg, QPalette::AlternateBase, pal->alternateBackground);
     if (pal->placeholderForeground.style() != Qt::NoBrush)
         p->setBrush(cg, QPalette::PlaceholderText, pal->placeholderForeground);
+    if (pal->accentColor.style() != Qt::NoBrush)
+        p->setBrush(cg, QPalette::AccentColor, pal->accentColor);
 }
 
 bool QRenderRule::hasModification() const
diff --git a/tests/auto/gui/text/qcssparser/tst_qcssparser.cpp b/tests/auto/gui/text/qcssparser/tst_qcssparser.cpp
index 5ca983450a..778c4a002e 100644
--- a/tests/auto/gui/text/qcssparser/tst_qcssparser.cpp
+++ b/tests/auto/gui/text/qcssparser/tst_qcssparser.cpp
@@ -1543,20 +1543,26 @@ void tst_QCssParser::gradient()
     QList<QCss::StyleRule> rules = testSelector.styleRulesForNode(n);
     QList<QCss::Declaration> decls = rules.at(0).declarations;
     QCss::ValueExtractor ve(decls);
-    QBrush fg, sfg, pfg;
-    QBrush sbg, abg;
-    QVERIFY(ve.extractPalette(&fg, &sfg, &sbg, &abg, &pfg));
+    QBrush foreground;
+    QBrush selectedForeground;
+    QBrush selectedBackground;
+    QBrush alternateBackground;
+    QBrush placeHolderTextForeground;
+    QBrush accentColor;
+    QVERIFY(ve.extractPalette(&foreground, &selectedForeground, &selectedBackground,
+                              &alternateBackground, &placeHolderTextForeground, &accentColor));
+
     if (type == "linear") {
-        QCOMPARE(sbg.style(), Qt::LinearGradientPattern);
-        const QLinearGradient *lg = static_cast<const QLinearGradient *>(sbg.gradient());
+        QCOMPARE(selectedBackground.style(), Qt::LinearGradientPattern);
+        const auto *lg = static_cast<const QLinearGradient *>(selectedBackground.gradient());
         QCOMPARE(lg->start(), start);
         QCOMPARE(lg->finalStop(), finalStop);
     } else if (type == "conical") {
-        QCOMPARE(sbg.style(), Qt::ConicalGradientPattern);
-        const QConicalGradient *cg = static_cast<const QConicalGradient *>(sbg.gradient());
+        QCOMPARE(selectedBackground.style(), Qt::ConicalGradientPattern);
+        const auto *cg = static_cast<const QConicalGradient *>(selectedBackground.gradient());
         QCOMPARE(cg->center(), start);
     }
-    const QGradient *g = sbg.gradient();
+    const QGradient *g = selectedBackground.gradient();
     QCOMPARE(g->spread(), QGradient::Spread(spread));
     QCOMPARE(g->stops().at(0).first, stop0);
     QCOMPARE(g->stops().at(0).second, color0);
diff --git a/tests/auto/widgets/styles/qstylesheetstyle/tst_qstylesheetstyle.cpp b/tests/auto/widgets/styles/qstylesheetstyle/tst_qstylesheetstyle.cpp
index c36f3ada01..39a568008a 100644
--- a/tests/auto/widgets/styles/qstylesheetstyle/tst_qstylesheetstyle.cpp
+++ b/tests/auto/widgets/styles/qstylesheetstyle/tst_qstylesheetstyle.cpp
@@ -106,6 +106,7 @@ private slots:
     void QTBUG36933_brokenPseudoClassLookup();
     void styleSheetChangeBeforePolish();
     void placeholderColor();
+    void accentColor();
     void enumPropertySelector_data();
     void enumPropertySelector();
     //at the end because it mess with the style.
@@ -2360,6 +2361,15 @@ void tst_QStyleSheetStyle::placeholderColor()
     QCOMPARE(le1.palette().placeholderText().color(), QColor(phSpec));
 }
 
+void tst_QStyleSheetStyle::accentColor()
+{
+    QLineEdit lineEdit;
+    const QColor universe(42, 42, 42);
+    lineEdit.setStyleSheet(QString("QLineEdit { accent-color: %1; }").arg(universe.name()));
+    lineEdit.ensurePolished();
+    QCOMPARE(lineEdit.palette().accentColor().color(), universe);
+}
+
 void tst_QStyleSheetStyle::enumPropertySelector_data()
 {
     QTest::addColumn<QString>("styleSheet");