Theme 'dark': Use accent color on macOS

Fixes: QTCREATORBUG-28374
Change-Id: Ifb7fa83c8afc1be0a919c775f7d04e229f146438
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

share/qtcreator/themes/dark.creatortheme

@@ -2,6 +2,7 @@
 ThemeName=Dark
 PreferredStyles=
 DefaultTextEditorColorScheme=dark.xml
+EnforceAccentColorOnMacOS=selectedBackground
 
 [Palette]
 shadowBackground=ff232323
@@ -10,7 +11,6 @@ textDisabled=7fffffff
 textHighlighted=ffe7e7e7
 hoverBackground=18ffffff
 selectedBackground=aa1f75cc
-selectedBackgroundText=aa1f75cc
 normalBackground=ff333333
 alternateBackground=ff515151
 error=ffd84044
@@ -358,7 +358,7 @@ PaletteText=text
 PaletteButtonText=text
 PaletteButtonTextDisabled=textDisabled
 PaletteToolTipBase=66000000
-PaletteHighlight=selectedBackgroundText
+PaletteHighlight=selectedBackground
 PaletteDark=shadowBackground
 PaletteHighlightedText=textHighlighted
 PaletteToolTipText=text

src/libs/utils/theme/theme.cpp

@@ -120,6 +120,10 @@ bool Theme::flag(Theme::Flag f) const
 
 QColor Theme::color(Theme::Color role) const
 {
+    const auto color = d->colors[role];
+    if (HostOsInfo::isMacHost() && !d->enforceAccentColorOnMacOS.isEmpty()
+        && color.second == d->enforceAccentColorOnMacOS)
+        return initialPalette().color(QPalette::Highlight);
     return d->colors[role].first;
 }
 
@@ -171,6 +175,7 @@ void Theme::readSettings(QSettings &settings)
         d->preferredStyles.removeAll(QString());
         d->defaultTextEditorColorScheme =
                 settings.value(QLatin1String("DefaultTextEditorColorScheme")).toString();
+        d->enforceAccentColorOnMacOS = settings.value("EnforceAccentColorOnMacOS").toString();
     }
     {
         settings.beginGroup(QLatin1String("Palette"));

src/libs/utils/theme/theme_p.h

@@ -22,6 +22,7 @@ public:
     QString displayName;
     QStringList preferredStyles;
     QString defaultTextEditorColorScheme;
+    QString enforceAccentColorOnMacOS;
     QVector<QPair<QColor, QString> > colors;
     QVector<QString> imageFiles;
     QVector<bool> flags;