Promote Fusion to default theme, rename Default to System

Fresh installs and new profiles now default to the Fusion (dark) theme
instead of the platform-native theme. The old "Default" theme is
renamed "System" to better describe its purpose — using the OS-native
Qt style (windowsvista, macOS, etc.).

Existing users who had "Default" selected are automatically migrated
to "System" so they keep their platform-native styling. Users with
an empty or invalid theme name now fall back to Fusion.

cockatrice/src/interface/theme_config.cpp

@@ -16,7 +16,7 @@ QString ThemeConfig::toIni() const
     out += "[Appearance]\n";
     out += QString("ColorScheme = %1\n").arg(colorScheme.isEmpty() ? "System" : colorScheme);
     out += "\n[Style]\n";
-    out += QString("Name = %1\n").arg(styleName.isEmpty() ? "Default" : styleName);
+    out += QString("Name = %1\n").arg(styleName.isEmpty() ? "System" : styleName);
     return out;
 }
 

cockatrice/src/interface/theme_manager.cpp

@@ -22,7 +22,7 @@
 #include <Qt>
 #include <libcockatrice/settings/paths_settings.h>
 
-#define NONE_THEME_NAME "Default"
+#define SYSTEM_THEME_NAME "System"
 #define FUSION_THEME_NAME "Fusion"
 #define STYLE_CSS_NAME "style.css"
 #define HANDZONE_BG_NAME "handzone"
@@ -96,7 +96,7 @@ struct PaletteColorInfo
 static QString usableDefaultStyle(const QString &style)
 {
     // The Windows 11 native style is broken: when the OS default
-    // ("Default" theme selection) would use it, fall back to the Vista style.
+    // ("System" theme selection) would use it, fall back to the Vista style.
     // Explicitly choosing "windows11" in a theme is still honored.
     return style.compare("windows11", Qt::CaseInsensitive) == 0 ? QStringLiteral("windowsvista") : style;
 }
@@ -119,10 +119,16 @@ ThemeManager::ThemeManager(QObject *parent) : QObject(parent)
 
 void ThemeManager::ensureThemeDirectoryExists()
 {
-    if (SettingsCache::instance().getThemeName().isEmpty() ||
+    auto &settings = SettingsCache::instance();
-        !getAvailableThemes().contains(SettingsCache::instance().getThemeName())) {
+
+    // Migrate the old "Default" theme name to "System"
+    if (settings.getThemeName() == "Default") {
+        settings.setThemeName(SYSTEM_THEME_NAME);
+    }
+
+    if (settings.getThemeName().isEmpty() || !getAvailableThemes().contains(settings.getThemeName())) {
         qCInfo(ThemeManagerLog) << "Theme name not set, setting default value";
-        SettingsCache::instance().setThemeName(NONE_THEME_NAME);
+        settings.setThemeName(FUSION_THEME_NAME);
     }
 }
 
@@ -235,9 +241,7 @@ QStringMap &ThemeManager::getAvailableThemes()
     // load themes from user profile dir
     dir.setPath(SettingsCache::instance().paths().getThemesPath());
 
-    // add default value
+    availableThemes.insert(SYSTEM_THEME_NAME, dir.absoluteFilePath("System"));
-    availableThemes.insert(NONE_THEME_NAME, dir.absoluteFilePath("Default"));
-
     availableThemes.insert(FUSION_THEME_NAME, dir.absoluteFilePath("Fusion"));
 
     for (QString themeName : dir.entryList(QDir::AllDirs | QDir::NoDotAndDotDot, QDir::Name)) {
@@ -395,7 +399,7 @@ void ThemeManager::applyStyleAndPalette(const QString &themeName,
     Q_UNUSED(activeScheme)
 #endif
     QString styleName = themeCfg.styleName;
-    if (styleName.isEmpty() || styleName.compare("Default", Qt::CaseInsensitive) == 0) {
+    if (styleName.isEmpty() || styleName.compare("System", Qt::CaseInsensitive) == 0) {
         if (themeName == FUSION_THEME_NAME) {
             styleName = "Fusion";
         } else {

cockatrice/src/interface/widgets/settings_page/appearance_settings_page.cpp

@@ -59,8 +59,8 @@ AppearanceSettingsPage::AppearanceSettingsPage()
     connect(&schemeCombo, &QComboBox::currentIndexChanged, this,
             [this] { themeManager->setColorScheme(schemeCombo.currentData().toString()); });
 
-    // Qt widget style; "Default" lets the application decide
+    // Qt widget style; "System" lets the application decide
-    styleCombo.addItem(tr("Default"), QStringLiteral("Default"));
+    styleCombo.addItem(tr("System"), QStringLiteral("System"));
     for (const QString &key : QStyleFactory::keys()) {
         styleCombo.addItem(key, key);
     }

cockatrice/themes/CMakeLists.txt

@@ -2,7 +2,7 @@
 #
 # add themes subfolders
 
-set(defthemes Default Fabric Fusion Leather Plasma VelvetMarble)
+set(defthemes Fabric Fusion Leather Plasma VelvetMarble System)
 
 if(UNIX)
   if(APPLE)

cockatrice/themes/System/theme.cfg

@@ -2,4 +2,4 @@
 ColorScheme = Light
 
 [Style]
-Name = Default
+Name = System

libcockatrice_settings/libcockatrice/settings/settings_migration.cpp

@@ -374,7 +374,11 @@ static void migrateAppearanceSettings(const QString &settingsPath, QSettings &gl
     QSettings appearanceIni(settingsPath + "appearance.ini", QSettings::IniFormat);
     for (auto it = appearanceKeyMap.constBegin(); it != appearanceKeyMap.constEnd(); ++it) {
         if (globalIni.contains(it.key())) {
-            appearanceIni.setValue(it.value(), globalIni.value(it.key()));
+            QVariant value = globalIni.value(it.key());
+            if (it.key() == "theme/name" && value.toString() == "Default") {
+                value = "System";
+            }
+            appearanceIni.setValue(it.value(), value);
         }
     }
 }