[Theme] Add scheme-variant asset resolution (#7275)

* Add scheme-variant theme asset resolution (#7209-1)

ThemeManager::assetPath() and schemeVariantPath() resolve a theme asset to its scheme-variant file (prefix-light/dark.png) with fallback to the plain asset, and themePixmap()/loadBrush()/loadExtraBrush() use them. CSS files load style-dark.css or style-light.css when present. Home widget re-resolves its background on theme change.

Link pixel_map_generator.cpp into the oracle target, which needs Qt6::Xml for QDomDocument.

* Fix clang-format wrap of theme format probe lists

---------

Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>

cmake/FindQtRuntime.cmake

@@ -28,7 +28,7 @@ if(WITH_CLIENT)
   )
 endif()
 if(WITH_ORACLE)
-  set(_ORACLE_NEEDED Concurrent Network Svg Widgets)
+  set(_ORACLE_NEEDED Concurrent Network Svg Widgets Xml)
 endif()
 if(TEST)
   # Union of Qt modules required across all test targets (independent of application targets).

cockatrice/src/interface/pixel_map_generator.cpp

@@ -1,5 +1,7 @@
 #include "pixel_map_generator.h"
 
+#include "theme_manager.h"
+
 #include <QApplication>
 #include <QDomDocument>
 #include <QFile>
@@ -83,7 +85,13 @@ static QPixmap loadSvg(const QString &svgPath, const QSize &size, bool expandOnl
 /**
  * Try to load path image from non-SVG formats, otherwise fall back to SVG.
  * This is to allow custom themes to support non-SVG format type overrides, since SVG requires custom loading.
- * @param path The path to the file, with no file extension. File formats will be automatically detected.
+ *
+ * The path may already carry the resolved file extension (e.g. via
+ * ThemeManager::assetPath); such paths are loaded directly. Otherwise a
+ * format-agnostic lookup probes png, jpg and finally svg.
+ *
+ * @param path The path to the file, with no file extension unless the caller
+ * already resolved it. File formats will be automatically detected.
  * @param size The desired size of the pixmap.
  * @param expandOnly If true, then keep the size of the initial pixmap to at least the size (Only relevant if SVG).
  *
@@ -91,6 +99,19 @@ static QPixmap loadSvg(const QString &svgPath, const QSize &size, bool expandOnl
  */
 static QPixmap tryLoadImage(const QString &path, const QSize &size, bool expandOnly = false)
 {
+    if (path.endsWith(QLatin1String(".svg"), Qt::CaseInsensitive)) {
+        return loadSvg(path, size, expandOnly);
+    }
+    if (path.endsWith(QLatin1String(".png"), Qt::CaseInsensitive) ||
+        path.endsWith(QLatin1String(".jpg"), Qt::CaseInsensitive) ||
+        path.endsWith(QLatin1String(".jpeg"), Qt::CaseInsensitive)) {
+        QPixmap pix(path);
+        if (!pix.isNull()) {
+            return pix.scaled(size, Qt::KeepAspectRatio, Qt::SmoothTransformation);
+        }
+        return {};
+    }
+
     const auto formats = {"png", "jpg"};
 
     QPixmap returnPixmap;
@@ -112,7 +133,8 @@ QPixmap PhasePixmapGenerator::generatePixmap(int height, QString name)
         return pmCache.value(key);
     }
 
-    QPixmap pixmap = tryLoadImage("theme:phases/" + name, QSize(height, height));
+    QPixmap pixmap = tryLoadImage(QStringLiteral("theme:") + themeManager->assetPath(QStringLiteral("phases/") + name),
+                                  QSize(height, height));
 
     pmCache.insert(key, pixmap);
     return pixmap;
@@ -399,7 +421,8 @@ QPixmap LockPixmapGenerator::generatePixmap(int height)
         return pmCache.value(key);
     }
 
-    QPixmap pixmap = tryLoadImage("theme:icons/lock", QSize(height, height), true);
+    QPixmap pixmap = tryLoadImage(QStringLiteral("theme:") + themeManager->assetPath(QStringLiteral("icons/lock")),
+                                  QSize(height, height), true);
     pmCache.insert(key, pixmap);
     return pixmap;
 }
@@ -414,7 +437,8 @@ QPixmap DropdownIconPixmapGenerator::generatePixmap(int height, bool expanded)
     }
 
     QString name = expanded ? "dropdown_expanded" : "dropdown_collapsed";
-    QPixmap pixmap = tryLoadImage("theme:icons/" + name, QSize(height, height), true);
+    QPixmap pixmap = tryLoadImage(QStringLiteral("theme:") + themeManager->assetPath(QStringLiteral("icons/") + name),
+                                  QSize(height, height), true);
 
     pmCache.insert(key, pixmap);
     return pixmap;
@@ -475,6 +499,13 @@ QHash<QString, QPixmap> ManaSymbolPixmapGenerator::scaledCache;
 
 QPixmap loadColorAdjustedPixmap(const QString &name)
 {
+    // Prefer an authored scheme-qualified variant when one exists for this asset.
+    const QString variant = themeManager->schemeVariantPath(QStringView(name).mid(QStringLiteral("theme:").size()));
+    if (!variant.isEmpty()) {
+        return QPixmap(QStringLiteral("theme:") + variant);
+    }
+
+    // Legacy fallback: runtime-invert for dark mode when no authored variant.
     if (qApp->palette().windowText().color().lightness() > 200) {
         QImage img(name);
         img.invertPixels();
@@ -485,3 +516,21 @@ QPixmap loadColorAdjustedPixmap(const QString &name)
         return QPixmap(name);
     }
 }
+
+QPixmap themePixmap(QStringView prefix)
+{
+    const QString resolved = themeManager->assetPath(prefix);
+    return QPixmap(QStringLiteral("theme:") + resolved);
+}
+
+void clearPixmapGeneratorCaches()
+{
+    PhasePixmapGenerator::clear();
+    CounterPixmapGenerator::clear();
+    PingPixmapGenerator::clear();
+    CountryPixmapGenerator::clear();
+    UserLevelPixmapGenerator::clear();
+    LockPixmapGenerator::clear();
+    DropdownIconPixmapGenerator::clear();
+    ManaSymbolPixmapGenerator::clear();
+}

cockatrice/src/interface/pixel_map_generator.h

@@ -156,4 +156,15 @@ public:
 
 QPixmap loadColorAdjustedPixmap(const QString &name);
 
+// Loads a "theme:" asset (with no file extension in prefix), preferring the
+// scheme-qualified variant (prefix-dark / prefix-light, resolved via
+// ThemeManager::assetPath) and falling back to the plain asset. Callers load
+// the returned path directly. Use for scheme-sensitive pixmaps like
+// backgrounds, the card back, and the app logo.
+QPixmap themePixmap(QStringView prefix);
+
+// Clears every PixmapGenerator's static cache so scheme variants are
+// re-resolved when the active theme or color scheme changes.
+void clearPixmapGeneratorCaches();
+
 #endif

cockatrice/src/interface/theme_manager.cpp

@@ -1,10 +1,12 @@
 #include "theme_manager.h"
 
 #include "../../client/settings/cache_settings.h"
+#include "pixel_map_generator.h"
 
 #include <QApplication>
 #include <QColor>
 #include <QDebug>
+#include <QFileInfo>
 #include <QLibraryInfo>
 #include <QMap>
 #include <QMetaEnum>
@@ -140,6 +142,48 @@ bool ThemeManager::isDarkMode(const QString &themeDirPath) const
     }
 }
 
+QString ThemeManager::schemeVariantPath(QStringView prefix) const
+{
+    static const QStringList formats = {QStringLiteral(".png"), QStringLiteral(".jpg"), QStringLiteral(".jpeg"),
+                                        QStringLiteral(".svg")};
+    const QString scheme = isDarkMode(currentThemePath) ? QStringLiteral("dark") : QStringLiteral("light");
+    const QString variantStem = prefix.toString() + QLatin1Char('-') + scheme;
+
+    for (const QString &format : formats) {
+        if (QFileInfo::exists(QStringLiteral("theme:") + variantStem + format)) {
+            return variantStem + format;
+        }
+    }
+    return QString();
+}
+
+QString ThemeManager::assetPath(QStringView prefix) const
+{
+    // Probe order mirrors tryLoadImage: a theme may override the default SVG
+    // with a raster of the same stem, so raster wins over SVG within a stem.
+    static const QStringList formats = {QStringLiteral(".png"), QStringLiteral(".jpg"), QStringLiteral(".jpeg"),
+                                        QStringLiteral(".svg")};
+
+    auto findExisting = [](const QString &stem) {
+        for (const QString &format : formats) {
+            if (QFileInfo::exists(QStringLiteral("theme:") + stem + format)) {
+                return stem + format;
+            }
+        }
+        return QString();
+    };
+
+    // Prefer the scheme-qualified variant when it exists, else the plain
+    // asset as the super fallback. Both return the resolved path including
+    // its file extension so callers can load it directly.
+    const QString variant = schemeVariantPath(prefix);
+    if (!variant.isEmpty()) {
+        return variant;
+    }
+    const QString resolvedPlain = findExisting(prefix.toString());
+    return resolvedPlain.isEmpty() ? prefix.toString() : resolvedPlain;
+}
+
 bool ThemeManager::isBuiltInTheme()
 {
     const auto themeName = SettingsCache::instance().getThemeName();
@@ -195,7 +239,7 @@ QStringMap &ThemeManager::getAvailableThemes()
 QBrush ThemeManager::loadBrush(QString fileName, QColor fallbackColor)
 {
     QBrush brush;
-    QPixmap tmp = QPixmap("theme:zones/" + fileName);
+    QPixmap tmp = QPixmap("theme:" + assetPath(QStringLiteral("zones/") + fileName));
     if (tmp.isNull()) {
         brush.setColor(fallbackColor);
         brush.setStyle(Qt::SolidPattern);
@@ -209,7 +253,7 @@ QBrush ThemeManager::loadBrush(QString fileName, QColor fallbackColor)
 QBrush ThemeManager::loadExtraBrush(QString fileName, QBrush &fallbackBrush)
 {
     QBrush brush;
-    QPixmap tmp = QPixmap("theme:zones/" + fileName);
+    QPixmap tmp = QPixmap("theme:" + assetPath(QStringLiteral("zones/") + fileName));
 
     if (tmp.isNull()) {
         brush = fallbackBrush;
@@ -393,9 +437,19 @@ void ThemeManager::themeChangedSlot()
     currentThemePath = dirPath;
     QDir dir(dirPath);
 
-    // CSS
+    // CSS — prefer the scheme-qualified stylesheet (style-dark.css /
-    if (!dirPath.isEmpty() && dir.exists(STYLE_CSS_NAME)) {
+    // style-light.css) when present, else the plain style.css as fallback.
-        qApp->setStyleSheet("file:///" + dir.absoluteFilePath(STYLE_CSS_NAME));
+    if (!dirPath.isEmpty()) {
+        const QString scheme = isDarkMode(dirPath) ? QStringLiteral("dark") : QStringLiteral("light");
+        const QString schemeCss = QFileInfo(QStringLiteral(STYLE_CSS_NAME)).completeBaseName() + QLatin1Char('-') +
+                                  scheme + QStringLiteral(".css");
+        if (dir.exists(schemeCss)) {
+            qApp->setStyleSheet("file:///" + dir.absoluteFilePath(schemeCss));
+        } else if (dir.exists(STYLE_CSS_NAME)) {
+            qApp->setStyleSheet("file:///" + dir.absoluteFilePath(STYLE_CSS_NAME));
+        } else {
+            qApp->setStyleSheet("");
+        }
     } else {
         qApp->setStyleSheet("");
     }
@@ -446,6 +500,7 @@ void ThemeManager::themeChangedSlot()
     }
 
     QPixmapCache::clear();
+    clearPixmapGeneratorCaches();
 
     emit themeChanged();
 }

cockatrice/src/interface/theme_manager.h

@@ -87,6 +87,20 @@ public:
     // Load/save per-scheme palette colors
     static PaletteConfig loadPaletteConfig(const QString &themeDirPath, const QString &colorScheme);
     static bool savePaletteConfig(const QString &themeDirPath, const QString &colorScheme, const PaletteConfig &cfg);
+    // Resolve prefix to a scheme-qualified "theme:" path. Existence is probed
+    // internally across the formats themes may ship (.png/.jpg/.svg), so
+    // callers load the returned path directly. Prefers "<prefix>-<dark|light>"
+    // when a file exists at that stem, otherwise the plain "<prefix>" as the
+    // super fallback. The resolved scheme covers explicit light/dark as well
+    // as OS-resolved "system". Returns the path with its file extension when a
+    // match is found; unqualified assets keep working unchanged.
+    QString assetPath(QStringView prefix) const;
+    // Like assetPath, but resolves only the scheme-qualified variant
+    // ("<prefix>-<dark|light>.<ext>") and returns an empty string when no
+    // variant exists — it never falls back to the plain "<prefix>" asset.
+    // Callers that must distinguish "no authored variant" (e.g. to keep a
+    // legacy runtime fallback alive) should use this instead of assetPath.
+    QString schemeVariantPath(QStringView prefix) const;
     // Load the theme's shipped default palette, falling back to the system
     // theme directory when it is absent from the resolved (user) directory.
     static PaletteConfig

cockatrice/src/interface/widgets/general/home_widget.cpp

@@ -2,6 +2,7 @@
 
 #include "../../../client/settings/cache_settings.h"
 #include "../../../interface/widgets/tabs/tab_supervisor.h"
+#include "../../pixel_map_generator.h"
 #include "../../theme_manager.h"
 #include "../../window_main.h"
 #include "../cards/art_crop_attribution.h"
@@ -20,7 +21,8 @@
 #include <libcockatrice/settings/paths_settings.h>
 
 HomeWidget::HomeWidget(QWidget *parent, TabSupervisor *_tabSupervisor)
-    : QWidget(parent), tabSupervisor(_tabSupervisor), background("theme:backgrounds/home"), overlay("theme:cockatrice")
+    : QWidget(parent), tabSupervisor(_tabSupervisor), background(themePixmap(QStringLiteral("backgrounds/home"))),
+      overlay(themePixmap(QStringLiteral("cockatrice")))
 {
     layout = new QGridLayout(this);
 
@@ -56,6 +58,9 @@ HomeWidget::HomeWidget(QWidget *parent, TabSupervisor *_tabSupervisor)
             &HomeWidget::initializeBackgroundFromSource);
     connect(&SettingsCache::instance(), &SettingsCache::themeChanged, this,
             &HomeWidget::updateButtonsToBackgroundColor);
+    // Scheme flips (light/dark/system with an OS switch) fire on themeManager,
+    // not on SettingsCache::themeChanged, so re-resolve the variant background.
+    connect(themeManager, &ThemeManager::themeChanged, this, &HomeWidget::initializeBackgroundFromSource);
     connect(&SettingsCache::instance().appearance(), &AppearanceSettings::homeTabButtonColorChanged, this,
             &HomeWidget::updateButtonsToBackgroundColor);
 }
@@ -74,7 +79,7 @@ void HomeWidget::initializeBackgroundFromSource()
     switch (backgroundSourceType) {
         case BackgroundSources::Theme:
             cardChangeTimer->stop();
-            background = QPixmap("theme:backgrounds/home");
+            background = themePixmap(QStringLiteral("backgrounds/home"));
             backgroundSourceDeck = DeckList();
             backgroundSourceCard->setCard(ExactCard());
             updateButtonsToBackgroundColor();

oracle/CMakeLists.txt

@@ -28,6 +28,7 @@ set(oracle_SOURCES
     ../cockatrice/src/client/settings/card_counter_settings.cpp
     ../cockatrice/src/client/settings/shortcuts_settings.cpp
     ../cockatrice/src/client/network/update/client/release_channel.cpp
+    ../cockatrice/src/interface/pixel_map_generator.cpp
     ../cockatrice/src/interface/theme_config.cpp
     ../cockatrice/src/interface/theme_manager.cpp
     ../cockatrice/src/interface/widgets/quick_settings/settings_button_widget.cpp