Add KDE color schemes support

CMakeLists.txt

@@ -26,6 +26,7 @@ add_definitions(-DQT_DISABLE_DEPRECATED_BEFORE=0x060000 -DUSE_WIDGETS)
 
 find_package(Qt6 REQUIRED COMPONENTS BuildInternals Core Widgets OPTIONAL_COMPONENTS QuickControls2 LinguistTools)
 find_package(KF6Config)
+find_package(KF6ColorScheme)
 
 get_target_property(QT_QTPATHS_EXECUTABLE Qt6::qtpaths IMPORTED_LOCATION)
 

src/qt6ct-common/CMakeLists.txt

@@ -26,5 +26,6 @@ include_directories(${CMAKE_CURRENT_SOURCE_DIR}/../)
 
 add_library(qt6ct-common SHARED ${app_SRCS})
 set_target_properties(qt6ct-common PROPERTIES VERSION ${QT6CT_VERSION})
-target_link_libraries(qt6ct-common PRIVATE Qt6::Gui)
+target_link_libraries(qt6ct-common PRIVATE Qt6::Gui $<TARGET_NAME_IF_EXISTS:KF6::ConfigCore> $<TARGET_NAME_IF_EXISTS:KF6::ColorScheme>)
+target_compile_definitions(qt6ct-common PRIVATE $<$<TARGET_EXISTS:KF6::ConfigCore>:KF_CONFIGCORE_LIB> $<$<TARGET_EXISTS:KF6::ColorScheme>:KF_COLORSCHEME_LIB>)
 install(TARGETS qt6ct-common DESTINATION ${CMAKE_INSTALL_LIBDIR})

src/qt6ct-common/qt6ct.cpp

@@ -34,6 +34,10 @@
 #include <QFile>
 #include <QSettings>
 #include <QtDebug>
+#if defined KF_CONFIGCORE_LIB && defined KF_COLORSCHEME_LIB
+#include <KSharedConfig>
+#include <KColorScheme>
+#endif
 #include "qt6ct.h"
 
 #ifndef QT6CT_DATADIR
@@ -116,6 +120,9 @@ QStringList Qt6CT::sharedColorSchemePaths()
     for(const QString &p : QStandardPaths::standardLocations(QStandardPaths::GenericDataLocation))
     {
         paths << (p + QLatin1String("/qt6ct/colors"));
+#if defined KF_CONFIGCORE_LIB && defined KF_COLORSCHEME_LIB
+        paths << (p + QLatin1String("/color-schemes"));
+#endif
     }
     paths << QLatin1String(QT6CT_DATADIR"/qt6ct/colors");
     paths.removeDuplicates();
@@ -143,8 +150,18 @@ QString Qt6CT::resolvePath(const QString &path)
     return tmp;
 }
 
+bool Qt6CT::isKColorScheme(const QString &filePath)
+{
+    return filePath.toLower().endsWith(".colors");
+}
+
 QPalette Qt6CT::loadColorScheme(const QString &filePath, const QPalette &fallback)
 {
+#if defined KF_CONFIGCORE_LIB && defined KF_COLORSCHEME_LIB
+    if(isKColorScheme(filePath))
+        return KColorScheme::createApplicationPalette(KSharedConfig::openConfig(filePath));
+#endif
+
     QPalette customPalette;
     QSettings settings(filePath, QSettings::IniFormat);
     settings.beginGroup("ColorScheme");

src/qt6ct-common/qt6ct.h

@@ -67,6 +67,7 @@ class QT6CT_EXPORT Qt6CT
     static QString userColorSchemePath();
     static QStringList sharedColorSchemePaths();
     static QString resolvePath(const QString &path);
+    static bool isKColorScheme(const QString &filePath);
     static QPalette loadColorScheme(const QString &filePath, const QPalette &fallback);
 
     static void registerStyleInstance(StyleInstance *instance);

src/qt6ct-qtplugin/qt6ctplatformtheme.cpp

@@ -70,6 +70,9 @@ Qt6CTPlatformTheme::Qt6CTPlatformTheme()
         QMetaObject::invokeMethod(this, "createFSWatcher", Qt::QueuedConnection);
 #endif
         QGuiApplication::setFont(m_generalFont);
+        //must be applied before Q_COREAPP_STARTUP_FUNCTION execution
+        if(Qt6CT::isKColorScheme(m_schemePath))
+            qApp->setProperty("KDE_COLOR_SCHEME_PATH", m_schemePath);
 #if defined QT_WIDGETS_LIB && defined QT_QUICKCONTROLS2_LIB
         if(hasWidgets())
             //don't override the value explicitly set by the user
@@ -82,6 +85,7 @@ Qt6CTPlatformTheme::Qt6CTPlatformTheme()
     if(!QStyleFactory::keys().contains("qt6ct-style"))
         qCCritical(lqt6ct) << "unable to find qt6ct proxy style";
 #endif
+    QCoreApplication::instance()->installEventFilter(this);
 }
 
 Qt6CTPlatformTheme::~Qt6CTPlatformTheme()
@@ -178,6 +182,9 @@ void Qt6CTPlatformTheme::applySettings()
 
     QGuiApplication::setFont(m_generalFont); //apply font
 
+    if(Qt6CT::isKColorScheme(m_schemePath))
+        qApp->setProperty("KDE_COLOR_SCHEME_PATH", m_schemePath);
+
 #ifdef QT_WIDGETS_LIB
     if(hasWidgets())
     {
@@ -259,6 +266,7 @@ void Qt6CTPlatformTheme::updateSettings()
 
 void Qt6CTPlatformTheme::readSettings()
 {
+    m_schemePath.clear();
     m_palette.reset();
 
     QSettings settings(Qt6CT::configFile(), QSettings::IniFormat);
@@ -269,6 +277,7 @@ void Qt6CTPlatformTheme::readSettings()
     if(!schemePath.isEmpty() && settings.value("custom_palette", false).toBool())
     {
         schemePath = Qt6CT::resolvePath(schemePath); //replace environment variables
+        m_schemePath = schemePath;
         m_palette = std::make_unique<QPalette>(Qt6CT::loadColorScheme(schemePath, *QPlatformTheme::palette(SystemPalette)));
     }
     m_iconTheme = settings.value("icon_theme").toString();
@@ -378,3 +387,17 @@ QString Qt6CTPlatformTheme::loadStyleSheets(const QStringList &paths)
     content.replace(regExp, "\n");
     return content;
 }
+
+//There's such a thing as KColorSchemeManager that lets the user to change the color scheme
+//application-wide and we should re-apply the color scheme if KCSM resets it to the default
+//which leads KColorScheme to get the color scheme from kdeglobals which won't help us.
+bool Qt6CTPlatformTheme::eventFilter(QObject *obj, QEvent *e)
+{
+    if(obj == qApp &&
+            e->type() == QEvent::DynamicPropertyChange &&
+            static_cast<QDynamicPropertyChangeEvent*>(e)->propertyName() == "KDE_COLOR_SCHEME_PATH" &&
+            qApp->property("KDE_COLOR_SCHEME_PATH").toString().isEmpty() &&
+            Qt6CT::isKColorScheme(m_schemePath))
+        applySettings();
+    return QObject::eventFilter(obj, e);
+}

src/qt6ct-qtplugin/qt6ctplatformtheme.h

@@ -66,6 +66,9 @@ class Qt6CTPlatformTheme : public QObject, public QGenericUnixTheme
     //virtual QList<QKeySequence> keyBindings(QKeySequence::StandardKey key) const;
     //virtual QString standardButtonText(int button) const;
 
+protected:
+    bool eventFilter(QObject *obj, QEvent *e) override;
+
 private slots:
     void applySettings();
 #ifdef QT_WIDGETS_LIB
@@ -79,7 +82,7 @@ private slots:
     bool hasWidgets();
 #endif
     QString loadStyleSheets(const QStringList &paths);
-    QString m_style, m_iconTheme, m_userStyleSheet, m_prevStyleSheet;
+    QString m_style, m_schemePath, m_iconTheme, m_userStyleSheet, m_prevStyleSheet;
     std::unique_ptr<QPalette> m_palette;
     QFont m_generalFont, m_fixedFont;
     int m_doubleClickInterval;

src/qt6ct/CMakeLists.txt

@@ -32,6 +32,6 @@ endif()
 
 add_executable(qt6ct ${app_SRCS})
 target_link_libraries(qt6ct PRIVATE Qt6::Widgets Qt6::WidgetsPrivate $<TARGET_NAME_IF_EXISTS:KF6::ConfigCore> qt6ct-common)
-target_compile_definitions(qt6ct PRIVATE $<$<TARGET_EXISTS:KF6::ConfigCore>:KF_CONFIGCORE_LIB>)
+target_compile_definitions(qt6ct PRIVATE $<$<TARGET_EXISTS:KF6::ConfigCore>:KF_CONFIGCORE_LIB> $<$<TARGET_EXISTS:KF6::ColorScheme>:KF_COLORSCHEME_LIB>)
 install(TARGETS qt6ct DESTINATION ${CMAKE_INSTALL_BINDIR})
 install(FILES qt6ct.desktop DESTINATION ${CMAKE_INSTALL_DATADIR}/applications)

src/qt6ct/appearancepage.cpp

@@ -74,7 +74,7 @@ AppearancePage::AppearancePage(QWidget *parent) :
     QMenu *menu = new QMenu(this);
     menu->addAction(QIcon::fromTheme("document-new"), tr("Create"), this, SLOT(createColorScheme()));
     m_changeColorSchemeAction = menu->addAction(QIcon::fromTheme("accessories-text-editor"), tr("Edit"), this, SLOT(changeColorScheme()));
-    menu->addAction(QIcon::fromTheme("edit-copy"), tr("Create a Copy"), this, SLOT(copyColorScheme()));
+    m_copyColorSchemeAction = menu->addAction(QIcon::fromTheme("edit-copy"), tr("Create a Copy"), this, SLOT(copyColorScheme()));
     m_renameColorSchemeAction = menu->addAction(tr("Rename"), this, SLOT(renameColorScheme()));
     menu->addSeparator();
     m_removeColorSchemeAction = menu->addAction(QIcon::fromTheme("edit-delete"), tr("Remove"), this, SLOT(removeColorScheme()));
@@ -315,6 +315,7 @@ void AppearancePage::setPreviewPalette(const QPalette &p)
 
 void AppearancePage::updateActions()
 {
+    m_copyColorSchemeAction->setVisible(!Qt6CT::isKColorScheme(m_ui->colorSchemeComboBox->currentData().toString()));
     if(m_ui->colorSchemeComboBox->count() == 0 ||
             !QFileInfo(m_ui->colorSchemeComboBox->currentData().toString()).isWritable())
     {
@@ -393,11 +394,26 @@ void AppearancePage::findColorSchemes(const QString &path)
 {
     QDir dir(path);
     dir.setFilter(QDir::Files);
-    dir.setNameFilters(QStringList() << "*.conf");
+    QStringList nameFilters;
+    nameFilters << "*.conf";
+#if defined KF_CONFIGCORE_LIB && defined KF_COLORSCHEME_LIB
+    nameFilters << "*.colors";
+#endif
+    dir.setNameFilters(nameFilters);
 
     for(const QFileInfo &info : dir.entryInfoList())
     {
-        m_ui->colorSchemeComboBox->addItem(info.baseName(), info.filePath());
+        QString name = info.baseName();
+        QString path = info.filePath();
+#if defined KF_CONFIGCORE_LIB && defined KF_COLORSCHEME_LIB
+        if(Qt6CT::isKColorScheme(path))
+        {
+            KSharedConfigPtr config = KSharedConfig::openConfig(path, KConfig::SimpleConfig);
+            KConfigGroup group(config, "General");
+            name = group.readEntry("Name", name) + " (KColorScheme)";
+        }
+#endif
+        m_ui->colorSchemeComboBox->addItem(name, path);
     }
 }
 

src/qt6ct/appearancepage.h

@@ -76,7 +76,7 @@ private slots:
     QStyle *m_selectedStyle = nullptr;
     QPalette m_customPalette;
     QWidget *m_previewWidget;
-    QAction *m_changeColorSchemeAction, *m_renameColorSchemeAction, *m_removeColorSchemeAction;
+    QAction *m_changeColorSchemeAction, *m_copyColorSchemeAction, *m_renameColorSchemeAction, *m_removeColorSchemeAction;
     Ui::PreviewForm *m_previewUi;
 };