Write widget style and icon theme to kdeglobals

This allows to style applications that use KStyleManager

CMakeLists.txt

@@ -25,6 +25,7 @@ set(CMAKE_BUILD_RPATH_USE_ORIGIN ON)
 add_definitions(-DQT_DISABLE_DEPRECATED_BEFORE=0x060000 -DUSE_WIDGETS)
 
 find_package(Qt6 REQUIRED COMPONENTS BuildInternals Core Widgets OPTIONAL_COMPONENTS QuickControls2 LinguistTools)
+find_package(KF6Config)
 
 get_target_property(QT_QTPATHS_EXECUTABLE Qt6::qtpaths IMPORTED_LOCATION)
 

src/qt6ct/CMakeLists.txt

@@ -31,6 +31,7 @@ if(Qt6LinguistTools_FOUND)
 endif()
 
 add_executable(qt6ct ${app_SRCS})
-target_link_libraries(qt6ct PRIVATE Qt6::Widgets Qt6::WidgetsPrivate qt6ct-common)
+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>)
 install(TARGETS qt6ct DESTINATION ${CMAKE_INSTALL_BINDIR})
 install(FILES qt6ct.desktop DESTINATION ${CMAKE_INSTALL_DATADIR}/applications)

src/qt6ct/appearancepage.cpp

@@ -35,6 +35,10 @@
 #include <QMenu>
 #include <QIcon>
 #include <QStringList>
+#ifdef KF_CONFIGCORE_LIB
+#include <KSharedConfig>
+#include <KConfigGroup>
+#endif
 #include <qpa/qplatformthemefactory_p.h>
 #include "qt6ct.h"
 #include "appearancepage.h"
@@ -110,6 +114,13 @@ void AppearancePage::writeSettings(QSettings *settings)
     settings->setValue("color_scheme_path", m_ui->colorSchemeComboBox->currentData().toString());
     settings->setValue("standard_dialogs", m_ui->dialogComboBox->currentData().toString());
     settings->endGroup();
+
+#ifdef KF_CONFIGCORE_LIB
+    KSharedConfigPtr config = KSharedConfig::openConfig("kdeglobals");
+    KConfigGroup group(config, "KDE");
+    group.writeEntry("widgetStyle", "qt6ct-style");
+    group.sync();
+#endif
 }
 
 void AppearancePage::on_styleComboBox_textActivated(const QString &text)

src/qt6ct/iconthemepage.cpp

@@ -34,6 +34,10 @@
 #include <QProgressBar>
 #include <QMetaObject>
 #include <QThread>
+#ifdef KF_CONFIGCORE_LIB
+#include <KSharedConfig>
+#include <KConfigGroup>
+#endif
 #include "qt6ct.h"
 #include "iconthemepage.h"
 #include "ui_iconthemepage.h"
@@ -67,8 +71,17 @@ IconThemePage::~IconThemePage()
 void IconThemePage::writeSettings(QSettings *settings)
 {
     QTreeWidgetItem *item = m_ui->treeWidget->currentItem();
-    if(item)
-        settings->setValue("Appearance/icon_theme", item->data(3, Qt::UserRole));
+    if(!item)
+        return;
+
+    settings->setValue("Appearance/icon_theme", item->data(3, Qt::UserRole));
+
+#ifdef KF_CONFIGCORE_LIB
+    KSharedConfigPtr config = KSharedConfig::openConfig("kdeglobals");
+    KConfigGroup group(config, "Icons");
+    group.writeEntry("Theme", item->data(3, Qt::UserRole));
+    group.sync();
+#endif
 }
 
 void IconThemePage::onFinished()