From ff3e831ac1b71638d366132a9025817769632c02 Mon Sep 17 00:00:00 2001
From: Ilya Fedin <fedin-ilja2010@ya.ru>
Date: Mon, 21 Oct 2024 01:58:02 +0400
Subject: [PATCH] Use KDE's icon engine

It has KDE color schemes support that prevents dark icons on dark background
---
 CMakeLists.txt                            |  1 +
 src/qt6ct-qtplugin/CMakeLists.txt         |  3 ++-
 src/qt6ct-qtplugin/qt6ctplatformtheme.cpp | 12 ++++++++++++
 src/qt6ct-qtplugin/qt6ctplatformtheme.h   |  4 +++-
 4 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e09dc0a..1cc9f61 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -27,6 +27,7 @@ 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)
+find_package(KF6IconThemes)
 
 get_target_property(QT_QTPATHS_EXECUTABLE Qt6::qtpaths IMPORTED_LOCATION)
 
diff --git a/src/qt6ct-qtplugin/CMakeLists.txt b/src/qt6ct-qtplugin/CMakeLists.txt
index edf7029..6542289 100644
--- a/src/qt6ct-qtplugin/CMakeLists.txt
+++ b/src/qt6ct-qtplugin/CMakeLists.txt
@@ -9,5 +9,6 @@ include_directories(${CMAKE_CURRENT_SOURCE_DIR}/../)
 
 add_library(qt6ct-qtplugin MODULE ${app_SRCS})
 set_target_properties(qt6ct-qtplugin PROPERTIES OUTPUT_NAME qt6ct)
-target_link_libraries(qt6ct-qtplugin PRIVATE Qt6::Widgets Qt6::GuiPrivate $<TARGET_NAME_IF_EXISTS:Qt6::QuickControls2> qt6ct-common)
+target_link_libraries(qt6ct-qtplugin PRIVATE Qt6::Widgets Qt6::GuiPrivate $<TARGET_NAME_IF_EXISTS:Qt6::QuickControls2> $<TARGET_NAME_IF_EXISTS:KF6::IconThemes> qt6ct-common)
+target_compile_definitions(qt6ct-qtplugin PRIVATE $<$<BOOL:${KF6IconThemes_FOUND}>:KF_ICONTHEMES_LIB>)
 install(TARGETS qt6ct-qtplugin DESTINATION ${PLUGINDIR}/platformthemes)
diff --git a/src/qt6ct-qtplugin/qt6ctplatformtheme.cpp b/src/qt6ct-qtplugin/qt6ctplatformtheme.cpp
index e03dbbc..c71496b 100644
--- a/src/qt6ct-qtplugin/qt6ctplatformtheme.cpp
+++ b/src/qt6ct-qtplugin/qt6ctplatformtheme.cpp
@@ -55,6 +55,11 @@
 #include <QStringList>
 #include <qpa/qplatformthemefactory_p.h>
 
+#ifdef KF_ICONTHEMES_LIB
+#include <KIconEngine>
+#include <KIconLoader>
+#endif
+
 Q_LOGGING_CATEGORY(lqt6ct, "qt6ct", QtWarningMsg)
 
 //QT_QPA_PLATFORMTHEME=qt6ct
@@ -160,6 +165,13 @@ QIcon Qt6CTPlatformTheme::fileIcon(const QFileInfo &fileInfo, QPlatformTheme::Ic
     return QIcon::fromTheme(type.iconName());
 }
 
+#ifdef KF_ICONTHEMES_LIB
+QIconEngine *Qt6CTPlatformTheme::createIconEngine(const QString &iconName) const
+{
+    return new KIconEngine(iconName, KIconLoader::global());
+}
+#endif
+
 void Qt6CTPlatformTheme::applySettings()
 {
     if(!QGuiApplication::desktopSettingsAware() || m_isIgnored)
diff --git a/src/qt6ct-qtplugin/qt6ctplatformtheme.h b/src/qt6ct-qtplugin/qt6ctplatformtheme.h
index 358166d..79db7fa 100644
--- a/src/qt6ct-qtplugin/qt6ctplatformtheme.h
+++ b/src/qt6ct-qtplugin/qt6ctplatformtheme.h
@@ -62,7 +62,9 @@ class Qt6CTPlatformTheme : public QObject, public QGenericUnixTheme
     //virtual QPixmap fileIconPixmap(const QFileInfo &fileInfo, const QSizeF &size,
     //                               QPlatformTheme::IconOptions iconOptions = 0) const;
 
-    //virtual QIconEngine *createIconEngine(const QString &iconName) const;
+#ifdef KF_ICONTHEMES_LIB
+    virtual QIconEngine *createIconEngine(const QString &iconName) const override;
+#endif
     //virtual QList<QKeySequence> keyBindings(QKeySequence::StandardKey key) const;
     //virtual QString standardButtonText(int button) const;