avoid depend on qGuiApp directly

CMakeLists.txt

@@ -8,6 +8,7 @@ set(CMAKE_INCLUDE_CURRENT_DIR ON) # ensure adapter class can include related hea
 
 find_package(Qt6 6.8 CONFIG REQUIRED COMPONENTS DBus)
 find_package(ECM REQUIRED NO_MODULE)
+find_package(PkgConfig REQUIRED)
 set(CMAKE_MODULE_PATH ${ECM_MODULE_PATH} ${CMAKE_CURRENT_SOURCE_DIR}/cmake)
 include(ECMQtDeclareLoggingCategory)
 include(KDEInstallDirs)
@@ -16,33 +17,14 @@ include(ECMConfiguredInstall)
 find_package(KF6 6.6 REQUIRED COMPONENTS
     WindowSystem)
 
-find_package(XCB
-    REQUIRED COMPONENTS
-        XCB
-        XFIXES
-        DAMAGE
-        COMPOSITE
-        RANDR
-        SHM
-        UTIL
-        IMAGE
-)
-
-set(XCB_LIBS
-    XCB::XCB
-    XCB::XFIXES
-    XCB::DAMAGE
-    XCB::COMPOSITE
-    XCB::RANDR
-    XCB::SHM
-    XCB::UTIL
-    XCB::IMAGE
-)
+pkg_check_modules(X11 REQUIRED IMPORTED_TARGET x11 xcb xcb-image xcb-damage xcb-composite xcb-xfixes xcb-util xcb-shape xtst xcb-xtest xcb-res xcb-ewmh)
 
 set(XEMBED_SNI_PROXY_SOURCES
     main.cpp
     fdoselectionmanager.cpp fdoselectionmanager.h
     traymanager1.cpp traymanager1.h
+    util.cpp util.h
+    xcbthread.cpp xcbthread.h
  )
 
 set_source_files_properties(
@@ -72,8 +54,7 @@ target_link_libraries(xembed-traymanager-proxy
     Qt::Core
     Qt::DBus
     KF6::WindowSystem
-    ${XCB_LIBS}
-    X11::Xtst
+    PkgConfig::X11
 )
 
 install(TARGETS xembed-traymanager-proxy ${KDE_INSTALL_TARGETS_DEFAULT_ARGS})