gnu: sddm: Enable qt6.

* gnu/packages/display-managers.scm (sddm): Enable qt6.
[native-inputs]: Use qttools replace qttools-5.
[inputs]: Add xsetroot, qtwayland. Remove qtgraphicaleffects,
qtquickcontrols-5, qtquickcontrols2-5. Use qtbase, qtsvg and qtdeclarative
replace qtbase-5, qtsvg-5 and qtdeclarative-5.
[arguments]<#:configure-flags>: When input qtbase is qt6, Add
-DBUILD_WITH_QT6=ON and adjust CMAKE_CXX_FLAGS and QT_IMPORTS_DIR.
<#:phases>: Add embed-xsetroot-reference. When When input qtbase is qt6, Add
fix-QML_IMPORT_PATH phase.

Change-Id: Id2b7f6e44e507e306e6ccd2baaf3becd8c812c22

gnu/packages/display-managers.scm

@@ -81,28 +81,30 @@
                 "0mxrh0z9x4r4bli25g746n66adwnf3r42lzq0yssc50v9y7fc1a1"))))
     (build-system qt-build-system)
     (native-inputs
-     (list extra-cmake-modules pkg-config qttools-5))
+     (list extra-cmake-modules pkg-config qttools))
     (inputs
      (list elogind
            glib
            libxcb
            libxkbcommon
            linux-pam
-           qtbase-5
-           qtdeclarative-5
-           ;; Some user-defined themes use QtQuick components internally.  Adding
-           ;; QtQuick & co. here; they end up in QML2_IMPORT_PATH thanks to
-           ;; 'wrap-qt-program'.
-           qtgraphicaleffects
-           qtquickcontrols-5
-           qtquickcontrols2-5
-           qtsvg-5
+           qtdeclarative
+           qtsvg
            shadow
-           wayland))
+           wayland
+           qtwayland
+           qtbase
+           xsetroot))
     (arguments
+     (let* ((qtbase (this-package-input "qtbase"))
+            (qt6? (string= "6" (version-major (package-version qtbase)))))
        (list
+        #:qtbase qtbase
         #:configure-flags
         #~(list
+           #$@(if qt6?
+                  #~("-DBUILD_WITH_QT6=ON")
+                  #~())
            "-DENABLE_WAYLAND=ON"
            "-DENABLE_PAM=ON"
            ;; PAM is configured by pam service.
@@ -116,11 +118,11 @@
            (string-append "-DLOGIN_DEFS_PATH="
                           #$(this-package-input "shadow")
                           "/etc/login.defs")
-         (string-append "-DCMAKE_CXX_FLAGS=-I"
-                        #$(this-package-input
-                           "qtdeclarative") "/include/qt5")
+           (string-append
+            "-DCMAKE_CXX_FLAGS=-I"
+            #$(this-package-input "qtdeclarative") "/include/qt" #$(if qt6? "6" "5"))
            (string-append "-DQT_IMPORTS_DIR="
-                        #$output "/lib/qt5/qml")
+                          #$output "/lib/qt" #$(if qt6? "6" "5") "/qml")
            (string-append "-DCMAKE_INSTALL_SYSCONFDIR="
                           #$output "/etc"))
         #:phases
@@ -129,7 +131,20 @@
               (lambda _
                 (substitute* "CMakeLists.txt"
                   (("/usr/bin/loginctl")
-                 (which "loginctl"))))))))
+                   (which "loginctl")))))
+            (add-after 'unpack 'embed-xsetroot-reference
+              (lambda* (#:key inputs #:allow-other-keys)
+                (substitute* '("src/daemon/XorgDisplayServer.cpp"
+                               "src/helper/xorguserhelper.cpp")
+                  (("xsetroot")
+                   (search-input-file inputs "/bin/xsetroot")))))
+            #$@(if qt6?
+                   #~((add-after 'unpack 'fix-QML_IMPORT_PATH
+                        (lambda _
+                          (substitute* "src/daemon/Greeter.cpp"
+                            (("QML2_IMPORT_PATH")
+                             "QML_IMPORT_PATH")))))
+                   #~())))))
     (synopsis "QML based X11 and Wayland display manager")
     (description "SDDM is a display manager for X11 and Wayland aiming to be
 fast, simple and beautiful.  SDDM is themeable and puts no restrictions on the