From b4ea37c633d809eaa1b998f72d9d86c1a6a558cb Mon Sep 17 00:00:00 2001
From: Thiago Kenji Okada <thiagokokada@gmail.com>
Date: Wed, 18 Oct 2023 11:58:05 +0100
Subject: [PATCH 01/11] qt: remove remaining Qt 4 support

Qt 4 was removed from nixpkgs so it doesn't make sense to support it
anymore.
---
 modules/misc/qt.nix | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/modules/misc/qt.nix b/modules/misc/qt.nix
index d1197683..314a4a2c 100644
--- a/modules/misc/qt.nix
+++ b/modules/misc/qt.nix
@@ -38,7 +38,7 @@ in {
 
   options = {
     qt = {
-      enable = mkEnableOption "Qt 4, 5 and 6 configuration";
+      enable = mkEnableOption "Qt 5 and 6 configuration";
 
       platformTheme = mkOption {
         type = types.nullOr (types.enum [ "gtk" "gnome" "qtct" "kde" ]);
@@ -170,14 +170,5 @@ in {
 
     xsession.importedVariables = [ "QT_QPA_PLATFORMTHEME" ]
       ++ lib.optionals (cfg.style.name != null) [ "QT_STYLE_OVERRIDE" ];
-
-    # Enable GTK+ style for Qt4 in Gtk/GNOME.
-    # It doesn’t support the platform theme packages.
-    home.activation.useGtkThemeInQt4 =
-      mkIf (cfg.platformTheme == "gtk" || cfg.platformTheme == "gnome")
-      (hm.dag.entryAfter [ "writeBoundary" ] ''
-        $DRY_RUN_CMD ${pkgs.crudini}/bin/crudini $VERBOSE_ARG \
-          --set "${config.xdg.configHome}/Trolltech.conf" Qt style GTK+
-      '');
   };
 }

From 5744ebf3593ed95516e47d1895b7f19f57de7eb4 Mon Sep 17 00:00:00 2001
From: Thiago Kenji Okada <thiagokokada@gmail.com>
Date: Wed, 18 Oct 2023 12:54:36 +0100
Subject: [PATCH 02/11] qt: export QT_PLUGIN_PATH/QML2_IMPORT_PATH

Those 2 variables are necessary to make e.g.: qt6ct work correctly.

See issue: https://github.com/NixOS/nixpkgs/issues/239909.
---
 modules/misc/qt.nix                              | 16 ++++++++++++++--
 .../modules/misc/qt/qt-platform-theme-gnome.nix  |  4 ++++
 tests/modules/misc/qt/qt-platform-theme-gtk.nix  |  4 ++++
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/modules/misc/qt.nix b/modules/misc/qt.nix
index 314a4a2c..e78a8aca 100644
--- a/modules/misc/qt.nix
+++ b/modules/misc/qt.nix
@@ -127,7 +127,10 @@ in {
   config = let
 
     # Necessary because home.sessionVariables doesn't support mkIf
-    envVars = filterAttrs (n: v: v != null) {
+    envVars = let
+      inherit (config.home) profileDirectory;
+      qtVersions = with pkgs; [ qt5 qt6 ];
+    in filterAttrs (n: v: v != null) {
       QT_QPA_PLATFORMTHEME = if cfg.platformTheme == "gtk" then
         "gtk2"
       else if cfg.platformTheme == "qtct" then
@@ -135,6 +138,14 @@ in {
       else
         cfg.platformTheme;
       QT_STYLE_OVERRIDE = cfg.style.name;
+      QT_PLUGIN_PATH = "$QT_PLUGIN_PATH\${QT_PLUGIN_PATH:+:}"
+        + (lib.concatStringsSep ":"
+          (map (qt: "${profileDirectory}/${qt.qtbase.qtPluginPrefix}")
+            qtVersions));
+      QML2_IMPORT_PATH = "$QML2_IMPORT_PATH\${QML2_IMPORT_PATH:+:}"
+        + (lib.concatStringsSep ":"
+          (map (qt: "${profileDirectory}/${qt.qtbase.qtQmlPrefix}")
+            qtVersions));
     };
 
   in mkIf (cfg.enable && cfg.platformTheme != null) {
@@ -168,7 +179,8 @@ in {
       ++ lib.optionals (cfg.style.package != null)
       (lib.toList cfg.style.package);
 
-    xsession.importedVariables = [ "QT_QPA_PLATFORMTHEME" ]
+    xsession.importedVariables =
+      [ "QT_QPA_PLATFORMTHEME" "QT_PLUGIN_PATH" "QML2_IMPORT_PATH" ]
       ++ lib.optionals (cfg.style.name != null) [ "QT_STYLE_OVERRIDE" ];
   };
 }
diff --git a/tests/modules/misc/qt/qt-platform-theme-gnome.nix b/tests/modules/misc/qt/qt-platform-theme-gnome.nix
index 58b4cd7a..d95ef704 100644
--- a/tests/modules/misc/qt/qt-platform-theme-gnome.nix
+++ b/tests/modules/misc/qt/qt-platform-theme-gnome.nix
@@ -15,6 +15,10 @@
         'QT_QPA_PLATFORMTHEME="gnome"'
       assertFileRegex home-path/etc/profile.d/hm-session-vars.sh \
         'QT_STYLE_OVERRIDE="adwaita"'
+      assertFileRegex home-path/etc/profile.d/hm-session-vars.sh \
+        'QT_PLUGIN_PATH'
+      assertFileRegex home-path/etc/profile.d/hm-session-vars.sh \
+        'QML2_IMPORT_PATH'
     '';
   };
 }
diff --git a/tests/modules/misc/qt/qt-platform-theme-gtk.nix b/tests/modules/misc/qt/qt-platform-theme-gtk.nix
index d3324652..b91496b5 100644
--- a/tests/modules/misc/qt/qt-platform-theme-gtk.nix
+++ b/tests/modules/misc/qt/qt-platform-theme-gtk.nix
@@ -10,6 +10,10 @@
     nmt.script = ''
       assertFileRegex home-path/etc/profile.d/hm-session-vars.sh \
         'QT_QPA_PLATFORMTHEME="gtk2"'
+      assertFileRegex home-path/etc/profile.d/hm-session-vars.sh \
+        'QT_PLUGIN_PATH'
+      assertFileRegex home-path/etc/profile.d/hm-session-vars.sh \
+        'QML2_IMPORT_PATH'
     '';
   };
 }

From 4b2d3b03becc184f2d1485e109c6a55f94d5f886 Mon Sep 17 00:00:00 2001
From: Thiago Kenji Okada <thiagokokada@gmail.com>
Date: Wed, 18 Oct 2023 13:24:09 +0100
Subject: [PATCH 03/11] qt: remove top-level `with lib`

---
 modules/misc/qt.nix | 36 ++++++++++++++++++------------------
 1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/modules/misc/qt.nix b/modules/misc/qt.nix
index e78a8aca..e50f416a 100644
--- a/modules/misc/qt.nix
+++ b/modules/misc/qt.nix
@@ -1,9 +1,6 @@
 { config, lib, pkgs, ... }:
 
-with lib;
-
 let
-
   cfg = config.qt;
 
   # Maps known lowercase style names to style packages. Non-exhaustive.
@@ -28,20 +25,23 @@ let
   };
 
 in {
-  meta.maintainers = with maintainers; [ rycee thiagokokada ];
+  meta.maintainers = with lib.maintainers; [ rycee thiagokokada ];
 
   imports = [
-    (mkChangedOptionModule [ "qt" "useGtkTheme" ] [ "qt" "platformTheme" ]
+    (lib.mkChangedOptionModule [ "qt" "useGtkTheme" ] [ "qt" "platformTheme" ]
       (config:
-        if getAttrFromPath [ "qt" "useGtkTheme" ] config then "gtk" else null))
+        if lib.getAttrFromPath [ "qt" "useGtkTheme" ] config then
+          "gtk"
+        else
+          null))
   ];
 
   options = {
     qt = {
-      enable = mkEnableOption "Qt 5 and 6 configuration";
+      enable = lib.mkEnableOption "Qt 5 and 6 configuration";
 
-      platformTheme = mkOption {
-        type = types.nullOr (types.enum [ "gtk" "gnome" "qtct" "kde" ]);
+      platformTheme = lib.mkOption {
+        type = with lib.types; nullOr (enum [ "gtk" "gnome" "qtct" "kde" ]);
         default = null;
         example = "gnome";
         relatedPackages = [
@@ -77,8 +77,8 @@ in {
       };
 
       style = {
-        name = mkOption {
-          type = types.nullOr types.str;
+        name = lib.mkOption {
+          type = with lib.types; nullOr str;
           default = null;
           example = "adwaita-dark";
           relatedPackages = [
@@ -111,10 +111,10 @@ in {
           '';
         };
 
-        package = mkOption {
-          type = with types; nullOr (either package (listOf package));
+        package = lib.mkOption {
+          type = with lib.types; nullOr (either package (listOf package));
           default = null;
-          example = literalExpression "pkgs.adwaita-qt";
+          example = lib.literalExpression "pkgs.adwaita-qt";
           description = ''
             Theme package to be used in Qt5/Qt6 applications.
             Auto-detected from {option}`qt.style.name` if possible.
@@ -130,7 +130,7 @@ in {
     envVars = let
       inherit (config.home) profileDirectory;
       qtVersions = with pkgs; [ qt5 qt6 ];
-    in filterAttrs (n: v: v != null) {
+    in lib.filterAttrs (n: v: v != null) {
       QT_QPA_PLATFORMTHEME = if cfg.platformTheme == "gtk" then
         "gtk2"
       else if cfg.platformTheme == "qtct" then
@@ -148,7 +148,7 @@ in {
             qtVersions));
     };
 
-  in mkIf (cfg.enable && cfg.platformTheme != null) {
+  in lib.mkIf (cfg.enable && cfg.platformTheme != null) {
     assertions = [{
       assertion = cfg.platformTheme == "gnome" -> cfg.style.name != null
         && cfg.style.package != null;
@@ -158,8 +158,8 @@ in {
       '';
     }];
 
-    qt.style.package = mkIf (cfg.style.name != null)
-      (mkDefault (stylePackages.${toLower cfg.style.name} or null));
+    qt.style.package = lib.mkIf (cfg.style.name != null)
+      (lib.mkDefault (stylePackages.${lib.toLower cfg.style.name} or null));
 
     home.sessionVariables = envVars;
 

From 3452e14ec729e0582a5fb120c14ed5c6d7fb64d3 Mon Sep 17 00:00:00 2001
From: Thiago Kenji Okada <thiagokokada@gmail.com>
Date: Wed, 18 Oct 2023 16:15:49 +0100
Subject: [PATCH 04/11] qt: workaround issue when i18n.inputMethod.enabled =
 'fcitx5'

---
 modules/i18n/input-method/fcitx5.nix            |  5 +++--
 modules/misc/qt.nix                             | 12 ++++++++----
 tests/modules/misc/qt/qt-platform-theme-gtk.nix |  1 +
 3 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/modules/i18n/input-method/fcitx5.nix b/modules/i18n/input-method/fcitx5.nix
index 1787a236..371f1cea 100644
--- a/modules/i18n/input-method/fcitx5.nix
+++ b/modules/i18n/input-method/fcitx5.nix
@@ -28,8 +28,9 @@ in {
       GTK_IM_MODULE = "fcitx";
       QT_IM_MODULE = "fcitx";
       XMODIFIERS = "@im=fcitx";
-      QT_PLUGIN_PATH =
-        "${fcitx5Package}/${pkgs.qt6.qtbase.qtPluginPrefix}:\${QT_PLUGIN_PATH}";
+      # Using mkDefault here since we override this value in qt module if enabled
+      QT_PLUGIN_PATH = lib.mkDefault
+        "$QT_PLUGIN_PATH\${QT_PLUGIN_PATH:+:}${fcitx5Package}/${pkgs.qt6.qtbase.qtPluginPrefix}";
     };
 
     systemd.user.services.fcitx5-daemon = {
diff --git a/modules/misc/qt.nix b/modules/misc/qt.nix
index e50f416a..a5a4f163 100644
--- a/modules/misc/qt.nix
+++ b/modules/misc/qt.nix
@@ -130,6 +130,7 @@ in {
     envVars = let
       inherit (config.home) profileDirectory;
       qtVersions = with pkgs; [ qt5 qt6 ];
+      makeQtPath = prefix: basePath: qt: "${basePath}/${qt.qtbase.${prefix}}";
     in lib.filterAttrs (n: v: v != null) {
       QT_QPA_PLATFORMTHEME = if cfg.platformTheme == "gtk" then
         "gtk2"
@@ -140,12 +141,15 @@ in {
       QT_STYLE_OVERRIDE = cfg.style.name;
       QT_PLUGIN_PATH = "$QT_PLUGIN_PATH\${QT_PLUGIN_PATH:+:}"
         + (lib.concatStringsSep ":"
-          (map (qt: "${profileDirectory}/${qt.qtbase.qtPluginPrefix}")
-            qtVersions));
+          # Workaround issue with home.sessionVariables that does not support
+          # multiple different values since fcitx5 also needs to set QT_PLUGIN_PATH.
+          (lib.optional (config.i18n.inputMethod == "fcitx5")
+            (makeQtPath "qtPluginPrefix" config.i18n.inputMethod.package
+              pkgs.qt6) ++ (map (makeQtPath "qtPluginPrefix" profileDirectory)
+                qtVersions)));
       QML2_IMPORT_PATH = "$QML2_IMPORT_PATH\${QML2_IMPORT_PATH:+:}"
         + (lib.concatStringsSep ":"
-          (map (qt: "${profileDirectory}/${qt.qtbase.qtQmlPrefix}")
-            qtVersions));
+          (map (makeQtPath "qtQmlPrefix" profileDirectory) qtVersions));
     };
 
   in lib.mkIf (cfg.enable && cfg.platformTheme != null) {
diff --git a/tests/modules/misc/qt/qt-platform-theme-gtk.nix b/tests/modules/misc/qt/qt-platform-theme-gtk.nix
index b91496b5..070c8020 100644
--- a/tests/modules/misc/qt/qt-platform-theme-gtk.nix
+++ b/tests/modules/misc/qt/qt-platform-theme-gtk.nix
@@ -6,6 +6,7 @@
       enable = true;
       platformTheme = "gtk";
     };
+    i18n.inputMethod.enabled = "fcitx5";
 
     nmt.script = ''
       assertFileRegex home-path/etc/profile.d/hm-session-vars.sh \

From 4ba652d8a8a02348790100ffec69c8787aca9fe9 Mon Sep 17 00:00:00 2001
From: Thiago Kenji Okada <thiagokokada@gmail.com>
Date: Wed, 18 Oct 2023 18:00:45 +0100
Subject: [PATCH 05/11] qt: add style mappings for Qt 6

---
 modules/misc/qt.nix | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/modules/misc/qt.nix b/modules/misc/qt.nix
index a5a4f163..8c56063c 100644
--- a/modules/misc/qt.nix
+++ b/modules/misc/qt.nix
@@ -8,15 +8,15 @@ let
     bb10bright = libsForQt5.qtstyleplugins;
     bb10dark = libsForQt5.qtstyleplugins;
     cleanlooks = libsForQt5.qtstyleplugins;
-    gtk2 = libsForQt5.qtstyleplugins;
+    gtk2 = [ libsForQt5.qtstyleplugins qt6Packages.qt6gtk2 ];
     motif = libsForQt5.qtstyleplugins;
     cde = libsForQt5.qtstyleplugins;
     plastique = libsForQt5.qtstyleplugins;
 
-    adwaita = adwaita-qt;
-    adwaita-dark = adwaita-qt;
-    adwaita-highcontrast = adwaita-qt;
-    adwaita-highcontrastinverse = adwaita-qt;
+    adwaita = [ adwaita-qt adwaita-qt6 ];
+    adwaita-dark = [ adwaita-qt adwaita-qt6 ];
+    adwaita-highcontrast = [ adwaita-qt adwaita-qt6 ];
+    adwaita-highcontrastinverse = [ adwaita-qt adwaita-qt6 ];
 
     breeze = libsForQt5.breeze-qt5;
 
@@ -83,9 +83,11 @@ in {
           example = "adwaita-dark";
           relatedPackages = [
             "adwaita-qt"
+            "adwaita-qt6"
             [ "libsForQt5" "breeze-qt5" ]
-            [ "libsForQt5" "qtstyleplugins" ]
             [ "libsForQt5" "qtstyleplugin-kvantum" ]
+            [ "libsForQt5" "qtstyleplugins" ]
+            [ "qt6Packages" "qt6gtk2" ]
             [ "qt6Packages" "qtstyleplugin-kvantum" ]
           ];
           description = ''

From 541d32d8b868753b0a627d542182cba9216325d9 Mon Sep 17 00:00:00 2001
From: Thiago Kenji Okada <thiagokokada@gmail.com>
Date: Wed, 18 Oct 2023 18:22:06 +0100
Subject: [PATCH 06/11] qt: add support for platformTheme lxqt

---
 modules/misc/qt.nix | 36 ++++++++++++++++++++++--------------
 1 file changed, 22 insertions(+), 14 deletions(-)

diff --git a/modules/misc/qt.nix b/modules/misc/qt.nix
index 8c56063c..3040fb1c 100644
--- a/modules/misc/qt.nix
+++ b/modules/misc/qt.nix
@@ -3,6 +3,14 @@
 let
   cfg = config.qt;
 
+  platformPackages = with pkgs; {
+    gnome = [ qgnomeplatform ];
+    gtk = [ libsForQt5.qtstyleplugins qt6Packages.qt6gtk2 ];
+    kde = [ libsForQt5.plasma-integration libsForQt5.systemsettings ];
+    lxqt = [ lxqt.lxqt-qtplugin lxqt.lxqt-config ];
+    qtct = [ libsForQt5.qt5ct qt6Packages.qt6ct ];
+  };
+
   # Maps known lowercase style names to style packages. Non-exhaustive.
   stylePackages = with pkgs; {
     bb10bright = libsForQt5.qtstyleplugins;
@@ -41,16 +49,20 @@ in {
       enable = lib.mkEnableOption "Qt 5 and 6 configuration";
 
       platformTheme = lib.mkOption {
-        type = with lib.types; nullOr (enum [ "gtk" "gnome" "qtct" "kde" ]);
+        type = with lib.types;
+          nullOr (enum [ "gtk" "gnome" "lxqt" "qtct" "kde" ]);
         default = null;
         example = "gnome";
         relatedPackages = [
           "qgnomeplatform"
-          [ "libsForQt5" "qtstyleplugins" ]
-          [ "libsForQt5" "qt5ct" ]
-          [ "qt6Packages" "qt6ct" ]
           [ "libsForQt5" "plasma-integration" ]
+          [ "libsForQt5" "qt5ct" ]
+          [ "libsForQt5" "qtstyleplugins" ]
           [ "libsForQt5" "systemsettings" ]
+          [ "lxqt" "lxqt-config" ]
+          [ "lxqt" "lxqt-qtplugin" ]
+          [ "qt6Packages" "qt6ct" ]
+          [ "qt6Packages" "qt6gtk2" ]
         ];
         description = ''
           Platform theme to use for Qt applications.
@@ -65,6 +77,11 @@ in {
           : Use GNOME theme with
             [`qgnomeplatform`](https://github.com/FedoraQt/QGnomePlatform)
 
+          `lxqt`
+          : Use LXQt theme style set using the
+            [`lxqt-config-appearance`](https://github.com/lxqt/lxqt-config)
+            application
+
           `qtct`
           : Use Qt style set using
             [`qt5ct`](https://github.com/desktop-app/qt5ct)
@@ -172,16 +189,7 @@ in {
     # Apply theming also to apps started by systemd.
     systemd.user.sessionVariables = envVars;
 
-    home.packages = (if cfg.platformTheme == "gnome" then
-      [ pkgs.qgnomeplatform ]
-    else if cfg.platformTheme == "qtct" then [
-      pkgs.libsForQt5.qt5ct
-      pkgs.qt6Packages.qt6ct
-    ] else if cfg.platformTheme == "kde" then [
-      pkgs.libsForQt5.plasma-integration
-      pkgs.libsForQt5.systemsettings
-    ] else
-      [ pkgs.libsForQt5.qtstyleplugins ])
+    home.packages = (platformPackages.${cfg.platformTheme} or [ ])
       ++ lib.optionals (cfg.style.package != null)
       (lib.toList cfg.style.package);
 

From bc53e4c240ea71d2f4b271d95c262369ab7adc7c Mon Sep 17 00:00:00 2001
From: Thiago Kenji Okada <thiagokokada@gmail.com>
Date: Wed, 18 Oct 2023 18:36:13 +0100
Subject: [PATCH 07/11] qt: add qgnomeplatform-qt6 when platformTheme is set to
 gnome

---
 modules/misc/qt.nix | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/modules/misc/qt.nix b/modules/misc/qt.nix
index 3040fb1c..a968f31a 100644
--- a/modules/misc/qt.nix
+++ b/modules/misc/qt.nix
@@ -4,7 +4,7 @@ let
   cfg = config.qt;
 
   platformPackages = with pkgs; {
-    gnome = [ qgnomeplatform ];
+    gnome = [ qgnomeplatform qgnomeplatform-qt6 ];
     gtk = [ libsForQt5.qtstyleplugins qt6Packages.qt6gtk2 ];
     kde = [ libsForQt5.plasma-integration libsForQt5.systemsettings ];
     lxqt = [ lxqt.lxqt-qtplugin lxqt.lxqt-config ];
@@ -55,6 +55,7 @@ in {
         example = "gnome";
         relatedPackages = [
           "qgnomeplatform"
+          "qgnomeplatform-qt6"
           [ "libsForQt5" "plasma-integration" ]
           [ "libsForQt5" "qt5ct" ]
           [ "libsForQt5" "qtstyleplugins" ]

From eaee696b6e77b8ec848fe6c49c9bc0fdfadafb3a Mon Sep 17 00:00:00 2001
From: Thiago Kenji Okada <thiagokokada@gmail.com>
Date: Wed, 18 Oct 2023 19:23:17 +0100
Subject: [PATCH 08/11] qt: simplify style.name mappings

---
 modules/misc/qt.nix | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/modules/misc/qt.nix b/modules/misc/qt.nix
index a968f31a..1655d437 100644
--- a/modules/misc/qt.nix
+++ b/modules/misc/qt.nix
@@ -3,6 +3,7 @@
 let
   cfg = config.qt;
 
+  # Map platform names to their packages.
   platformPackages = with pkgs; {
     gnome = [ qgnomeplatform qgnomeplatform-qt6 ];
     gtk = [ libsForQt5.qtstyleplugins qt6Packages.qt6gtk2 ];
@@ -11,6 +12,12 @@ let
     qtct = [ libsForQt5.qt5ct qt6Packages.qt6ct ];
   };
 
+  # Maps style names to their QT_QPA_PLATFORMTHEME, if necessary.
+  styleNames = {
+    gtk = "gtk2";
+    qtct = "qt5ct";
+  };
+
   # Maps known lowercase style names to style packages. Non-exhaustive.
   stylePackages = with pkgs; {
     bb10bright = libsForQt5.qtstyleplugins;
@@ -152,12 +159,8 @@ in {
       qtVersions = with pkgs; [ qt5 qt6 ];
       makeQtPath = prefix: basePath: qt: "${basePath}/${qt.qtbase.${prefix}}";
     in lib.filterAttrs (n: v: v != null) {
-      QT_QPA_PLATFORMTHEME = if cfg.platformTheme == "gtk" then
-        "gtk2"
-      else if cfg.platformTheme == "qtct" then
-        "qt5ct"
-      else
-        cfg.platformTheme;
+      QT_QPA_PLATFORMTHEME =
+        styleNames.${cfg.platformTheme} or cfg.platformTheme;
       QT_STYLE_OVERRIDE = cfg.style.name;
       QT_PLUGIN_PATH = "$QT_PLUGIN_PATH\${QT_PLUGIN_PATH:+:}"
         + (lib.concatStringsSep ":"

From 55eee5bd67fee341e86a457646bd4b78c5a77d26 Mon Sep 17 00:00:00 2001
From: Thiago Kenji Okada <thiagokokada@gmail.com>
Date: Wed, 18 Oct 2023 19:51:00 +0100
Subject: [PATCH 09/11] qt: use sessionVariablesExtra to export
 QT_PLUGIN_PATH/QML2_IMPORT_PATH

---
 modules/i18n/input-method/fcitx5.nix |  3 +-
 modules/misc/qt.nix                  | 41 +++++++++++++++++-----------
 2 files changed, 26 insertions(+), 18 deletions(-)

diff --git a/modules/i18n/input-method/fcitx5.nix b/modules/i18n/input-method/fcitx5.nix
index 371f1cea..3599fd2d 100644
--- a/modules/i18n/input-method/fcitx5.nix
+++ b/modules/i18n/input-method/fcitx5.nix
@@ -28,8 +28,7 @@ in {
       GTK_IM_MODULE = "fcitx";
       QT_IM_MODULE = "fcitx";
       XMODIFIERS = "@im=fcitx";
-      # Using mkDefault here since we override this value in qt module if enabled
-      QT_PLUGIN_PATH = lib.mkDefault
+      QT_PLUGIN_PATH =
         "$QT_PLUGIN_PATH\${QT_PLUGIN_PATH:+:}${fcitx5Package}/${pkgs.qt6.qtbase.qtPluginPrefix}";
     };
 
diff --git a/modules/misc/qt.nix b/modules/misc/qt.nix
index 1655d437..f45b8e3d 100644
--- a/modules/misc/qt.nix
+++ b/modules/misc/qt.nix
@@ -154,25 +154,23 @@ in {
   config = let
 
     # Necessary because home.sessionVariables doesn't support mkIf
-    envVars = let
-      inherit (config.home) profileDirectory;
-      qtVersions = with pkgs; [ qt5 qt6 ];
-      makeQtPath = prefix: basePath: qt: "${basePath}/${qt.qtbase.${prefix}}";
-    in lib.filterAttrs (n: v: v != null) {
+    envVars = lib.filterAttrs (n: v: v != null) {
       QT_QPA_PLATFORMTHEME =
         styleNames.${cfg.platformTheme} or cfg.platformTheme;
       QT_STYLE_OVERRIDE = cfg.style.name;
+    };
+
+    envVarsExtra = let
+      inherit (config.home) profileDirectory;
+      qtVersions = with pkgs; [ qt5 qt6 ];
+      makeQtPath = prefix:
+        lib.concatStringsSep ":"
+        (map (qt: "${profileDirectory}/${qt.qtbase.${prefix}}") qtVersions);
+    in {
       QT_PLUGIN_PATH = "$QT_PLUGIN_PATH\${QT_PLUGIN_PATH:+:}"
-        + (lib.concatStringsSep ":"
-          # Workaround issue with home.sessionVariables that does not support
-          # multiple different values since fcitx5 also needs to set QT_PLUGIN_PATH.
-          (lib.optional (config.i18n.inputMethod == "fcitx5")
-            (makeQtPath "qtPluginPrefix" config.i18n.inputMethod.package
-              pkgs.qt6) ++ (map (makeQtPath "qtPluginPrefix" profileDirectory)
-                qtVersions)));
+        + (makeQtPath "qtPluginPrefix");
       QML2_IMPORT_PATH = "$QML2_IMPORT_PATH\${QML2_IMPORT_PATH:+:}"
-        + (lib.concatStringsSep ":"
-          (map (makeQtPath "qtQmlPrefix" profileDirectory) qtVersions));
+        + (makeQtPath "qtQmlPrefix");
     };
 
   in lib.mkIf (cfg.enable && cfg.platformTheme != null) {
@@ -188,10 +186,21 @@ in {
     qt.style.package = lib.mkIf (cfg.style.name != null)
       (lib.mkDefault (stylePackages.${lib.toLower cfg.style.name} or null));
 
-    home.sessionVariables = envVars;
+    home = {
+      sessionVariables = envVars;
+      # home.sessionVariables does not support setting the same environment
+      # variable to different values.
+      # Since some other modules may set the QT_PLUGIN_PATH or QML2_IMPORT_PATH
+      # to their own value, e.g.: fcitx5, we avoid conflicts by setting
+      # the values in home.sessionVariablesExtra instead.
+      sessionVariablesExtra = ''
+        export QT_PLUGIN_PATH=${envVarsExtra.QT_PLUGIN_PATH}
+        export QML2_IMPORT_PATH=${envVarsExtra.QML2_IMPORT_PATH}
+      '';
+    };
 
     # Apply theming also to apps started by systemd.
-    systemd.user.sessionVariables = envVars;
+    systemd.user.sessionVariables = envVars // envVarsExtra;
 
     home.packages = (platformPackages.${cfg.platformTheme} or [ ])
       ++ lib.optionals (cfg.style.package != null)

From 1e80a0b3d8ef2a9ffc0399b32edcd588ac396fa6 Mon Sep 17 00:00:00 2001
From: Thiago Kenji Okada <thiagokokada@gmail.com>
Date: Sun, 22 Oct 2023 19:13:20 +0100
Subject: [PATCH 10/11] qt: allow usage without setting platformTheme

---
 modules/misc/qt.nix | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/modules/misc/qt.nix b/modules/misc/qt.nix
index f45b8e3d..19986579 100644
--- a/modules/misc/qt.nix
+++ b/modules/misc/qt.nix
@@ -173,7 +173,7 @@ in {
         + (makeQtPath "qtQmlPrefix");
     };
 
-  in lib.mkIf (cfg.enable && cfg.platformTheme != null) {
+  in lib.mkIf cfg.enable {
     assertions = [{
       assertion = cfg.platformTheme == "gnome" -> cfg.style.name != null
         && cfg.style.package != null;
@@ -206,8 +206,8 @@ in {
       ++ lib.optionals (cfg.style.package != null)
       (lib.toList cfg.style.package);
 
-    xsession.importedVariables =
-      [ "QT_QPA_PLATFORMTHEME" "QT_PLUGIN_PATH" "QML2_IMPORT_PATH" ]
+    xsession.importedVariables = [ "QT_PLUGIN_PATH" "QML2_IMPORT_PATH" ]
+      ++ lib.optionals (cfg.platformTheme != null) [ "QT_QPA_PLATFORMTHEME" ]
       ++ lib.optionals (cfg.style.name != null) [ "QT_STYLE_OVERRIDE" ];
   };
 }

From 1160454c791fa777ce59373fca86c25ad075265a Mon Sep 17 00:00:00 2001
From: Thiago Kenji Okada <thiagokokada@gmail.com>
Date: Sun, 22 Oct 2023 19:19:51 +0100
Subject: [PATCH 11/11] qt: support gtk3 platform theme

This theme is part of qtbase and requires no extra packages.

Co-authored-by: novenary <novenary@kwak.zip>
---
 modules/misc/qt.nix | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/modules/misc/qt.nix b/modules/misc/qt.nix
index 19986579..495841ea 100644
--- a/modules/misc/qt.nix
+++ b/modules/misc/qt.nix
@@ -57,7 +57,7 @@ in {
 
       platformTheme = lib.mkOption {
         type = with lib.types;
-          nullOr (enum [ "gtk" "gnome" "lxqt" "qtct" "kde" ]);
+          nullOr (enum [ "gtk" "gtk3" "gnome" "lxqt" "qtct" "kde" ]);
         default = null;
         example = "gnome";
         relatedPackages = [
@@ -81,6 +81,10 @@ in {
           : Use GTK theme with
             [`qtstyleplugins`](https://github.com/qt/qtstyleplugins)
 
+          `gtk3`
+          : Use [GTK3 integration](https://github.com/qt/qtbase/tree/dev/src/plugins/platformthemes/gtk3)
+            for file picker dialogs, font and theme configuration
+
           `gnome`
           : Use GNOME theme with
             [`qgnomeplatform`](https://github.com/FedoraQt/QGnomePlatform)