From df3eda58166fd20560272bd2c53bba4f7b34abd3 Mon Sep 17 00:00:00 2001
From: Guanran Wang <guanran928@outlook.com>
Date: Fri, 21 Nov 2025 22:30:52 +0800
Subject: [PATCH] fcitx5: set im-module for X11 GTK apps

---
 modules/i18n/input-method/fcitx5.nix | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/modules/i18n/input-method/fcitx5.nix b/modules/i18n/input-method/fcitx5.nix
index 99014a23c..b2f53c52c 100644
--- a/modules/i18n/input-method/fcitx5.nix
+++ b/modules/i18n/input-method/fcitx5.nix
@@ -215,6 +215,14 @@ in
       sessionSearchVariables.QT_PLUGIN_PATH = [ "${fcitx5Package}/${pkgs.qt6.qtbase.qtPluginPrefix}" ];
     };
 
+    # Make sure X11 GTK apps still use IM module.
+    # https://wiki.archlinux.org/title/Fcitx5#IM_modules
+    gtk = lib.optionalAttrs cfg.waylandFrontend {
+      gtk2.extraConfig = ''gtk-im-module="fcitx"'';
+      gtk3.extraConfig.gtk-im-module = "fcitx";
+      gtk4.extraConfig.gtk-im-module = "fcitx";
+    };
+
     xdg = {
       configFile.fcitx5 =
         let