Merge pull request #167032 from Vonfry/feature/fcitx5/rime/with-custom-data-dirs

fcitx5-rime: support custom data dir from environment variable for nixos and nix specially

nixos/modules/i18n/input-method/fcitx5.nix

···
 let
   im = config.i18n.inputMethod;
   cfg = im.fcitx5;
-  fcitx5Package = pkgs.fcitx5-with-addons.override { inherit (cfg) addons; };
+  addons = cfg.addons ++ optional cfg.enableRimeData pkgs.rime-data;
+  fcitx5Package = pkgs.fcitx5-with-addons.override { inherit addons; };
+  whetherRimeDataDir = any (p: p.pname == "fcitx5-rime") cfg.addons;
 in {
   options = {
     i18n.inputMethod.fcitx5 = {
···
           Enabled Fcitx5 addons.
         '';
       };
+
+      enableRimeData = mkEnableOption "default rime-data with fcitx5-rime";
     };
   };
 
   config = mkIf (im.enabled == "fcitx5") {
     i18n.inputMethod.package = fcitx5Package;
 
-    environment.variables = {
-      GTK_IM_MODULE = "fcitx";
-      QT_IM_MODULE = "fcitx";
-      XMODIFIERS = "@im=fcitx";
-    };
+    environment = mkMerge [{
+      variables = {
+        GTK_IM_MODULE = "fcitx";
+        QT_IM_MODULE = "fcitx";
+        XMODIFIERS = "@im=fcitx";
+      };
+    }
+    (mkIf whetherRimeDataDir {
+      pathsToLink = [
+        "/share/rime-data"
+      ];
+
+      variables =  {
+        NIX_RIME_DATA_DIR = "/run/current-system/sw/share/rime-data";
+      };
+    })];
   };
 }

pkgs/tools/inputmethods/fcitx5/fcitx5-rime-with-nix-env-variable.patch

···
+:100644 100644 fac4f53 aed9617 M	src/rimeengine.cpp
+
+diff --git a/src/rimeengine.cpp b/src/rimeengine.cpp
+index fac4f53..aed9617 100644
+--- a/src/rimeengine.cpp
++++ b/src/rimeengine.cpp
+@@ -164,7 +164,10 @@ void RimeEngine::rimeStart(bool fullcheck) {
+             RIME_ERROR() << "Failed to create user directory: " << userDir;
+         }
+     }
+-    const char *sharedDataDir = RIME_DATA_DIR;
++    const char *sharedDataDir = getenv("NIX_RIME_DATA_DIR");
++    if (!sharedDataDir) {
++        sharedDataDir = RIME_DATA_DIR;
++    }
+ 
+     RIME_STRUCT(RimeTraits, fcitx_rime_traits);
+     fcitx_rime_traits.shared_data_dir = sharedDataDir;

pkgs/tools/inputmethods/fcitx5/fcitx5-rime.nix

···
     librime
   ];
 
+  patches = [ ./fcitx5-rime-with-nix-env-variable.patch ];
+
   meta = with lib; {
     description = "RIME support for Fcitx5";
     homepage = "https://github.com/fcitx/fcitx5-rime";