feat: respect system-configured interface font

.gitignore

@@ -9,3 +9,4 @@
 /target/
 /vendor.tar
 /vendor/
+result*

daemon/src/lib.rs

@@ -9,6 +9,7 @@ pub struct UserData {
     pub full_name_opt: Option<String>,
     pub icon_opt: Option<Vec<u8>>,
     pub theme_opt: Option<Theme>,
+    pub interface_font_opt: Option<String>,
     pub wallpapers_opt: Option<Vec<(String, WallpaperData)>>,
     pub xkb_config_opt: Option<XkbConfig>,
     pub clock_military_time: bool,

daemon/src/main.rs

@@ -113,6 +113,7 @@ impl GreeterProxy {
                     .map(|gecos| gecos.split(',').next().unwrap_or_default().to_string()),
                 icon_opt,
                 theme_opt: None,
+                interface_font_opt: None,
                 //TODO: should wallpapers come from a per-user call?
                 wallpapers_opt: None,
                 xkb_config_opt: None,
@@ -226,6 +227,15 @@ impl GreeterProxy {
                         );
                     }
                 };
+
+                match cosmic_config::Config::new("com.system76.CosmicTk", 1) {
+                    Ok(config_handler) => {
+                        user_data.interface_font_opt = config_handler.get("interface_font").unwrap_or_default();
+                    }
+                    Err(err) => {
+                        log::error!("failed to create CosmicTk config handler: {:?}", err);
+                    }
+                };
             })
             .map_err(|err| GreeterError::RunAsUser(err.to_string()))?;
 

flake.nix

@@ -0,0 +1,34 @@
+{
+  inputs = {
+    flake-parts.url = "github:hercules-ci/flake-parts";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+  };
+
+  outputs =
+    inputs:
+    inputs.flake-parts.lib.mkFlake { inherit inputs; } {
+      systems = [
+        "aarch64-linux"
+        "x86_64-linux"
+      ];
+
+      perSystem =
+        { pkgs, self', ... }:
+        {
+          devShells.default = pkgs.mkShell {
+            nativeBuildInputs = with pkgs; [
+              cargo
+              clippy
+              rustc
+              rustfmt
+            ];
+
+            strictDeps = true;
+          };
+          packages = {
+            default = self'.packages.cosmic-greeter;
+            cosmic-greeter = pkgs.callPackage ./package.nix { };
+          };
+        };
+    };
+}

package.nix

@@ -0,0 +1,113 @@
+# Based on lilyinstarlight's work on:
+# https://github.com/lilyinstarlight/nixos-cosmic/blob/main/pkgs/cosmic-greeter/package.nix
+{
+  lib,
+  rustPlatform,
+  cmake,
+  coreutils,
+  just,
+  libinput,
+  linux-pam,
+  stdenv,
+  udev,
+  xkeyboard_config,
+  wayland,
+  vulkan-loader,
+  xorg,
+  libGL,
+  libxkbcommon,
+  makeBinaryWrapper,
+  pkg-config,
+  cosmic-icons,
+}:
+rustPlatform.buildRustPackage {
+  pname = "cosmic-greeter";
+  version = "1.0.0-alpha.5.1";
+
+  src = lib.fileset.toSource {
+    root = ./.;
+    fileset = lib.fileset.difference ./. (
+      lib.fileset.unions [
+        (lib.fileset.maybeMissing ./result)
+        (lib.fileset.maybeMissing ./target)
+        (lib.fileset.maybeMissing ./.git)
+        (lib.fileset.fileFilter (
+          file:
+          builtins.elem file.name [
+            "flake.nix"
+            "flake.lock"
+            "LICENSE"
+            "README.md"
+            ".gitignore"
+            ".gitattributes"
+            "package.nix"
+          ]
+        ) ./.)
+      ]
+    );
+  };
+
+  nativeBuildInputs = [
+    cmake
+    just
+    makeBinaryWrapper
+    pkg-config
+    rustPlatform.bindgenHook
+  ];
+
+  buildInputs = [
+    libinput
+    linux-pam
+    udev
+    wayland
+    vulkan-loader
+    xorg.libX11
+    xorg.libXcursor
+    xorg.libXi
+    xorg.libxcb
+    libGL
+    libxkbcommon
+  ];
+
+  useFetchCargoVendor = true;
+  cargoHash = "sha256-nmkM/Jm2P5ftZFfzX+O1Fe6eobRbgBkajZsbyI67Zfw=";
+  cargoBuildFlags = [ "--all" ];
+
+  dontUseJustBuild = true;
+  dontUseJustCheck = true;
+
+  justFlags = [
+    "--set"
+    "prefix"
+    (placeholder "out")
+    "--set"
+    "bin-src"
+    "target/${stdenv.hostPlatform.rust.cargoShortTarget}/release/cosmic-greeter"
+    "--set"
+    "daemon-src"
+    "target/${stdenv.hostPlatform.rust.cargoShortTarget}/release/cosmic-greeter-daemon"
+  ];
+
+  postPatch = ''
+    substituteInPlace src/greeter.rs --replace-fail '/usr/bin/env' '${lib.getExe' coreutils "env"}'
+  '';
+
+  postInstall = ''
+    wrapProgram "$out/bin/cosmic-greeter" \
+      --set-default X11_BASE_RULES_XML "${xkeyboard_config}/share/X11/xkb/rules/base.xml" \
+      --set-default X11_EXTRA_RULES_XML "${xkeyboard_config}/share/X11/xkb/rules/base.extras.xml" \
+      --suffix XDG_DATA_DIRS : "${cosmic-icons}/share" \
+      --prefix LD_LIBRARY_PATH : "${
+        lib.makeLibraryPath [
+          xorg.libX11
+          xorg.libXcursor
+          xorg.libXi
+          xorg.libxcb
+          libGL
+          libxkbcommon
+          wayland
+          vulkan-loader
+        ]
+      }"
+  '';
+}

src/greeter.rs

@@ -109,6 +109,7 @@ fn user_data_fallback() -> Vec<UserData> {
                         .map(|gecos| gecos.split(',').next().unwrap_or_default().to_string()),
                     icon_opt,
                     theme_opt: None,
+                    interface_font_opt: None,
                     wallpapers_opt: None,
                     xkb_config_opt: None,
                     clock_military_time: false,
@@ -299,6 +300,14 @@ pub fn main() -> Result<(), Box<dyn Error>> {
             }
         };
 
+    let tk_config_handler = match cosmic_config::Config::new("com.system76.CosmicTk", 1) {
+        Ok(config_handler) => Some(config_handler),
+        Err(err) => {
+            log::error!("failed to create cosmic-tk config handler: {}", err);
+            None
+        }
+    };
+
     let fallback_background =
         widget::image::Handle::from_memory(include_bytes!("../res/background.jpg"));
 
@@ -307,6 +316,7 @@ pub fn main() -> Result<(), Box<dyn Error>> {
         sessions,
         layouts_opt,
         comp_config_handler,
+        tk_config_handler,
         greeter_config,
         greeter_config_handler,
         fallback_background,
@@ -325,6 +335,7 @@ pub struct Flags {
     sessions: HashMap<String, (Vec<String>, Vec<String>)>,
     layouts_opt: Option<Arc<xkb_data::KeyboardLayouts>>,
     comp_config_handler: Option<cosmic_config::Config>,
+    tk_config_handler: Option<cosmic_config::Config>,
     greeter_config: CosmicGreeterConfig,
     greeter_config_handler: Option<cosmic_config::Config>,
     fallback_background: widget::image::Handle,
@@ -480,6 +491,26 @@ impl App {
         }
     }
 
+    fn set_interface_font(&self) {
+        let user_data = match self
+            .selected_username
+            .data_idx
+            .and_then(|i| self.flags.user_datas.get(i))
+        {
+            Some(some) => some,
+            None => return,
+        };
+
+        if let Some(tk_config_handler) = &self.flags.tk_config_handler {
+            if let Some(font) = &user_data.interface_font_opt {
+                match tk_config_handler.set("interface_font", font) {
+                    Ok(()) => log::info!("updated cosmic-tk interface_font"),
+                    Err(err) => log::error!("failed to update cosmic-tk interface_font: {}", err),
+                }
+            }
+        }
+    }
+
     fn update_user_config(&mut self) -> Command<Message> {
         let user_data = match self
             .selected_username
@@ -573,6 +604,10 @@ impl App {
             }
         }
 
+        if let Some(font) = &user_data.interface_font_opt {
+            self.set_interface_font();
+        }
+
         match &user_data.theme_opt {
             Some(theme) => {
                 cosmic::app::command::set_theme(cosmic::Theme::custom(Arc::new(theme.clone())))