obsidian and signal: sharp font on wayland

modules/obsidian.nix

@@ -6,10 +6,6 @@
   #   export LD_LIBRARY_PATH=$(nix --extra-experimental-features nix-command --extra-experimental-features flakes build --print-out-paths --no-link nixpkgs#libGL)/lib
   #   obsidian
 
-  # TODO: Only if on wayland and display scaling != 1
-  # To have sharp font, start obsidian with:
-  #   obsidian --enable-features=UseOzonePlatform --ozone-platform=x11
-
   # This `config` is only for "stable" `nixpkgs`, not for "unstable".
   # See nur-and-unstable.nix
 #  nixpkgs.config.allowUnfreePredicate = pkg: builtins.elem (lib.getName pkg) [
@@ -24,4 +20,8 @@
       unstable.obsidian # Markdown notes
     ];
   };
+
+  # TODO: if on wayland and scaling != 1
+  # Sharp fonts.
+  #   obsidian --enable-features=UseOzonePlatform --ozone-platform=x11
 }

modules/signal-desktop.nix

@@ -8,4 +8,19 @@
 
   # Signal does also use the NIXOS_OZONE_WL variable to enable Wayland support.
   environment.sessionVariables.NIXOS_OZONE_WL = lib.mkIf (config.services.xserver.displayManager.gdm.wayland) "1";
+
+  # TODO: if on wayland and scaling != 1
+  # Sharp fonts.
+  nixpkgs.overlays = lib.mkIf (config.services.xserver.displayManager.gdm.wayland) [
+    (self: super: {
+      signal-desktop = super.signal-desktop.overrideAttrs (old: {
+        preFixup = (old.preFixup or "") + ''
+          gappsWrapperArgs+=(
+            --add-flags "--enable-features=UseOzonePlatform"
+            --add-flags "--ozone-platform=x11"
+          )
+        '';
+      });
+    })
+  ];
 }