Desktop: Make embedded resources optional (#3094)

* Make embedding resources optional

* Move remaining cef rc to internal module

* Move embedded resources to separate crate

* Review fixup

* Fix

* Fix read

* Add read error

desktop/embedded-resources/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "graphite-desktop-embedded-resources"
+version = "0.1.0"
+description = "Graphite Desktop Embedded Resources"
+authors = ["Graphite Authors <contact@graphite.rs>"]
+license = "Apache-2.0"
+repository = ""
+edition = "2024"
+rust-version = "1.87"
+
+[dependencies]
+include_dir = { workspace = true }
+
+[lints.rust]
+unexpected_cfgs = { level = "warn", check-cfg = ['cfg(embedded_resources)'] }

desktop/embedded-resources/build.rs

@@ -0,0 +1,17 @@
+const RESOURCES: &str = "../../frontend/dist";
+
+// Check if the directory `RESOURCES` exists and sets the embedded_resources cfg accordingly
+// Absolute path of `RESOURCES` available via the `EMBEDDED_RESOURCES` environment variable
+fn main() {
+	let crate_dir = std::path::PathBuf::from(std::env::var("CARGO_MANIFEST_DIR").unwrap());
+
+	println!("cargo:rerun-if-changed={RESOURCES}");
+	if let Ok(resources) = crate_dir.join(RESOURCES).canonicalize()
+		&& resources.exists()
+	{
+		println!("cargo:rustc-cfg=embedded_resources");
+		println!("cargo:rustc-env=EMBEDDED_RESOURCES={}", resources.to_string_lossy());
+	} else {
+		println!("cargo:warning=Resource directory does not exist. Resources will not be embedded. Did you forget to build the frontend?");
+	}
+}

desktop/embedded-resources/src/lib.rs

@@ -0,0 +1,10 @@
+//! This crate provides `EMBEDDED_RESOURCES` that can be included in the desktop application binary.
+//! It is intended to be used by the `embedded_resources` feature of the `graphite-desktop` crate.
+//! The build script checks if the specified resources directory exists and sets the `embedded_resources` cfg flag accordingly.
+//! If the resources directory does not exist, resources will not be embedded and a warning will be reported during compilation.
+
+#[cfg(embedded_resources)]
+pub static EMBEDDED_RESOURCES: Option<include_dir::Dir> = Some(include_dir::include_dir!("$EMBEDDED_RESOURCES"));
+
+#[cfg(not(embedded_resources))]
+pub static EMBEDDED_RESOURCES: Option<include_dir::Dir> = None;