[desktop] Add rust-dark-light as direct dependency

desktop/tauri/rust-dark-light/src/platforms/websys/detect.rs

@@ -0,0 +1,11 @@
+use crate::Mode;
+
+pub fn detect() -> crate::Mode {
+    if let Some(window) = web_sys::window() {
+        let query_result = window.match_media("(prefers-color-scheme: dark)");
+        if let Ok(Some(mql)) = query_result {
+            return Mode::from_bool(mql.matches());
+        }
+    }
+    Mode::Light
+}

desktop/tauri/rust-dark-light/src/platforms/websys/mod.rs

@@ -0,0 +1,2 @@
+pub mod detect;
+pub mod notify;

desktop/tauri/rust-dark-light/src/platforms/websys/notify.rs

@@ -0,0 +1,23 @@
+use std::task::Poll;
+
+use futures::{stream, Stream};
+
+use crate::{detect, Mode};
+
+pub async fn subscribe() -> anyhow::Result<impl Stream<Item = Mode> + Send> {
+    let mut last_mode = detect();
+
+    let stream = stream::poll_fn(move |ctx| -> Poll<Option<Mode>> {
+        let current_mode = detect();
+
+        if current_mode != last_mode {
+            last_mode = current_mode;
+            Poll::Ready(Some(current_mode))
+        } else {
+            ctx.waker().wake_by_ref();
+            Poll::Pending
+        }
+    });
+
+    Ok(stream)
+}