Add http fetch to eframe and implement it in egui_glium using ureq

eframe/src/lib.rs

@@ -52,3 +52,34 @@ pub fn start_web(canvas_id: &str, app: Box<dyn epi::App>) -> Result<(), wasm_bin
 pub fn run_native(app: Box<dyn epi::App>) {
     egui_glium::run(app)
 }
+
+// ----------------------------------------------------------------------------
+
+pub mod http {
+    pub use epi::http::*;
+
+    /// Do a HTTP request and call the callback when done.
+    pub fn fetch(
+        request: Request,
+        on_done: impl 'static + Send + FnOnce(Result<Response, String>),
+    ) {
+        fetch_dyn(request, Box::new(on_done))
+    }
+
+    fn fetch_dyn(request: Request, on_done: Box<dyn FnOnce(Result<Response, String>) + Send>) {
+        #[cfg(target_arch = "wasm32")]
+        {
+            egui_web::spawn_future(async move {
+                let result = egui_web::http::fetch_async(&request).await;
+                on_done(result)
+            });
+        }
+        #[cfg(not(target_arch = "wasm32"))]
+        {
+            std::thread::spawn(move || {
+                let result = egui_glium::http::fetch_blocking(&request);
+                on_done(result)
+            });
+        }
+    }
+}