polish: examples

packages/web/src/ric_raf.rs

@@ -4,7 +4,7 @@ use gloo_timers::future::TimeoutFuture;
 use js_sys::Function;
 use wasm_bindgen::JsCast;
 use wasm_bindgen::{prelude::Closure, JsValue};
-use web_sys::Window;
+use web_sys::{window, Window};
 
 pub struct RafLoop {
     window: Window,
@@ -24,10 +24,21 @@ impl RafLoop {
 
         let (ric_sender, ric_receiver) = async_channel::unbounded();
 
-        let ric_closure: Closure<dyn Fn(JsValue)> = Closure::wrap(Box::new(move |_v: JsValue| {
-            //
-            let deadline = _v.dyn_into::<web_sys::IdleDeadline>().unwrap();
-            let time_remaining = deadline.time_remaining() as u32;
+        let has_idle_callback = {
+            let bo = window().unwrap().dyn_into::<js_sys::Object>().unwrap();
+            bo.has_own_property(&JsValue::from_str("requestIdleCallback"))
+        };
+        let ric_closure: Closure<dyn Fn(JsValue)> = Closure::wrap(Box::new(move |v: JsValue| {
+            let time_remaining = if has_idle_callback {
+                if let Ok(deadline) = v.dyn_into::<web_sys::IdleDeadline>() {
+                    deadline.time_remaining() as u32
+                } else {
+                    10
+                }
+            } else {
+                10
+            };
+
             ric_sender.try_send(time_remaining).unwrap()
         }));