tasks initial impl (still working on task_on trait method)

examples/task.rs

@@ -0,0 +1,33 @@
+use std::time::Duration;
+
+iris::state_prelude!(DefaultRsc<State>);
+
+fn main() {
+    DefaultApp::<State>::run();
+}
+
+#[derive(DefaultUiState)]
+struct State {
+    ui_state: DefaultUiState,
+}
+
+impl DefaultAppState for State {
+    fn new(ui_state: DefaultUiState, rsc: &mut DefaultRsc<Self>, _: Proxy<Self::Event>) -> Self {
+        let rect = rect(Color::RED).add(rsc);
+        rect.on(CursorSense::click(), move |_, rsc| {
+            rsc.tasks.spawn(async move |ctx| {
+                tokio::time::sleep(Duration::from_secs(1)).await;
+                ctx.update(move |_, rsc| {
+                    let rect = rect(rsc);
+                    if rect.color == Color::RED {
+                        rect.color = Color::GREEN;
+                    } else {
+                        rect.color = Color::RED;
+                    }
+                });
+            });
+        })
+        .set_root(rsc);
+        Self { ui_state }
+    }
+}