Simplify Iris app initialization and task updates

examples/task/lib.rs

@@ -6,16 +6,17 @@ where
     Rsc::State: FocusHost,
 {
     let rect = rect(PaintId::RED).add(rsc);
-    rect.task_on(CursorSense::click(), async move |mut ctx| {
-        iris::task::sleep(Duration::from_secs(1)).await;
-        ctx.update(move |_, rsc| {
-            let rect = rect(rsc);
-            if rect.is_paint(&PaintId::RED) {
-                rect.set_paint(PaintId::BLUE);
-            } else {
-                rect.set_paint(PaintId::RED);
-            }
-        });
-    })
-    .set_root(rsc, ui_state);
+    rect.label("Toggle color")
+        .task_on(CursorSense::click(), async move |mut ctx| {
+            iris::task::sleep(Duration::from_secs(1)).await;
+            ctx.update(move |_, rsc| {
+                let rect = rect(rsc);
+                if rect.is_paint(&PaintId::RED) {
+                    rect.set_paint(PaintId::BLUE);
+                } else {
+                    rect.set_paint(PaintId::RED);
+                }
+            });
+        })
+        .set_root(rsc, ui_state);
 }