Coalesce resize layout diagnostics

tests/layout_diagnostics.rs

@@ -21,6 +21,53 @@ use std::time::Instant;
 
 const OUTPUT: (f32, f32) = (1920.0, 1200.0);
 
+#[cfg(feature = "layout-diagnostics")]
+#[test]
+fn a_selected_widget_retains_its_layout_events() {
+    use iris::core::layout_diagnostics::{self as diagnostics, TraceEvent};
+
+    diagnostics::clear_traced_widgets();
+    let _ = diagnostics::take();
+    let mut harness = Harness::new((400, 200));
+    let leaf = rect(Color::RED).add(&mut harness.rsc);
+    let other = rect(Color::BLUE).add(&mut harness.rsc);
+    let root = (leaf, other).span(Dir::RIGHT).add(&mut harness.rsc);
+    harness.set_root(root);
+    diagnostics::trace_widget(leaf.id());
+    let _ = diagnostics::take();
+
+    let _ = harness.rsc.widgets_mut().get_dyn_mut(root.id());
+    let _ = harness.rsc.widgets_mut().get_dyn_mut(leaf.id());
+    harness.frame();
+
+    let report = diagnostics::take();
+    assert!(
+        report
+            .traces()
+            .iter()
+            .any(|event| matches!(event, TraceEvent::Placed { id, .. } if *id == leaf.id()))
+    );
+    assert!(
+        report
+            .traces()
+            .iter()
+            .any(|event| matches!(event, TraceEvent::DrawRequest { id, .. } if *id == leaf.id()))
+    );
+    assert!(
+        report
+            .traces()
+            .iter()
+            .any(|event| matches!(event, TraceEvent::SizeRead { id, .. } if *id == leaf.id()))
+    );
+    assert!(
+        report
+            .traces()
+            .iter()
+            .any(|event| matches!(event, TraceEvent::SizeReported { id, .. } if *id == leaf.id()))
+    );
+    diagnostics::clear_traced_widgets();
+}
+
 fn env<T: std::str::FromStr>(name: &str, fallback: T) -> T {
     std::env::var(name)
         .ok()