Cleanup

lib/ui/src/layout.rs

@@ -2611,4 +2611,38 @@ mod tests {
             "offscreen descendants must keep geometry for widget-ref scrolling"
         );
     }
+
+    #[test]
+    fn scroll_culling_keeps_visible_text_selectable_inside_viewport_clip() {
+        let text_id = ElementId::new(77);
+        let root = Element::new().child(
+            Element::scroll_box(120.0).width(360.0).height(120.0).child(
+                Element::paragraph(
+                    "line 01\nline 02\nline 03\nline 04\nline 05\nline 06\nline 07\nline 08\nline 09",
+                    text_style().with_line_height(20.0),
+                )
+                .id(text_id),
+            ),
+        );
+
+        let snapshot = layout_snapshot(1, UiSize::new(360.0, 120.0), &root);
+        let text = snapshot
+            .interaction_tree
+            .text_for_element(text_id)
+            .expect("selectable text should remain in the interaction tree");
+        let visible_hit = snapshot
+            .interaction_tree
+            .text_hit_test(Point::new(8.0, 8.0))
+            .expect("visible scrolled text should be selectable");
+
+        assert_eq!(text.element_id, Some(text_id));
+        assert_eq!(visible_hit.target.element_id, Some(text_id));
+        assert!(
+            snapshot
+                .interaction_tree
+                .text_hit_test(Point::new(8.0, 160.0))
+                .is_none(),
+            "text hit testing should still honor the scroll viewport clip"
+        );
+    }
 }