removeListener in unit (apache#23593)

akvelon · Oct 21, 2022 · 8035775 · 8035775
1 parent d9acc0f
commit 8035775
Showing 1 changed file with 11 additions and 3 deletions.
diff --git a/learning/tour-of-beam/frontend/lib/pages/tour/widgets/unit.dart b/learning/tour-of-beam/frontend/lib/pages/tour/widgets/unit.dart
@@ -41,9 +41,17 @@ class _UnitWidgetState extends State<UnitWidget> {
   @override
   void initState() {
     super.initState();
-    widget.contentTreeController.addListener(() {
-      setState(() {});
-    });
+    widget.contentTreeController.addListener(_rebuild);
+  }
+
+  @override
+  void dispose() {
+    widget.contentTreeController.removeListener(_rebuild);
+    super.dispose();
+  }
+
+  void _rebuild() {
+    setState(() {});
   }
 
   @override