From afe01503d8f5121313da5de1e17346c3e4a4fda2 Mon Sep 17 00:00:00 2001
From: Ian Hickson <ian@hixie.ch>
Date: Thu, 21 Mar 2024 14:28:07 -0700
Subject: [PATCH] Clarify AutomaticKeepAliveClientMixin semantics in build
 method (#145297)

This should help folks who trace the code before reading the documentation.
---
 packages/flutter/lib/src/widgets/automatic_keep_alive.dart | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/packages/flutter/lib/src/widgets/automatic_keep_alive.dart b/packages/flutter/lib/src/widgets/automatic_keep_alive.dart
index e5573db4a98..dd729d8cfc8 100644
--- a/packages/flutter/lib/src/widgets/automatic_keep_alive.dart
+++ b/packages/flutter/lib/src/widgets/automatic_keep_alive.dart
@@ -400,6 +400,10 @@ mixin AutomaticKeepAliveClientMixin<T extends StatefulWidget> on State<T> {
   Widget build(BuildContext context) {
     if (wantKeepAlive && _keepAliveHandle == null) {
       _ensureKeepAlive();
+      // Whenever wantKeepAlive's value changes (or might change), the
+      // subclass should call [updateKeepAlive].
+      // That will ensure that the keepalive is disabled (or enabled)
+      // without requiring a rebuild.
     }
     return const _NullWidget();
   }