From cb5a04f82f7e60bb8e87a02a4eb69ec93d120797 Mon Sep 17 00:00:00 2001
From: Mikael Grankvist <mgrankvi@vaadin.com>
Date: Fri, 27 Sep 2024 12:35:56 +0300
Subject: [PATCH] fix: Store layout packages

Store layout packages
in development mode reload
cache as layouts may not be
in same packages as routes.

Fixes #20066
---
 .../com/vaadin/flow/spring/ReloadCache.java   |  1 +
 .../VaadinServletContextInitializer.java      | 20 +++++++++++++++++--
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/vaadin-spring/src/main/java/com/vaadin/flow/spring/ReloadCache.java b/vaadin-spring/src/main/java/com/vaadin/flow/spring/ReloadCache.java
index 273a0cd0bb3..40446a3ecb8 100644
--- a/vaadin-spring/src/main/java/com/vaadin/flow/spring/ReloadCache.java
+++ b/vaadin-spring/src/main/java/com/vaadin/flow/spring/ReloadCache.java
@@ -29,6 +29,7 @@ class ReloadCache implements Serializable {
     static Set<String> skippedResources = new HashSet<>();
     static Set<String> dynamicWhiteList;
     static Set<String> routePackages;
+    static Set<String> layoutPackages;
     static Set<String> jarClassNames = new HashSet<>();
     static Set<Class<?>> jarClasses = new HashSet<>();
 }
\ No newline at end of file
diff --git a/vaadin-spring/src/main/java/com/vaadin/flow/spring/VaadinServletContextInitializer.java b/vaadin-spring/src/main/java/com/vaadin/flow/spring/VaadinServletContextInitializer.java
index 52cd193c24a..3983e8bb19c 100644
--- a/vaadin-spring/src/main/java/com/vaadin/flow/spring/VaadinServletContextInitializer.java
+++ b/vaadin-spring/src/main/java/com/vaadin/flow/spring/VaadinServletContextInitializer.java
@@ -327,7 +327,7 @@ public void failFastContextInitialized(ServletContextEvent event) {
                 getLogger().debug("There are no discovered routes yet. "
                         + "Start to collect all routes from the classpath...");
                 try {
-                    Collection<String> routePackages = null;
+                    Collection<String> routePackages;
                     if (devModeCachingEnabled
                             && ReloadCache.routePackages != null) {
                         routePackages = ReloadCache.routePackages;
@@ -356,11 +356,27 @@ public void failFastContextInitialized(ServletContextEvent event) {
                             "There are {} navigation targets after filtering route classes: {}",
                             navigationTargets.size(), navigationTargets);
 
+                    Collection<String> layoutPackages;
+                    if (devModeCachingEnabled
+                            && ReloadCache.layoutPackages != null) {
+                        layoutPackages = ReloadCache.layoutPackages;
+                    } else {
+                        layoutPackages = getDefaultPackages();
+                    }
+
                     Set<Class<?>> layoutClasses = findByAnnotation(
-                            routePackages, Layout.class)
+                            layoutPackages, Layout.class)
                             .collect(Collectors.toSet());
+
+                    if (devModeCachingEnabled) {
+                        ReloadCache.layoutPackages = layoutClasses.stream()
+                                .map(Class::getPackageName)
+                                .collect(Collectors.toSet());
+                    }
+
                     RouteRegistryInitializer
                             .validateLayoutAnnotations(layoutClasses);
+
                     // Collect all layouts to use with Hilla as a main layout
                     layoutClasses.stream().filter(
                             clazz -> RouterLayout.class.isAssignableFrom(clazz))