Fix Grid DetailsGenerator being removed on Container change (#19593)

Change-Id: Ied328804260b1a7bb35093fca1d972735559cf41

1 files changed, 13 insertions, 2 deletions

diff --git a/server/src/com/vaadin/ui/Grid.java b/server/src/com/vaadin/ui/Grid.java
index 0774afd582..06ab8d1581 100644
--- a/server/src/com/vaadin/ui/Grid.java
+++ b/server/src/com/vaadin/ui/Grid.java
@@ -312,7 +312,7 @@ public class Grid extends AbstractFocusable implements SelectionNotifier,
          * 
          * @see #setDetailsGenerator(DetailsGenerator)
          */
-        private DetailsGenerator detailsGenerator = DetailsGenerator.NULL;
+        private DetailsGenerator detailsGenerator;
 
         /**
          * This map represents all details that are currently visible on the
@@ -334,7 +334,13 @@ public class Grid extends AbstractFocusable implements SelectionNotifier,
         private final Set<Object> openDetails = new HashSet<Object>();
 
         public DetailComponentManager(Grid grid) {
+            this(grid, DetailsGenerator.NULL);
+        }
+
+        public DetailComponentManager(Grid grid,
+                DetailsGenerator detailsGenerator) {
             super(grid);
+            setDetailsGenerator(detailsGenerator);
         }
 
         /**
@@ -4914,7 +4920,12 @@ public class Grid extends AbstractFocusable implements SelectionNotifier,
             }
         }
 
-        detailComponentManager = new DetailComponentManager(this);
+        if (detailComponentManager != null) {
+            detailComponentManager = new DetailComponentManager(this,
+                    detailComponentManager.getDetailsGenerator());
+        } else {
+            detailComponentManager = new DetailComponentManager(this);
+        }
 
         /*
          * selectionModel == null when the invocation comes from the