TreeDataProvider: Apply filters to children (#11868)

Fixes: https://github.com/vaadin/framework/issues/9933

Cherry pick from: https://github.com/vaadin/flow/pull/7317

1 files changed, 13 insertions, 2 deletions

diff --git a/server/src/main/java/com/vaadin/data/provider/TreeDataProvider.java b/server/src/main/java/com/vaadin/data/provider/TreeDataProvider.java
index 5436685e58..6fcd029003 100644
--- a/server/src/main/java/com/vaadin/data/provider/TreeDataProvider.java
+++ b/server/src/main/java/com/vaadin/data/provider/TreeDataProvider.java
@@ -172,9 +172,20 @@ public class TreeDataProvider<T>
 
     private Stream<T> getFilteredStream(Stream<T> stream,
             Optional<SerializablePredicate<T>> queryFilter) {
+        final Optional<SerializablePredicate<T>> combinedFilter;
         if (filter != null) {
-            stream = stream.filter(filter);
+            combinedFilter = Optional
+                    .of(queryFilter.map(filter::and).orElse(filter));
+        } else {
+            combinedFilter = queryFilter;
         }
-        return queryFilter.map(stream::filter).orElse(stream);
+        return combinedFilter.map(
+                f -> stream.filter(element -> flatten(element).anyMatch(f)))
+                .orElse(stream);
+    }
+
+    private Stream<T> flatten(T element) {
+        return Stream.concat(Stream.of(element), getTreeData()
+                .getChildren(element).stream().flatMap(this::flatten));
     }
 }