refactor!: fire events on expanding and collapsing recursively

vaadin-grid-flow-parent/vaadin-grid-flow/src/main/java/com/vaadin/flow/component/treegrid/TreeGrid.java

@@ -755,8 +755,7 @@ public void expand(Collection<T> items) {
      */
     protected void expand(Collection<T> items, boolean userOriginated) {
         Collection<T> expandedItems = getDataCommunicator().expand(items);
-        fireEvent(new ExpandEvent<T, TreeGrid<T>>(this, userOriginated,
-                expandedItems));
+        fireEvent(new ExpandEvent<>(this, userOriginated, expandedItems));
     }
 
     /**
@@ -767,8 +766,6 @@ protected void expand(Collection<T> items, boolean userOriginated) {
      * descendant, meaning that {@code expandRecursively(items, 0)} expands only
      * the given items while {@code expandRecursively(items, 2)} expands the
      * given items as well as their children and grandchildren.
-     * <p>
-     * This method will <i>not</i> fire events for expanded nodes.
      *
      * @param items
      *            the items to expand recursively
@@ -777,7 +774,7 @@ protected void expand(Collection<T> items, boolean userOriginated) {
      * @since 8.4
      */
     public void expandRecursively(Stream<T> items, int depth) {
-        expandRecursively(items.collect(Collectors.toList()), depth);
+        expandRecursively(items.toList(), depth);
     }
 
     /**
@@ -788,8 +785,6 @@ public void expandRecursively(Stream<T> items, int depth) {
      * descendant, meaning that {@code expandRecursively(items, 0)} expands only
      * the given items while {@code expandRecursively(items, 2)} expands the
      * given items as well as their children and grandchildren.
-     * <p>
-     * This method will <i>not</i> fire events for expanded nodes.
      *
      * @param items
      *            the items to expand recursively
@@ -798,8 +793,9 @@ public void expandRecursively(Stream<T> items, int depth) {
      * @since 8.4
      */
     public void expandRecursively(Collection<T> items, int depth) {
-        getDataCommunicator()
+        var expandedItems = getDataCommunicator()
                 .expand(getItemsWithChildrenRecursively(items, depth));
+        fireEvent(new ExpandEvent<>(this, false, expandedItems));
     }
 
     /**
@@ -838,8 +834,7 @@ public void collapse(Collection<T> items) {
      */
     protected void collapse(Collection<T> items, boolean userOriginated) {
         Collection<T> collapsedItems = getDataCommunicator().collapse(items);
-        fireEvent(new CollapseEvent<T, TreeGrid<T>>(this, userOriginated,
-                collapsedItems));
+        fireEvent(new CollapseEvent<>(this, userOriginated, collapsedItems));
     }
 
     /**
@@ -850,8 +845,6 @@ protected void collapse(Collection<T> items, boolean userOriginated) {
      * descendant, meaning that {@code collapseRecursively(items, 0)} collapses
      * only the given items while {@code collapseRecursively(items, 2)}
      * collapses the given items as well as their children and grandchildren.
-     * <p>
-     * This method will <i>not</i> fire events for collapsed nodes.
      *
      * @param items
      *            the items to collapse recursively
@@ -860,7 +853,7 @@ protected void collapse(Collection<T> items, boolean userOriginated) {
      * @since 8.4
      */
     public void collapseRecursively(Stream<T> items, int depth) {
-        collapseRecursively(items.collect(Collectors.toList()), depth);
+        collapseRecursively(items.toList(), depth);
     }
 
     /**
@@ -871,8 +864,6 @@ public void collapseRecursively(Stream<T> items, int depth) {
      * descendant, meaning that {@code collapseRecursively(items, 0)} collapses
      * only the given items while {@code collapseRecursively(items, 2)}
      * collapses the given items as well as their children and grandchildren.
-     * <p>
-     * This method will <i>not</i> fire events for collapsed nodes.
      *
      * @param items
      *            the items to collapse recursively
@@ -881,8 +872,9 @@ public void collapseRecursively(Stream<T> items, int depth) {
      * @since 8.4
      */
     public void collapseRecursively(Collection<T> items, int depth) {
-        getDataCommunicator()
+        var collapsedItems = getDataCommunicator()
                 .collapse(getItemsWithChildrenRecursively(items, depth));
+        fireEvent(new CollapseEvent<>(this, false, collapsedItems));
     }
 
     /**

vaadin-grid-flow-parent/vaadin-grid-flow/src/test/java/com/vaadin/flow/component/treegrid/ExpandCollapseTest.java

@@ -0,0 +1,107 @@
+/*
+ * Copyright 2000-2025 Vaadin Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+package com.vaadin.flow.component.treegrid;
+
+import java.util.List;
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import com.vaadin.flow.data.provider.hierarchy.TreeData;
+import com.vaadin.flow.data.provider.hierarchy.TreeDataProvider;
+
+public class ExpandCollapseTest {
+
+    private TreeGrid<String> treeGrid;
+    private AtomicReference<ExpandEvent<String, TreeGrid<String>>> expandEvent;
+    private AtomicReference<CollapseEvent<String, TreeGrid<String>>> collapseEvent;
+
+    @Before
+    public void init() {
+        treeGrid = new TreeGrid<>();
+        var treeData = new TreeData<String>();
+        treeData.addRootItems("Item 0", "Item 1");
+        treeData.addItems("Item 0", "Item 0-0", "Item 0-1");
+        treeData.addItems("Item 0-0", "Item 0-0-0", "Item 0-0-1");
+        treeData.addItems("Item 0-0-0", "Item 0-0-0-0", "Item 0-0-0-1");
+        var treeDataProvider = new TreeDataProvider<>(treeData);
+        treeGrid.setDataProvider(treeDataProvider);
+        expandEvent = new AtomicReference<>();
+        treeGrid.addExpandListener(expandEvent::set);
+        collapseEvent = new AtomicReference<>();
+        treeGrid.addCollapseListener(collapseEvent::set);
+    }
+
+    @Test
+    public void expand_itemExpandedCorrectly() {
+        treeGrid.expand("Item 0");
+        Assert.assertTrue(treeGrid.isExpanded("Item 0"));
+        Assert.assertFalse(treeGrid.isExpanded("Item 0-0"));
+        Assert.assertEquals(List.of("Item 0"), expandEvent.get().getItems());
+    }
+
+    @Test
+    public void collapse_itemCollapsedCorrectly() {
+        treeGrid.expand("Item 0");
+        treeGrid.collapse("Item 0");
+        Assert.assertFalse(treeGrid.isExpanded("Item 0"));
+        Assert.assertEquals(List.of("Item 0"), collapseEvent.get().getItems());
+    }
+
+    @Test
+    public void expandRecursivelyWithNonMaxDepth_itemsExpandedCorrectly() {
+        treeGrid.expandRecursively(List.of("Item 0"), 1);
+        Assert.assertTrue(treeGrid.isExpanded("Item 0"));
+        Assert.assertTrue(treeGrid.isExpanded("Item 0-0"));
+        Assert.assertFalse(treeGrid.isExpanded("Item 0-0-0"));
+        Assert.assertEquals(List.of("Item 0", "Item 0-0"),
+                expandEvent.get().getItems());
+    }
+
+    @Test
+    public void expandRecursivelyWithMaxDepth_itemsExpandedCorrectly() {
+        treeGrid.expandRecursively(List.of("Item 0"), 2);
+        Assert.assertTrue(treeGrid.isExpanded("Item 0"));
+        Assert.assertTrue(treeGrid.isExpanded("Item 0-0"));
+        Assert.assertTrue(treeGrid.isExpanded("Item 0-0-0"));
+        Assert.assertEquals(List.of("Item 0", "Item 0-0", "Item 0-0-0"),
+                expandEvent.get().getItems());
+    }
+
+    @Test
+    public void collapseRecursivelyWithNonMaxDepth_itemsCollapsedCorrectly() {
+        treeGrid.expandRecursively(List.of("Item 0"), 2);
+        treeGrid.collapseRecursively(List.of("Item 0"), 1);
+        Assert.assertFalse(treeGrid.isExpanded("Item 0"));
+        Assert.assertFalse(treeGrid.isExpanded("Item 0-0"));
+        Assert.assertTrue(treeGrid.isExpanded("Item 0-0-0"));
+        Assert.assertEquals(List.of("Item 0", "Item 0-0"),
+                collapseEvent.get().getItems());
+    }
+
+    @Test
+    public void collapseRecursivelyWithMaxDepth_itemsCollapsedCorrectly() {
+        treeGrid.expandRecursively(List.of("Item 0"), 2);
+        treeGrid.collapseRecursively(List.of("Item 0"), 2);
+        Assert.assertFalse(treeGrid.isExpanded("Item 0"));
+        Assert.assertFalse(treeGrid.isExpanded("Item 0-0"));
+        Assert.assertFalse(treeGrid.isExpanded("Item 0-0-0"));
+        Assert.assertEquals(List.of("Item 0", "Item 0-0", "Item 0-0-0"),
+                collapseEvent.get().getItems());
+    }
+}