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ugur-vaadinvursen
ugur-vaadin
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vursen
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feat: add getItemIndex and getParent to hierarchical data providers (#22356)
This PR adds getItemIndex and getParent to HierarchicalDataProviders. This allows the users to define ways to provide item indexes and parents of items efficiently. This allows the TreeGrid component to implement scrollToItem functionality for any data provider without breaking existing implementations. Part of vaadin/flow-components#8076 --------- Co-authored-by: Sergey Vinogradov <mr.vursen@gmail.com>
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‎flow-data/src/main/java/com/vaadin/flow/data/provider/hierarchy/HierarchicalDataProvider.java‎

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@@ -15,10 +15,12 @@
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*/
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package com.vaadin.flow.data.provider.hierarchy;
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import java.util.Objects;
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import java.util.stream.Stream;
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import com.vaadin.flow.data.provider.DataProvider;
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import com.vaadin.flow.data.provider.FilterUtils;
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import com.vaadin.flow.data.provider.InMemoryDataProvider;
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import com.vaadin.flow.data.provider.Query;
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import com.vaadin.flow.data.provider.hierarchy.HierarchicalFilterUtils.HierarchialConfigurableFilterDataProviderWrapper;
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import com.vaadin.flow.data.provider.hierarchy.HierarchicalFilterUtils.HierarchicalFilterDataProviderWrapper;
@@ -316,6 +318,54 @@ public default Stream<T> fetch(Query<T, F> query) {
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*/
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public boolean hasChildren(T item);
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/**
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* Gets the parent item for the given item.
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*
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* @param item
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* the item for which to retrieve the parent item for
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* @return parent item for the given item or {@code null} if the item is a
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* root item
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* @throws UnsupportedOperationException
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* if not implemented
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*/
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default T getParent(T item) {
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throw new UnsupportedOperationException(
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"The getParent method is not implemented for this data provider");
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}
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/**
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* Gets the index of a given item based on the given hierarchical query.
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* <p>
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* This method must be implemented in accordance with the selected hierarchy
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* type, see {@link #getHierarchyFormat()} and {@link HierarchyFormat}.
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* <ul>
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* <li>If {@link HierarchyFormat#FLATTENED} is used, it should be
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* implemented to return the index in the entire flattened tree.
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* <li>If {@link HierarchyFormat#NESTED} is used, it should be implemented
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* to return the index within the given parent item.
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* </ul>
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* <p>
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* This method has a default implementation for in-memory data providers.
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*
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* @param item
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* the item to get the index for
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* @param query
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* given query to request data with
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* @return the index of the provided item or -1 if not found
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* @throws UnsupportedOperationException
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* if not implemented
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*/
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default int getItemIndex(T item, HierarchicalQuery<T, F> query) {
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if (isInMemory()) {
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Objects.requireNonNull(item, "Item cannot be null");
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Objects.requireNonNull(query, "Query cannot be null");
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return fetchChildren(query).map(this::getId).toList()
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.indexOf(getId(item));
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}
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throw new UnsupportedOperationException(
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"The getItemIndex method is not implemented for this data provider");
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}
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/**
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* Gets the depth of a given item in the hierarchy, starting from zero
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* (root).

‎flow-data/src/main/java/com/vaadin/flow/data/provider/hierarchy/TreeDataProvider.java‎

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@@ -109,6 +109,16 @@ public boolean hasChildren(T item) {
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return !treeData.getChildren(item).isEmpty();
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}
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@Override
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public T getParent(T item) {
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Objects.requireNonNull(item, "Item cannot be null.");
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try {
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return getTreeData().getParent(item);
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} catch (IllegalArgumentException e) {
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return null;
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}
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}
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@Override
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public int getDepth(T item) {
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int depth = 0;

‎flow-data/src/test/java/com/vaadin/flow/data/provider/hierarchy/HierarchicalDataProviderTest.java‎

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/*
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* Copyright 2000-2025 Vaadin Ltd.
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*
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* Licensed under the Apache License, Version 2.0 (the "License"); you may not
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* use this file except in compliance with the License. You may obtain a copy of
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* the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations under
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* the License.
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*/
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package com.vaadin.flow.data.provider.hierarchy;
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import com.vaadin.flow.data.provider.*;
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import com.vaadin.flow.shared.Registration;
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import org.junit.Assert;
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import org.junit.Test;
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import java.util.stream.IntStream;
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import java.util.stream.Stream;
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public class HierarchicalDataProviderTest {
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@Test
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public void getParent_throwsUnsupportedOperationException() {
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var dataProvider = new TestDataProvider();
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var rootItem = new TestBean(null, 0, 3);
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Assert.assertThrows(UnsupportedOperationException.class,
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() -> dataProvider.getParent(rootItem));
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}
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@Test
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public void inMemoryDataProvider_getNullItemIndex_throwsNullPointerException() {
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var dataProvider = new TestDataProvider();
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dataProvider.setInMemory(true);
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var query = new HierarchicalQuery<TestBean, Object>(null, null);
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Assert.assertThrows(NullPointerException.class,
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() -> dataProvider.getItemIndex(null, query));
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}
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@Test
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public void inMemoryDataProvider_getItemIndexWithNullQuery_throwsNullPointerException() {
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var dataProvider = new TestDataProvider();
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dataProvider.setInMemory(true);
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var rootItem = new TestBean(null, 0, 3);
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Assert.assertThrows(NullPointerException.class,
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() -> dataProvider.getItemIndex(rootItem, null));
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}
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@Test
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public void defaultDataProvider_getItemIndex_throwsUnsupportedOperationException() {
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var dataProvider = new TestDataProvider();
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var rootItem = new TestBean(null, 0, 3);
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Assert.assertThrows(UnsupportedOperationException.class,
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() -> dataProvider.getItemIndex(rootItem, null));
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}
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@Test
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public void inMemoryDataProvider_getItemIndex_returnsCorrectIndex() {
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var dataProvider = new TestDataProvider();
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dataProvider.setInMemory(true);
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var rootItem = new TestBean(null, 0, 3);
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var query = new HierarchicalQuery<TestBean, Object>(null, null);
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var itemIndex = dataProvider.getItemIndex(rootItem, query);
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Assert.assertEquals(3, itemIndex);
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}
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@Test
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public void inMemoryDataProvider_getChildItemIndex_returnsCorrectIndex() {
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var dataProvider = new TestDataProvider();
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dataProvider.setInMemory(true);
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var rootItem = new TestBean(null, 0, 3);
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var childItem = new TestBean(rootItem.getId(), 1, 3);
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var query = new HierarchicalQuery<>(null, rootItem);
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var itemIndex = dataProvider.getItemIndex(childItem, query);
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Assert.assertEquals(3, itemIndex);
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}
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@Test
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public void inMemoryDataProvider_getItemIndexInIncorrectParent_returnsMinusOne() {
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var dataProvider = new TestDataProvider();
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dataProvider.setInMemory(true);
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var rootItem = new TestBean(null, 0, 3);
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var anotherRootItem = new TestBean(null, 0, 4);
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var query = new HierarchicalQuery<>(null, anotherRootItem);
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var itemIndex = dataProvider.getItemIndex(rootItem, query);
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Assert.assertEquals(-1, itemIndex);
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}
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@Test
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public void inMemoryDataProvider_getItemIndexForAnIncorrectItem_returnsMinusOne() {
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var dataProvider = new TestDataProvider();
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dataProvider.setInMemory(true);
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var notPresentItem = new TestBean(null, 0, 20000);
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var query = new HierarchicalQuery<TestBean, Object>(null, null);
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var itemIndex = dataProvider.getItemIndex(notPresentItem, query);
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Assert.assertEquals(-1, itemIndex);
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}
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private static class TestDataProvider
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implements HierarchicalDataProvider<TestBean, Object> {
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private static final int DEPTH = 3;
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private static final int ROOT_ITEM_COUNT = 50;
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private static final int CHILD_PER_LEVEL = 10;
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private boolean inMemory;
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@Override
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public int getChildCount(HierarchicalQuery<TestBean, Object> query) {
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return hasChildren(query.getParent()) ? ROOT_ITEM_COUNT : 0;
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}
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@Override
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public Stream<TestBean> fetchChildren(
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HierarchicalQuery<TestBean, Object> query) {
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if (query.getParent() == null) {
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return IntStream.range(0, ROOT_ITEM_COUNT)
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.mapToObj(i -> new TestBean(null, 0, i));
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}
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return IntStream.range(0, CHILD_PER_LEVEL)
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.mapToObj(i -> new TestBean(query.getParent().getId(),
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query.getParent().getDepth() + 1, i));
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}
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@Override
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public boolean hasChildren(TestBean o) {
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if (o == null) {
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return true;
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}
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return o.getDepth() < DEPTH - 1;
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}
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public void setInMemory(boolean inMemory) {
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this.inMemory = inMemory;
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}
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@Override
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public boolean isInMemory() {
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return inMemory;
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}
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@Override
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public void refreshItem(TestBean o) {
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// NO-OP
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}
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@Override
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public void refreshAll() {
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// NO-OP
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}
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@Override
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public Registration addDataProviderListener(
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DataProviderListener<TestBean> listener) {
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return null;
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}
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}
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private static class TestBean {
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private final String id;
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private final int depth;
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private final int index;
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public TestBean(String parentId, int depth, int index) {
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id = (parentId == null ? "" : parentId) + "/" + depth + "/" + index;
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this.depth = depth;
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this.index = index;
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}
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public int getDepth() {
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return depth;
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}
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public int getIndex() {
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return index;
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}
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public String getId() {
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return id;
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}
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@Override
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public String toString() {
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return depth + " | " + index;
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}
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@Override
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public int hashCode() {
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return id.hashCode();
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}
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@Override
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public boolean equals(Object obj) {
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if (obj instanceof TestBean other) {
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return id.equals(other.id);
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}
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return false;
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}
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}
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}

‎flow-data/src/test/java/com/vaadin/flow/data/provider/hierarchy/TreeDataProviderTest.java‎

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@@ -288,6 +288,25 @@ public void addFilter() {
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assertEquals(8, sizeWithUnfilteredQuery());
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}
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@Test
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public void rootItem_getParent_returnsNull() {
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var rootItem = rootData.get(0);
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assertNull(getDataProvider().getParent(rootItem));
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}
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@Test
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public void childItem_getParent_returnsParent() {
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var rootItem = rootData.get(0);
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var childItem = data.getChildren(rootItem).get(0);
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assertEquals(rootItem, data.getParent(childItem));
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}
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@Test
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public void notPresentItem_getParent_returnsNull() {
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var itemNotPresentInProvider = new StrBean("Not present", -1, 0);
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assertNull(getDataProvider().getParent(itemNotPresentInProvider));
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}
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@Override
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public void filteringListDataProvider_convertFilter() {
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HierarchicalDataProvider<StrBean, String> strFilterDataProvider = getDataProvider()

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