[3875] Refactor the tree event classes related to the explorer

CHANGELOG.adoc

@@ -19,7 +19,7 @@
 === Breaking changes
 
 - https://github.com/eclipse-sirius/sirius-web/issues/3846[#3846] [core] Migrate frontend to React 18, you now need React 18 to import sirius web modules.
-
+- https://github.com/eclipse-sirius/sirius-web/issues/3875[#3875] [sirius-web] The `ExplorerView` component has been moved from `sirius-components-trees` to `sirius-web-application` module
 
 === Dependency update
 
@@ -39,6 +39,7 @@
 - https://github.com/eclipse-sirius/sirius-web/issues/2604[#2604] [diagram] Expand a tool section when the mouse is over it
 - https://github.com/eclipse-sirius/sirius-web/issues/3887[#3887] [diagram] Memoize diagram representation (improve performance when selecting an element on large diagram)
 - https://github.com/eclipse-sirius/sirius-web/issues/3987[#3987] [sirius-web] Transform `widgetFields` fragment to retrieve custom widget fields
+- https://github.com/eclipse-sirius/sirius-web/issues/3875[#3875] [sirius-web] Move explorer related code from `sirius-components-trees` to `sirius-web-application`
 
 
 == v2024.9.0

packages/forms/backend/sirius-components-collaborative-widget-reference/src/main/java/org/eclipse/sirius/components/collaborative/widget/reference/browser/ModelBrowserEventProcessorFactory.java

@@ -0,0 +1,100 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Obeo.
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Obeo - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.sirius.components.collaborative.widget.reference.browser;
+
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+
+import org.eclipse.sirius.components.collaborative.api.IRepresentationConfiguration;
+import org.eclipse.sirius.components.collaborative.api.IRepresentationEventProcessor;
+import org.eclipse.sirius.components.collaborative.api.IRepresentationEventProcessorFactory;
+import org.eclipse.sirius.components.collaborative.api.IRepresentationRefreshPolicyRegistry;
+import org.eclipse.sirius.components.collaborative.api.ISubscriptionManagerFactory;
+import org.eclipse.sirius.components.collaborative.trees.TreeEventProcessor;
+import org.eclipse.sirius.components.collaborative.trees.api.ITreeEventHandler;
+import org.eclipse.sirius.components.collaborative.trees.api.ITreeService;
+import org.eclipse.sirius.components.collaborative.trees.api.TreeCreationParameters;
+import org.eclipse.sirius.components.collaborative.widget.reference.configurations.ModelBrowserConfiguration;
+import org.eclipse.sirius.components.core.api.IEditingContext;
+import org.eclipse.sirius.components.core.api.IRepresentationDescriptionSearchService;
+import org.eclipse.sirius.components.trees.description.TreeDescription;
+import org.springframework.stereotype.Service;
+
+import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
+
+/**
+ * Used to create the tree event processors in the context of model browser.
+ *
+ * @author Jerome Gout
+ */
+@Service
+public class ModelBrowserEventProcessorFactory implements IRepresentationEventProcessorFactory {
+
+    private final IRepresentationDescriptionSearchService representationDescriptionSearchService;
+
+    private final ITreeService treeService;
+
+    private final List<ITreeEventHandler> treeEventHandlers;
+
+    private final ISubscriptionManagerFactory subscriptionManagerFactory;
+
+    private final IRepresentationRefreshPolicyRegistry representationRefreshPolicyRegistry;
+
+    public ModelBrowserEventProcessorFactory(IRepresentationDescriptionSearchService representationDescriptionSearchService, List<ITreeEventHandler> treeEventHandlers, ITreeService treeService, IRepresentationRefreshPolicyRegistry representationRefreshPolicyRegistry, ISubscriptionManagerFactory subscriptionManagerFactory) {
+        this.representationDescriptionSearchService = Objects.requireNonNull(representationDescriptionSearchService);
+        this.treeService = Objects.requireNonNull(treeService);
+        this.treeEventHandlers = Objects.requireNonNull(treeEventHandlers);
+        this.subscriptionManagerFactory = Objects.requireNonNull(subscriptionManagerFactory);
+        this.representationRefreshPolicyRegistry = Objects.requireNonNull(representationRefreshPolicyRegistry);
+    }
+
+    @Override
+    public boolean canHandle(IRepresentationConfiguration configuration) {
+        return configuration instanceof ModelBrowserConfiguration;
+    }
+
+    @Override
+    public Optional<IRepresentationEventProcessor> createRepresentationEventProcessor(IRepresentationConfiguration configuration, IEditingContext editingContext) {
+        if (configuration instanceof ModelBrowserConfiguration modelBrowserConfiguration) {
+
+            String descriptionId;
+            if (modelBrowserConfiguration.getId().startsWith(ModelBrowsersDescriptionProvider.MODEL_BROWSER_CONTAINER_PREFIX)) {
+                descriptionId = ModelBrowsersDescriptionProvider.CONTAINER_DESCRIPTION_ID;
+            } else {
+                descriptionId = ModelBrowsersDescriptionProvider.REFERENCE_DESCRIPTION_ID;
+            }
+
+            Optional<TreeDescription> optionalTreeDescription = this.representationDescriptionSearchService
+                    .findById(editingContext, descriptionId)
+                    .filter(TreeDescription.class::isInstance)
+                    .map(TreeDescription.class::cast);
+            if (optionalTreeDescription.isPresent()) {
+                var treeDescription = optionalTreeDescription.get();
+
+                TreeCreationParameters treeCreationParameters = TreeCreationParameters.newTreeCreationParameters(modelBrowserConfiguration.getId())
+                        .treeDescription(treeDescription)
+                        .activeFilterIds(List.of())
+                        .expanded(modelBrowserConfiguration.getExpanded())
+                        .editingContext(editingContext)
+                        .build();
+
+                IRepresentationEventProcessor treeEventProcessor = new TreeEventProcessor(editingContext, this.treeService, treeCreationParameters, this.treeEventHandlers,
+                        this.subscriptionManagerFactory.create(), new SimpleMeterRegistry(), this.representationRefreshPolicyRegistry);
+                return Optional.of(treeEventProcessor);
+            }
+        }
+        return Optional.empty();
+    }
+
+}

packages/forms/backend/sirius-components-collaborative-widget-reference/src/main/java/org/eclipse/sirius/components/collaborative/widget/reference/browser/ModelBrowsersDescriptionProvider.java

@@ -22,7 +22,6 @@
 import java.util.Optional;
 import java.util.UUID;
 import java.util.function.Function;
-import java.util.function.Predicate;
 
 import org.eclipse.emf.common.util.URI;
 import org.eclipse.emf.ecore.EClass;
@@ -34,7 +33,6 @@
 import org.eclipse.emf.ecore.util.EcoreUtil;
 import org.eclipse.emf.edit.command.CommandParameter;
 import org.eclipse.emf.edit.domain.EditingDomain;
-import org.eclipse.sirius.components.collaborative.trees.api.TreeConfiguration;
 import org.eclipse.sirius.components.collaborative.widget.reference.api.IReferenceWidgetRootCandidateSearchProvider;
 import org.eclipse.sirius.components.core.CoreImageConstants;
 import org.eclipse.sirius.components.core.URLParser;
@@ -99,34 +97,28 @@ public ModelBrowsersDescriptionProvider(IObjectService objectService, IURLParser
 
     @Override
     public List<IRepresentationDescription> getRepresentationDescriptions(IEditingContext editingContext) {
-        Predicate<VariableManager> containerDescriptionCanCreatePredicate = variableManager -> variableManager.get(TreeConfiguration.TREE_ID, String.class)
-                .map(treeId -> treeId.startsWith(MODEL_BROWSER_CONTAINER_PREFIX))
-                .orElse(false);
         Function<VariableManager, Boolean> containerDescriptionIsSelectableProvider = variableManager -> {
             EClass referenceKind = this.resolveReferenceEClass(variableManager).orElse(null);
             return this.isContainerSelectable(variableManager, referenceKind);
         };
-        var containerDescription = this.getModelBrowserDescription(CONTAINER_DESCRIPTION_ID, containerDescriptionCanCreatePredicate, containerDescriptionIsSelectableProvider, this::getCreationScopeElements);
+        var containerDescription = this.getModelBrowserDescription(CONTAINER_DESCRIPTION_ID, containerDescriptionIsSelectableProvider, this::getCreationScopeElements, MODEL_BROWSER_CONTAINER_PREFIX);
 
-        Predicate<VariableManager> referenceDescriptionCanCreatePredicate = variableManager -> variableManager.get(TreeConfiguration.TREE_ID, String.class)
-                .map(treeId -> treeId.startsWith(MODEL_BROWSER_REFERENCE_PREFIX))
-                .orElse(false);
         Function<VariableManager, Boolean> referenceDescriptionIsSelectableProvider = variableManager -> {
             EClass targetType = this.resolveTargetType(variableManager).orElse(null);
             boolean isContainment = this.resolveIsContainment(variableManager);
             return this.isTypeSelectable(variableManager, targetType, isContainment);
         };
-        var referenceDescription = this.getModelBrowserDescription(REFERENCE_DESCRIPTION_ID, referenceDescriptionCanCreatePredicate, referenceDescriptionIsSelectableProvider, this::getSearchScopeElements);
+        var referenceDescription = this.getModelBrowserDescription(REFERENCE_DESCRIPTION_ID, referenceDescriptionIsSelectableProvider, this::getSearchScopeElements, MODEL_BROWSER_REFERENCE_PREFIX);
 
         return List.of(containerDescription, referenceDescription);
     }
 
-    private TreeDescription getModelBrowserDescription(String descriptionId, Predicate<VariableManager> canCreatePredicate, Function<VariableManager, Boolean> isSelectableProvider,
-            Function<VariableManager, List<?>> elementsProvider) {
+    private TreeDescription getModelBrowserDescription(String descriptionId, Function<VariableManager, Boolean> isSelectableProvider,
+            Function<VariableManager, List<?>> elementsProvider, String treeId) {
 
         return TreeDescription.newTreeDescription(descriptionId)
                 .label(REPRESENTATION_NAME)
-                .idProvider(variableManager -> variableManager.get(TreeConfiguration.TREE_ID, String.class).orElse(null))
+                .idProvider(variableManager -> variableManager.get(GetOrCreateRandomIdProvider.PREVIOUS_REPRESENTATION_ID, String.class).orElse(treeId))
                 .treeItemIdProvider(this::getTreeItemId)
                 .kindProvider(this::getKind)
                 .labelProvider(this::getLabel)
@@ -140,7 +132,7 @@ private TreeDescription getModelBrowserDescription(String descriptionId, Predica
                 .childrenProvider(variableManager -> this.getChildren(variableManager, isSelectableProvider))
                 // This predicate will NOT be used while creating the model browser, but we don't want to see the description of the
                 // model browser in the list of representations that can be created. Thus, we will return false all the time.
-                .canCreatePredicate(canCreatePredicate)
+                .canCreatePredicate(variableManager -> false)
                 .deleteHandler(this::getDeleteHandler)
                 .renameHandler(this::getRenameHandler)
                 .treeItemObjectProvider(this::getTreeItemObject)

packages/forms/backend/sirius-components-collaborative-widget-reference/src/main/java/org/eclipse/sirius/components/collaborative/widget/reference/configurations/ModelBrowserConfiguration.java

@@ -0,0 +1,59 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Obeo.
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Obeo - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.sirius.components.collaborative.widget.reference.configurations;
+
+import java.net.URLEncoder;
+import java.nio.charset.StandardCharsets;
+import java.util.List;
+import java.util.Objects;
+
+import org.eclipse.sirius.components.collaborative.api.IRepresentationConfiguration;
+import org.eclipse.sirius.components.collaborative.widget.reference.browser.ModelBrowsersDescriptionProvider;
+
+/**
+ * The configuration of the model browser event processor.
+ *
+ * @author Jerome Gout
+ */
+public class ModelBrowserConfiguration implements IRepresentationConfiguration {
+
+    private final String treeId;
+
+    private final List<String> expanded;
+
+    public ModelBrowserConfiguration(String editingContextId, String treeId, List<String> expanded) {
+        this.expanded = Objects.requireNonNull(expanded);
+
+        StringBuilder idBuilder = new StringBuilder(treeId);
+        if (treeId.endsWith(ModelBrowsersDescriptionProvider.MODEL_BROWSER_CONTAINER_PREFIX) || treeId.endsWith(ModelBrowsersDescriptionProvider.MODEL_BROWSER_REFERENCE_PREFIX)) {
+            idBuilder.append("?");
+        } else {
+            idBuilder.append("&");
+        }
+
+        List<String> expandedObjectIds = expanded.stream().map(id -> URLEncoder.encode(id, StandardCharsets.UTF_8)).toList();
+        idBuilder.append("expandedIds=[").append(String.join(",", expandedObjectIds)).append("]");
+
+        this.treeId = idBuilder.toString();
+    }
+
+    @Override
+    public String getId() {
+        return this.treeId;
+    }
+
+    public List<String> getExpanded() {
+        return this.expanded;
+    }
+
+}

packages/forms/backend/sirius-components-collaborative-widget-reference/src/main/java/org/eclipse/sirius/components/collaborative/widget/reference/dto/ModelBrowserEventInput.java

@@ -0,0 +1,26 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Obeo.
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Obeo - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.sirius.components.collaborative.widget.reference.dto;
+
+import java.util.List;
+import java.util.UUID;
+
+import org.eclipse.sirius.components.core.api.IInput;
+
+/**
+ * The input of the model browser event subscription.
+ *
+ * @author Jerome Gout
+ */
+public record ModelBrowserEventInput(UUID id, String editingContextId, String treeId, List<String> expanded) implements IInput {
+}

packages/forms/backend/sirius-components-collaborative-widget-reference/src/test/java/org/eclipse/sirius/components/collaborative/widget/reference/provider/ModelBrowserTests.java

@@ -16,7 +16,6 @@
 
 import java.util.List;
 
-import org.eclipse.sirius.components.collaborative.trees.api.TreeConfiguration;
 import org.eclipse.sirius.components.collaborative.widget.reference.browser.ModelBrowsersDescriptionProvider;
 import org.eclipse.sirius.components.core.URLParser;
 import org.eclipse.sirius.components.core.api.IEditingContext;
@@ -55,15 +54,13 @@ public void testModelBrowserDescriptionProvider() {
         variableManager.put(IEditingContext.EDITING_CONTEXT, editingContext);
 
         var referenceTreeId = "modelBrowser://reference";
-        variableManager.put(TreeConfiguration.TREE_ID, referenceTreeId);
         var tree = new TreeRenderer(variableManager, referenceBrowserDescription.get()).render();
         assertThat(tree).isNotNull();
         assertThat(tree.getId()).isEqualTo(referenceTreeId);
         assertThat(tree.getDescriptionId()).isEqualTo(ModelBrowsersDescriptionProvider.REFERENCE_DESCRIPTION_ID);
         assertThat(tree.getKind()).isEqualTo(Tree.KIND);
 
         var containerTreeId = "modelBrowser://container";
-        variableManager.put(TreeConfiguration.TREE_ID, containerTreeId);
         tree = new TreeRenderer(variableManager, containerBrowserDescription.get()).render();
         assertThat(tree).isNotNull();
         assertThat(tree.getId()).isEqualTo(containerTreeId);

packages/forms/backend/sirius-components-widget-reference-graphql/src/main/java/org/eclipse/sirius/components/widget/reference/graphql/datafetchers/subscription/SubscriptionModelBrowserEventDataFetcher.java

@@ -0,0 +1,72 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Obeo.
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Obeo - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.sirius.components.widget.reference.graphql.datafetchers.subscription;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+
+import org.eclipse.sirius.components.annotations.spring.graphql.SubscriptionDataFetcher;
+import org.eclipse.sirius.components.collaborative.widget.reference.configurations.ModelBrowserConfiguration;
+import org.eclipse.sirius.components.collaborative.widget.reference.dto.ModelBrowserEventInput;
+import org.eclipse.sirius.components.core.api.IPayload;
+import org.eclipse.sirius.components.graphql.api.IDataFetcherWithFieldCoordinates;
+import org.eclipse.sirius.components.graphql.api.IEventProcessorSubscriptionProvider;
+import org.eclipse.sirius.components.graphql.api.IExceptionWrapper;
+import org.eclipse.sirius.components.graphql.api.LocalContextConstants;
+import org.reactivestreams.Publisher;
+
+import graphql.execution.DataFetcherResult;
+import graphql.schema.DataFetchingEnvironment;
+
+/**
+ * The data fetcher used to send the refreshed tree to a model browser subscription .
+ *
+ * @author Jerome Gout
+ */
+@SubscriptionDataFetcher(type = "Subscription", field = "modelBrowserEvent")
+public class SubscriptionModelBrowserEventDataFetcher implements IDataFetcherWithFieldCoordinates<Publisher<DataFetcherResult<IPayload>>> {
+
+    private static final String INPUT_ARGUMENT = "input";
+
+    private final ObjectMapper objectMapper;
+
+    private final IExceptionWrapper exceptionWrapper;
+
+    private final IEventProcessorSubscriptionProvider eventProcessorSubscriptionProvider;
+
+    public SubscriptionModelBrowserEventDataFetcher(ObjectMapper objectMapper, IExceptionWrapper exceptionWrapper, IEventProcessorSubscriptionProvider eventProcessorSubscriptionProvider) {
+        this.objectMapper = Objects.requireNonNull(objectMapper);
+        this.exceptionWrapper = Objects.requireNonNull(exceptionWrapper);
+        this.eventProcessorSubscriptionProvider = Objects.requireNonNull(eventProcessorSubscriptionProvider);
+    }
+
+    @Override
+    public Publisher<DataFetcherResult<IPayload>> get(DataFetchingEnvironment environment) throws Exception {
+        Object argument = environment.getArgument(INPUT_ARGUMENT);
+        var input = this.objectMapper.convertValue(argument, ModelBrowserEventInput.class);
+        var modelBrowserConfiguration = new ModelBrowserConfiguration(input.editingContextId(), input.treeId(), input.expanded());
+
+        Map<String, Object> localContext = new HashMap<>();
+        localContext.put(LocalContextConstants.EDITING_CONTEXT_ID, input.editingContextId());
+        localContext.put(LocalContextConstants.REPRESENTATION_ID, modelBrowserConfiguration.getId());
+
+        return this.exceptionWrapper.wrapFlux(() -> this.eventProcessorSubscriptionProvider.getSubscription(input.editingContextId(), modelBrowserConfiguration, input), input)
+                .map(payload ->  DataFetcherResult.<IPayload>newResult()
+                        .data(payload)
+                        .localContext(localContext)
+                        .build());
+    }
+}

packages/forms/backend/sirius-components-widget-reference/src/main/resources/schema/modelbrowser.graphqls

@@ -0,0 +1,10 @@
+extend type Subscription {
+  modelBrowserEvent(input: ModelBrowserEventInput!): TreeEventPayload!
+}
+
+input ModelBrowserEventInput {
+  id: ID!
+  treeId: String!
+  editingContextId: ID!
+  expanded: [String!]!
+}