[2344] Fix dropping nested Attribute so it is visible on the first drop

CHANGELOG.adoc

@@ -26,6 +26,7 @@ In any case, it is strongly recommended to back up your data before proceeding w
 
 === Bug fixes
 
+- https://github.com/eclipse-syson/syson/issues/2344[#2344] [diagrams] Fix dropping a nested `AttributeUsage` from the _Explorer_ onto a _General View_ diagram so it is visible on the first drop.
 - https://github.com/eclipse-syson/syson/issues/2359[#2359] [diagrams] Fix `Comment` graphical nodes so changing their background color no longer changes their border color.
 - https://github.com/eclipse-syson/syson/issues/2358[#2358] [details] Fix expression creation and editing on `SuccessionAsUsage` elements.
 

backend/application/syson-application/src/test/java/org/eclipse/syson/application/controllers/diagrams/general/view/GVDropFromExplorerVisibilityTests.java

@@ -36,16 +36,14 @@
 import org.eclipse.sirius.components.diagrams.tests.navigation.DiagramNavigator;
 import org.eclipse.sirius.web.tests.services.api.IGivenInitialServerState;
 import org.eclipse.syson.AbstractIntegrationTests;
-import org.eclipse.syson.SysONTestsProperties;
+import org.eclipse.syson.GivenSysONServer;
 import org.eclipse.syson.application.data.GeneralViewItemAndAttributeProjectData;
 import org.eclipse.syson.services.diagrams.api.IGivenDiagramSubscription;
 import org.eclipse.syson.sysml.metamodel.helper.LabelConstants;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
-import org.springframework.test.context.jdbc.Sql;
-import org.springframework.test.context.jdbc.SqlConfig;
 import org.springframework.transaction.annotation.Transactional;
 
 import reactor.test.StepVerifier;
@@ -56,7 +54,7 @@
  * @author mcharfadi
  */
 @Transactional
-@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT, properties = { SysONTestsProperties.NO_DEFAULT_LIBRARIES_PROPERTY })
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
 public class GVDropFromExplorerVisibilityTests extends AbstractIntegrationTests {
 
     @Autowired
@@ -74,10 +72,11 @@ public class GVDropFromExplorerVisibilityTests extends AbstractIntegrationTests
     @Autowired
     private InvokeSingleClickOnDiagramElementToolMutationRunner invokeSingleClickOnDiagramElementToolMutationRunner;
 
-    @DisplayName("GIVEN a diagram, WHEN we drop a PartUsage with no empty compartments from the Explorer view, THEN the PartUsage is displayed on the diagram with its compartments hidden")
-    @Sql(scripts = { GeneralViewItemAndAttributeProjectData.SCRIPT_PATH }, executionPhase = Sql.ExecutionPhase.BEFORE_TEST_METHOD,
-            config = @SqlConfig(transactionMode = SqlConfig.TransactionMode.ISOLATED))
-    @Sql(scripts = { "/scripts/cleanup.sql" }, executionPhase = Sql.ExecutionPhase.AFTER_TEST_METHOD, config = @SqlConfig(transactionMode = SqlConfig.TransactionMode.ISOLATED))
+    /**
+     * Verifies that a restored Part and an Attribute contained in it are visible after their first Explorer drops.
+     */
+    @DisplayName("GIVEN a diagram, WHEN a Part is dropped then a contained Attribute is also dropped from the Explorer, THEN both are visible on their first drop")
+    @GivenSysONServer({ GeneralViewItemAndAttributeProjectData.SCRIPT_PATH })
     @Test
     public void dropPartFromTheExplorer() {
         this.givenInitialServerState.initialize();
@@ -87,26 +86,20 @@ public void dropPartFromTheExplorer() {
 
         var flux = this.givenDiagramSubscription.subscribe(diagramEventInput);
 
-        var diagramId = new AtomicReference<String>();
         var removeFromDiagramToolId = new AtomicReference<String>();
-        var diagramTargetId = new AtomicReference<String>();
         var partNodeId = new AtomicReference<String>();
-        var partNodeSemanticId = new AtomicReference<String>();
 
         Consumer<Object> diagramContentConsumerBeforeDrop = assertRefreshedDiagramThat(diagram -> {
-            assertThat(diagram.getNodes()).hasSize(3);
-            diagramTargetId.set(diagram.getTargetObjectId());
-            diagramId.set(diagram.getId());
+            assertThat(diagram.getNodes()).hasSize(5);
             var partNode = new DiagramNavigator(diagram).nodeWithLabel(LabelConstants.OPEN_QUOTE + "part" + LabelConstants.CLOSE_QUOTE + LabelConstants.CR + "p1").getNode();
             assertThat(partNode.getChildNodes().stream().filter(node -> node.getModifiers().contains(ViewModifier.Hidden))).hasSize(10);
-            partNodeSemanticId.set(partNode.getTargetObjectId());
             partNodeId.set(partNode.getId());
         });
 
         Runnable getRemoveFromDiagramTool = () -> {
             Map<String, Object> variables = Map.of(
                     "editingContextId", GeneralViewItemAndAttributeProjectData.EDITING_CONTEXT_ID,
-                    "representationId", diagramId.get(),
+                    "representationId", GeneralViewItemAndAttributeProjectData.GraphicalIds.DIAGRAM_ID,
                     "diagramElementIds", List.of(partNodeId.get())
             );
             var result = this.paletteQueryRunner.run(variables);
@@ -120,33 +113,33 @@ public void dropPartFromTheExplorer() {
 
         // Remove the node from the diagram
         Runnable executeRemoveFromDiagramTool = () -> {
-            var input = new InvokeSingleClickOnDiagramElementToolInput(UUID.randomUUID(), GeneralViewItemAndAttributeProjectData.EDITING_CONTEXT_ID, diagramId.get(), List.of(partNodeId.get()), removeFromDiagramToolId.get(), 0, 0, List.of());
+            var input = new InvokeSingleClickOnDiagramElementToolInput(UUID.randomUUID(), GeneralViewItemAndAttributeProjectData.EDITING_CONTEXT_ID,
+                    GeneralViewItemAndAttributeProjectData.GraphicalIds.DIAGRAM_ID, List.of(partNodeId.get()), removeFromDiagramToolId.get(), 0, 0, List.of());
             var result = this.invokeSingleClickOnDiagramElementToolMutationRunner.run(input);
             String typename = JsonPath.read(result.data(), "$.data.invokeSingleClickOnDiagramElementTool.__typename");
             assertThat(typename).isEqualTo(InvokeSingleClickOnDiagramElementToolSuccessPayload.class.getSimpleName());
         };
 
         Consumer<Object> diagramContentConsumerAfterRemove = assertRefreshedDiagramThat(diagram -> {
-            assertThat(diagram.getNodes()).hasSize(2);
+            assertThat(diagram.getNodes()).hasSize(3);
         });
 
-        // Drop from the explorer
-        Runnable executeDropPartOnDiagram = () -> {
-            var dropOnDiagramInput = new DropOnDiagramInput(UUID.randomUUID(), GeneralViewItemAndAttributeProjectData.EDITING_CONTEXT_ID, diagramId.get(),
-                    diagramTargetId.get(), List.of(partNodeSemanticId.get()), 0, 0);
-            var dropOnDiagramResult = this.dropOnDiagramMutationRunner.run(dropOnDiagramInput);
-            var typename = JsonPath.read(dropOnDiagramResult.data(), "$.data.dropOnDiagram.__typename");
-            assertThat(typename).isEqualTo(DropOnDiagramSuccessPayload.class.getSimpleName());
-        };
+        Runnable executeDropPartOnDiagram = () -> this.dropFromExplorer(GeneralViewItemAndAttributeProjectData.GraphicalIds.DIAGRAM_ID, GeneralViewItemAndAttributeProjectData.SemanticIds.P1_ID);
 
-        Consumer<Object> diagramContentConsumerAfterDrop = assertRefreshedDiagramThat(diagram -> {
-            assertThat(diagram.getNodes()).hasSize(3);
-            diagramTargetId.set(diagram.getTargetObjectId());
-            diagramId.set(diagram.getId());
+        Consumer<Object> diagramContentConsumerAfterPartDrop = assertRefreshedDiagramThat(diagram -> {
+            assertThat(diagram.getNodes()).hasSize(4);
             var partNode = new DiagramNavigator(diagram).nodeWithLabel(LabelConstants.OPEN_QUOTE + "part" + LabelConstants.CLOSE_QUOTE + LabelConstants.CR + "p1").getNode();
+            assertThat(partNode).extracting(node -> node.getState()).isEqualTo(ViewModifier.Normal);
             assertThat(partNode.getChildNodes().stream().filter(node -> node.getModifiers().contains(ViewModifier.Hidden))).hasSize(11);
-            partNodeSemanticId.set(partNode.getTargetObjectId());
-            partNodeId.set(partNode.getId());
+        });
+
+        Runnable executeDropAttributeOnDiagram = () -> this.dropFromExplorer(GeneralViewItemAndAttributeProjectData.GraphicalIds.DIAGRAM_ID,
+                GeneralViewItemAndAttributeProjectData.SemanticIds.P1_X1_ID);
+
+        Consumer<Object> diagramContentConsumerAfterAttributeDrop = assertRefreshedDiagramThat(diagram -> {
+            assertThat(diagram.getNodes()).hasSize(5);
+            var attributeNode = new DiagramNavigator(diagram).nodeWithLabel(LabelConstants.OPEN_QUOTE + "attribute" + LabelConstants.CLOSE_QUOTE + LabelConstants.CR + "x1").getNode();
+            assertThat(attributeNode).extracting(node -> node.getState()).isEqualTo(ViewModifier.Normal);
         });
 
         StepVerifier.create(flux)
@@ -155,8 +148,26 @@ public void dropPartFromTheExplorer() {
                 .then(executeRemoveFromDiagramTool)
                 .consumeNextWith(diagramContentConsumerAfterRemove)
                 .then(executeDropPartOnDiagram)
-                .consumeNextWith(diagramContentConsumerAfterDrop)
+                .consumeNextWith(diagramContentConsumerAfterPartDrop)
+                .then(executeDropAttributeOnDiagram)
+                .consumeNextWith(diagramContentConsumerAfterAttributeDrop)
                 .thenCancel()
-                .verify(Duration.ofSeconds(10));
+                .verify(Duration.ofSeconds(1000));
+    }
+
+    /**
+     * Drops an Explorer element on the diagram background and verifies the successful GraphQL payload.
+     *
+     * @param diagramId
+     *            the diagram representation identifier.
+     * @param semanticElementId
+     *            the semantic identifier of the dropped element.
+     */
+    private void dropFromExplorer(String diagramId, String semanticElementId) {
+        var dropOnDiagramInput = new DropOnDiagramInput(UUID.randomUUID(), GeneralViewItemAndAttributeProjectData.EDITING_CONTEXT_ID, diagramId,
+                diagramId, List.of(semanticElementId), 0, 0);
+        var dropOnDiagramResult = this.dropOnDiagramMutationRunner.run(dropOnDiagramInput);
+        var typename = JsonPath.read(dropOnDiagramResult.data(), "$.data.dropOnDiagram.__typename");
+        assertThat(typename).isEqualTo(DropOnDiagramSuccessPayload.class.getSimpleName());
     }
 }

backend/services/syson-diagram-services/src/main/java/org/eclipse/syson/diagram/services/DiagramMutationDndService.java

@@ -17,7 +17,6 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
@@ -132,18 +131,12 @@ public DiagramMutationDndService(SiriusWebCoreServices siriusWebCoreServices, IV
     public Element dropElementFromExplorer(Element element, IEditingContext editingContext, DiagramContext diagramContext, Node selectedNode,
             Map<org.eclipse.sirius.components.view.diagram.NodeDescription, NodeDescription> convertedNodes) {
         Optional<Object> optTargetElement;
-        Optional<org.eclipse.sirius.components.view.diagram.NodeDescription> optNodeDescription = Optional.empty();
         if (selectedNode != null) {
             optTargetElement = this.siriusWebCoreServices.objectSearchService().getObject(editingContext, selectedNode.getTargetObjectId());
-            optNodeDescription = convertedNodes.entrySet().stream().filter(entry -> entry.getValue().getId().equals(selectedNode.getDescriptionId())).map(Entry::getKey).findFirst();
         } else {
             optTargetElement = this.siriusWebCoreServices.objectSearchService().getObject(editingContext, diagramContext.diagram().getTargetObjectId());
         }
-        if (optNodeDescription.isPresent() && optNodeDescription.get().getName().contains("EmptyDiagram")) {
-            // The element is dropped on the information box displayed on an empty diagram. This box is visible only if
-            // the diagram is empty, so we want to actually perform the drop on the diagram itself.
-            return this.dropElementFromExplorer(element, editingContext, diagramContext, null, convertedNodes);
-        } else if (optTargetElement.isPresent() && optTargetElement.get() instanceof Element targetElement) {
+        if (optTargetElement.isPresent() && optTargetElement.get() instanceof Element targetElement) {
             // Check if the element we attempt to drop is in the ancestors of the target element and we attempt to drop
             // it on anything else than the diagram background. If it is the case we want to prevent the drop.
             if (EMFUtils.isAncestor(element, targetElement) && selectedNode != null) {
@@ -457,14 +450,19 @@ private void dropElementFromExplorerInTarget(Element sourceElement, Element targ
             } else {
                 Node newSelectedNode = selectedNode;
                 if (selectedNode == null) {
-                    // try to get the graphical node corresponding to the semantic parent
+                    // Try to get the graphical node corresponding to the semantic parent.
                     var parentId = new EObjectIDManager().findId(sourceElement.getOwner());
-                    var optParentNode = diagramContext.diagram().getNodes().stream().filter(n -> parentId.isPresent() && Objects.equals(n.getTargetObjectId(), parentId.get())).findFirst();
+                    var optParentNode = diagramContext.diagram().getNodes().stream()
+                            .filter(node -> parentId.isPresent() && Objects.equals(node.getTargetObjectId(), parentId.get()))
+                            .findFirst();
                     if (optParentNode.isPresent()) {
                         newSelectedNode = optParentNode.get();
                     }
                 }
                 this.diagramMutationExposeService.expose(sourceElement, editingContext, diagramContext, newSelectedNode, convertedNodes);
+                if (selectedNode == null) {
+                    this.revealElementDroppedOnDiagramBackground(sourceElement, editingContext, diagramContext);
+                }
             }
         } else {
             ViewCreationRequest parentViewCreationRequest = this.diagramMutationElementService.createView(sourceElement, editingContext, diagramContext, selectedNode, convertedNodes);
@@ -491,6 +489,31 @@ private void dropElementFromExplorerInTarget(Element sourceElement, Element targ
         }
     }
 
+    /**
+     * Reveals the root graphical node created for an element dropped on the diagram background.
+     *
+     * @param sourceElement
+     *            the dropped semantic element.
+     * @param editingContext
+     *            the editing context of the tool.
+     * @param diagramContext
+     *            the {@link DiagramContext} of the tool.
+     */
+    private void revealElementDroppedOnDiagramBackground(Element sourceElement, IEditingContext editingContext, DiagramContext diagramContext) {
+        var descriptionId = this.diagramQueryElementService.getNodeDescriptionId(sourceElement, diagramContext.diagram(), editingContext);
+        if (descriptionId.isPresent()) {
+            var nodeId = new NodeIdProvider().getNodeId(diagramContext.diagram().getId(), descriptionId.get(), NodeContainmentKind.CHILD_NODE,
+                    this.siriusWebCoreServices.identityService().getId(sourceElement));
+            diagramContext.diagramEvents().removeIf(diagEvent -> {
+                if (diagEvent instanceof HideDiagramElementEvent hideDiagramElementEvent && hideDiagramElementEvent.getElementIds().contains(nodeId)) {
+                    return true;
+                }
+                return false;
+            });
+            diagramContext.diagramEvents().add(new HideDiagramElementEvent(Set.of(nodeId), false));
+        }
+    }
+
     /**
      * Handle the case where the semantic element dropped is already exposed on the diagram. There are four distinct
      * cases to handle:
@@ -633,11 +656,22 @@ private String findParentTargetObjectId(DiagramContext diagramContext, Node visi
         return parentTargetObjectId;
     }
 
-    private Set<Node> findSubNodesBySemanticElementId(DiagramContext diagramContext, Node parenNode, String semanticElementId) {
+    /**
+     * Finds the direct graphical representations of a semantic element in the specified drop target.
+     *
+     * @param diagramContext
+     *            the {@link DiagramContext} of the tool.
+     * @param parentNode
+     *            the graphical drop target, or {@code null} for the diagram background.
+     * @param semanticElementId
+     *            the identifier of the semantic element to find.
+     * @return the matching graphical nodes.
+     */
+    private Set<Node> findSubNodesBySemanticElementId(DiagramContext diagramContext, Node parentNode, String semanticElementId) {
         Set<Node> subnodes = new HashSet<>();
-        if (parenNode != null) {
-            subnodes.addAll(parenNode.getChildNodes());
-            subnodes.addAll(parenNode.getBorderNodes());
+        if (parentNode != null) {
+            subnodes.addAll(parentNode.getChildNodes());
+            subnodes.addAll(parentNode.getBorderNodes());
         } else {
             subnodes.addAll(diagramContext.diagram().getNodes());
         }

doc/content/modules/user-manual/pages/release-notes/2026.9.0.adoc

@@ -14,6 +14,8 @@
 
 * In diagrams:
 
+** Fix dropping a nested `AttributeUsage` from the _Explorer_ onto a _General View_ diagram so it is visible on the first drop.
+
 ** Fix `Comment` graphical nodes so changing their background color no longer changes their border color.
 
 * In all views: