[2113] Handle control node graphical nodes on AFV diagram background

CHANGELOG.adoc

@@ -71,6 +71,7 @@ It leverages the selection dialog to either create an _occurrence timeslice/snap
 - https://github.com/eclipse-syson/syson/issues/2250[#2250] [diagrams] Leverage the selection dialog to improve the graphical node tools creating a _require_ `ConstraintUsage`, or an _assume_ `ConstraintUsage`, from `RequirementUsage` and `RequirementDefinition` graphical nodes.
 - https://github.com/eclipse-syson/syson/issues/2254[#2254] [diagrams] Add the support for _assume_ and _require_ graphical edges.
 - https://github.com/eclipse-syson/syson/issues/2260[#2260] [diagrams] Add the _New Assume Constraint_ or _New Require Constraint_ edge tools to create _assume_ and _require_ graphical edges.
+- https://github.com/eclipse-syson/syson/issues/2113[#2113] [diagrams] Handle start/end/merge/decision... graphical nodes on Action Flow View diagram background
 
 == v2026.5.0
 

backend/application/syson-application-configuration/src/main/java/org/eclipse/syson/application/migration/StartDoneAndControlNodeMigrationParticipant.java

@@ -0,0 +1,87 @@
+/*******************************************************************************
+ * Copyright (c) 2026 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.syson.application.migration;
+
+import org.eclipse.sirius.components.collaborative.representations.migration.IRepresentationMigrationParticipant;
+import org.eclipse.sirius.components.core.api.IEditingContext;
+import org.springframework.stereotype.Service;
+
+import tools.jackson.databind.JsonNode;
+import tools.jackson.databind.node.ObjectNode;
+
+/**
+ * Migration participant used to migrate start, done actions and control nodes elements previous to 2026.7.0.
+ *
+ * We need to update descriptionId, because it has been changed due to VSM description change.
+ *
+ * @author Jerome Gout
+ */
+@Service
+public class StartDoneAndControlNodeMigrationParticipant implements IRepresentationMigrationParticipant {
+
+    public static final String PARTICIPANT_VERSION = "2026.7.0-202606240000";
+    public static final String DESCRIPTION_ID = "descriptionId";
+
+    public static final String OLD_START_DESCRIPTION_ID = "siriusComponents://nodeDescription?sourceKind=view&sourceId=8dcd14b0-6259-3193-ad2c-743f394c68e4&sourceElementId=bf75f645-8a6d-30d9-9514-4e9738e212a3";
+    public static final String NEW_START_DESCRIPTION_ID = "siriusComponents://nodeDescription?sourceKind=view&sourceId=8dcd14b0-6259-3193-ad2c-743f394c68e4&sourceElementId=596f7e8d-ba35-38d6-937f-011e05b74063";
+
+    public static final String OLD_DONE_DESCRIPTION_ID = "siriusComponents://nodeDescription?sourceKind=view&sourceId=8dcd14b0-6259-3193-ad2c-743f394c68e4&sourceElementId=03789d5f-51d6-3f66-a496-146b1685930c";
+    public static final String NEW_DONE_DESCRIPTION_ID = "siriusComponents://nodeDescription?sourceKind=view&sourceId=8dcd14b0-6259-3193-ad2c-743f394c68e4&sourceElementId=e7465fdc-fec8-38da-b7c0-26ba953b96de";
+
+    public static final String OLD_DECISION_DESCRIPTION_ID = "siriusComponents://nodeDescription?sourceKind=view&sourceId=8dcd14b0-6259-3193-ad2c-743f394c68e4&sourceElementId=d6e7c035-98ae-3fcf-a5a8-a8e502cd447e";
+    public static final String NEW_DECISION_DESCRIPTION_ID = "siriusComponents://nodeDescription?sourceKind=view&sourceId=8dcd14b0-6259-3193-ad2c-743f394c68e4&sourceElementId=b2f1248d-2a25-37a2-8822-9e21ed709c72";
+
+    public static final String OLD_FORK_DESCRIPTION_ID = "siriusComponents://nodeDescription?sourceKind=view&sourceId=8dcd14b0-6259-3193-ad2c-743f394c68e4&sourceElementId=46dc7020-1788-3413-967d-e1e3053349ca";
+    public static final String NEW_FORK_DESCRIPTION_ID = "siriusComponents://nodeDescription?sourceKind=view&sourceId=8dcd14b0-6259-3193-ad2c-743f394c68e4&sourceElementId=e940b643-cce5-3904-b785-fb3814493642";
+
+    public static final String OLD_JOIN_DESCRIPTION_ID = "siriusComponents://nodeDescription?sourceKind=view&sourceId=8dcd14b0-6259-3193-ad2c-743f394c68e4&sourceElementId=ae252080-4a68-3129-970b-2d049bb3e5a3";
+    public static final String NEW_JOIN_DESCRIPTION_ID = "siriusComponents://nodeDescription?sourceKind=view&sourceId=8dcd14b0-6259-3193-ad2c-743f394c68e4&sourceElementId=963e573a-d0ff-3134-9e96-9ce55e3384ec";
+
+    public static final String OLD_MERGE_DESCRIPTION_ID = "siriusComponents://nodeDescription?sourceKind=view&sourceId=8dcd14b0-6259-3193-ad2c-743f394c68e4&sourceElementId=91f597c3-96b8-3a9e-8b30-99e5401952fa";
+    public static final String NEW_MERGE_DESCRIPTION_ID = "siriusComponents://nodeDescription?sourceKind=view&sourceId=8dcd14b0-6259-3193-ad2c-743f394c68e4&sourceElementId=d47553da-9705-3eca-99ea-dc05ff972f55";
+
+    @Override
+    public String getVersion() {
+        return PARTICIPANT_VERSION;
+    }
+
+    @Override
+    public String getKind() {
+        return "siriusComponents://representation?type=Diagram";
+    }
+
+    @Override
+    public void replaceJsonNode(IEditingContext editingContext, ObjectNode root, String currentAttribute, JsonNode currentValue) {
+        if (currentAttribute.equals(DESCRIPTION_ID) && currentValue.isString()) {
+            if (OLD_START_DESCRIPTION_ID.equals(currentValue.asString())) {
+                root.put(DESCRIPTION_ID, NEW_START_DESCRIPTION_ID);
+            }
+            if (OLD_DONE_DESCRIPTION_ID.equals(currentValue.asString())) {
+                root.put(DESCRIPTION_ID, NEW_DONE_DESCRIPTION_ID);
+            }
+            if (OLD_DECISION_DESCRIPTION_ID.equals(currentValue.asString())) {
+                root.put(DESCRIPTION_ID, NEW_DECISION_DESCRIPTION_ID);
+            }
+            if (OLD_FORK_DESCRIPTION_ID.equals(currentValue.asString())) {
+                root.put(DESCRIPTION_ID, NEW_FORK_DESCRIPTION_ID);
+            }
+            if (OLD_JOIN_DESCRIPTION_ID.equals(currentValue.asString())) {
+                root.put(DESCRIPTION_ID, NEW_JOIN_DESCRIPTION_ID);
+            }
+            if (OLD_MERGE_DESCRIPTION_ID.equals(currentValue.asString())) {
+                root.put(DESCRIPTION_ID, NEW_MERGE_DESCRIPTION_ID);
+            }
+        }
+    }
+}

backend/application/syson-application/src/test/java/org/eclipse/syson/application/controllers/diagrams/actionflow/view/AFVAddTopControlNodeActionTests.java

@@ -0,0 +1,148 @@
+/*******************************************************************************
+ * Copyright (c) 2026 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.syson.application.controllers.diagrams.actionflow.view;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.eclipse.sirius.components.diagrams.tests.DiagramEventPayloadConsumer.assertRefreshedDiagramThat;
+
+import java.time.Duration;
+import java.util.UUID;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.Consumer;
+import java.util.stream.Stream;
+
+import org.eclipse.sirius.components.collaborative.diagrams.dto.DiagramEventInput;
+import org.eclipse.sirius.components.collaborative.diagrams.dto.DiagramRefreshedEventPayload;
+import org.eclipse.sirius.components.diagrams.Diagram;
+import org.eclipse.sirius.components.view.emf.diagram.IDiagramIdProvider;
+import org.eclipse.sirius.web.tests.services.api.IGivenInitialServerState;
+import org.eclipse.syson.AbstractIntegrationTests;
+import org.eclipse.syson.GivenSysONServer;
+import org.eclipse.syson.application.controllers.diagrams.checkers.CheckDiagramElementCount;
+import org.eclipse.syson.application.controllers.diagrams.checkers.CheckNodeOnDiagram;
+import org.eclipse.syson.application.controllers.diagrams.testers.ToolTester;
+import org.eclipse.syson.application.data.ActionFlowViewInsideActionUsageEmptyTestProjectData;
+import org.eclipse.syson.services.diagrams.DiagramComparator;
+import org.eclipse.syson.services.diagrams.DiagramDescriptionIdProvider;
+import org.eclipse.syson.services.diagrams.api.IGivenDiagramDescription;
+import org.eclipse.syson.services.diagrams.api.IGivenDiagramSubscription;
+import org.eclipse.syson.standard.diagrams.view.SDVDescriptionNameGenerator;
+import org.eclipse.syson.sysml.SysmlPackage;
+import org.eclipse.syson.util.SysONRepresentationDescriptionIdentifiers;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.transaction.annotation.Transactional;
+
+import reactor.core.publisher.Flux;
+import reactor.test.StepVerifier;
+
+/**
+ * Tests the creation of control nodes (Decision, Fork, Join and Merge) as well as Start and Done actions in a Action Flow view diagram background when it is contained by an ActionUsage.
+ *
+ * @author Jerome Gout
+ */
+@Transactional
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+public class AFVAddTopControlNodeActionTests extends AbstractIntegrationTests {
+
+    @Autowired
+    private IGivenInitialServerState givenInitialServerState;
+
+    @Autowired
+    private IGivenDiagramDescription givenDiagramDescription;
+
+    @Autowired
+    private IGivenDiagramSubscription givenDiagramSubscription;
+
+    @Autowired
+    private IDiagramIdProvider diagramIdProvider;
+
+    @Autowired
+    private ToolTester toolTester;
+
+    @Autowired
+    private DiagramComparator diagramComparator;
+
+    private final SDVDescriptionNameGenerator descriptionNameGenerator = new SDVDescriptionNameGenerator();
+
+    private static Stream<Arguments> topControlNodeParameters() {
+        return Stream.of(
+                Arguments.of("New Start Action", "StartAction"),
+                Arguments.of("New Done Action", "DoneAction"),
+                Arguments.of("New Decision", SysmlPackage.eINSTANCE.getDecisionNode().getName()),
+                Arguments.of("New Fork", SysmlPackage.eINSTANCE.getForkNode().getName()),
+                Arguments.of("New Join", SysmlPackage.eINSTANCE.getJoinNode().getName()),
+                Arguments.of("New Merge", SysmlPackage.eINSTANCE.getMergeNode().getName())
+        );
+    }
+
+    private Flux<DiagramRefreshedEventPayload> givenSubscriptionToDiagram() {
+        var diagramEventInput = new DiagramEventInput(UUID.randomUUID(),
+                ActionFlowViewInsideActionUsageEmptyTestProjectData.EDITING_CONTEXT_ID,
+                ActionFlowViewInsideActionUsageEmptyTestProjectData.GraphicalIds.AFV_IN_ACTION_DIAGRAM_ID);
+        return this.givenDiagramSubscription.subscribe(diagramEventInput);
+    }
+
+    @BeforeEach
+    public void beforeEach() {
+        this.givenInitialServerState.initialize();
+    }
+
+    @DisplayName("GIVEN an ActionFlow View diagram, WHEN control node creation tool is requested on digram background, THEN a new control node is created")
+    @GivenSysONServer({ ActionFlowViewInsideActionUsageEmptyTestProjectData.SCRIPT_PATH })
+    @ParameterizedTest
+    @MethodSource("topControlNodeParameters")
+    public void givenAnAFVDiagramWhenControlNodeCreationToolIsRequestedOnDiagramBackgroundThenANewControlNodeIsCreated(String toolLabel, String nodeName) {
+        var flux = this.givenSubscriptionToDiagram();
+
+        var diagramDescription = this.givenDiagramDescription.getDiagramDescription(ActionFlowViewInsideActionUsageEmptyTestProjectData.EDITING_CONTEXT_ID,
+                SysONRepresentationDescriptionIdentifiers.GENERAL_VIEW_DIAGRAM_DESCRIPTION_ID);
+        var diagramDescriptionIdProvider = new DiagramDescriptionIdProvider(diagramDescription, this.diagramIdProvider);
+
+        String creationToolId = diagramDescriptionIdProvider.getDiagramCreationToolId(toolLabel);
+        assertThat(creationToolId).as("The tool '" + toolLabel + "' should exist on diagram background").isNotNull();
+
+        var diagram = new AtomicReference<Diagram>();
+
+        Consumer<Object> initialDiagramContentConsumer = assertRefreshedDiagramThat(diagram::set);
+
+        Runnable createNodeRunnable = () -> {
+            this.toolTester.invokeTool(ActionFlowViewInsideActionUsageEmptyTestProjectData.EDITING_CONTEXT_ID, diagram, null, creationToolId);
+        };
+
+        Consumer<Object> diagramCheck = assertRefreshedDiagramThat(newDiagram -> {
+            var initialDiagram = diagram.get();
+            new CheckDiagramElementCount(this.diagramComparator)
+                    .hasNewEdgeCount(0)
+                    .hasNewNodeCount(1)
+                    .check(initialDiagram, newDiagram);
+
+            new CheckNodeOnDiagram(diagramDescriptionIdProvider, this.diagramComparator)
+                    .hasNodeDescriptionName(this.descriptionNameGenerator.getNodeName(nodeName))
+                    .check(initialDiagram, newDiagram);
+        });
+
+        StepVerifier.create(flux)
+                .consumeNextWith(initialDiagramContentConsumer)
+                .then(createNodeRunnable)
+                .consumeNextWith(diagramCheck)
+                .thenCancel()
+                .verify(Duration.ofSeconds(10));
+    }
+}

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

@@ -76,6 +76,8 @@ public class GVAddExistingElementsTests extends AbstractIntegrationTests {
 
     private static final String PART2 = "part2";
 
+    private static final String SUCCESSION = "SuccessionAsUsage";
+
     private static final String ATTRIBUTE_DEFINITION = "AttributeDefinition1";
 
     private static final String NODE_SHOULD_BE_ON_DIAGRAM_MESSAGE = "Node {0} should exist on the diagram";
@@ -166,15 +168,17 @@ public void addExistingElementsRecursiveOnDiagram() {
         Runnable addExistingElementTool = () -> this.nodeCreationTester.invokeTool(GeneralViewAddExistingElementsTestProjectData.EDITING_CONTEXT_ID, diagram, addExistingElementToolId);
 
         Consumer<Object> updatedDiagramConsumer = assertRefreshedDiagramThat(newDiagram -> {
-            assertThat(newDiagram.getNodes()).as("7 root nodes should be visible on the diagram").hasSize(7);
+            assertThat(newDiagram.getNodes()).as("8 root nodes should be visible on the diagram").hasSize(8);
             assertThat(newDiagram.getEdges().stream().filter(e -> ViewModifier.Normal.equals(e.getState())).toList())
-                    .as("3 edges should be visible on the diagram").hasSize(3)
+                    .as("4 edges should be visible on the diagram").hasSize(4)
                     .as("The diagram should contain a composite edge between part2 and part1")
                     .anyMatch(edge -> edge.getTargetObjectLabel().equals(PART1))
                     .as("The diagram should contain a composite edge between action1 and action2")
                     .anyMatch(edge -> edge.getTargetObjectLabel().equals(ACTION1))
                     .as("The diagram should contain a composite edge between action2 and action3")
-                    .anyMatch(edge -> edge.getTargetObjectLabel().equals(ACTION2));
+                    .anyMatch(edge -> edge.getTargetObjectLabel().equals(ACTION2))
+                    .as("The diagram should contain a SuccessionAsUsage edge between start and action2")
+                    .anyMatch(edge -> edge.getTargetObjectLabel().equals(SUCCESSION));
             assertThat(newDiagram.getNodes())
                     .as(MessageFormat.format(NODE_SHOULD_BE_ON_DIAGRAM_MESSAGE, PACKAGE1))
                     .anyMatch(n -> Objects.equals(n.getTargetObjectLabel(), PACKAGE1))
@@ -185,7 +189,9 @@ public void addExistingElementsRecursiveOnDiagram() {
                     .as(MessageFormat.format(NODE_SHOULD_BE_ON_DIAGRAM_MESSAGE, PART2))
                     .anyMatch(n -> Objects.equals(n.getTargetObjectLabel(), PART2))
                     .as(MessageFormat.format(NODE_SHOULD_BE_ON_DIAGRAM_MESSAGE, "RequirementUsage"))
-                    .anyMatch(n -> Objects.equals(n.getTargetObjectLabel(), "RequirementUsage"));
+                    .anyMatch(n -> Objects.equals(n.getTargetObjectLabel(), "RequirementUsage"))
+                    .as(MessageFormat.format(NODE_SHOULD_BE_ON_DIAGRAM_MESSAGE, "start"))
+                    .anyMatch(n -> Objects.equals(n.getTargetObjectLabel(), "start"));
 
             this.checkPackageNode(newDiagram);
 

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

@@ -168,10 +168,10 @@ private static Stream<Arguments> actionDefinitionBorderAndChildNodeParameters()
 
     private static Stream<Arguments> actionUsageFreeFormNodeParameters() {
         return Stream.of(
-                Arguments.of(SysmlPackage.eINSTANCE.getDecisionNode(), SysmlPackage.eINSTANCE.getUsage_NestedAction(), 0, 0, 0),
-                Arguments.of(SysmlPackage.eINSTANCE.getForkNode(), SysmlPackage.eINSTANCE.getUsage_NestedAction(), 0, 0, 0),
-                Arguments.of(SysmlPackage.eINSTANCE.getJoinNode(), SysmlPackage.eINSTANCE.getUsage_NestedAction(), 0, 0, 0),
-                Arguments.of(SysmlPackage.eINSTANCE.getMergeNode(), SysmlPackage.eINSTANCE.getUsage_NestedAction(), 0, 0, 0),
+                Arguments.of(SysmlPackage.eINSTANCE.getDecisionNode(), SysmlPackage.eINSTANCE.getUsage_NestedAction(), 1, 0, 1),
+                Arguments.of(SysmlPackage.eINSTANCE.getForkNode(), SysmlPackage.eINSTANCE.getUsage_NestedAction(), 1, 0, 1),
+                Arguments.of(SysmlPackage.eINSTANCE.getJoinNode(), SysmlPackage.eINSTANCE.getUsage_NestedAction(), 1, 0, 1),
+                Arguments.of(SysmlPackage.eINSTANCE.getMergeNode(), SysmlPackage.eINSTANCE.getUsage_NestedAction(), 1, 0, 1),
                 Arguments.of(SysmlPackage.eINSTANCE.getAcceptActionUsage(), SysmlPackage.eINSTANCE.getUsage_NestedAction(), 5, 2, 1))
                 .map(TestNameGenerator::namedArguments);
     }
@@ -191,10 +191,10 @@ private static Stream<Arguments> actionDefinitionSiblingNodeParameters() {
 
     private static Stream<Arguments> actionDefinitionFreeFormNodeParameters() {
         return Stream.of(
-                Arguments.of(SysmlPackage.eINSTANCE.getDecisionNode(), SysmlPackage.eINSTANCE.getDefinition_OwnedAction(), 0, 0, 0),
-                Arguments.of(SysmlPackage.eINSTANCE.getForkNode(), SysmlPackage.eINSTANCE.getDefinition_OwnedAction(), 0, 0, 0),
-                Arguments.of(SysmlPackage.eINSTANCE.getJoinNode(), SysmlPackage.eINSTANCE.getDefinition_OwnedAction(), 0, 0, 0),
-                Arguments.of(SysmlPackage.eINSTANCE.getMergeNode(), SysmlPackage.eINSTANCE.getDefinition_OwnedAction(), 0, 0, 0),
+                Arguments.of(SysmlPackage.eINSTANCE.getDecisionNode(), SysmlPackage.eINSTANCE.getDefinition_OwnedAction(), 1, 0, 1),
+                Arguments.of(SysmlPackage.eINSTANCE.getForkNode(), SysmlPackage.eINSTANCE.getDefinition_OwnedAction(), 1, 0, 1),
+                Arguments.of(SysmlPackage.eINSTANCE.getJoinNode(), SysmlPackage.eINSTANCE.getDefinition_OwnedAction(), 1, 0, 1),
+                Arguments.of(SysmlPackage.eINSTANCE.getMergeNode(), SysmlPackage.eINSTANCE.getDefinition_OwnedAction(), 1, 0, 1),
                 Arguments.of(SysmlPackage.eINSTANCE.getAcceptActionUsage(), SysmlPackage.eINSTANCE.getDefinition_OwnedAction(), 5, 2, 1))
                 .map(TestNameGenerator::namedArguments);
     }