[1869] Make sure actions are visible and has the correct label when created in a state

CHANGELOG.adoc

@@ -55,6 +55,7 @@ This fix ensure that imported models containing, for example, a top-level `Libra
 - https://github.com/eclipse-syson/syson/issues/1857[#1857] [diagrams] Fix an issue where existing graphical node could disappear when new graphical node was created.
 - https://github.com/eclipse-syson/syson/issues/1865[#1865] [explorer] Fix focus loss on some characters in the _New object from text_ modal.
 - https://github.com/eclipse-syson/syson/issues/1876[#1876] [explorer] Fix potential NPE when trying to delete elements with associated `EAnnotations` from the _Explorer_.
+- https://github.com/eclipse-syson/syson/issues/1869[#1869] [diagram] When creating a _Do action with referenced action_ on a `State`, ensure the corresponding compartements are made visible
 
 === Improvements
 

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

@@ -562,8 +562,11 @@ public void createReferencingPerformActionUsageInActionUsage() {
 
         IDiagramChecker diagramChecker = (initialDiagram, newDiagram) -> {
             new CheckDiagramElementCount(this.diagramComparator)
-                    .hasNewNodeCount(1) // 1 visible new PerformActionUsage node
-                    .hasNewEdgeCount(2) // 1 visible composition edge and 1 visible ReferenceSubsetting edge
+                    .hasNewNodeCount(4) // 1 visible new PerformActionUsage node + 2 list items (in 'actions' and
+                                        // 'perform actions' compartments, now visible) + 1 node in 'action flow'
+                                        // compartment
+                    .hasNewEdgeCount(3) // 1 visible composition edge and 2 visible ReferenceSubsetting edge (one for
+                                        // the top-level node, one for the node in "action flow" compartment
                     .check(initialDiagram, newDiagram, true);
             String listNodeDescription = this.descriptionNameGenerator.getCompartmentItemName(parentEClass, containmentReference);
             new CheckNodeInCompartment(this.diagramDescriptionIdProvider, this.diagramComparator)

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

@@ -89,7 +89,7 @@ public class DiagramQueryLabelService implements IDiagramLabelService {
     public String getIdentificationLabel(Element element) {
         StringBuilder label = new StringBuilder();
         if (element instanceof ActionUsage && element.eContainer() instanceof StateSubactionMembership ssm) {
-            label.append(ssm.getKind());
+            label.append(ssm.getKind()).append(LabelConstants.SPACE);
         }
         label.append(this.getShortNameLabel(element));
         String declaredName = element.getDeclaredName();
@@ -483,6 +483,7 @@ private String getCompartmentItemStringRepresentation(Usage usage, boolean direc
             label.append(this.getTypingLabel(usage));
             label.append(this.getRedefinitionLabel(usage));
             label.append(this.getSubsettingLabel(usage));
+            label.append(this.getReferenceSubsettingLabel(usage));
             label.append(this.getValueStringRepresentation(usage, directEditInput));
         }
         return label.toString();

backend/views/syson-diagram-common-view/src/main/java/org/eclipse/syson/diagram/common/view/services/RevealCompartmentSwitch.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2025 Obeo.
+ * Copyright (c) 2025, 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
@@ -21,6 +21,7 @@
 import org.eclipse.syson.sysml.MergeNode;
 import org.eclipse.syson.sysml.OccurrenceDefinition;
 import org.eclipse.syson.sysml.OccurrenceUsage;
+import org.eclipse.syson.sysml.PerformActionUsage;
 import org.eclipse.syson.sysml.PortUsage;
 import org.eclipse.syson.sysml.StateUsage;
 import org.eclipse.syson.sysml.util.SysmlSwitch;
@@ -48,6 +49,11 @@ public Boolean defaultCase(EObject object) {
         return Boolean.TRUE;
     }
 
+    @Override
+    public Boolean casePerformActionUsage(PerformActionUsage object) {
+        return Boolean.TRUE;
+    }
+
     @Override
     public Boolean caseActionUsage(ActionUsage object) {
         return !this.isGeneralView;

doc/content/modules/user-manual/pages/release-notes/2026.1.0.adoc

@@ -51,6 +51,7 @@ The following structure is not yet handled `connection bus : C connect (d1, d2,
 
 ** Fix an issue where the creation of an `Element` inside a `sub-Package` created two graphical nodes instead of one.
 ** Fix an issue where the creation of an `Element` inside a `sub-Package` could hide unrelated graphical nodes.
+** Fix an issue where the creation of a `PerformAction` inside a `State` did not reveal the corresponding compartments in the state graphical node.
 
 * In _Explorer_ view: