[2045] Prevent compartments from being revealed at node creation

Bug: #2045
Signed-off-by: Guillaume Coutable <guillaume.coutable@obeo.fr>

Author: gcoutable

CHANGELOG.adoc

@@ -1,23 +1,28 @@
 = Changelog
 
 == v2026.5.0 (work in progress)
- 
+
 === Shapes
- 
+
 === Breaking changes
 
 - SysON now requires **Java 21** or later.
 - [cleanup] The definition of the tools specific to the requirements table has been moved to the backend.
 As a result, the following GraphQL mutations have been removed `exposeRequirements` and `createRequirement`.
 - [test] Reduce our call to `DiagramNavigator#nodeWithTargetObjectLabel` which has been deprecated for removal.
 + The API of `ToolTester#invokeTool` and `NodeCreationTestsService#createNode` has been updated accordingly to take a `targetObjectId` instead of a `label`.
+- https://github.com/eclipse-syson/syson/issues/2045[#2045] [diagrams] The service `ViewNodeService#revealCompartment` has been changed to reveal a compartment only when it is needed.
++ Only reveal a compartment of a node when none of the revealed compartment can display the `targetElement`.
++ If many compartment candidates exist, choose the first free form compartment.
 
 === Dependency update
 
 - As of version 2026.5.0, SysON now requires **Java 21** or later.
 
 === Bug fixes
 
+- https://github.com/eclipse-syson/syson/issues/2045[#2045] [diagrams] In Interconnection View diagrams, fix an issue where the `parts` compartment of a `PartDefinition` graphical node was incorrectly revealed when creating a `PartUsage` from the `PartDefinition` graphical node, even if the `interconnection` compartment was already visible.
+
 === Improvements
 
 === New features
@@ -123,7 +128,7 @@ Now the _end_ keyword is not displayed anymore in the label of these graphical n
 - https://github.com/eclipse-syson/syson/issues/2053[#2053] [diagrams] Prevent incoming and outgoing graphical edges of a graphical `ForkNode` or `JoinNode` to point empty space.
 - https://github.com/eclipse-syson/syson/issues/2059[#2059] [diagrams] Fix an issue where the _Add existing elements_ tool was not working correctly on the _action flow_ compartment of `ActionUsage` graphical nodes.
 - https://github.com/eclipse-syson/syson/issues/2043[#2043] [explorer] Prevent user libraries from being moved to the root of the project when a child is created in it.
-- https://github.com/eclipse-syson/syson/issues/2056[#2056] [diagams] Fix the user feedback when dropping an `Element` which is already exposed on a diagram.
+- https://github.com/eclipse-syson/syson/issues/2056[#2056] [diagrams] Fix the user feedback when dropping an `Element` which is already exposed on a diagram.
 - https://github.com/eclipse-syson/syson/issues/2048[#2048] [diagrams] Fix an issue where the non-empty compartments of graphical nodes were being displayed when executing the _Add existing elements_ tool.
 
 === Improvements

backend/application/syson-application/src/test/java/org/eclipse/syson/application/controllers/diagrams/checkers/CheckNodeInCompartment.java

@@ -46,6 +46,8 @@ public class CheckNodeInCompartment implements IDiagramChecker {
 
     private boolean isRevealed;
 
+    private boolean isHidden;
+
     public CheckNodeInCompartment(DiagramDescriptionIdProvider diagramDescriptionIdProvider, DiagramComparator diagramComparator) {
         this.diagramDescriptionIdProvider = diagramDescriptionIdProvider;
         this.diagramComparator = diagramComparator;
@@ -76,6 +78,11 @@ public CheckNodeInCompartment isRevealed() {
         return this;
     }
 
+    public CheckNodeInCompartment isHidden() {
+        this.isHidden = true;
+        return this;
+    }
+
     @Override
     public void check(Diagram previousDiagram, Diagram newDiagram) {
         List<Node> newNodes = this.diagramComparator.newNodes(previousDiagram, newDiagram);
@@ -93,5 +100,8 @@ public void check(Diagram previousDiagram, Diagram newDiagram) {
         if (this.isRevealed) {
             assertThat(compartmentNode.getState()).isEqualTo(ViewModifier.Normal);
         }
+        if (this.isHidden) {
+            assertThat(compartmentNode.getState()).isEqualTo(ViewModifier.Hidden);
+        }
     }
 }