[426] Handle horizontal stack container

Before this commit, this kind of container was not correctly handled.

Bug: #426

plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/business/api/query/ViewQuery.java

@@ -420,7 +420,7 @@ public boolean isRegion() {
     }
 
     /**
-     * Return if this GMF node is contained in an vertical stack layout container.
+     * Return if this GMF node is contained in a vertical stack layout container.
      */
     public boolean isVerticalRegion() {
         return view.eContainer() instanceof View container && new ViewQuery(container).isVerticalRegionContainerCompartment();
@@ -445,7 +445,7 @@ public boolean isVerticalRegionContainer() {
     }
 
     /**
-     * Return if this GMF node is a compartment of a container having horizontal stack layout.
+     * Return if this GMF node is a compartment of a container having vertical stack layout.
      */
     public boolean isVerticalRegionContainerCompartment() {
         if (isFreeFormCompartment()) {
@@ -458,6 +458,48 @@ public boolean isVerticalRegionContainerCompartment() {
 
     }
 
+    /**
+     * Return if this GMF node is contained in an horizontal stack layout container.
+     */
+    public boolean isHorizontalRegion() {
+        return view.eContainer() instanceof View container && new ViewQuery(container).isHorizontalRegionContainerCompartment();
+    }
+
+    /**
+     * Return if this GMF node have horizontal stack layout.
+     */
+    public boolean isHorizontalRegionContainer() {
+        return this.view.getElement() instanceof DDiagramElement element //
+                && element.getDiagramElementMapping() instanceof ContainerMapping mapping //
+                && new ContainerMappingQuery(mapping).isHorizontalStackContainer();
+    }
+
+    /**
+     * Return if this GMF node is a compartment of a container having horizontal stack layout.
+     */
+    public boolean isHorizontalRegionContainerCompartment() {
+        if (isFreeFormCompartment()) {
+            if (view.eContainer() instanceof Node container) {
+                return new ViewQuery(container).isHorizontalRegionContainer();
+            }
+
+        }
+        return false;
+    }
+
+    /**
+     * Return if this GMF node is a compartment of a container having an horizontal or a vertical stack layout.
+     */
+    public boolean isRegionContainerCompartment() {
+        if (isFreeFormCompartment()) {
+            if (view.eContainer() instanceof Node container) {
+                return new ViewQuery(container).isRegionContainer();
+            }
+
+        }
+        return false;
+    }
+
     /**
      * Return if this GMF node is associated to DNode Sirius diagram element.
      */