[509070] Update generic layout algorithm integration to handle options

Options supported are String, Integer, Double, Boolean, Enum, EnumSet

Bug: 509070
Change-Id: I1a03ba2adf199797a7107642030dae0adb38fe1a
Signed-off-by: pguilet <pierre.guilet@obeo.fr>

36 files changed, 1752 insertions, 267 deletions

diff --git a/plugins/org.eclipse.sirius.diagram.elk/src/org/eclipse/sirius/diagram/elk/DiagramElkPlugin.java b/plugins/org.eclipse.sirius.diagram.elk/src/org/eclipse/sirius/diagram/elk/DiagramElkPlugin.java
index 89ad1c31a1..7c9ee89132 100644
--- a/plugins/org.eclipse.sirius.diagram.elk/src/org/eclipse/sirius/diagram/elk/DiagramElkPlugin.java
+++ b/plugins/org.eclipse.sirius.diagram.elk/src/org/eclipse/sirius/diagram/elk/DiagramElkPlugin.java
@@ -10,10 +10,20 @@
  *******************************************************************************/
 package org.eclipse.sirius.diagram.elk;
 
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.List;
 
 import org.eclipse.elk.core.data.LayoutAlgorithmData;
 import org.eclipse.elk.core.data.LayoutMetaDataService;
+import org.eclipse.elk.core.data.LayoutOptionData;
+import org.eclipse.elk.core.data.LayoutOptionData.Target;
+import org.eclipse.elk.core.data.LayoutOptionData.Type;
+import org.eclipse.elk.core.data.LayoutOptionData.Visibility;
+import org.eclipse.elk.core.options.CoreOptions;
+import org.eclipse.sirius.diagram.description.LayoutOption;
+import org.eclipse.sirius.diagram.ui.api.layout.EnumChoice;
+import org.eclipse.sirius.diagram.ui.api.layout.LayoutOptionFactory;
 import org.eclipse.sirius.diagram.ui.provider.DiagramUIPlugin;
 import org.eclipse.ui.plugin.AbstractUIPlugin;
 import org.osgi.framework.BundleContext;
@@ -36,9 +46,60 @@ public class DiagramElkPlugin extends AbstractUIPlugin {
         super.start(context);
         plugin = this;
 
+        // we fill the Sirius layout algorithm registry with all ELK algorithms.
         Collection<LayoutAlgorithmData> algorithmData = LayoutMetaDataService.getInstance().getAlgorithmData();
         for (LayoutAlgorithmData layoutAlgorithmData : algorithmData) {
-            DiagramUIPlugin.getPlugin().addLayoutProvider(layoutAlgorithmData.getId(), layoutAlgorithmData.getName(), () -> new ELKLayoutNodeProvider(), null);
+
+            List<LayoutOptionData> optionDatas = LayoutMetaDataService.getInstance().getOptionData(layoutAlgorithmData, Target.PARENTS);
+            List<LayoutOption> layoutOptions = new ArrayList<>();
+            LayoutOptionFactory layoutOptionFactory = new LayoutOptionFactory();
+            for (LayoutOptionData layoutOptionData : optionDatas) {
+                if (!CoreOptions.ALGORITHM.getId().equals(layoutOptionData.getId()) && !layoutOptionData.getVisibility().equals(Visibility.HIDDEN)) {
+                    switch (layoutOptionData.getType()) {
+                    case STRING:
+                        layoutOptions.add(layoutOptionFactory.createStringOption((String) layoutOptionData.getDefault(), layoutOptionData.getId(), layoutOptionData.getDescription(),
+                                layoutOptionData.getName()));
+                        break;
+                    case BOOLEAN:
+                        layoutOptions.add(layoutOptionFactory.createBooleanOption((Boolean) layoutOptionData.getDefault(), layoutOptionData.getId(), layoutOptionData.getDescription(),
+                                layoutOptionData.getName()));
+                        break;
+                    case INT:
+                        layoutOptions.add(layoutOptionFactory.createIntegerOption((Integer) layoutOptionData.getDefault(), layoutOptionData.getId(), layoutOptionData.getDescription(),
+                                layoutOptionData.getName()));
+                        break;
+                    case DOUBLE:
+                        layoutOptions.add(layoutOptionFactory.createDoubleOption((Double) layoutOptionData.getDefault(), layoutOptionData.getId(), layoutOptionData.getDescription(),
+                                layoutOptionData.getName()));
+                        break;
+                    case ENUMSET:
+                    case ENUM:
+
+                        String[] choices = layoutOptionData.getChoices();
+                        List<EnumChoice> choicesList = new ArrayList<>();
+                        for (int i = 0; i < choices.length; i++) {
+                            String choiceId = choices[i];
+                            choicesList.add(new EnumChoice(choiceId, ""));
+
+                        }
+                        String defaultValue = null;
+                        Object defaultObject = layoutOptionData.getDefaultDefault();
+                        if (defaultObject instanceof Enum) {
+                            defaultValue = ((Enum<?>) defaultObject).name();
+                        }
+                        if (layoutOptionData.getType() == Type.ENUM) {
+                            layoutOptions.add(layoutOptionFactory.createEnumOption(choicesList, layoutOptionData.getId(), layoutOptionData.getDescription(), layoutOptionData.getName(), defaultValue));
+                        } else {
+                            layoutOptions.add(layoutOptionFactory.createEnumSetOption(choicesList, layoutOptionData.getId(), layoutOptionData.getDescription(), layoutOptionData.getName()));
+                        }
+
+                        break;
+                    default:
+                        break;
+                    }
+                }
+            }
+            DiagramUIPlugin.getPlugin().addLayoutProvider(layoutAlgorithmData.getId(), layoutAlgorithmData.getName(), () -> new ELKLayoutNodeProvider(), layoutOptions);
         }
     }
 
diff --git a/plugins/org.eclipse.sirius.diagram.elk/src/org/eclipse/sirius/diagram/elk/ElkDiagramLayoutConnector.java b/plugins/org.eclipse.sirius.diagram.elk/src/org/eclipse/sirius/diagram/elk/ElkDiagramLayoutConnector.java
index 111601a5f0..acc9b9c3d3 100644
--- a/plugins/org.eclipse.sirius.diagram.elk/src/org/eclipse/sirius/diagram/elk/ElkDiagramLayoutConnector.java
+++ b/plugins/org.eclipse.sirius.diagram.elk/src/org/eclipse/sirius/diagram/elk/ElkDiagramLayoutConnector.java
@@ -13,6 +13,7 @@ package org.eclipse.sirius.diagram.elk;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.EnumSet;
 import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
@@ -32,6 +33,8 @@ import org.eclipse.draw2d.geometry.Point;
 import org.eclipse.draw2d.geometry.PointList;
 import org.eclipse.draw2d.geometry.Rectangle;
 import org.eclipse.elk.core.IGraphLayoutEngine;
+import org.eclipse.elk.core.data.LayoutMetaDataService;
+import org.eclipse.elk.core.data.LayoutOptionData;
 import org.eclipse.elk.core.math.ElkPadding;
 import org.eclipse.elk.core.math.KVector;
 import org.eclipse.elk.core.options.CoreOptions;
@@ -53,6 +56,7 @@ import org.eclipse.elk.graph.properties.IProperty;
 import org.eclipse.elk.graph.properties.IPropertyHolder;
 import org.eclipse.elk.graph.properties.Property;
 import org.eclipse.elk.graph.util.ElkGraphUtil;
+import org.eclipse.emf.common.util.EList;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.EReference;
 import org.eclipse.emf.transaction.impl.InternalTransactionalEditingDomain;
@@ -70,11 +74,18 @@ import org.eclipse.gmf.runtime.diagram.ui.editparts.ShapeNodeEditPart;
 import org.eclipse.gmf.runtime.diagram.ui.figures.ResizableCompartmentFigure;
 import org.eclipse.gmf.runtime.diagram.ui.parts.DiagramEditor;
 import org.eclipse.gmf.runtime.draw2d.ui.figures.WrappingLabel;
-import org.eclipse.gmf.runtime.notation.Diagram;
-import org.eclipse.gmf.runtime.notation.View;
-import org.eclipse.sirius.diagram.DDiagram;
+import org.eclipse.sirius.diagram.description.BooleanLayoutOption;
+import org.eclipse.sirius.diagram.description.CustomLayoutConfiguration;
+import org.eclipse.sirius.diagram.description.DescriptionPackage;
 import org.eclipse.sirius.diagram.description.DiagramDescription;
-import org.eclipse.sirius.diagram.description.GenericLayout;
+import org.eclipse.sirius.diagram.description.DoubleLayoutOption;
+import org.eclipse.sirius.diagram.description.EnumLayoutOption;
+import org.eclipse.sirius.diagram.description.EnumLayoutValue;
+import org.eclipse.sirius.diagram.description.EnumSetLayoutOption;
+import org.eclipse.sirius.diagram.description.IntegerLayoutOption;
+import org.eclipse.sirius.diagram.description.LayoutOption;
+import org.eclipse.sirius.diagram.description.StringLayoutOption;
+import org.eclipse.sirius.diagram.ui.business.api.query.EditPartQuery;
 import org.eclipse.sirius.diagram.ui.tools.api.figure.SiriusWrapLabel;
 import org.eclipse.swt.SWTException;
 import org.eclipse.swt.graphics.Font;
@@ -296,6 +307,11 @@ public class ElkDiagramLayoutConnector implements IDiagramLayoutConnector {
         return false;
     }
 
+    public <E extends Enum<E>> EnumSet<E> of(E e, EnumSet<E> enumSet) {
+        enumSet.add(e);
+        return enumSet;
+    }
+
     /**
      * Creates the actual mapping given an edit part which functions as the root
      * for the layout.
@@ -339,22 +355,13 @@ public class ElkDiagramLayoutConnector implements IDiagramLayoutConnector {
             mapping.getGraphMap().put(topNode, layoutRootPart);
         }
 
-        // we set the ELK algorithm to use from viewpoint id defined.
-        final View view = layoutRootPart.getNotationView();
-        final EObject modelElement = view.getElement();
-        if (view instanceof Diagram && modelElement instanceof DDiagram) {
-            final DDiagram vp = (DDiagram) modelElement;
-            final DiagramDescription desc = vp.getDescription();
-            if (desc != null) {
-                final GenericLayout layout = (GenericLayout) desc.getLayout();
-                topNode.setProperty(CoreOptions.ALGORITHM, layout.getID().trim());
-                // topNode.setProperty(CoreOptions.PADDING, new ElkPadding(50));
-            }
-        }
+        configureGlobalOptions(layoutRootPart, topNode);
 
         mapping.setLayoutGraph(topNode);
 
-        if (selection != null && !selection.isEmpty()) {
+        if (selection != null && !selection.isEmpty())
+
+        {
             // layout only the selected elements
             double minx = Integer.MAX_VALUE;
             double miny = Integer.MAX_VALUE;
@@ -378,6 +385,91 @@ public class ElkDiagramLayoutConnector implements IDiagramLayoutConnector {
     }
 
     /**
+     * Configure global options for top node of the graph coming from VSM
+     * specification.
+     * 
+     * @param layoutRootPart
+     *            root edit part.
+     * @param topNode
+     *            top node to be configured with global options.
+     */
+    @SuppressWarnings({ "rawtypes", "unchecked" })
+    private void configureGlobalOptions(final IGraphicalEditPart layoutRootPart, ElkNode topNode) {
+        // we set the ELK algorithm to use from viewpoint id defined and the
+        // global options.
+
+        EditPartQuery editPartQuery = new EditPartQuery(layoutRootPart);
+        DiagramDescription diagramDescription = editPartQuery.getDiagramDescription();
+
+        if (diagramDescription != null) {
+            final CustomLayoutConfiguration layout = (CustomLayoutConfiguration) diagramDescription.getLayout();
+            topNode.setProperty(CoreOptions.ALGORITHM, layout.getId().trim());
+            EList<LayoutOption> layoutOptions = layout.getLayoutOptions();
+            for (LayoutOption layoutOption : layoutOptions) {
+                LayoutOptionData layoutProperty = LayoutMetaDataService.getInstance().getOptionData(layoutOption.getId());
+
+                switch (layoutOption.eClass().getClassifierID()) {
+                case DescriptionPackage.ENUM_LAYOUT_OPTION:
+                    EnumLayoutOption enumOption = (EnumLayoutOption) layoutOption;
+                    int enumValueCount = layoutProperty.getEnumValueCount();
+                    Enum<?> elkEnum = null;
+                    int i = 0;
+                    while (i < enumValueCount && elkEnum == null) {
+                        layoutProperty.getEnumValue(i);
+                        Enum<?> enumValue = layoutProperty.getEnumValue(i);
+                        if (enumOption.getValue().getName().equals(enumValue.name())) {
+                            elkEnum = enumValue;
+                        }
+                        i++;
+                    }
+                    topNode.setProperty(layoutProperty, elkEnum);
+                    break;
+
+                case DescriptionPackage.ENUM_SET_LAYOUT_OPTION:
+                    EnumSetLayoutOption enumSetOption = (EnumSetLayoutOption) layoutOption;
+                    enumValueCount = layoutProperty.getEnumValueCount();
+
+                    if (enumValueCount > 0) {
+                        EnumSet enumSet = EnumSet.noneOf(layoutProperty.getEnumValue(0).getDeclaringClass());
+                        List<EnumLayoutValue> values = enumSetOption.getValues();
+                        for (EnumLayoutValue enumLayoutValue : values) {
+                            i = 0;
+                            while (i < enumValueCount) {
+                                Enum enumValue = layoutProperty.getEnumValue(i);
+                                if (enumLayoutValue.getName().equals(enumValue.name())) {
+                                    enumSet = of(enumValue, enumSet);
+                                    break;
+                                }
+                                i++;
+                            }
+                        }
+                        topNode.setProperty(layoutProperty, enumSet);
+                    }
+                    break;
+                case DescriptionPackage.BOOLEAN_LAYOUT_OPTION:
+                    BooleanLayoutOption booleanOption = (BooleanLayoutOption) layoutOption;
+                    topNode.setProperty(layoutProperty, booleanOption.isValue());
+                    break;
+                case DescriptionPackage.INTEGER_LAYOUT_OPTION:
+                    IntegerLayoutOption integerOption = (IntegerLayoutOption) layoutOption;
+                    topNode.setProperty(layoutProperty, integerOption.getValue());
+                    break;
+                case DescriptionPackage.DOUBLE_LAYOUT_OPTION:
+                    DoubleLayoutOption doubleOption = (DoubleLayoutOption) layoutOption;
+                    topNode.setProperty(layoutProperty, doubleOption.getValue());
+                    break;
+                case DescriptionPackage.STRING_LAYOUT_OPTION:
+                    StringLayoutOption stringOption = (StringLayoutOption) layoutOption;
+                    topNode.setProperty(layoutProperty, stringOption.getValue().trim());
+                    break;
+                default:
+                    break;
+                }
+            }
+        }
+    }
+
+    /**
      * Transfer all layout data from the last created KGraph instance to the
      * original diagram. The diagram is not modified yet, but all required
      * preparations are performed. This is separated from
diff --git a/plugins/org.eclipse.sirius.diagram.ui/META-INF/MANIFEST.MF b/plugins/org.eclipse.sirius.diagram.ui/META-INF/MANIFEST.MF
index 4ad069c190..9afbfe8652 100644
--- a/plugins/org.eclipse.sirius.diagram.ui/META-INF/MANIFEST.MF
+++ b/plugins/org.eclipse.sirius.diagram.ui/META-INF/MANIFEST.MF
@@ -53,11 +53,12 @@ Export-Package: org.eclipse.sirius.diagram.description.concern.provider;version=
  org.eclipse.sirius.diagram.description.tool.provider;version="3.0.0",
  org.eclipse.sirius.diagram.internal.description.provider;version="4.0.0",
  org.eclipse.sirius.diagram.provider;version="4.0.0",
- org.eclipse.sirius.diagram.ui.business.api;version="5.1.0",
+ org.eclipse.sirius.diagram.ui.api.layout;version="6.0.0",
+ org.eclipse.sirius.diagram.ui.business.api;version="6.0.0",
  org.eclipse.sirius.diagram.ui.business.api.helper.graphicalfilters;version="2.0.4",
  org.eclipse.sirius.diagram.ui.business.api.image;version="2.0.4",
  org.eclipse.sirius.diagram.ui.business.api.provider;version="2.1.1",
- org.eclipse.sirius.diagram.ui.business.api.query;version="2.0.4",
+ org.eclipse.sirius.diagram.ui.business.api.query;version="5.1.0",
  org.eclipse.sirius.diagram.ui.business.api.view;version="2.0.4",
  org.eclipse.sirius.diagram.ui.business.internal.bracket;version="2.1.0";x-internal:=true,
  org.eclipse.sirius.diagram.ui.business.internal.bracket.handles;version="2.0.4";x-internal:=true,
diff --git a/plugins/org.eclipse.sirius.diagram.ui/icons/full/obj16/CustomLayoutConfiguration.gif b/plugins/org.eclipse.sirius.diagram.ui/icons/full/obj16/CustomLayoutConfiguration.gif
index d92f34c8ae..c4f19bdf85 100644
--- a/plugins/org.eclipse.sirius.diagram.ui/icons/full/obj16/CustomLayoutConfiguration.gif
+++ b/plugins/org.eclipse.sirius.diagram.ui/icons/full/obj16/CustomLayoutConfiguration.gif
diff --git a/plugins/org.eclipse.sirius.diagram.ui/icons/full/obj16/LayoutOption.gif b/plugins/org.eclipse.sirius.diagram.ui/icons/full/obj16/LayoutOption.gif
index c00aedf413..92075a8a35 100644
--- a/plugins/org.eclipse.sirius.diagram.ui/icons/full/obj16/LayoutOption.gif
+++ b/plugins/org.eclipse.sirius.diagram.ui/icons/full/obj16/LayoutOption.gif
diff --git a/plugins/org.eclipse.sirius.diagram.ui/plugin.properties b/plugins/org.eclipse.sirius.diagram.ui/plugin.properties
index f2efe6cb2c..93edbedfdc 100644
--- a/plugins/org.eclipse.sirius.diagram.ui/plugin.properties
+++ b/plugins/org.eclipse.sirius.diagram.ui/plugin.properties
@@ -1298,3 +1298,9 @@ _UI_EnumLayoutOption_choices_feature = Choices
 _UI_EnumLayoutValue_description_feature = Description
 _UI_EnumLayoutValue_name_feature = Name
 _UI_CustomLayoutConfiguration_description_feature = Description
+_UI_EnumSetLayoutOption_type = Enum Set Layout Option
+_UI_EnumSetLayoutOption_value_feature = Value
+_UI_EnumSetLayoutOption_choices_feature = Choices
+_UI_EnumSetLayoutOption_values_feature = Values
+_UI_EnumOption_type = Enum Option
+_UI_EnumOption_choices_feature = Choices
diff --git a/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/internal/description/provider/CustomLayoutConfigurationItemProviderSpec.java b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/internal/description/provider/CustomLayoutConfigurationItemProviderSpec.java
index 1e49d7e2df..c587485034 100644
--- a/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/internal/description/provider/CustomLayoutConfigurationItemProviderSpec.java
+++ b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/internal/description/provider/CustomLayoutConfigurationItemProviderSpec.java
@@ -15,8 +15,8 @@ import java.util.Map;
 
 import org.eclipse.emf.common.notify.AdapterFactory;
 import org.eclipse.emf.ecore.util.EcoreUtil;
-import org.eclipse.sirius.diagram.description.EnumLayoutOption;
-import org.eclipse.sirius.diagram.description.GenericLayout;
+import org.eclipse.sirius.diagram.description.CustomLayoutConfiguration;
+import org.eclipse.sirius.diagram.description.EnumOption;
 import org.eclipse.sirius.diagram.description.LayoutOption;
 import org.eclipse.sirius.diagram.description.provider.CustomLayoutConfigurationItemProvider;
 import org.eclipse.sirius.diagram.ui.internal.layout.GenericLayoutProviderSupplier;
@@ -43,21 +43,21 @@ public class CustomLayoutConfigurationItemProviderSpec extends CustomLayoutConfi
 
     @Override
     public String getText(Object object) {
-        GenericLayout layout = (GenericLayout) object;
+        CustomLayoutConfiguration layout = (CustomLayoutConfiguration) object;
         return layout.getLabel();
     }
 
     @Override
     protected void collectNewChildDescriptors(Collection<Object> newChildDescriptors, Object object) {
         Map<String, GenericLayoutProviderSupplier> layoutProviderRegistry = DiagramUIPlugin.getPlugin().getLayoutProviderRegistry();
-        GenericLayout layout = (GenericLayout) object;
+        CustomLayoutConfiguration layout = (CustomLayoutConfiguration) object;
 
-        GenericLayoutProviderSupplier genericLayoutProviderSupplier = layoutProviderRegistry.get(layout.getID());
+        GenericLayoutProviderSupplier genericLayoutProviderSupplier = layoutProviderRegistry.get(layout.getId());
         Map<String, LayoutOption> layoutOptions = genericLayoutProviderSupplier.getLayoutOptions();
         for (LayoutOption layoutOption : layoutOptions.values()) {
             LayoutOption copy = EcoreUtil.copy(layoutOption);
-            if (copy instanceof EnumLayoutOption) {
-                ((EnumLayoutOption) copy).getChoices().clear();
+            if (copy instanceof EnumOption) {
+                ((EnumOption) copy).getChoices().clear();
             }
             newChildDescriptors.add(createChildParameter(org.eclipse.sirius.diagram.description.DescriptionPackage.Literals.CUSTOM_LAYOUT_CONFIGURATION__LAYOUT_OPTIONS, copy));
         }
diff --git a/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/internal/description/provider/DiagramDescriptionItemProviderSpec.java b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/internal/description/provider/DiagramDescriptionItemProviderSpec.java
index ea956fc897..00c0512509 100644
--- a/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/internal/description/provider/DiagramDescriptionItemProviderSpec.java
+++ b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/internal/description/provider/DiagramDescriptionItemProviderSpec.java
@@ -10,8 +10,11 @@
  *******************************************************************************/
 package org.eclipse.sirius.diagram.internal.description.provider;
 
+import java.util.Collection;
+
 import org.eclipse.emf.common.notify.AdapterFactory;
 import org.eclipse.sirius.common.tools.api.util.MessageTranslator;
+import org.eclipse.sirius.diagram.description.CustomLayoutConfiguration;
 import org.eclipse.sirius.diagram.description.provider.DiagramDescriptionItemProvider;
 import org.eclipse.sirius.viewpoint.description.IdentifiedElement;
 
@@ -35,11 +38,20 @@ public class DiagramDescriptionItemProviderSpec extends DiagramDescriptionItemPr
     /**
      * {@inheritDoc}
      * 
-     * This method has been overridden in order to return a localized text if
-     * available.
+     * This method has been overridden in order to return a localized text if available.
      */
+    @Override
     public String getText(Object object) {
         return MessageTranslator.INSTANCE.getMessage((IdentifiedElement) object, super.getText(object));
     }
 
+    @Override
+    public String getCreateChildText(Object owner, Object feature, Object child, Collection<?> selection) {
+        if (child instanceof CustomLayoutConfiguration) {
+            return ((CustomLayoutConfiguration) child).getLabel();
+        }
+
+        return super.getCreateChildText(owner, feature, child, selection);
+    }
+
 }
diff --git a/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/internal/description/provider/EnumLayoutOptionItemProviderSpec.java b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/internal/description/provider/EnumLayoutOptionItemProviderSpec.java
index 3bc0fd3def..eec6e228f6 100644
--- a/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/internal/description/provider/EnumLayoutOptionItemProviderSpec.java
+++ b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/internal/description/provider/EnumLayoutOptionItemProviderSpec.java
@@ -16,9 +16,9 @@ import java.util.Map;
 import org.eclipse.emf.common.notify.AdapterFactory;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.emf.ecore.util.EcoreUtil;
+import org.eclipse.sirius.diagram.description.CustomLayoutConfiguration;
 import org.eclipse.sirius.diagram.description.EnumLayoutOption;
 import org.eclipse.sirius.diagram.description.EnumLayoutValue;
-import org.eclipse.sirius.diagram.description.GenericLayout;
 import org.eclipse.sirius.diagram.description.LayoutOption;
 import org.eclipse.sirius.diagram.description.provider.EnumLayoutOptionItemProvider;
 import org.eclipse.sirius.diagram.ui.internal.layout.GenericLayoutProviderSupplier;
@@ -53,8 +53,8 @@ public class EnumLayoutOptionItemProviderSpec extends EnumLayoutOptionItemProvid
     protected void collectNewChildDescriptors(Collection<Object> newChildDescriptors, Object object) {
         Map<String, GenericLayoutProviderSupplier> layoutProviderRegistry = DiagramUIPlugin.getPlugin().getLayoutProviderRegistry();
         EnumLayoutOption layoutOption = (EnumLayoutOption) object;
-        GenericLayout layout = (GenericLayout) layoutOption.eContainer();
-        GenericLayoutProviderSupplier genericLayoutProviderSupplier = layoutProviderRegistry.get(layout.getID());
+        CustomLayoutConfiguration layout = (CustomLayoutConfiguration) layoutOption.eContainer();
+        GenericLayoutProviderSupplier genericLayoutProviderSupplier = layoutProviderRegistry.get(layout.getId());
         Map<String, LayoutOption> layoutOptions = genericLayoutProviderSupplier.getLayoutOptions();
         EnumLayoutOption layoutOptionTemplate = (EnumLayoutOption) layoutOptions.get(layoutOption.getId());
         EList<EnumLayoutValue> choices = layoutOptionTemplate.getChoices();
diff --git a/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/internal/description/provider/EnumSetLayoutOptionItemProviderSpec.java b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/internal/description/provider/EnumSetLayoutOptionItemProviderSpec.java
new file mode 100644
index 0000000000..93a05916d0
--- /dev/null
+++ b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/internal/description/provider/EnumSetLayoutOptionItemProviderSpec.java
@@ -0,0 +1,76 @@
+/*******************************************************************************
+ * Copyright (c) 2018 Obeo
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Obeo - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.sirius.diagram.internal.description.provider;
+
+import java.util.Collection;
+import java.util.Map;
+
+import org.eclipse.emf.common.notify.AdapterFactory;
+import org.eclipse.emf.common.util.EList;
+import org.eclipse.emf.ecore.util.EcoreUtil;
+import org.eclipse.sirius.diagram.description.CustomLayoutConfiguration;
+import org.eclipse.sirius.diagram.description.EnumLayoutOption;
+import org.eclipse.sirius.diagram.description.EnumLayoutValue;
+import org.eclipse.sirius.diagram.description.EnumSetLayoutOption;
+import org.eclipse.sirius.diagram.description.LayoutOption;
+import org.eclipse.sirius.diagram.description.provider.EnumSetLayoutOptionItemProvider;
+import org.eclipse.sirius.diagram.ui.internal.layout.GenericLayoutProviderSupplier;
+import org.eclipse.sirius.diagram.ui.provider.DiagramUIPlugin;
+
+/**
+ * Customize the label of {@link EnumLayoutOption} items in VSM editor. Also override child descriptor to propose
+ * available {@link EnumLayoutValue} with their attributes already filled.
+ * 
+ * @author <a href="mailto:pierre.guilet@obeo.fr">Pierre Guilet</a>
+ *
+ */
+public class EnumSetLayoutOptionItemProviderSpec extends EnumSetLayoutOptionItemProvider {
+
+    /**
+     * Default constructor.
+     * 
+     * @param adapterFactory
+     *            factory to use.
+     */
+    public EnumSetLayoutOptionItemProviderSpec(AdapterFactory adapterFactory) {
+        super(adapterFactory);
+    }
+
+    @Override
+    public String getText(Object object) {
+        LayoutOption layout = (LayoutOption) object;
+        return layout.getLabel();
+    }
+
+    @Override
+    protected void collectNewChildDescriptors(Collection<Object> newChildDescriptors, Object object) {
+        Map<String, GenericLayoutProviderSupplier> layoutProviderRegistry = DiagramUIPlugin.getPlugin().getLayoutProviderRegistry();
+        EnumSetLayoutOption layoutOption = (EnumSetLayoutOption) object;
+        CustomLayoutConfiguration layout = (CustomLayoutConfiguration) layoutOption.eContainer();
+        GenericLayoutProviderSupplier genericLayoutProviderSupplier = layoutProviderRegistry.get(layout.getId());
+        Map<String, LayoutOption> layoutOptions = genericLayoutProviderSupplier.getLayoutOptions();
+        EnumSetLayoutOption layoutOptionTemplate = (EnumSetLayoutOption) layoutOptions.get(layoutOption.getId());
+        EList<EnumLayoutValue> choices = layoutOptionTemplate.getChoices();
+        for (EnumLayoutValue enumLayoutValue : choices) {
+            newChildDescriptors.add(createChildParameter(org.eclipse.sirius.diagram.description.DescriptionPackage.Literals.ENUM_SET_LAYOUT_OPTION__VALUES, EcoreUtil.copy(enumLayoutValue)));
+        }
+    }
+
+    @Override
+    public String getCreateChildText(Object owner, Object feature, Object child, Collection<?> selection) {
+        if (child instanceof EnumLayoutValue) {
+            return ((EnumLayoutValue) child).getName();
+        }
+
+        return super.getCreateChildText(owner, feature, child, selection);
+    }
+
+}
diff --git a/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/CustomLayoutConfigurationItemProvider.java b/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/CustomLayoutConfigurationItemProvider.java
index 82b28f5c05..edf148ea81 100644
--- a/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/CustomLayoutConfigurationItemProvider.java
+++ b/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/CustomLayoutConfigurationItemProvider.java
@@ -192,6 +192,8 @@ public class CustomLayoutConfigurationItemProvider extends DocumentedElementItem
         newChildDescriptors.add(createChildParameter(DescriptionPackage.Literals.CUSTOM_LAYOUT_CONFIGURATION__LAYOUT_OPTIONS, DescriptionFactory.eINSTANCE.createDoubleLayoutOption()));
 
         newChildDescriptors.add(createChildParameter(DescriptionPackage.Literals.CUSTOM_LAYOUT_CONFIGURATION__LAYOUT_OPTIONS, DescriptionFactory.eINSTANCE.createEnumLayoutOption()));
+
+        newChildDescriptors.add(createChildParameter(DescriptionPackage.Literals.CUSTOM_LAYOUT_CONFIGURATION__LAYOUT_OPTIONS, DescriptionFactory.eINSTANCE.createEnumSetLayoutOption()));
     }
 
     /**
diff --git a/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/DescriptionItemProviderAdapterFactory.java b/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/DescriptionItemProviderAdapterFactory.java
index 1cf9ebb889..dba1c65e73 100644
--- a/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/DescriptionItemProviderAdapterFactory.java
+++ b/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/DescriptionItemProviderAdapterFactory.java
@@ -44,6 +44,7 @@ import org.eclipse.sirius.diagram.internal.description.provider.DiagramDescripti
 import org.eclipse.sirius.diagram.internal.description.provider.DoubleLayoutOptionItemProviderSpec;
 import org.eclipse.sirius.diagram.internal.description.provider.EnumLayoutOptionItemProviderSpec;
 import org.eclipse.sirius.diagram.internal.description.provider.EnumLayoutValueItemProviderSpec;
+import org.eclipse.sirius.diagram.internal.description.provider.EnumSetLayoutOptionItemProviderSpec;
 import org.eclipse.sirius.diagram.internal.description.provider.IntegerLayoutOptionItemProviderSpec;
 import org.eclipse.sirius.diagram.internal.description.provider.StringLayoutOptionItemProviderSpec;
 import org.eclipse.sirius.diagram.ui.provider.DiagramUIPlugin;
@@ -573,6 +574,30 @@ public class DescriptionItemProviderAdapterFactory extends DescriptionAdapterFac
     }
 
     /**
+     * This keeps track of the one adapter used for all
+     * {@link org.eclipse.sirius.diagram.description.EnumSetLayoutOption} instances. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @generated
+     */
+    protected EnumSetLayoutOptionItemProvider enumSetLayoutOptionItemProvider;
+
+    /**
+     * This creates an adapter for a {@link org.eclipse.sirius.diagram.description.EnumSetLayoutOption}. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated NOT
+     */
+    @Override
+    public Adapter createEnumSetLayoutOptionAdapter() {
+        if (enumSetLayoutOptionItemProvider == null) {
+            enumSetLayoutOptionItemProvider = new EnumSetLayoutOptionItemProviderSpec(this);
+        }
+
+        return enumSetLayoutOptionItemProvider;
+    }
+
+    /**
      * This keeps track of the one adapter used for all {@link org.eclipse.sirius.diagram.description.EnumLayoutValue}
      * instances. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
@@ -825,6 +850,9 @@ public class DescriptionItemProviderAdapterFactory extends DescriptionAdapterFac
         if (enumLayoutOptionItemProvider != null) {
             enumLayoutOptionItemProvider.dispose();
         }
+        if (enumSetLayoutOptionItemProvider != null) {
+            enumSetLayoutOptionItemProvider.dispose();
+        }
         if (enumLayoutValueItemProvider != null) {
             enumLayoutValueItemProvider.dispose();
         }
diff --git a/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/DiagramDescriptionItemProvider.java b/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/DiagramDescriptionItemProvider.java
index 22630c62a6..c1999d0dde 100644
--- a/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/DiagramDescriptionItemProvider.java
+++ b/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/DiagramDescriptionItemProvider.java
@@ -31,7 +31,6 @@ import org.eclipse.sirius.diagram.description.CustomLayoutConfiguration;
 import org.eclipse.sirius.diagram.description.DescriptionFactory;
 import org.eclipse.sirius.diagram.description.DiagramDescription;
 import org.eclipse.sirius.diagram.description.EdgeMapping;
-import org.eclipse.sirius.diagram.description.GenericLayout;
 import org.eclipse.sirius.diagram.description.Layer;
 import org.eclipse.sirius.diagram.description.concern.ConcernFactory;
 import org.eclipse.sirius.diagram.description.concern.ConcernSet;
@@ -544,9 +543,6 @@ public class DiagramDescriptionItemProvider extends DragAndDropTargetDescription
         concernSet.getOwnedConcernDescriptions().add(ConcernFactory.eINSTANCE.createConcernDescription());
         newChildDescriptors.add(createChildParameter(org.eclipse.sirius.diagram.description.DescriptionPackage.Literals.DIAGRAM_DESCRIPTION__CONCERNS, concernSet));
 
-        newChildDescriptors.add(
-                createChildParameter(org.eclipse.sirius.diagram.description.DescriptionPackage.Literals.DIAGRAM_DESCRIPTION__LAYOUT, DescriptionFactory.eINSTANCE.createCustomLayoutConfiguration()));
-        addAllCustomLayoutChildDescriptors(newChildDescriptors);
         newChildDescriptors
                 .add(createChildParameter(org.eclipse.sirius.diagram.description.DescriptionPackage.Literals.DIAGRAM_DESCRIPTION__LAYOUT, DescriptionFactory.eINSTANCE.createOrderedTreeLayout()));
 
@@ -617,7 +613,7 @@ public class DiagramDescriptionItemProvider extends DragAndDropTargetDescription
 
         newChildDescriptors.add(
                 createChildParameter(org.eclipse.sirius.diagram.description.DescriptionPackage.Literals.DIAGRAM_DESCRIPTION__LAYOUT, DescriptionFactory.eINSTANCE.createCustomLayoutConfiguration()));
-
+        addAllCustomLayoutChildDescriptors(newChildDescriptors);
         newChildDescriptors.add(
                 createChildParameter(org.eclipse.sirius.diagram.description.DescriptionPackage.Literals.DIAGRAM_DESCRIPTION__DIAGRAM_INITIALISATION, ToolFactory.eINSTANCE.createInitialOperation()));
 
@@ -684,8 +680,8 @@ public class DiagramDescriptionItemProvider extends DragAndDropTargetDescription
             // child type currently available for is Layer (see
             // collectNewChildDescriptors).
             return getString("_UI_CreateChild_text2", new Object[] { getTypeText(child), "Default", getTypeText(owner) }); //$NON-NLS-1$ //$NON-NLS-2$
-        } else if (child instanceof GenericLayout) {
-            return ((GenericLayout) child).getLabel();
+        } else if (child instanceof CustomLayoutConfiguration) {
+            return ((CustomLayoutConfiguration) child).getLabel();
         }
         String createChildText = super.getCreateChildText(owner, feature, child, selection);
         if (child != null && isNormalEdgeMapping(child)) {
diff --git a/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/EnumLayoutOptionItemProvider.java b/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/EnumLayoutOptionItemProvider.java
index bad6d3dd70..914c835b45 100644
--- a/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/EnumLayoutOptionItemProvider.java
+++ b/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/EnumLayoutOptionItemProvider.java
@@ -29,7 +29,7 @@ import org.eclipse.sirius.diagram.description.EnumLayoutOption;
  *
  * @generated
  */
-public class EnumLayoutOptionItemProvider extends LayoutOptionItemProvider {
+public class EnumLayoutOptionItemProvider extends EnumOptionItemProvider {
     /**
      * This constructs an instance from a factory and a notifier. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
@@ -66,7 +66,6 @@ public class EnumLayoutOptionItemProvider extends LayoutOptionItemProvider {
         if (childrenFeatures == null) {
             super.getChildrenFeatures(object);
             childrenFeatures.add(DescriptionPackage.Literals.ENUM_LAYOUT_OPTION__VALUE);
-            childrenFeatures.add(DescriptionPackage.Literals.ENUM_LAYOUT_OPTION__CHOICES);
         }
         return childrenFeatures;
     }
@@ -109,7 +108,6 @@ public class EnumLayoutOptionItemProvider extends LayoutOptionItemProvider {
 
         switch (notification.getFeatureID(EnumLayoutOption.class)) {
         case DescriptionPackage.ENUM_LAYOUT_OPTION__VALUE:
-        case DescriptionPackage.ENUM_LAYOUT_OPTION__CHOICES:
             fireNotifyChanged(new ViewerNotification(notification, notification.getNotifier(), true, false));
             return;
         }
@@ -127,8 +125,6 @@ public class EnumLayoutOptionItemProvider extends LayoutOptionItemProvider {
         super.collectNewChildDescriptors(newChildDescriptors, object);
 
         newChildDescriptors.add(createChildParameter(DescriptionPackage.Literals.ENUM_LAYOUT_OPTION__VALUE, DescriptionFactory.eINSTANCE.createEnumLayoutValue()));
-
-        newChildDescriptors.add(createChildParameter(DescriptionPackage.Literals.ENUM_LAYOUT_OPTION__CHOICES, DescriptionFactory.eINSTANCE.createEnumLayoutValue()));
     }
 
     /**
@@ -142,7 +138,7 @@ public class EnumLayoutOptionItemProvider extends LayoutOptionItemProvider {
         Object childFeature = feature;
         Object childObject = child;
 
-        boolean qualify = childFeature == DescriptionPackage.Literals.ENUM_LAYOUT_OPTION__VALUE || childFeature == DescriptionPackage.Literals.ENUM_LAYOUT_OPTION__CHOICES;
+        boolean qualify = childFeature == DescriptionPackage.Literals.ENUM_OPTION__CHOICES || childFeature == DescriptionPackage.Literals.ENUM_LAYOUT_OPTION__VALUE;
 
         if (qualify) {
             return getString("_UI_CreateChild_text2", //$NON-NLS-1$
diff --git a/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/EnumOptionItemProvider.java b/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/EnumOptionItemProvider.java
new file mode 100644
index 0000000000..e857935a9e
--- /dev/null
+++ b/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/EnumOptionItemProvider.java
@@ -0,0 +1,130 @@
+/**
+ * Copyright (c) 2007, 2017 THALES GLOBAL SERVICES.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Obeo - initial API and implementation
+ *
+ */
+package org.eclipse.sirius.diagram.description.provider;
+
+import java.util.Collection;
+import java.util.List;
+
+import org.eclipse.emf.common.notify.AdapterFactory;
+import org.eclipse.emf.common.notify.Notification;
+import org.eclipse.emf.ecore.EStructuralFeature;
+import org.eclipse.emf.edit.provider.IItemPropertyDescriptor;
+import org.eclipse.emf.edit.provider.ViewerNotification;
+import org.eclipse.sirius.diagram.description.DescriptionFactory;
+import org.eclipse.sirius.diagram.description.DescriptionPackage;
+import org.eclipse.sirius.diagram.description.EnumOption;
+
+/**
+ * This is the item provider adapter for a {@link org.eclipse.sirius.diagram.description.EnumOption} object. <!--
+ * begin-user-doc --> <!-- end-user-doc -->
+ *
+ * @generated
+ */
+public class EnumOptionItemProvider extends LayoutOptionItemProvider {
+    /**
+     * This constructs an instance from a factory and a notifier. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    public EnumOptionItemProvider(AdapterFactory adapterFactory) {
+        super(adapterFactory);
+    }
+
+    /**
+     * This returns the property descriptors for the adapted class. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public List<IItemPropertyDescriptor> getPropertyDescriptors(Object object) {
+        if (itemPropertyDescriptors == null) {
+            super.getPropertyDescriptors(object);
+
+        }
+        return itemPropertyDescriptors;
+    }
+
+    /**
+     * This specifies how to implement {@link #getChildren} and is used to deduce an appropriate feature for an
+     * {@link org.eclipse.emf.edit.command.AddCommand}, {@link org.eclipse.emf.edit.command.RemoveCommand} or
+     * {@link org.eclipse.emf.edit.command.MoveCommand} in {@link #createCommand}. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public Collection<? extends EStructuralFeature> getChildrenFeatures(Object object) {
+        if (childrenFeatures == null) {
+            super.getChildrenFeatures(object);
+            childrenFeatures.add(DescriptionPackage.Literals.ENUM_OPTION__CHOICES);
+        }
+        return childrenFeatures;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    protected EStructuralFeature getChildFeature(Object object, Object child) {
+        // Check the type of the specified child object and return the proper feature to use for
+        // adding (see {@link AddCommand}) it as a child.
+
+        return super.getChildFeature(object, child);
+    }
+
+    /**
+     * This returns the label text for the adapted class. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public String getText(Object object) {
+        String label = ((EnumOption) object).getId();
+        return label == null || label.length() == 0 ? getString("_UI_EnumOption_type") : //$NON-NLS-1$
+                getString("_UI_EnumOption_type") + " " + label; //$NON-NLS-1$ //$NON-NLS-2$
+    }
+
+    /**
+     * This handles model notifications by calling {@link #updateChildren} to update any cached children and by creating
+     * a viewer notification, which it passes to {@link #fireNotifyChanged}. <!-- begin-user-doc --> <!-- end-user-doc
+     * -->
+     *
+     * @generated
+     */
+    @Override
+    public void notifyChanged(Notification notification) {
+        updateChildren(notification);
+
+        switch (notification.getFeatureID(EnumOption.class)) {
+        case DescriptionPackage.ENUM_OPTION__CHOICES:
+            fireNotifyChanged(new ViewerNotification(notification, notification.getNotifier(), true, false));
+            return;
+        }
+        super.notifyChanged(notification);
+    }
+
+    /**
+     * This adds {@link org.eclipse.emf.edit.command.CommandParameter}s describing the children that can be created
+     * under this object. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    protected void collectNewChildDescriptors(Collection<Object> newChildDescriptors, Object object) {
+        super.collectNewChildDescriptors(newChildDescriptors, object);
+
+        newChildDescriptors.add(createChildParameter(DescriptionPackage.Literals.ENUM_OPTION__CHOICES, DescriptionFactory.eINSTANCE.createEnumLayoutValue()));
+    }
+
+}
diff --git a/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/EnumSetLayoutOptionItemProvider.java b/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/EnumSetLayoutOptionItemProvider.java
new file mode 100644
index 0000000000..77a770edcc
--- /dev/null
+++ b/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/description/provider/EnumSetLayoutOptionItemProvider.java
@@ -0,0 +1,150 @@
+/**
+ * Copyright (c) 2007, 2017 THALES GLOBAL SERVICES.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Obeo - initial API and implementation
+ *
+ */
+package org.eclipse.sirius.diagram.description.provider;
+
+import java.util.Collection;
+import java.util.List;
+
+import org.eclipse.emf.common.notify.AdapterFactory;
+import org.eclipse.emf.common.notify.Notification;
+import org.eclipse.emf.ecore.EStructuralFeature;
+import org.eclipse.emf.edit.provider.IItemPropertyDescriptor;
+import org.eclipse.emf.edit.provider.ViewerNotification;
+import org.eclipse.sirius.diagram.description.DescriptionFactory;
+import org.eclipse.sirius.diagram.description.DescriptionPackage;
+import org.eclipse.sirius.diagram.description.EnumSetLayoutOption;
+
+/**
+ * This is the item provider adapter for a {@link org.eclipse.sirius.diagram.description.EnumSetLayoutOption} object.
+ * <!-- begin-user-doc --> <!-- end-user-doc -->
+ *
+ * @generated
+ */
+public class EnumSetLayoutOptionItemProvider extends EnumOptionItemProvider {
+    /**
+     * This constructs an instance from a factory and a notifier. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    public EnumSetLayoutOptionItemProvider(AdapterFactory adapterFactory) {
+        super(adapterFactory);
+    }
+
+    /**
+     * This returns the property descriptors for the adapted class. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public List<IItemPropertyDescriptor> getPropertyDescriptors(Object object) {
+        if (itemPropertyDescriptors == null) {
+            super.getPropertyDescriptors(object);
+
+        }
+        return itemPropertyDescriptors;
+    }
+
+    /**
+     * This specifies how to implement {@link #getChildren} and is used to deduce an appropriate feature for an
+     * {@link org.eclipse.emf.edit.command.AddCommand}, {@link org.eclipse.emf.edit.command.RemoveCommand} or
+     * {@link org.eclipse.emf.edit.command.MoveCommand} in {@link #createCommand}. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public Collection<? extends EStructuralFeature> getChildrenFeatures(Object object) {
+        if (childrenFeatures == null) {
+            super.getChildrenFeatures(object);
+            childrenFeatures.add(DescriptionPackage.Literals.ENUM_SET_LAYOUT_OPTION__VALUES);
+        }
+        return childrenFeatures;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    protected EStructuralFeature getChildFeature(Object object, Object child) {
+        // Check the type of the specified child object and return the proper feature to use for
+        // adding (see {@link AddCommand}) it as a child.
+
+        return super.getChildFeature(object, child);
+    }
+
+    /**
+     * This returns the label text for the adapted class. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public String getText(Object object) {
+        String label = ((EnumSetLayoutOption) object).getId();
+        return label == null || label.length() == 0 ? getString("_UI_EnumSetLayoutOption_type") : //$NON-NLS-1$
+                getString("_UI_EnumSetLayoutOption_type") + " " + label; //$NON-NLS-1$ //$NON-NLS-2$
+    }
+
+    /**
+     * This handles model notifications by calling {@link #updateChildren} to update any cached children and by creating
+     * a viewer notification, which it passes to {@link #fireNotifyChanged}. <!-- begin-user-doc --> <!-- end-user-doc
+     * -->
+     *
+     * @generated
+     */
+    @Override
+    public void notifyChanged(Notification notification) {
+        updateChildren(notification);
+
+        switch (notification.getFeatureID(EnumSetLayoutOption.class)) {
+        case DescriptionPackage.ENUM_SET_LAYOUT_OPTION__VALUES:
+            fireNotifyChanged(new ViewerNotification(notification, notification.getNotifier(), true, false));
+            return;
+        }
+        super.notifyChanged(notification);
+    }
+
+    /**
+     * This adds {@link org.eclipse.emf.edit.command.CommandParameter}s describing the children that can be created
+     * under this object. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    protected void collectNewChildDescriptors(Collection<Object> newChildDescriptors, Object object) {
+        super.collectNewChildDescriptors(newChildDescriptors, object);
+
+        newChildDescriptors.add(createChildParameter(DescriptionPackage.Literals.ENUM_SET_LAYOUT_OPTION__VALUES, DescriptionFactory.eINSTANCE.createEnumLayoutValue()));
+    }
+
+    /**
+     * This returns the label text for {@link org.eclipse.emf.edit.command.CreateChildCommand}. <!-- begin-user-doc -->
+     * <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public String getCreateChildText(Object owner, Object feature, Object child, Collection<?> selection) {
+        Object childFeature = feature;
+        Object childObject = child;
+
+        boolean qualify = childFeature == DescriptionPackage.Literals.ENUM_OPTION__CHOICES || childFeature == DescriptionPackage.Literals.ENUM_SET_LAYOUT_OPTION__VALUES;
+
+        if (qualify) {
+            return getString("_UI_CreateChild_text2", //$NON-NLS-1$
+                    new Object[] { getTypeText(childObject), getFeatureText(childFeature), getTypeText(owner) });
+        }
+        return super.getCreateChildText(owner, feature, child, selection);
+    }
+
+}
diff --git a/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/ui/provider/DiagramUIPlugin.java b/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/ui/provider/DiagramUIPlugin.java
index 799061c050..6b3cfd7138 100644
--- a/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/ui/provider/DiagramUIPlugin.java
+++ b/plugins/org.eclipse.sirius.diagram.ui/src-gen/org/eclipse/sirius/diagram/ui/provider/DiagramUIPlugin.java
@@ -157,7 +157,8 @@ public final class DiagramUIPlugin extends EMFPlugin {
         private DynamicDiagramUIPreferences dynamicPreferences;
 
         /**
-         * A registry containing all layout providers that can be specified directly in the VSM.
+         * A registry containing all layout providers that can be specified directly in the VSM. A layout provider
+         * provides a layout algorithm that can be used when doing an arrange all on a Sirius diagram.
          */
         private Map<String, GenericLayoutProviderSupplier> layoutProviderRegistry;
 
diff --git a/plugins/org.eclipse.sirius.diagram.ui/src/org/eclipse/sirius/diagram/ui/api/layout/EnumChoice.java b/plugins/org.eclipse.sirius.diagram.ui/src/org/eclipse/sirius/diagram/ui/api/layout/EnumChoice.java
new file mode 100644
index 0000000000..9d97b77b82
--- /dev/null
+++ b/plugins/org.eclipse.sirius.diagram.ui/src/org/eclipse/sirius/diagram/ui/api/layout/EnumChoice.java
@@ -0,0 +1,63 @@
+/*******************************************************************************
+ * Copyright (c) 2018 Obeo
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Obeo - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.sirius.diagram.ui.api.layout;
+
+/**
+ * 
+ * A component defining an Enum choice with its name and a description. It is used to provide Enum choice for an enum
+ * option of a layout algorithm in VSM editor.
+ * 
+ * @author <a href="mailto:pierre.guilet@obeo.fr">Pierre Guilet</a>
+ *
+ */
+public class EnumChoice {
+    /**
+     * The name of the enum choice.
+     */
+    private String name;
+
+    /**
+     * The description of the enum choice.
+     */
+    private String description;
+
+    /**
+     * Initialize this Enum choice with given name and description.
+     * 
+     * @param name
+     *            the name of this enum choice.
+     * @param description
+     *            the description of this enum choice.
+     */
+    public EnumChoice(String name, String description) {
+        this.name = name;
+        this.description = description;
+    }
+
+    /**
+     * Returns the description of the enum choice.
+     * 
+     * @return the description of the enum choice.
+     */
+    public String getDescription() {
+        return description;
+    }
+
+    /**
+     * Returns the name of the enum choice.
+     * 
+     * @return the name of the enum choice.
+     */
+    public String getName() {
+        return name;
+    }
+
+}
diff --git a/plugins/org.eclipse.sirius.diagram.ui/src/org/eclipse/sirius/diagram/ui/api/layout/LayoutOptionFactory.java b/plugins/org.eclipse.sirius.diagram.ui/src/org/eclipse/sirius/diagram/ui/api/layout/LayoutOptionFactory.java
new file mode 100644
index 0000000000..029c651b6d
--- /dev/null
+++ b/plugins/org.eclipse.sirius.diagram.ui/src/org/eclipse/sirius/diagram/ui/api/layout/LayoutOptionFactory.java
@@ -0,0 +1,210 @@
+/*******************************************************************************
+ * Copyright (c) 2018 Obeo
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Obeo - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.sirius.diagram.ui.api.layout;
+
+import java.util.List;
+
+import org.eclipse.emf.ecore.util.EcoreUtil;
+import org.eclipse.sirius.diagram.description.BooleanLayoutOption;
+import org.eclipse.sirius.diagram.description.DescriptionFactory;
+import org.eclipse.sirius.diagram.description.DescriptionPackage;
+import org.eclipse.sirius.diagram.description.DoubleLayoutOption;
+import org.eclipse.sirius.diagram.description.EnumLayoutOption;
+import org.eclipse.sirius.diagram.description.EnumLayoutValue;
+import org.eclipse.sirius.diagram.description.EnumOption;
+import org.eclipse.sirius.diagram.description.IntegerLayoutOption;
+import org.eclipse.sirius.diagram.description.LayoutOption;
+import org.eclipse.sirius.diagram.description.StringLayoutOption;
+
+/**
+ * This factory allows to create layout algorithm options that should be available for edition in the VSM editor. You
+ * can specify its id, description. The label that should be used to display your option in UI. And the default value.
+ * Option types supported are String, Boolean, Integer, Double and Enum. For Enum you must specify available
+ * choices/literal.
+ * 
+ * @author <a href="mailto:pierre.guilet@obeo.fr">Pierre Guilet</a>
+ *
+ */
+public class LayoutOptionFactory {
+    /**
+     * Returns a new layout option with the type EnumSet.
+     * 
+     * @param choices
+     *            a list of {@link EnumChoice} that will be proposed to the VSM specifier to configure an enum option of
+     *            a layout algorithm.
+     * @param id
+     *            the enumset option id allowing to identified it from other options.
+     * @param description
+     *            a description of the option.
+     * @param label
+     *            a label used in Sirius UI to represent the option.
+     * @return a new layout option with the type Enum.
+     */
+    public LayoutOption createEnumSetOption(List<EnumChoice> choices, String id, String description, String label) {
+        EnumOption layoutOption = DescriptionFactory.eINSTANCE.createEnumSetLayoutOption();
+        layoutOption.setDescription(description);
+        layoutOption.setLabel(label);
+        layoutOption.setId(id);
+
+        for (EnumChoice enumChoice : choices) {
+            EnumLayoutValue layoutValue = DescriptionFactory.eINSTANCE.createEnumLayoutValue();
+            layoutValue.setDescription(enumChoice.getDescription());
+            layoutValue.setName(enumChoice.getName());
+            layoutOption.setDescription(description);
+            layoutOption.getChoices().add(layoutValue);
+        }
+        return layoutOption;
+    }
+
+    /**
+     * Returns a new layout option with the type Enum.
+     * 
+     * @param choices
+     *            a list of {@link EnumChoice} that will be proposed to the VSM specifier to configure an enum option of
+     *            a layout algorithm.
+     * @param id
+     *            the enum option id allowing to identified it from other options.
+     * @param description
+     *            a description of the option.
+     * @param label
+     *            a label used in Sirius UI to represent the option.
+     * @param defaultValue
+     *            the default option's value of the layout algorithm.
+     * @return a new layout option with the type Enum.
+     */
+    public LayoutOption createEnumOption(List<EnumChoice> choices, String id, String description, String label, String defaultValue) {
+        EnumLayoutOption layoutOption = DescriptionFactory.eINSTANCE.createEnumLayoutOption();
+        layoutOption.setDescription(description);
+        layoutOption.setLabel(label);
+        layoutOption.setId(id);
+
+        for (EnumChoice enumChoice : choices) {
+            EnumLayoutValue layoutValue = DescriptionFactory.eINSTANCE.createEnumLayoutValue();
+            layoutValue.setDescription(enumChoice.getDescription());
+            layoutValue.setName(enumChoice.getName());
+            layoutOption.setDescription(description);
+            layoutOption.getChoices().add(layoutValue);
+            if (enumChoice.getName().equals(defaultValue)) {
+                layoutOption.setValue(layoutValue);
+            }
+        }
+
+        return layoutOption;
+    }
+
+    /**
+     * Returns a new layout option with the type String.
+     * 
+     * @param defaultValue
+     *            the default option's value of the layout algorithm.
+     * @param id
+     *            the option's id allowing to identified it from other options.
+     * @param description
+     *            a description of the option.
+     * @param label
+     *            a label used in Sirius UI to represent the option.
+     * @return a new layout option with the type String.
+     */
+    public LayoutOption createStringOption(String defaultValue, String id, String description, String label) {
+        StringLayoutOption layoutOption = DescriptionFactory.eINSTANCE.createStringLayoutOption();
+        setCommonAttributes(id, description, label, layoutOption);
+        if (defaultValue != null) {
+            layoutOption.setValue(defaultValue);
+        }
+        return layoutOption;
+    }
+
+    /**
+     * Returns a new layout option with the type Integer.
+     * 
+     * @param defaultValue
+     *            the default option's value of the layout algorithm.
+     * @param id
+     *            the option's id allowing to identified it from other options.
+     * @param description
+     *            a description of the option.
+     * @param label
+     *            a label used in Sirius UI to represent the option.
+     * @return a new layout option with the type Integer.
+     */
+    public LayoutOption createIntegerOption(Integer defaultValue, String id, String description, String label) {
+        IntegerLayoutOption layoutOption = DescriptionFactory.eINSTANCE.createIntegerLayoutOption();
+        setCommonAttributes(id, description, label, layoutOption);
+        if (defaultValue != null) {
+            layoutOption.setValue(defaultValue);
+        }
+        return layoutOption;
+    }
+
+    /**
+     * Returns a new layout option with the type Double.
+     * 
+     * @param defaultValue
+     *            the default option's value of the layout algorithm.
+     * @param id
+     *            the option's id allowing to identified it from other options.
+     * @param description
+     *            a description of the option.
+     * @param label
+     *            a label used in Sirius UI to represent the option.
+     * @return a new layout option with the type Double.
+     */
+    public LayoutOption createDoubleOption(Double defaultValue, String id, String description, String label) {
+
+        DoubleLayoutOption layoutOption = DescriptionFactory.eINSTANCE.createDoubleLayoutOption();
+        setCommonAttributes(id, description, label, layoutOption);
+        if (defaultValue != null) {
+            layoutOption.setValue(defaultValue);
+        }
+        return layoutOption;
+    }
+
+    /**
+     * Method to set commons attributes of different options.
+     * 
+     * @param id
+     *            the id to set.
+     * @param descriptionthe
+     *            description to set.
+     * @param label
+     *            the label to set.
+     * @param layoutOption
+     *            the options that needs to have its attributes set.
+     */
+    private void setCommonAttributes(String id, String description, String label, LayoutOption layoutOption) {
+        layoutOption.setId(id);
+        layoutOption.setLabel(label);
+        layoutOption.setDescription(description);
+    }
+
+    /**
+     * Returns a new layout option with the type Boolean.
+     * 
+     * @param defaultValue
+     *            the default option's value of the layout algorithm.
+     * @param id
+     *            the option's id allowing to identified it from other options.
+     * @param description
+     *            a description of the option.
+     * @param label
+     *            a label used in Sirius UI to represent the option.
+     * @return a new layout option with the type Boolean.
+     */
+    public LayoutOption createBooleanOption(Boolean defaultValue, String id, String description, String label) {
+        BooleanLayoutOption layoutOption = (BooleanLayoutOption) EcoreUtil.create(DescriptionPackage.eINSTANCE.getBooleanLayoutOption());
+        setCommonAttributes(id, description, label, layoutOption);
+        if (defaultValue != null) {
+            layoutOption.setValue(defaultValue);
+        }
+        return layoutOption;
+    }
+
+}
diff --git a/plugins/org.eclipse.sirius.diagram.ui/src/org/eclipse/sirius/diagram/ui/business/api/query/EditPartQuery.java b/plugins/org.eclipse.sirius.diagram.ui/src/org/eclipse/sirius/diagram/ui/business/api/query/EditPartQuery.java
new file mode 100644
index 0000000000..1bc398a300
--- /dev/null
+++ b/plugins/org.eclipse.sirius.diagram.ui/src/org/eclipse/sirius/diagram/ui/business/api/query/EditPartQuery.java
@@ -0,0 +1,82 @@
+/*******************************************************************************
+ * Copyright (c) 2018 Obeo
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Obeo - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.sirius.diagram.ui.business.api.query;
+
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.gef.EditPart;
+import org.eclipse.gmf.runtime.diagram.ui.editparts.IGraphicalEditPart;
+import org.eclipse.sirius.diagram.DDiagram;
+import org.eclipse.sirius.diagram.description.DiagramDescription;
+import org.eclipse.sirius.diagram.ui.edit.api.part.IDDiagramEditPart;
+import org.eclipse.sirius.diagram.ui.edit.api.part.IDiagramElementEditPart;
+
+/**
+ * A class aggregating all the queries (read-only!) having an {@link IGraphicalEditPart} as a starting point.
+ * 
+ * @author <a href="mailto:pierre.guilet@obeo.fr">Pierre Guilet</a>
+ *
+ */
+public final class EditPartQuery {
+
+    private IGraphicalEditPart editPart;
+
+    /**
+     * Create a new query.
+     * 
+     * @param editPart
+     *            the {@link IGraphicalEditPart} to query.
+     */
+    public EditPartQuery(IGraphicalEditPart editPart) {
+        this.editPart = editPart;
+    }
+
+    /**
+     * Return the {@link DiagramDescription} associated to the edit part or to one of its ancestor.
+     * 
+     * @return the {@link DiagramDescription} associated to the edit part or to one of its ancestor. Null if no such
+     *         element exists.
+     */
+    public DiagramDescription getDiagramDescription() {
+        IDDiagramEditPart effectiveDiagramEditPart = null;
+        if (editPart instanceof IDiagramElementEditPart) {
+            effectiveDiagramEditPart = getDiagramEditPart(editPart);
+        } else if (editPart instanceof IDDiagramEditPart) {
+            effectiveDiagramEditPart = (IDDiagramEditPart) editPart;
+        }
+        if (effectiveDiagramEditPart != null) {
+            EObject resolvedSemanticElement = effectiveDiagramEditPart.resolveSemanticElement();
+            if (resolvedSemanticElement instanceof DDiagram) {
+                return ((DDiagram) resolvedSemanticElement).getDescription();
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * Returns the {@link IDDiagramEditPart} that is an ancestor of the given {@link EditPart}.
+     * 
+     * @param editPart
+     *            the edit part from which we look for an {@link IDDiagramEditPart} ancestor.
+     * @return the {@link IDDiagramEditPart} that is an ancestor of the given {@link EditPart}. Null if no such element
+     *         exists.
+     */
+    private IDDiagramEditPart getDiagramEditPart(EditPart theEditPart) {
+        IDDiagramEditPart result = null;
+        EditPart parent = theEditPart.getParent();
+        if (parent instanceof IDDiagramEditPart) {
+            result = (IDDiagramEditPart) parent;
+        } else if (parent != null) {
+            result = getDiagramEditPart(parent);
+        }
+        return result;
+    }
+}
diff --git a/plugins/org.eclipse.sirius.diagram.ui/src/org/eclipse/sirius/diagram/ui/internal/layout/GenericLayoutProvider.java b/plugins/org.eclipse.sirius.diagram.ui/src/org/eclipse/sirius/diagram/ui/internal/layout/GenericLayoutProvider.java
index ed89f9eab2..fe543cdf35 100644
--- a/plugins/org.eclipse.sirius.diagram.ui/src/org/eclipse/sirius/diagram/ui/internal/layout/GenericLayoutProvider.java
+++ b/plugins/org.eclipse.sirius.diagram.ui/src/org/eclipse/sirius/diagram/ui/internal/layout/GenericLayoutProvider.java
@@ -18,8 +18,8 @@ import org.eclipse.gmf.runtime.diagram.ui.services.layout.AbstractLayoutEditPart
 import org.eclipse.gmf.runtime.notation.Diagram;
 import org.eclipse.gmf.runtime.notation.View;
 import org.eclipse.sirius.diagram.DDiagram;
+import org.eclipse.sirius.diagram.description.CustomLayoutConfiguration;
 import org.eclipse.sirius.diagram.description.DiagramDescription;
-import org.eclipse.sirius.diagram.description.GenericLayout;
 import org.eclipse.sirius.diagram.description.Layout;
 import org.eclipse.sirius.diagram.ui.provider.DiagramUIPlugin;
 import org.eclipse.sirius.diagram.ui.tools.api.layout.provider.DefaultLayoutProvider;
@@ -70,8 +70,8 @@ public class GenericLayoutProvider implements LayoutProvider {
             final DiagramDescription desc = vp.getDescription();
             if (desc != null) {
                 final Layout layout = desc.getLayout();
-                if (layout instanceof GenericLayout) {
-                    return DiagramUIPlugin.getPlugin().getLayoutProviderRegistry().get(((GenericLayout) layout).getID()).getLayoutProviderSupplier();
+                if (layout instanceof CustomLayoutConfiguration) {
+                    return DiagramUIPlugin.getPlugin().getLayoutProviderRegistry().get(((CustomLayoutConfiguration) layout).getId()).getLayoutProviderSupplier();
                 }
             }
         }
diff --git a/plugins/org.eclipse.sirius.diagram/model/diagram.ecore b/plugins/org.eclipse.sirius.diagram/model/diagram.ecore
index 54190a0372..8baf3e4fb9 100644
--- a/plugins/org.eclipse.sirius.diagram/model/diagram.ecore
+++ b/plugins/org.eclipse.sirius.diagram/model/diagram.ecore
@@ -1716,9 +1716,15 @@
     <eClassifiers xsi:type="ecore:EClass" name="DoubleLayoutOption" eSuperTypes="#//description/LayoutOption">
       <eStructuralFeatures xsi:type="ecore:EAttribute" name="value" eType="ecore:EDataType platform:/plugin/org.eclipse.emf.ecore/model/Ecore.ecore#//EDouble"/>
     </eClassifiers>
-    <eClassifiers xsi:type="ecore:EClass" name="EnumLayoutOption" eSuperTypes="#//description/LayoutOption">
+    <eClassifiers xsi:type="ecore:EClass" name="EnumLayoutOption" eSuperTypes="#//description/EnumOption">
       <eStructuralFeatures xsi:type="ecore:EReference" name="value" eType="#//description/EnumLayoutValue"
           containment="true"/>
+    </eClassifiers>
+    <eClassifiers xsi:type="ecore:EClass" name="EnumSetLayoutOption" eSuperTypes="#//description/EnumOption">
+      <eStructuralFeatures xsi:type="ecore:EReference" name="values" upperBound="-1"
+          eType="#//description/EnumLayoutValue" containment="true"/>
+    </eClassifiers>
+    <eClassifiers xsi:type="ecore:EClass" name="EnumOption" abstract="true" eSuperTypes="#//description/LayoutOption">
       <eStructuralFeatures xsi:type="ecore:EReference" name="choices" upperBound="-1"
           eType="#//description/EnumLayoutValue" containment="true"/>
     </eClassifiers>
diff --git a/plugins/org.eclipse.sirius.diagram/model/diagram.genmodel b/plugins/org.eclipse.sirius.diagram/model/diagram.genmodel
index d93f0c3912..b5e50efb12 100644
--- a/plugins/org.eclipse.sirius.diagram/model/diagram.genmodel
+++ b/plugins/org.eclipse.sirius.diagram/model/diagram.genmodel
@@ -620,7 +620,12 @@
       </genClasses>
       <genClasses image="false" ecoreClass="diagram.ecore#//description/EnumLayoutOption">
         <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference diagram.ecore#//description/EnumLayoutOption/value"/>
-        <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference diagram.ecore#//description/EnumLayoutOption/choices"/>
+      </genClasses>
+      <genClasses image="false" ecoreClass="diagram.ecore#//description/EnumSetLayoutOption">
+        <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference diagram.ecore#//description/EnumSetLayoutOption/values"/>
+      </genClasses>
+      <genClasses image="false" ecoreClass="diagram.ecore#//description/EnumOption">
+        <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference diagram.ecore#//description/EnumOption/choices"/>
       </genClasses>
       <genClasses ecoreClass="diagram.ecore#//description/EnumLayoutValue">
         <genFeatures createChild="false" ecoreFeature="ecore:EAttribute diagram.ecore#//description/EnumLayoutValue/name"/>
diff --git a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/DescriptionFactory.java b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/DescriptionFactory.java
index edbc415828..ffb4f9f158 100644
--- a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/DescriptionFactory.java
+++ b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/DescriptionFactory.java
@@ -203,6 +203,14 @@ public interface DescriptionFactory extends EFactory {
     EnumLayoutOption createEnumLayoutOption();
 
     /**
+     * Returns a new object of class '<em>Enum Set Layout Option</em>'. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @return a new object of class '<em>Enum Set Layout Option</em>'.
+     * @generated
+     */
+    EnumSetLayoutOption createEnumSetLayoutOption();
+
+    /**
      * Returns a new object of class '<em>Enum Layout Value</em>'. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @return a new object of class '<em>Enum Layout Value</em>'.
diff --git a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/DescriptionPackage.java b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/DescriptionPackage.java
index 1bb27850c3..051b68c182 100644
--- a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/DescriptionPackage.java
+++ b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/DescriptionPackage.java
@@ -68,7 +68,7 @@ public interface DescriptionPackage extends EPackage {
      * @see org.eclipse.sirius.diagram.description.impl.DescriptionPackageImpl#getDragAndDropTargetDescription()
      * @generated
      */
-    int DRAG_AND_DROP_TARGET_DESCRIPTION = 29;
+    int DRAG_AND_DROP_TARGET_DESCRIPTION = 31;
 
     /**
      * The feature id for the '<em><b>Drop Descriptions</b></em>' reference list. <!-- begin-user-doc --> <!--
@@ -2984,6 +2984,58 @@ public interface DescriptionPackage extends EPackage {
     int DOUBLE_LAYOUT_OPTION_FEATURE_COUNT = DescriptionPackage.LAYOUT_OPTION_FEATURE_COUNT + 1;
 
     /**
+     * The meta object id for the '{@link org.eclipse.sirius.diagram.description.impl.EnumOptionImpl <em>Enum
+     * Option</em>}' class. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @see org.eclipse.sirius.diagram.description.impl.EnumOptionImpl
+     * @see org.eclipse.sirius.diagram.description.impl.DescriptionPackageImpl#getEnumOption()
+     * @generated
+     */
+    int ENUM_OPTION = 26;
+
+    /**
+     * The feature id for the '<em><b>Id</b></em>' attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int ENUM_OPTION__ID = DescriptionPackage.LAYOUT_OPTION__ID;
+
+    /**
+     * The feature id for the '<em><b>Label</b></em>' attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int ENUM_OPTION__LABEL = DescriptionPackage.LAYOUT_OPTION__LABEL;
+
+    /**
+     * The feature id for the '<em><b>Description</b></em>' attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int ENUM_OPTION__DESCRIPTION = DescriptionPackage.LAYOUT_OPTION__DESCRIPTION;
+
+    /**
+     * The feature id for the '<em><b>Choices</b></em>' containment reference list. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int ENUM_OPTION__CHOICES = DescriptionPackage.LAYOUT_OPTION_FEATURE_COUNT + 0;
+
+    /**
+     * The number of structural features of the '<em>Enum Option</em>' class. <!-- begin-user-doc --> <!-- end-user-doc
+     * -->
+     *
+     * @generated
+     * @ordered
+     */
+    int ENUM_OPTION_FEATURE_COUNT = DescriptionPackage.LAYOUT_OPTION_FEATURE_COUNT + 1;
+
+    /**
      * The meta object id for the '{@link org.eclipse.sirius.diagram.description.impl.EnumLayoutOptionImpl <em>Enum
      * Layout Option</em>}' class. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
@@ -2999,7 +3051,7 @@ public interface DescriptionPackage extends EPackage {
      * @generated
      * @ordered
      */
-    int ENUM_LAYOUT_OPTION__ID = DescriptionPackage.LAYOUT_OPTION__ID;
+    int ENUM_LAYOUT_OPTION__ID = DescriptionPackage.ENUM_OPTION__ID;
 
     /**
      * The feature id for the '<em><b>Label</b></em>' attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
@@ -3007,7 +3059,7 @@ public interface DescriptionPackage extends EPackage {
      * @generated
      * @ordered
      */
-    int ENUM_LAYOUT_OPTION__LABEL = DescriptionPackage.LAYOUT_OPTION__LABEL;
+    int ENUM_LAYOUT_OPTION__LABEL = DescriptionPackage.ENUM_OPTION__LABEL;
 
     /**
      * The feature id for the '<em><b>Description</b></em>' attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
@@ -3015,7 +3067,16 @@ public interface DescriptionPackage extends EPackage {
      * @generated
      * @ordered
      */
-    int ENUM_LAYOUT_OPTION__DESCRIPTION = DescriptionPackage.LAYOUT_OPTION__DESCRIPTION;
+    int ENUM_LAYOUT_OPTION__DESCRIPTION = DescriptionPackage.ENUM_OPTION__DESCRIPTION;
+
+    /**
+     * The feature id for the '<em><b>Choices</b></em>' containment reference list. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int ENUM_LAYOUT_OPTION__CHOICES = DescriptionPackage.ENUM_OPTION__CHOICES;
 
     /**
      * The feature id for the '<em><b>Value</b></em>' containment reference. <!-- begin-user-doc --> <!-- end-user-doc
@@ -3024,7 +3085,50 @@ public interface DescriptionPackage extends EPackage {
      * @generated
      * @ordered
      */
-    int ENUM_LAYOUT_OPTION__VALUE = DescriptionPackage.LAYOUT_OPTION_FEATURE_COUNT + 0;
+    int ENUM_LAYOUT_OPTION__VALUE = DescriptionPackage.ENUM_OPTION_FEATURE_COUNT + 0;
+
+    /**
+     * The number of structural features of the '<em>Enum Layout Option</em>' class. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int ENUM_LAYOUT_OPTION_FEATURE_COUNT = DescriptionPackage.ENUM_OPTION_FEATURE_COUNT + 1;
+
+    /**
+     * The meta object id for the '{@link org.eclipse.sirius.diagram.description.impl.EnumSetLayoutOptionImpl <em>Enum
+     * Set Layout Option</em>}' class. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @see org.eclipse.sirius.diagram.description.impl.EnumSetLayoutOptionImpl
+     * @see org.eclipse.sirius.diagram.description.impl.DescriptionPackageImpl#getEnumSetLayoutOption()
+     * @generated
+     */
+    int ENUM_SET_LAYOUT_OPTION = 25;
+
+    /**
+     * The feature id for the '<em><b>Id</b></em>' attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int ENUM_SET_LAYOUT_OPTION__ID = DescriptionPackage.ENUM_OPTION__ID;
+
+    /**
+     * The feature id for the '<em><b>Label</b></em>' attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int ENUM_SET_LAYOUT_OPTION__LABEL = DescriptionPackage.ENUM_OPTION__LABEL;
+
+    /**
+     * The feature id for the '<em><b>Description</b></em>' attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int ENUM_SET_LAYOUT_OPTION__DESCRIPTION = DescriptionPackage.ENUM_OPTION__DESCRIPTION;
 
     /**
      * The feature id for the '<em><b>Choices</b></em>' containment reference list. <!-- begin-user-doc --> <!--
@@ -3033,16 +3137,25 @@ public interface DescriptionPackage extends EPackage {
      * @generated
      * @ordered
      */
-    int ENUM_LAYOUT_OPTION__CHOICES = DescriptionPackage.LAYOUT_OPTION_FEATURE_COUNT + 1;
+    int ENUM_SET_LAYOUT_OPTION__CHOICES = DescriptionPackage.ENUM_OPTION__CHOICES;
 
     /**
-     * The number of structural features of the '<em>Enum Layout Option</em>' class. <!-- begin-user-doc --> <!--
+     * The feature id for the '<em><b>Values</b></em>' containment reference list. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int ENUM_SET_LAYOUT_OPTION__VALUES = DescriptionPackage.ENUM_OPTION_FEATURE_COUNT + 0;
+
+    /**
+     * The number of structural features of the '<em>Enum Set Layout Option</em>' class. <!-- begin-user-doc --> <!--
      * end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int ENUM_LAYOUT_OPTION_FEATURE_COUNT = DescriptionPackage.LAYOUT_OPTION_FEATURE_COUNT + 2;
+    int ENUM_SET_LAYOUT_OPTION_FEATURE_COUNT = DescriptionPackage.ENUM_OPTION_FEATURE_COUNT + 1;
 
     /**
      * The meta object id for the '{@link org.eclipse.sirius.diagram.description.impl.EnumLayoutValueImpl <em>Enum
@@ -3052,7 +3165,7 @@ public interface DescriptionPackage extends EPackage {
      * @see org.eclipse.sirius.diagram.description.impl.DescriptionPackageImpl#getEnumLayoutValue()
      * @generated
      */
-    int ENUM_LAYOUT_VALUE = 25;
+    int ENUM_LAYOUT_VALUE = 27;
 
     /**
      * The feature id for the '<em><b>Name</b></em>' attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
@@ -3087,7 +3200,7 @@ public interface DescriptionPackage extends EPackage {
      * @see org.eclipse.sirius.diagram.description.impl.DescriptionPackageImpl#getMappingBasedDecoration()
      * @generated
      */
-    int MAPPING_BASED_DECORATION = 26;
+    int MAPPING_BASED_DECORATION = 28;
 
     /**
      * The feature id for the '<em><b>Name</b></em>' attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
@@ -3166,7 +3279,7 @@ public interface DescriptionPackage extends EPackage {
      * @see org.eclipse.sirius.diagram.description.impl.DescriptionPackageImpl#getLayer()
      * @generated
      */
-    int LAYER = 27;
+    int LAYER = 29;
 
     /**
      * The feature id for the '<em><b>Documentation</b></em>' attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
@@ -3323,7 +3436,7 @@ public interface DescriptionPackage extends EPackage {
      * @see org.eclipse.sirius.diagram.description.impl.DescriptionPackageImpl#getAdditionalLayer()
      * @generated
      */
-    int ADDITIONAL_LAYER = 28;
+    int ADDITIONAL_LAYER = 30;
 
     /**
      * The feature id for the '<em><b>Documentation</b></em>' attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
@@ -3498,7 +3611,7 @@ public interface DescriptionPackage extends EPackage {
      * @see org.eclipse.sirius.diagram.description.impl.DescriptionPackageImpl#getFoldingStyle()
      * @generated
      */
-    int FOLDING_STYLE = 30;
+    int FOLDING_STYLE = 32;
 
     /**
      * The meta object id for the '{@link org.eclipse.sirius.diagram.description.LayoutDirection <em>Layout
@@ -3508,7 +3621,7 @@ public interface DescriptionPackage extends EPackage {
      * @see org.eclipse.sirius.diagram.description.impl.DescriptionPackageImpl#getLayoutDirection()
      * @generated
      */
-    int LAYOUT_DIRECTION = 31;
+    int LAYOUT_DIRECTION = 33;
 
     /**
      * The meta object id for the '{@link org.eclipse.sirius.diagram.description.CenteringStyle <em>Centering
@@ -3518,7 +3631,7 @@ public interface DescriptionPackage extends EPackage {
      * @see org.eclipse.sirius.diagram.description.impl.DescriptionPackageImpl#getCenteringStyle()
      * @generated
      */
-    int CENTERING_STYLE = 32;
+    int CENTERING_STYLE = 34;
 
     /**
      * Returns the meta object for class '{@link org.eclipse.sirius.diagram.description.DiagramDescription <em>Diagram
@@ -4838,16 +4951,48 @@ public interface DescriptionPackage extends EPackage {
     EReference getEnumLayoutOption_Value();
 
     /**
+     * Returns the meta object for class '{@link org.eclipse.sirius.diagram.description.EnumSetLayoutOption <em>Enum Set
+     * Layout Option</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @return the meta object for class '<em>Enum Set Layout Option</em>'.
+     * @see org.eclipse.sirius.diagram.description.EnumSetLayoutOption
+     * @generated
+     */
+    EClass getEnumSetLayoutOption();
+
+    /**
      * Returns the meta object for the containment reference list
-     * '{@link org.eclipse.sirius.diagram.description.EnumLayoutOption#getChoices <em>Choices</em>}'. <!--
+     * '{@link org.eclipse.sirius.diagram.description.EnumSetLayoutOption#getValues <em>Values</em>}'. <!--
      * begin-user-doc --> <!-- end-user-doc -->
      *
+     * @return the meta object for the containment reference list '<em>Values</em>'.
+     * @see org.eclipse.sirius.diagram.description.EnumSetLayoutOption#getValues()
+     * @see #getEnumSetLayoutOption()
+     * @generated
+     */
+    EReference getEnumSetLayoutOption_Values();
+
+    /**
+     * Returns the meta object for class '{@link org.eclipse.sirius.diagram.description.EnumOption <em>Enum
+     * Option</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @return the meta object for class '<em>Enum Option</em>'.
+     * @see org.eclipse.sirius.diagram.description.EnumOption
+     * @generated
+     */
+    EClass getEnumOption();
+
+    /**
+     * Returns the meta object for the containment reference list
+     * '{@link org.eclipse.sirius.diagram.description.EnumOption#getChoices <em>Choices</em>}'. <!-- begin-user-doc -->
+     * <!-- end-user-doc -->
+     *
      * @return the meta object for the containment reference list '<em>Choices</em>'.
-     * @see org.eclipse.sirius.diagram.description.EnumLayoutOption#getChoices()
-     * @see #getEnumLayoutOption()
+     * @see org.eclipse.sirius.diagram.description.EnumOption#getChoices()
+     * @see #getEnumOption()
      * @generated
      */
-    EReference getEnumLayoutOption_Choices();
+    EReference getEnumOption_Choices();
 
     /**
      * Returns the meta object for class '{@link org.eclipse.sirius.diagram.description.EnumLayoutValue <em>Enum Layout
@@ -6133,12 +6278,40 @@ public interface DescriptionPackage extends EPackage {
         EReference ENUM_LAYOUT_OPTION__VALUE = DescriptionPackage.eINSTANCE.getEnumLayoutOption_Value();
 
         /**
+         * The meta object literal for the '{@link org.eclipse.sirius.diagram.description.impl.EnumSetLayoutOptionImpl
+         * <em>Enum Set Layout Option</em>}' class. <!-- begin-user-doc --> <!-- end-user-doc -->
+         *
+         * @see org.eclipse.sirius.diagram.description.impl.EnumSetLayoutOptionImpl
+         * @see org.eclipse.sirius.diagram.description.impl.DescriptionPackageImpl#getEnumSetLayoutOption()
+         * @generated
+         */
+        EClass ENUM_SET_LAYOUT_OPTION = DescriptionPackage.eINSTANCE.getEnumSetLayoutOption();
+
+        /**
+         * The meta object literal for the '<em><b>Values</b></em>' containment reference list feature. <!--
+         * begin-user-doc --> <!-- end-user-doc -->
+         *
+         * @generated
+         */
+        EReference ENUM_SET_LAYOUT_OPTION__VALUES = DescriptionPackage.eINSTANCE.getEnumSetLayoutOption_Values();
+
+        /**
+         * The meta object literal for the '{@link org.eclipse.sirius.diagram.description.impl.EnumOptionImpl <em>Enum
+         * Option</em>}' class. <!-- begin-user-doc --> <!-- end-user-doc -->
+         *
+         * @see org.eclipse.sirius.diagram.description.impl.EnumOptionImpl
+         * @see org.eclipse.sirius.diagram.description.impl.DescriptionPackageImpl#getEnumOption()
+         * @generated
+         */
+        EClass ENUM_OPTION = DescriptionPackage.eINSTANCE.getEnumOption();
+
+        /**
          * The meta object literal for the '<em><b>Choices</b></em>' containment reference list feature. <!--
          * begin-user-doc --> <!-- end-user-doc -->
          *
          * @generated
          */
-        EReference ENUM_LAYOUT_OPTION__CHOICES = DescriptionPackage.eINSTANCE.getEnumLayoutOption_Choices();
+        EReference ENUM_OPTION__CHOICES = DescriptionPackage.eINSTANCE.getEnumOption_Choices();
 
         /**
          * The meta object literal for the '{@link org.eclipse.sirius.diagram.description.impl.EnumLayoutValueImpl
diff --git a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/EnumLayoutOption.java b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/EnumLayoutOption.java
index 75c1537885..3d21635a4f 100644
--- a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/EnumLayoutOption.java
+++ b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/EnumLayoutOption.java
@@ -11,8 +11,6 @@
  */
 package org.eclipse.sirius.diagram.description;
 
-import org.eclipse.emf.common.util.EList;
-
 /**
  * <!-- begin-user-doc --> A representation of the model object '<em><b>Enum Layout Option</b></em>'. <!-- end-user-doc
  * -->
@@ -28,7 +26,7 @@ import org.eclipse.emf.common.util.EList;
  * @model abstract="true"
  * @generated
  */
-public interface EnumLayoutOption extends LayoutOption {
+public interface EnumLayoutOption extends EnumOption {
     /**
      * Returns the value of the '<em><b>Value</b></em>' containment reference. <!-- begin-user-doc -->
      * <p>
@@ -56,20 +54,4 @@ public interface EnumLayoutOption extends LayoutOption {
      */
     void setValue(EnumLayoutValue value);
 
-    /**
-     * Returns the value of the '<em><b>Choices</b></em>' containment reference list. The list contents are of type
-     * {@link org.eclipse.sirius.diagram.description.EnumLayoutValue}. <!-- begin-user-doc -->
-     * <p>
-     * If the meaning of the '<em>Choices</em>' containment reference list isn't clear, there really should be more of a
-     * description here...
-     * </p>
-     * <!-- end-user-doc -->
-     *
-     * @return the value of the '<em>Choices</em>' containment reference list.
-     * @see org.eclipse.sirius.diagram.description.DescriptionPackage#getEnumLayoutOption_Choices()
-     * @model containment="true" resolveProxies="true"
-     * @generated
-     */
-    EList<EnumLayoutValue> getChoices();
-
 } // EnumLayoutOption
diff --git a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/EnumOption.java b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/EnumOption.java
new file mode 100644
index 0000000000..348657e580
--- /dev/null
+++ b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/EnumOption.java
@@ -0,0 +1,47 @@
+/**
+ * Copyright (c) 2007, 2017 THALES GLOBAL SERVICES.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Obeo - initial API and implementation
+ *
+ */
+package org.eclipse.sirius.diagram.description;
+
+import org.eclipse.emf.common.util.EList;
+
+/**
+ * <!-- begin-user-doc --> A representation of the model object '<em><b>Enum Option</b></em>'. <!-- end-user-doc -->
+ *
+ * <p>
+ * The following features are supported:
+ * </p>
+ * <ul>
+ * <li>{@link org.eclipse.sirius.diagram.description.EnumOption#getChoices <em>Choices</em>}</li>
+ * </ul>
+ *
+ * @see org.eclipse.sirius.diagram.description.DescriptionPackage#getEnumOption()
+ * @model abstract="true"
+ * @generated
+ */
+public interface EnumOption extends LayoutOption {
+    /**
+     * Returns the value of the '<em><b>Choices</b></em>' containment reference list. The list contents are of type
+     * {@link org.eclipse.sirius.diagram.description.EnumLayoutValue}. <!-- begin-user-doc -->
+     * <p>
+     * If the meaning of the '<em>Choices</em>' containment reference list isn't clear, there really should be more of a
+     * description here...
+     * </p>
+     * <!-- end-user-doc -->
+     *
+     * @return the value of the '<em>Choices</em>' containment reference list.
+     * @see org.eclipse.sirius.diagram.description.DescriptionPackage#getEnumOption_Choices()
+     * @model containment="true" resolveProxies="true"
+     * @generated
+     */
+    EList<EnumLayoutValue> getChoices();
+
+} // EnumOption
diff --git a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/EnumSetLayoutOption.java b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/EnumSetLayoutOption.java
new file mode 100644
index 0000000000..b431fe2a14
--- /dev/null
+++ b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/EnumSetLayoutOption.java
@@ -0,0 +1,48 @@
+/**
+ * Copyright (c) 2007, 2017 THALES GLOBAL SERVICES.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Obeo - initial API and implementation
+ *
+ */
+package org.eclipse.sirius.diagram.description;
+
+import org.eclipse.emf.common.util.EList;
+
+/**
+ * <!-- begin-user-doc --> A representation of the model object '<em><b>Enum Set Layout Option</b></em>'. <!--
+ * end-user-doc -->
+ *
+ * <p>
+ * The following features are supported:
+ * </p>
+ * <ul>
+ * <li>{@link org.eclipse.sirius.diagram.description.EnumSetLayoutOption#getValues <em>Values</em>}</li>
+ * </ul>
+ *
+ * @see org.eclipse.sirius.diagram.description.DescriptionPackage#getEnumSetLayoutOption()
+ * @model
+ * @generated
+ */
+public interface EnumSetLayoutOption extends EnumOption {
+    /**
+     * Returns the value of the '<em><b>Values</b></em>' containment reference list. The list contents are of type
+     * {@link org.eclipse.sirius.diagram.description.EnumLayoutValue}. <!-- begin-user-doc -->
+     * <p>
+     * If the meaning of the '<em>Values</em>' containment reference list isn't clear, there really should be more of a
+     * description here...
+     * </p>
+     * <!-- end-user-doc -->
+     *
+     * @return the value of the '<em>Values</em>' containment reference list.
+     * @see org.eclipse.sirius.diagram.description.DescriptionPackage#getEnumSetLayoutOption_Values()
+     * @model containment="true" resolveProxies="true"
+     * @generated
+     */
+    EList<EnumLayoutValue> getValues();
+
+} // EnumSetLayoutOption
diff --git a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/GenericLayout.java b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/GenericLayout.java
deleted file mode 100644
index d0f6473024..0000000000
--- a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/GenericLayout.java
+++ /dev/null
@@ -1,130 +0,0 @@
-/**
- * Copyright (c) 2007, 2017 THALES GLOBAL SERVICES.
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Eclipse Public License v1.0
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/epl-v10.html
- *
- * Contributors:
- *    Obeo - initial API and implementation
- *
- */
-package org.eclipse.sirius.diagram.description;
-
-import org.eclipse.emf.common.util.EList;
-
-/**
- * <!-- begin-user-doc --> A representation of the model object '<em><b>Generic Layout</b></em>'. <!-- end-user-doc -->
- *
- * <p>
- * The following features are supported:
- * </p>
- * <ul>
- * <li>{@link org.eclipse.sirius.diagram.description.GenericLayout#getID <em>ID</em>}</li>
- * <li>{@link org.eclipse.sirius.diagram.description.GenericLayout#getLabel <em>Label</em>}</li>
- * <li>{@link org.eclipse.sirius.diagram.description.GenericLayout#getDescription <em>Description</em>}</li>
- * <li>{@link org.eclipse.sirius.diagram.description.GenericLayout#getLayoutOptions <em>Layout Options</em>}</li>
- * </ul>
- *
- * @see org.eclipse.sirius.diagram.description.DescriptionPackage#getGenericLayout()
- * @model
- * @generated
- */
-public interface GenericLayout extends Layout {
-    /**
-     * Returns the value of the '<em><b>ID</b></em>' attribute. <!-- begin-user-doc -->
-     * <p>
-     * If the meaning of the '<em>ID</em>' attribute isn't clear, there really should be more of a description here...
-     * </p>
-     * <!-- end-user-doc -->
-     *
-     * @return the value of the '<em>ID</em>' attribute.
-     * @see #setID(String)
-     * @see org.eclipse.sirius.diagram.description.DescriptionPackage#getGenericLayout_ID()
-     * @model
-     * @generated
-     */
-    String getID();
-
-    /**
-     * Sets the value of the '{@link org.eclipse.sirius.diagram.description.GenericLayout#getID <em>ID</em>}' attribute.
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @param value
-     *            the new value of the '<em>ID</em>' attribute.
-     * @see #getID()
-     * @generated
-     */
-    void setID(String value);
-
-    /**
-     * Returns the value of the '<em><b>Label</b></em>' attribute. <!-- begin-user-doc -->
-     * <p>
-     * If the meaning of the '<em>Label</em>' attribute isn't clear, there really should be more of a description
-     * here...
-     * </p>
-     * <!-- end-user-doc -->
-     *
-     * @return the value of the '<em>Label</em>' attribute.
-     * @see #setLabel(String)
-     * @see org.eclipse.sirius.diagram.description.DescriptionPackage#getGenericLayout_Label()
-     * @model
-     * @generated
-     */
-    String getLabel();
-
-    /**
-     * Sets the value of the '{@link org.eclipse.sirius.diagram.description.GenericLayout#getLabel <em>Label</em>}'
-     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @param value
-     *            the new value of the '<em>Label</em>' attribute.
-     * @see #getLabel()
-     * @generated
-     */
-    void setLabel(String value);
-
-    /**
-     * Returns the value of the '<em><b>Description</b></em>' attribute. <!-- begin-user-doc -->
-     * <p>
-     * If the meaning of the '<em>Description</em>' attribute isn't clear, there really should be more of a description
-     * here...
-     * </p>
-     * <!-- end-user-doc -->
-     *
-     * @return the value of the '<em>Description</em>' attribute.
-     * @see #setDescription(String)
-     * @see org.eclipse.sirius.diagram.description.DescriptionPackage#getGenericLayout_Description()
-     * @model
-     * @generated
-     */
-    String getDescription();
-
-    /**
-     * Sets the value of the '{@link org.eclipse.sirius.diagram.description.GenericLayout#getDescription
-     * <em>Description</em>}' attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @param value
-     *            the new value of the '<em>Description</em>' attribute.
-     * @see #getDescription()
-     * @generated
-     */
-    void setDescription(String value);
-
-    /**
-     * Returns the value of the '<em><b>Layout Options</b></em>' containment reference list. The list contents are of
-     * type {@link org.eclipse.sirius.diagram.description.LayoutOption}. <!-- begin-user-doc -->
-     * <p>
-     * If the meaning of the '<em>Layout Options</em>' reference list isn't clear, there really should be more of a
-     * description here...
-     * </p>
-     * <!-- end-user-doc -->
-     *
-     * @return the value of the '<em>Layout Options</em>' containment reference list.
-     * @see org.eclipse.sirius.diagram.description.DescriptionPackage#getGenericLayout_LayoutOptions()
-     * @model containment="true" resolveProxies="true"
-     * @generated
-     */
-    EList<LayoutOption> getLayoutOptions();
-
-} // GenericLayout
diff --git a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/DescriptionFactoryImpl.java b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/DescriptionFactoryImpl.java
index 6039230888..797ab2c5a3 100644
--- a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/DescriptionFactoryImpl.java
+++ b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/DescriptionFactoryImpl.java
@@ -49,6 +49,7 @@ import org.eclipse.sirius.diagram.description.EdgeMapping;
 import org.eclipse.sirius.diagram.description.EdgeMappingImport;
 import org.eclipse.sirius.diagram.description.EnumLayoutOption;
 import org.eclipse.sirius.diagram.description.EnumLayoutValue;
+import org.eclipse.sirius.diagram.description.EnumSetLayoutOption;
 import org.eclipse.sirius.diagram.description.FoldingStyle;
 import org.eclipse.sirius.diagram.description.IntegerLayoutOption;
 import org.eclipse.sirius.diagram.description.Layer;
@@ -139,6 +140,8 @@ public class DescriptionFactoryImpl extends EFactoryImpl implements DescriptionF
             return createDoubleLayoutOption();
         case DescriptionPackage.ENUM_LAYOUT_OPTION:
             return createEnumLayoutOption();
+        case DescriptionPackage.ENUM_SET_LAYOUT_OPTION:
+            return createEnumSetLayoutOption();
         case DescriptionPackage.ENUM_LAYOUT_VALUE:
             return createEnumLayoutValue();
         case DescriptionPackage.MAPPING_BASED_DECORATION:
@@ -429,6 +432,17 @@ public class DescriptionFactoryImpl extends EFactoryImpl implements DescriptionF
      * @generated
      */
     @Override
+    public EnumSetLayoutOption createEnumSetLayoutOption() {
+        EnumSetLayoutOptionImpl enumSetLayoutOption = new EnumSetLayoutOptionImpl();
+        return enumSetLayoutOption;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
     public EnumLayoutValue createEnumLayoutValue() {
         EnumLayoutValueImpl enumLayoutValue = new EnumLayoutValueImpl();
         return enumLayoutValue;
diff --git a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/DescriptionPackageImpl.java b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/DescriptionPackageImpl.java
index 959b206b08..c1eb2db405 100644
--- a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/DescriptionPackageImpl.java
+++ b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/DescriptionPackageImpl.java
@@ -43,6 +43,8 @@ import org.eclipse.sirius.diagram.description.EdgeMapping;
 import org.eclipse.sirius.diagram.description.EdgeMappingImport;
 import org.eclipse.sirius.diagram.description.EnumLayoutOption;
 import org.eclipse.sirius.diagram.description.EnumLayoutValue;
+import org.eclipse.sirius.diagram.description.EnumOption;
+import org.eclipse.sirius.diagram.description.EnumSetLayoutOption;
 import org.eclipse.sirius.diagram.description.FoldingStyle;
 import org.eclipse.sirius.diagram.description.IEdgeMapping;
 import org.eclipse.sirius.diagram.description.IntegerLayoutOption;
@@ -253,6 +255,20 @@ public class DescriptionPackageImpl extends EPackageImpl implements DescriptionP
      *
      * @generated
      */
+    private EClass enumSetLayoutOptionEClass = null;
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    private EClass enumOptionEClass = null;
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
     private EClass enumLayoutValueEClass = null;
 
     /**
@@ -1537,8 +1553,38 @@ public class DescriptionPackageImpl extends EPackageImpl implements DescriptionP
      * @generated
      */
     @Override
-    public EReference getEnumLayoutOption_Choices() {
-        return (EReference) enumLayoutOptionEClass.getEStructuralFeatures().get(1);
+    public EClass getEnumSetLayoutOption() {
+        return enumSetLayoutOptionEClass;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public EReference getEnumSetLayoutOption_Values() {
+        return (EReference) enumSetLayoutOptionEClass.getEStructuralFeatures().get(0);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public EClass getEnumOption() {
+        return enumOptionEClass;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public EReference getEnumOption_Choices() {
+        return (EReference) enumOptionEClass.getEStructuralFeatures().get(0);
     }
 
     /**
@@ -1969,7 +2015,12 @@ public class DescriptionPackageImpl extends EPackageImpl implements DescriptionP
 
         enumLayoutOptionEClass = createEClass(DescriptionPackage.ENUM_LAYOUT_OPTION);
         createEReference(enumLayoutOptionEClass, DescriptionPackage.ENUM_LAYOUT_OPTION__VALUE);
-        createEReference(enumLayoutOptionEClass, DescriptionPackage.ENUM_LAYOUT_OPTION__CHOICES);
+
+        enumSetLayoutOptionEClass = createEClass(DescriptionPackage.ENUM_SET_LAYOUT_OPTION);
+        createEReference(enumSetLayoutOptionEClass, DescriptionPackage.ENUM_SET_LAYOUT_OPTION__VALUES);
+
+        enumOptionEClass = createEClass(DescriptionPackage.ENUM_OPTION);
+        createEReference(enumOptionEClass, DescriptionPackage.ENUM_OPTION__CHOICES);
 
         enumLayoutValueEClass = createEClass(DescriptionPackage.ENUM_LAYOUT_VALUE);
         createEAttribute(enumLayoutValueEClass, DescriptionPackage.ENUM_LAYOUT_VALUE__NAME);
@@ -2089,7 +2140,9 @@ public class DescriptionPackageImpl extends EPackageImpl implements DescriptionP
         stringLayoutOptionEClass.getESuperTypes().add(this.getLayoutOption());
         integerLayoutOptionEClass.getESuperTypes().add(this.getLayoutOption());
         doubleLayoutOptionEClass.getESuperTypes().add(this.getLayoutOption());
-        enumLayoutOptionEClass.getESuperTypes().add(this.getLayoutOption());
+        enumLayoutOptionEClass.getESuperTypes().add(this.getEnumOption());
+        enumSetLayoutOptionEClass.getESuperTypes().add(this.getEnumOption());
+        enumOptionEClass.getESuperTypes().add(this.getLayoutOption());
         mappingBasedDecorationEClass.getESuperTypes().add(theDescriptionPackage_1.getDecorationDescription());
         layerEClass.getESuperTypes().add(theDescriptionPackage_1.getDocumentedElement());
         layerEClass.getESuperTypes().add(theDescriptionPackage_1.getEndUserDocumentedElement());
@@ -2489,7 +2542,14 @@ public class DescriptionPackageImpl extends EPackageImpl implements DescriptionP
         initEReference(getEnumLayoutOption_Value(), this.getEnumLayoutValue(), null, "value", null, 0, 1, EnumLayoutOption.class, !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, //$NON-NLS-1$
                 EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED,
                 EPackageImpl.IS_ORDERED);
-        initEReference(getEnumLayoutOption_Choices(), this.getEnumLayoutValue(), null, "choices", null, 0, -1, EnumLayoutOption.class, !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, //$NON-NLS-1$
+
+        initEClass(enumSetLayoutOptionEClass, EnumSetLayoutOption.class, "EnumSetLayoutOption", !EPackageImpl.IS_ABSTRACT, !EPackageImpl.IS_INTERFACE, EPackageImpl.IS_GENERATED_INSTANCE_CLASS); //$NON-NLS-1$
+        initEReference(getEnumSetLayoutOption_Values(), this.getEnumLayoutValue(), null, "values", null, 0, -1, EnumSetLayoutOption.class, !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, //$NON-NLS-1$
+                EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED,
+                EPackageImpl.IS_ORDERED);
+
+        initEClass(enumOptionEClass, EnumOption.class, "EnumOption", EPackageImpl.IS_ABSTRACT, !EPackageImpl.IS_INTERFACE, EPackageImpl.IS_GENERATED_INSTANCE_CLASS); //$NON-NLS-1$
+        initEReference(getEnumOption_Choices(), this.getEnumLayoutValue(), null, "choices", null, 0, -1, EnumOption.class, !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, //$NON-NLS-1$
                 EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED,
                 EPackageImpl.IS_ORDERED);
 
diff --git a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/EnumLayoutOptionImpl.java b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/EnumLayoutOptionImpl.java
index fd45491860..8604786432 100644
--- a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/EnumLayoutOptionImpl.java
+++ b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/EnumLayoutOptionImpl.java
@@ -11,16 +11,11 @@
  */
 package org.eclipse.sirius.diagram.description.impl;
 
-import java.util.Collection;
-
 import org.eclipse.emf.common.notify.Notification;
 import org.eclipse.emf.common.notify.NotificationChain;
-import org.eclipse.emf.common.util.EList;
 import org.eclipse.emf.ecore.EClass;
 import org.eclipse.emf.ecore.InternalEObject;
 import org.eclipse.emf.ecore.impl.ENotificationImpl;
-import org.eclipse.emf.ecore.util.EObjectContainmentEList;
-import org.eclipse.emf.ecore.util.InternalEList;
 import org.eclipse.sirius.diagram.description.DescriptionPackage;
 import org.eclipse.sirius.diagram.description.EnumLayoutOption;
 import org.eclipse.sirius.diagram.description.EnumLayoutValue;
@@ -37,7 +32,7 @@ import org.eclipse.sirius.diagram.description.EnumLayoutValue;
  *
  * @generated
  */
-public class EnumLayoutOptionImpl extends LayoutOptionImpl implements EnumLayoutOption {
+public class EnumLayoutOptionImpl extends EnumOptionImpl implements EnumLayoutOption {
     /**
      * The cached value of the '{@link #getValue() <em>Value</em>}' containment reference. <!-- begin-user-doc --> <!--
      * end-user-doc -->
@@ -49,16 +44,6 @@ public class EnumLayoutOptionImpl extends LayoutOptionImpl implements EnumLayout
     protected EnumLayoutValue value;
 
     /**
-     * The cached value of the '{@link #getChoices() <em>Choices</em>}' containment reference list. <!-- begin-user-doc
-     * --> <!-- end-user-doc -->
-     *
-     * @see #getChoices()
-     * @generated
-     * @ordered
-     */
-    protected EList<EnumLayoutValue> choices;
-
-    /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
@@ -162,25 +147,10 @@ public class EnumLayoutOptionImpl extends LayoutOptionImpl implements EnumLayout
      * @generated
      */
     @Override
-    public EList<EnumLayoutValue> getChoices() {
-        if (choices == null) {
-            choices = new EObjectContainmentEList.Resolving<EnumLayoutValue>(EnumLayoutValue.class, this, DescriptionPackage.ENUM_LAYOUT_OPTION__CHOICES);
-        }
-        return choices;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
     public NotificationChain eInverseRemove(InternalEObject otherEnd, int featureID, NotificationChain msgs) {
         switch (featureID) {
         case DescriptionPackage.ENUM_LAYOUT_OPTION__VALUE:
             return basicSetValue(null, msgs);
-        case DescriptionPackage.ENUM_LAYOUT_OPTION__CHOICES:
-            return ((InternalEList<?>) getChoices()).basicRemove(otherEnd, msgs);
         }
         return super.eInverseRemove(otherEnd, featureID, msgs);
     }
@@ -198,8 +168,6 @@ public class EnumLayoutOptionImpl extends LayoutOptionImpl implements EnumLayout
                 return getValue();
             }
             return basicGetValue();
-        case DescriptionPackage.ENUM_LAYOUT_OPTION__CHOICES:
-            return getChoices();
         }
         return super.eGet(featureID, resolve, coreType);
     }
@@ -216,10 +184,6 @@ public class EnumLayoutOptionImpl extends LayoutOptionImpl implements EnumLayout
         case DescriptionPackage.ENUM_LAYOUT_OPTION__VALUE:
             setValue((EnumLayoutValue) newValue);
             return;
-        case DescriptionPackage.ENUM_LAYOUT_OPTION__CHOICES:
-            getChoices().clear();
-            getChoices().addAll((Collection<? extends EnumLayoutValue>) newValue);
-            return;
         }
         super.eSet(featureID, newValue);
     }
@@ -235,9 +199,6 @@ public class EnumLayoutOptionImpl extends LayoutOptionImpl implements EnumLayout
         case DescriptionPackage.ENUM_LAYOUT_OPTION__VALUE:
             setValue((EnumLayoutValue) null);
             return;
-        case DescriptionPackage.ENUM_LAYOUT_OPTION__CHOICES:
-            getChoices().clear();
-            return;
         }
         super.eUnset(featureID);
     }
@@ -252,8 +213,6 @@ public class EnumLayoutOptionImpl extends LayoutOptionImpl implements EnumLayout
         switch (featureID) {
         case DescriptionPackage.ENUM_LAYOUT_OPTION__VALUE:
             return value != null;
-        case DescriptionPackage.ENUM_LAYOUT_OPTION__CHOICES:
-            return choices != null && !choices.isEmpty();
         }
         return super.eIsSet(featureID);
     }
diff --git a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/EnumOptionImpl.java b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/EnumOptionImpl.java
new file mode 100644
index 0000000000..7175fc3a35
--- /dev/null
+++ b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/EnumOptionImpl.java
@@ -0,0 +1,154 @@
+/**
+ * Copyright (c) 2007, 2017 THALES GLOBAL SERVICES.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Obeo - initial API and implementation
+ *
+ */
+package org.eclipse.sirius.diagram.description.impl;
+
+import java.util.Collection;
+
+import org.eclipse.emf.common.notify.NotificationChain;
+import org.eclipse.emf.common.util.EList;
+import org.eclipse.emf.ecore.EClass;
+import org.eclipse.emf.ecore.InternalEObject;
+import org.eclipse.emf.ecore.util.EObjectContainmentEList;
+import org.eclipse.emf.ecore.util.InternalEList;
+import org.eclipse.sirius.diagram.description.DescriptionPackage;
+import org.eclipse.sirius.diagram.description.EnumLayoutValue;
+import org.eclipse.sirius.diagram.description.EnumOption;
+
+/**
+ * <!-- begin-user-doc --> An implementation of the model object '<em><b>Enum Option</b></em>'. <!-- end-user-doc -->
+ * <p>
+ * The following features are implemented:
+ * </p>
+ * <ul>
+ * <li>{@link org.eclipse.sirius.diagram.description.impl.EnumOptionImpl#getChoices <em>Choices</em>}</li>
+ * </ul>
+ *
+ * @generated
+ */
+public abstract class EnumOptionImpl extends LayoutOptionImpl implements EnumOption {
+    /**
+     * The cached value of the '{@link #getChoices() <em>Choices</em>}' containment reference list. <!-- begin-user-doc
+     * --> <!-- end-user-doc -->
+     *
+     * @see #getChoices()
+     * @generated
+     * @ordered
+     */
+    protected EList<EnumLayoutValue> choices;
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    protected EnumOptionImpl() {
+        super();
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    protected EClass eStaticClass() {
+        return DescriptionPackage.Literals.ENUM_OPTION;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public EList<EnumLayoutValue> getChoices() {
+        if (choices == null) {
+            choices = new EObjectContainmentEList.Resolving<EnumLayoutValue>(EnumLayoutValue.class, this, DescriptionPackage.ENUM_OPTION__CHOICES);
+        }
+        return choices;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public NotificationChain eInverseRemove(InternalEObject otherEnd, int featureID, NotificationChain msgs) {
+        switch (featureID) {
+        case DescriptionPackage.ENUM_OPTION__CHOICES:
+            return ((InternalEList<?>) getChoices()).basicRemove(otherEnd, msgs);
+        }
+        return super.eInverseRemove(otherEnd, featureID, msgs);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public Object eGet(int featureID, boolean resolve, boolean coreType) {
+        switch (featureID) {
+        case DescriptionPackage.ENUM_OPTION__CHOICES:
+            return getChoices();
+        }
+        return super.eGet(featureID, resolve, coreType);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @SuppressWarnings("unchecked")
+    @Override
+    public void eSet(int featureID, Object newValue) {
+        switch (featureID) {
+        case DescriptionPackage.ENUM_OPTION__CHOICES:
+            getChoices().clear();
+            getChoices().addAll((Collection<? extends EnumLayoutValue>) newValue);
+            return;
+        }
+        super.eSet(featureID, newValue);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public void eUnset(int featureID) {
+        switch (featureID) {
+        case DescriptionPackage.ENUM_OPTION__CHOICES:
+            getChoices().clear();
+            return;
+        }
+        super.eUnset(featureID);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public boolean eIsSet(int featureID) {
+        switch (featureID) {
+        case DescriptionPackage.ENUM_OPTION__CHOICES:
+            return choices != null && !choices.isEmpty();
+        }
+        return super.eIsSet(featureID);
+    }
+
+} // EnumOptionImpl
diff --git a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/EnumSetLayoutOptionImpl.java b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/EnumSetLayoutOptionImpl.java
new file mode 100644
index 0000000000..1dcefa36f4
--- /dev/null
+++ b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/impl/EnumSetLayoutOptionImpl.java
@@ -0,0 +1,155 @@
+/**
+ * Copyright (c) 2007, 2017 THALES GLOBAL SERVICES.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *    Obeo - initial API and implementation
+ *
+ */
+package org.eclipse.sirius.diagram.description.impl;
+
+import java.util.Collection;
+
+import org.eclipse.emf.common.notify.NotificationChain;
+import org.eclipse.emf.common.util.EList;
+import org.eclipse.emf.ecore.EClass;
+import org.eclipse.emf.ecore.InternalEObject;
+import org.eclipse.emf.ecore.util.EObjectContainmentEList;
+import org.eclipse.emf.ecore.util.InternalEList;
+import org.eclipse.sirius.diagram.description.DescriptionPackage;
+import org.eclipse.sirius.diagram.description.EnumLayoutValue;
+import org.eclipse.sirius.diagram.description.EnumSetLayoutOption;
+
+/**
+ * <!-- begin-user-doc --> An implementation of the model object '<em><b>Enum Set Layout Option</b></em>'. <!--
+ * end-user-doc -->
+ * <p>
+ * The following features are implemented:
+ * </p>
+ * <ul>
+ * <li>{@link org.eclipse.sirius.diagram.description.impl.EnumSetLayoutOptionImpl#getValues <em>Values</em>}</li>
+ * </ul>
+ *
+ * @generated
+ */
+public class EnumSetLayoutOptionImpl extends EnumOptionImpl implements EnumSetLayoutOption {
+    /**
+     * The cached value of the '{@link #getValues() <em>Values</em>}' containment reference list. <!-- begin-user-doc
+     * --> <!-- end-user-doc -->
+     *
+     * @see #getValues()
+     * @generated
+     * @ordered
+     */
+    protected EList<EnumLayoutValue> values;
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    protected EnumSetLayoutOptionImpl() {
+        super();
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    protected EClass eStaticClass() {
+        return DescriptionPackage.Literals.ENUM_SET_LAYOUT_OPTION;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public EList<EnumLayoutValue> getValues() {
+        if (values == null) {
+            values = new EObjectContainmentEList.Resolving<EnumLayoutValue>(EnumLayoutValue.class, this, DescriptionPackage.ENUM_SET_LAYOUT_OPTION__VALUES);
+        }
+        return values;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public NotificationChain eInverseRemove(InternalEObject otherEnd, int featureID, NotificationChain msgs) {
+        switch (featureID) {
+        case DescriptionPackage.ENUM_SET_LAYOUT_OPTION__VALUES:
+            return ((InternalEList<?>) getValues()).basicRemove(otherEnd, msgs);
+        }
+        return super.eInverseRemove(otherEnd, featureID, msgs);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public Object eGet(int featureID, boolean resolve, boolean coreType) {
+        switch (featureID) {
+        case DescriptionPackage.ENUM_SET_LAYOUT_OPTION__VALUES:
+            return getValues();
+        }
+        return super.eGet(featureID, resolve, coreType);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @SuppressWarnings("unchecked")
+    @Override
+    public void eSet(int featureID, Object newValue) {
+        switch (featureID) {
+        case DescriptionPackage.ENUM_SET_LAYOUT_OPTION__VALUES:
+            getValues().clear();
+            getValues().addAll((Collection<? extends EnumLayoutValue>) newValue);
+            return;
+        }
+        super.eSet(featureID, newValue);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public void eUnset(int featureID) {
+        switch (featureID) {
+        case DescriptionPackage.ENUM_SET_LAYOUT_OPTION__VALUES:
+            getValues().clear();
+            return;
+        }
+        super.eUnset(featureID);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public boolean eIsSet(int featureID) {
+        switch (featureID) {
+        case DescriptionPackage.ENUM_SET_LAYOUT_OPTION__VALUES:
+            return values != null && !values.isEmpty();
+        }
+        return super.eIsSet(featureID);
+    }
+
+} // EnumSetLayoutOptionImpl
diff --git a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/util/DescriptionAdapterFactory.java b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/util/DescriptionAdapterFactory.java
index 497ef0ed4f..f3464d852f 100644
--- a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/util/DescriptionAdapterFactory.java
+++ b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/util/DescriptionAdapterFactory.java
@@ -36,6 +36,8 @@ import org.eclipse.sirius.diagram.description.EdgeMapping;
 import org.eclipse.sirius.diagram.description.EdgeMappingImport;
 import org.eclipse.sirius.diagram.description.EnumLayoutOption;
 import org.eclipse.sirius.diagram.description.EnumLayoutValue;
+import org.eclipse.sirius.diagram.description.EnumOption;
+import org.eclipse.sirius.diagram.description.EnumSetLayoutOption;
 import org.eclipse.sirius.diagram.description.IEdgeMapping;
 import org.eclipse.sirius.diagram.description.IntegerLayoutOption;
 import org.eclipse.sirius.diagram.description.Layer;
@@ -235,6 +237,16 @@ public class DescriptionAdapterFactory extends AdapterFactoryImpl {
         }
 
         @Override
+        public Adapter caseEnumSetLayoutOption(EnumSetLayoutOption object) {
+            return createEnumSetLayoutOptionAdapter();
+        }
+
+        @Override
+        public Adapter caseEnumOption(EnumOption object) {
+            return createEnumOptionAdapter();
+        }
+
+        @Override
         public Adapter caseEnumLayoutValue(EnumLayoutValue object) {
             return createEnumLayoutValueAdapter();
         }
@@ -682,6 +694,33 @@ public class DescriptionAdapterFactory extends AdapterFactoryImpl {
     }
 
     /**
+     * Creates a new adapter for an object of class '{@link org.eclipse.sirius.diagram.description.EnumSetLayoutOption
+     * <em>Enum Set Layout Option</em>}'. <!-- begin-user-doc --> This default implementation returns null so that we
+     * can easily ignore cases; it's useful to ignore a case when inheritance will catch all the cases anyway. <!--
+     * end-user-doc -->
+     *
+     * @return the new adapter.
+     * @see org.eclipse.sirius.diagram.description.EnumSetLayoutOption
+     * @generated
+     */
+    public Adapter createEnumSetLayoutOptionAdapter() {
+        return null;
+    }
+
+    /**
+     * Creates a new adapter for an object of class '{@link org.eclipse.sirius.diagram.description.EnumOption <em>Enum
+     * Option</em>}'. <!-- begin-user-doc --> This default implementation returns null so that we can easily ignore
+     * cases; it's useful to ignore a case when inheritance will catch all the cases anyway. <!-- end-user-doc -->
+     *
+     * @return the new adapter.
+     * @see org.eclipse.sirius.diagram.description.EnumOption
+     * @generated
+     */
+    public Adapter createEnumOptionAdapter() {
+        return null;
+    }
+
+    /**
      * Creates a new adapter for an object of class '{@link org.eclipse.sirius.diagram.description.EnumLayoutValue
      * <em>Enum Layout Value</em>}'. <!-- begin-user-doc --> This default implementation returns null so that we can
      * easily ignore cases; it's useful to ignore a case when inheritance will catch all the cases anyway. <!--
diff --git a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/util/DescriptionSwitch.java b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/util/DescriptionSwitch.java
index 81b8380d47..195d0df1ae 100644
--- a/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/util/DescriptionSwitch.java
+++ b/plugins/org.eclipse.sirius.diagram/src-gen/org/eclipse/sirius/diagram/description/util/DescriptionSwitch.java
@@ -36,6 +36,8 @@ import org.eclipse.sirius.diagram.description.EdgeMapping;
 import org.eclipse.sirius.diagram.description.EdgeMappingImport;
 import org.eclipse.sirius.diagram.description.EnumLayoutOption;
 import org.eclipse.sirius.diagram.description.EnumLayoutValue;
+import org.eclipse.sirius.diagram.description.EnumOption;
+import org.eclipse.sirius.diagram.description.EnumSetLayoutOption;
 import org.eclipse.sirius.diagram.description.IEdgeMapping;
 import org.eclipse.sirius.diagram.description.IntegerLayoutOption;
 import org.eclipse.sirius.diagram.description.Layer;
@@ -552,6 +554,9 @@ public class DescriptionSwitch<T> {
             EnumLayoutOption enumLayoutOption = (EnumLayoutOption) theEObject;
             T result = caseEnumLayoutOption(enumLayoutOption);
             if (result == null) {
+                result = caseEnumOption(enumLayoutOption);
+            }
+            if (result == null) {
                 result = caseLayoutOption(enumLayoutOption);
             }
             if (result == null) {
@@ -559,6 +564,31 @@ public class DescriptionSwitch<T> {
             }
             return result;
         }
+        case DescriptionPackage.ENUM_SET_LAYOUT_OPTION: {
+            EnumSetLayoutOption enumSetLayoutOption = (EnumSetLayoutOption) theEObject;
+            T result = caseEnumSetLayoutOption(enumSetLayoutOption);
+            if (result == null) {
+                result = caseEnumOption(enumSetLayoutOption);
+            }
+            if (result == null) {
+                result = caseLayoutOption(enumSetLayoutOption);
+            }
+            if (result == null) {
+                result = defaultCase(theEObject);
+            }
+            return result;
+        }
+        case DescriptionPackage.ENUM_OPTION: {
+            EnumOption enumOption = (EnumOption) theEObject;
+            T result = caseEnumOption(enumOption);
+            if (result == null) {
+                result = caseLayoutOption(enumOption);
+            }
+            if (result == null) {
+                result = defaultCase(theEObject);
+            }
+            return result;
+        }
         case DescriptionPackage.ENUM_LAYOUT_VALUE: {
             EnumLayoutValue enumLayoutValue = (EnumLayoutValue) theEObject;
             T result = caseEnumLayoutValue(enumLayoutValue);
@@ -1000,6 +1030,35 @@ public class DescriptionSwitch<T> {
     }
 
     /**
+     * Returns the result of interpreting the object as an instance of '<em>Enum Set Layout Option</em>'. <!--
+     * begin-user-doc --> This implementation returns null; returning a non-null result will terminate the switch. <!--
+     * end-user-doc -->
+     *
+     * @param object
+     *            the target of the switch.
+     * @return the result of interpreting the object as an instance of '<em>Enum Set Layout Option</em>'.
+     * @see #doSwitch(org.eclipse.emf.ecore.EObject) doSwitch(EObject)
+     * @generated
+     */
+    public T caseEnumSetLayoutOption(EnumSetLayoutOption object) {
+        return null;
+    }
+
+    /**
+     * Returns the result of interpreting the object as an instance of '<em>Enum Option</em>'. <!-- begin-user-doc -->
+     * This implementation returns null; returning a non-null result will terminate the switch. <!-- end-user-doc -->
+     *
+     * @param object
+     *            the target of the switch.
+     * @return the result of interpreting the object as an instance of '<em>Enum Option</em>'.
+     * @see #doSwitch(org.eclipse.emf.ecore.EObject) doSwitch(EObject)
+     * @generated
+     */
+    public T caseEnumOption(EnumOption object) {
+        return null;
+    }
+
+    /**
      * Returns the result of interpreting the object as an instance of '<em>Enum Layout Value</em>'. <!-- begin-user-doc
      * --> This implementation returns null; returning a non-null result will terminate the switch. <!-- end-user-doc
      * -->