[482528] Re-implement the support of reference widgets

One widget implements containment or not, single/multiple valued
references.

Bug: 482528
Change-Id: I4ee6f1549cfada8a73d0721e8b8baf6d5fbf6631
Signed-off-by: Mélanie Bats <melanie.bats@obeo.fr>

46 files changed, 3255 insertions, 3210 deletions

diff --git a/incubation/org.eclipse.sirius.editor.properties/help/contexts.xml b/incubation/org.eclipse.sirius.editor.properties/help/contexts.xml
index 034cc060cf..5dc605eef4 100644
--- a/incubation/org.eclipse.sirius.editor.properties/help/contexts.xml
+++ b/incubation/org.eclipse.sirius.editor.properties/help/contexts.xml
@@ -237,15 +237,15 @@
    
       </description>
    </context>
-   <context id="SingleReferenceDescription">
+   <context id="ReferenceDescription">
      <description>
-       Represents a single reference in the user interface.
+       Represents a reference in the user interface.
 
        
          
-   <!-- Start of user code SingleReferenceDescription description -->
+   <!-- Start of user code ReferenceDescription description -->
    
-   <!-- End of user code SingleReferenceDescription description -->
+   <!-- End of user code ReferenceDescription description -->
    
       </description>
    </context>
@@ -260,18 +260,6 @@
    
       </description>
    </context>
-   <context id="MultipleReferencesDescription">
-     <description>
-       Represents a radio button in the user interface.
-
-       
-         
-   <!-- Start of user code MultipleReferencesDescription description -->
-   
-   <!-- End of user code MultipleReferencesDescription description -->
-   
-      </description>
-   </context>
    <context id="CustomDescription">
      <description>
        
@@ -393,6 +381,17 @@
    
       </description>
    </context>
+   <context id="ReferenceWidgetStyle">
+     <description>
+       
+       
+         
+   <!-- Start of user code ReferenceWidgetStyle description -->
+   
+   <!-- End of user code ReferenceWidgetStyle description -->
+   
+      </description>
+   </context>
    <context id="WidgetConditionalStyle">
      <description>
        
@@ -481,4 +480,26 @@
    
       </description>
    </context>
+   <context id="ReferenceWidgetConditionalStyle">
+     <description>
+       
+       
+         
+   <!-- Start of user code ReferenceWidgetConditionalStyle description -->
+   
+   <!-- End of user code ReferenceWidgetConditionalStyle description -->
+   
+      </description>
+   </context>
+   <context id="WidgetAction">
+     <description>
+       
+       
+         
+   <!-- Start of user code WidgetAction description -->
+   
+   <!-- End of user code WidgetAction description -->
+   
+      </description>
+   </context>
 </contexts>
\ No newline at end of file
diff --git a/incubation/org.eclipse.sirius.editor.properties/plugin.xml b/incubation/org.eclipse.sirius.editor.properties/plugin.xml
index e6650eb7ad..fb60eaa046 100644
--- a/incubation/org.eclipse.sirius.editor.properties/plugin.xml
+++ b/incubation/org.eclipse.sirius.editor.properties/plugin.xml
@@ -17,6 +17,13 @@
   <extension point="org.eclipse.ui.views.properties.tabbed.propertySections">
     <propertySections contributorId="org.eclipse.sirius.editor.editorPlugin.SiriusEditorContributor">
   	  <propertySection
+               class="org.eclipse.sirius.properties.editor.properties.sections.properties.widgetaction.WidgetActionLabelExpressionPropertySection"
+               id="properties.section.widgetAction.LabelExpression"
+               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.widgetaction.WidgetActionLabelExpressionFilter"
+                tab="viewpoint.tab.general">
+        <input type="org.eclipse.sirius.properties.WidgetAction"/>
+      </propertySection>
+  	  <propertySection
                class="org.eclipse.sirius.properties.editor.properties.sections.properties.widgetconditionalstyle.WidgetConditionalStylePreconditionExpressionPropertySection"
                id="properties.section.widgetConditionalStyle.PreconditionExpression"
                filter="org.eclipse.sirius.properties.editor.properties.filters.properties.widgetconditionalstyle.WidgetConditionalStylePreconditionExpressionFilter"
@@ -163,34 +170,27 @@
         <input type="org.eclipse.sirius.properties.CustomExpression"/>
       </propertySection>
   	  <propertySection
-               class="org.eclipse.sirius.properties.editor.properties.sections.properties.multiplereferencesdescription.MultipleReferencesDescriptionDisplayExpressionPropertySection"
-               id="properties.section.multipleReferencesDescription.DisplayExpression"
-               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.multiplereferencesdescription.MultipleReferencesDescriptionDisplayExpressionFilter"
-               afterSection="properties.section.multipleReferencesDescription.ValueExpression"
-                tab="viewpoint.tab.general">
-        <input type="org.eclipse.sirius.properties.MultipleReferencesDescription"/>
-      </propertySection>
-  	  <propertySection
-               class="org.eclipse.sirius.properties.editor.properties.sections.properties.multiplereferencesdescription.MultipleReferencesDescriptionValueExpressionPropertySection"
-               id="properties.section.multipleReferencesDescription.ValueExpression"
-               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.multiplereferencesdescription.MultipleReferencesDescriptionValueExpressionFilter"
+               class="org.eclipse.sirius.properties.editor.properties.sections.properties.referencedescription.ReferenceDescriptionDisplayExpressionPropertySection"
+               id="properties.section.referenceDescription.DisplayExpression"
+               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.referencedescription.ReferenceDescriptionDisplayExpressionFilter"
+               afterSection="properties.section.referenceDescription.ValueExpression"
                 tab="viewpoint.tab.general">
-        <input type="org.eclipse.sirius.properties.MultipleReferencesDescription"/>
+        <input type="org.eclipse.sirius.properties.ReferenceDescription"/>
       </propertySection>
   	  <propertySection
-               class="org.eclipse.sirius.properties.editor.properties.sections.properties.singlereferencedescription.SingleReferenceDescriptionDisplayExpressionPropertySection"
-               id="properties.section.singleReferenceDescription.DisplayExpression"
-               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.singlereferencedescription.SingleReferenceDescriptionDisplayExpressionFilter"
-               afterSection="properties.section.singleReferenceDescription.ValueExpression"
+               class="org.eclipse.sirius.properties.editor.properties.sections.properties.referencedescription.ReferenceDescriptionValueExpressionPropertySection"
+               id="properties.section.referenceDescription.ValueExpression"
+               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.referencedescription.ReferenceDescriptionValueExpressionFilter"
+               afterSection="properties.section.referenceDescription.Multiple"
                 tab="viewpoint.tab.general">
-        <input type="org.eclipse.sirius.properties.SingleReferenceDescription"/>
+        <input type="org.eclipse.sirius.properties.ReferenceDescription"/>
       </propertySection>
   	  <propertySection
-               class="org.eclipse.sirius.properties.editor.properties.sections.properties.singlereferencedescription.SingleReferenceDescriptionValueExpressionPropertySection"
-               id="properties.section.singleReferenceDescription.ValueExpression"
-               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.singlereferencedescription.SingleReferenceDescriptionValueExpressionFilter"
+               class="org.eclipse.sirius.properties.editor.properties.sections.properties.referencedescription.ReferenceDescriptionMultiplePropertySection"
+               id="properties.section.referenceDescription.Multiple"
+               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.referencedescription.ReferenceDescriptionMultipleFilter"
                 tab="viewpoint.tab.general">
-        <input type="org.eclipse.sirius.properties.SingleReferenceDescription"/>
+        <input type="org.eclipse.sirius.properties.ReferenceDescription"/>
       </propertySection>
   	  <propertySection
                class="org.eclipse.sirius.properties.editor.properties.sections.properties.radiodescription.RadioDescriptionNumberOfColumnsPropertySection"
diff --git a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/singlereferencedescription/SingleReferenceDescriptionDisplayExpressionFilter.java b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/referencedescription/ReferenceDescriptionDisplayExpressionFilter.java
index 3a67687bdb..9fccc8443f 100644
--- a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/singlereferencedescription/SingleReferenceDescriptionDisplayExpressionFilter.java
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/referencedescription/ReferenceDescriptionDisplayExpressionFilter.java
@@ -7,7 +7,7 @@
  * Contributors:
  *    Obeo - initial API and implementation
  *******************************************************************************/
-package org.eclipse.sirius.properties.editor.properties.filters.properties.singlereferencedescription;
+package org.eclipse.sirius.properties.editor.properties.filters.properties.referencedescription;
 
 // Start of user code specific imports
 
@@ -20,14 +20,14 @@ import org.eclipse.sirius.properties.PropertiesPackage;
 /**
  * A filter for the displayExpression property section.
  */
-public class SingleReferenceDescriptionDisplayExpressionFilter extends ViewpointPropertyFilter {
+public class ReferenceDescriptionDisplayExpressionFilter extends ViewpointPropertyFilter {
 
     /**
      * {@inheritDoc}
      */
     @Override
     protected EStructuralFeature getFeature() {
-        return PropertiesPackage.eINSTANCE.getSingleReferenceDescription_DisplayExpression();
+        return PropertiesPackage.eINSTANCE.getReferenceDescription_DisplayExpression();
     }
 
     /**
@@ -35,7 +35,7 @@ public class SingleReferenceDescriptionDisplayExpressionFilter extends Viewpoint
      */
     @Override
     protected boolean isRightInputType(Object arg0) {
-        return arg0 instanceof org.eclipse.sirius.properties.SingleReferenceDescription;
+        return arg0 instanceof org.eclipse.sirius.properties.ReferenceDescription;
     }
 
     // Start of user code user methods
diff --git a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/multiplereferencesdescription/MultipleReferencesDescriptionValueExpressionFilter.java b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/referencedescription/ReferenceDescriptionMultipleFilter.java
index 3b323c1471..457dc0f7f1 100644
--- a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/multiplereferencesdescription/MultipleReferencesDescriptionValueExpressionFilter.java
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/referencedescription/ReferenceDescriptionMultipleFilter.java
@@ -7,7 +7,7 @@
  * Contributors:
  *    Obeo - initial API and implementation
  *******************************************************************************/
-package org.eclipse.sirius.properties.editor.properties.filters.properties.multiplereferencesdescription;
+package org.eclipse.sirius.properties.editor.properties.filters.properties.referencedescription;
 
 // Start of user code specific imports
 
@@ -18,16 +18,16 @@ import org.eclipse.sirius.properties.PropertiesPackage;
 // End of user code specific imports
 
 /**
- * A filter for the valueExpression property section.
+ * A filter for the multiple property section.
  */
-public class MultipleReferencesDescriptionValueExpressionFilter extends ViewpointPropertyFilter {
+public class ReferenceDescriptionMultipleFilter extends ViewpointPropertyFilter {
 
     /**
      * {@inheritDoc}
      */
     @Override
     protected EStructuralFeature getFeature() {
-        return PropertiesPackage.eINSTANCE.getMultipleReferencesDescription_ValueExpression();
+        return PropertiesPackage.eINSTANCE.getReferenceDescription_Multiple();
     }
 
     /**
@@ -35,7 +35,7 @@ public class MultipleReferencesDescriptionValueExpressionFilter extends Viewpoin
      */
     @Override
     protected boolean isRightInputType(Object arg0) {
-        return arg0 instanceof org.eclipse.sirius.properties.MultipleReferencesDescription;
+        return arg0 instanceof org.eclipse.sirius.properties.ReferenceDescription;
     }
 
     // Start of user code user methods
diff --git a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/singlereferencedescription/SingleReferenceDescriptionValueExpressionFilter.java b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/referencedescription/ReferenceDescriptionValueExpressionFilter.java
index c37a8c9264..c8523cbaeb 100644
--- a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/singlereferencedescription/SingleReferenceDescriptionValueExpressionFilter.java
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/referencedescription/ReferenceDescriptionValueExpressionFilter.java
@@ -7,7 +7,7 @@
  * Contributors:
  *    Obeo - initial API and implementation
  *******************************************************************************/
-package org.eclipse.sirius.properties.editor.properties.filters.properties.singlereferencedescription;
+package org.eclipse.sirius.properties.editor.properties.filters.properties.referencedescription;
 
 // Start of user code specific imports
 
@@ -20,14 +20,14 @@ import org.eclipse.sirius.properties.PropertiesPackage;
 /**
  * A filter for the valueExpression property section.
  */
-public class SingleReferenceDescriptionValueExpressionFilter extends ViewpointPropertyFilter {
+public class ReferenceDescriptionValueExpressionFilter extends ViewpointPropertyFilter {
 
     /**
      * {@inheritDoc}
      */
     @Override
     protected EStructuralFeature getFeature() {
-        return PropertiesPackage.eINSTANCE.getSingleReferenceDescription_ValueExpression();
+        return PropertiesPackage.eINSTANCE.getReferenceDescription_ValueExpression();
     }
 
     /**
@@ -35,7 +35,7 @@ public class SingleReferenceDescriptionValueExpressionFilter extends ViewpointPr
      */
     @Override
     protected boolean isRightInputType(Object arg0) {
-        return arg0 instanceof org.eclipse.sirius.properties.SingleReferenceDescription;
+        return arg0 instanceof org.eclipse.sirius.properties.ReferenceDescription;
     }
 
     // Start of user code user methods
diff --git a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/multiplereferencesdescription/MultipleReferencesDescriptionDisplayExpressionFilter.java b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/widgetaction/WidgetActionLabelExpressionFilter.java
index d2a4b22be8..7db50d98b6 100644
--- a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/multiplereferencesdescription/MultipleReferencesDescriptionDisplayExpressionFilter.java
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/widgetaction/WidgetActionLabelExpressionFilter.java
@@ -7,7 +7,7 @@
  * Contributors:
  *    Obeo - initial API and implementation
  *******************************************************************************/
-package org.eclipse.sirius.properties.editor.properties.filters.properties.multiplereferencesdescription;
+package org.eclipse.sirius.properties.editor.properties.filters.properties.widgetaction;
 
 // Start of user code specific imports
 
@@ -18,16 +18,16 @@ import org.eclipse.sirius.properties.PropertiesPackage;
 // End of user code specific imports
 
 /**
- * A filter for the displayExpression property section.
+ * A filter for the labelExpression property section.
  */
-public class MultipleReferencesDescriptionDisplayExpressionFilter extends ViewpointPropertyFilter {
+public class WidgetActionLabelExpressionFilter extends ViewpointPropertyFilter {
 
     /**
      * {@inheritDoc}
      */
     @Override
     protected EStructuralFeature getFeature() {
-        return PropertiesPackage.eINSTANCE.getMultipleReferencesDescription_DisplayExpression();
+        return PropertiesPackage.eINSTANCE.getWidgetAction_LabelExpression();
     }
 
     /**
@@ -35,7 +35,7 @@ public class MultipleReferencesDescriptionDisplayExpressionFilter extends Viewpo
      */
     @Override
     protected boolean isRightInputType(Object arg0) {
-        return arg0 instanceof org.eclipse.sirius.properties.MultipleReferencesDescription;
+        return arg0 instanceof org.eclipse.sirius.properties.WidgetAction;
     }
 
     // Start of user code user methods
diff --git a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/multiplereferencesdescription/MultipleReferencesDescriptionDisplayExpressionPropertySection.java b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/multiplereferencesdescription/MultipleReferencesDescriptionDisplayExpressionPropertySection.java
deleted file mode 100644
index fe87b558de..0000000000
--- a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/multiplereferencesdescription/MultipleReferencesDescriptionDisplayExpressionPropertySection.java
+++ /dev/null
@@ -1,121 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2016 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.properties.editor.properties.sections.properties.multiplereferencesdescription;
-
-import org.eclipse.emf.ecore.EAttribute;
-import org.eclipse.sirius.editor.editorPlugin.SiriusEditor;
-import org.eclipse.sirius.editor.properties.sections.common.AbstractTextWithButtonPropertySection;
-import org.eclipse.sirius.editor.tools.api.assist.TypeContentProposalProvider;
-import org.eclipse.sirius.editor.tools.internal.presentation.TextWithContentProposalDialog;
-import org.eclipse.sirius.properties.PropertiesPackage;
-import org.eclipse.sirius.ui.tools.api.assist.ContentProposalClient;
-import org.eclipse.swt.events.SelectionAdapter;
-import org.eclipse.swt.events.SelectionEvent;
-import org.eclipse.swt.events.SelectionListener;
-import org.eclipse.swt.widgets.Composite;
-import org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage;
-
-// End of user code imports
-
-/**
- * A section for the displayExpression property of a
- * MultipleReferencesDescription object.
- */
-public class MultipleReferencesDescriptionDisplayExpressionPropertySection extends AbstractTextWithButtonPropertySection implements ContentProposalClient {
-
-    /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getDefaultLabelText()
-     */
-    @Override
-    protected String getDefaultLabelText() {
-        return "DisplayExpression"; //$NON-NLS-1$
-    }
-
-    /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getLabelText()
-     */
-    @Override
-    protected String getLabelText() {
-        String labelText;
-        labelText = super.getLabelText() + ":"; //$NON-NLS-1$
-        // Start of user code get label text
-
-        // End of user code get label text
-        return labelText;
-    }
-
-    /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getFeature()
-     */
-    @Override
-    public EAttribute getFeature() {
-        return PropertiesPackage.eINSTANCE.getMultipleReferencesDescription_DisplayExpression();
-    }
-
-    /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getFeatureValue(String)
-     */
-    @Override
-    protected Object getFeatureValue(String newText) {
-        return newText;
-    }
-
-    /**
-     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#isEqual(String)
-     */
-    @Override
-    protected boolean isEqual(String newText) {
-        return getFeatureAsText().equals(newText);
-    }
-
-    /**
-     * {@inheritDoc}
-     */
-    @Override
-    public void createControls(Composite parent, TabbedPropertySheetPage tabbedPropertySheetPage) {
-        super.createControls(parent, tabbedPropertySheetPage);
-        /*
-         * We set the color as it's a InterpretedExpression
-         */
-        text.setBackground(SiriusEditor.getColorRegistry().get("yellow"));
-
-        TypeContentProposalProvider.bindPluginsCompletionProcessors(this, text);
-
-        // Start of user code create controls
-
-        // End of user code create controls
-
-    }
-
-    @Override
-    protected SelectionListener createButtonListener() {
-        return new SelectionAdapter() {
-            @Override
-            public void widgetSelected(SelectionEvent e) {
-                TextWithContentProposalDialog dialog = new TextWithContentProposalDialog(composite.getShell(), MultipleReferencesDescriptionDisplayExpressionPropertySection.this, text.getText());
-                dialog.open();
-                text.setText(dialog.getResult());
-                handleTextModified();
-            }
-        };
-    }
-
-    /**
-     * {@inheritDoc}
-     */
-    @Override
-    protected String getPropertyDescription() {
-        return "";
-    }
-
-    // Start of user code user operations
-
-    // End of user code user operations
-}
diff --git a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/singlereferencedescription/SingleReferenceDescriptionDisplayExpressionPropertySection.java b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/referencedescription/ReferenceDescriptionDisplayExpressionPropertySection.java
index 40a899de13..e50d1febff 100644
--- a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/singlereferencedescription/SingleReferenceDescriptionDisplayExpressionPropertySection.java
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/referencedescription/ReferenceDescriptionDisplayExpressionPropertySection.java
@@ -7,7 +7,7 @@
  * Contributors:
  *    Obeo - initial API and implementation
  *******************************************************************************/
-package org.eclipse.sirius.properties.editor.properties.sections.properties.singlereferencedescription;
+package org.eclipse.sirius.properties.editor.properties.sections.properties.referencedescription;
 
 import org.eclipse.emf.ecore.EAttribute;
 import org.eclipse.sirius.editor.editorPlugin.SiriusEditor;
@@ -25,10 +25,10 @@ import org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage;
 // End of user code imports
 
 /**
- * A section for the displayExpression property of a SingleReferenceDescription
+ * A section for the displayExpression property of a ReferenceDescription
  * object.
  */
-public class SingleReferenceDescriptionDisplayExpressionPropertySection extends AbstractTextWithButtonPropertySection implements ContentProposalClient {
+public class ReferenceDescriptionDisplayExpressionPropertySection extends AbstractTextWithButtonPropertySection implements ContentProposalClient {
 
     /**
      * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getDefaultLabelText()
@@ -56,7 +56,7 @@ public class SingleReferenceDescriptionDisplayExpressionPropertySection extends
      */
     @Override
     public EAttribute getFeature() {
-        return PropertiesPackage.eINSTANCE.getSingleReferenceDescription_DisplayExpression();
+        return PropertiesPackage.eINSTANCE.getReferenceDescription_DisplayExpression();
     }
 
     /**
@@ -99,7 +99,7 @@ public class SingleReferenceDescriptionDisplayExpressionPropertySection extends
         return new SelectionAdapter() {
             @Override
             public void widgetSelected(SelectionEvent e) {
-                TextWithContentProposalDialog dialog = new TextWithContentProposalDialog(composite.getShell(), SingleReferenceDescriptionDisplayExpressionPropertySection.this, text.getText());
+                TextWithContentProposalDialog dialog = new TextWithContentProposalDialog(composite.getShell(), ReferenceDescriptionDisplayExpressionPropertySection.this, text.getText());
                 dialog.open();
                 text.setText(dialog.getResult());
                 handleTextModified();
diff --git a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/referencedescription/ReferenceDescriptionMultiplePropertySection.java b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/referencedescription/ReferenceDescriptionMultiplePropertySection.java
new file mode 100644
index 0000000000..e09e135dd0
--- /dev/null
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/referencedescription/ReferenceDescriptionMultiplePropertySection.java
@@ -0,0 +1,109 @@
+/*******************************************************************************
+ * Copyright (c) 2016 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.properties.editor.properties.sections.properties.referencedescription;
+
+// Start of user code imports
+
+import org.eclipse.emf.ecore.EAttribute;
+import org.eclipse.sirius.editor.properties.sections.common.AbstractCheckBoxPropertySection;
+// End of user code imports
+import org.eclipse.sirius.properties.PropertiesPackage;
+import org.eclipse.swt.widgets.Composite;
+import org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage;
+
+/**
+ * A section for the multiple property of a ReferenceDescription object.
+ */
+public class ReferenceDescriptionMultiplePropertySection extends AbstractCheckBoxPropertySection {
+    /**
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractCheckBoxPropertySection#getDefaultLabelText()
+     */
+    @Override
+    protected String getDefaultLabelText() {
+        return "Multiple"; //$NON-NLS-1$
+    }
+
+    /**
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractCheckBoxPropertySection#getLabelText()
+     */
+    @Override
+    protected String getLabelText() {
+        String labelText;
+        labelText = super.getLabelText() + ":"; //$NON-NLS-1$
+        // Start of user code get label text
+
+        // End of user code get label text
+        return labelText;
+    }
+
+    /**
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractCheckBoxPropertySection#getFeature()
+     */
+    @Override
+    protected EAttribute getFeature() {
+        return PropertiesPackage.eINSTANCE.getReferenceDescription_Multiple();
+    }
+
+    /**
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractCheckBoxPropertySection#getFeatureAsInteger()
+     */
+    @Override
+    protected String getDefaultFeatureAsText() {
+        String value = new String();
+        if (eObject.eGet(getFeature()) != null) {
+            value = toBoolean(eObject.eGet(getFeature()).toString()).toString();
+        }
+        return value;
+    }
+
+    /**
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractCheckBoxPropertySection#getFeatureValue(int)
+     */
+    @Override
+    protected Object getFeatureValue(String newText) {
+        return toBoolean(newText);
+    }
+
+    /**
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractCheckBoxPropertySection#isEqual(int)
+     */
+    @Override
+    protected boolean isEqual(String newText) {
+        boolean equal = true;
+        if (toBoolean(newText) != null) {
+            equal = getFeatureAsText().equals(toBoolean(newText).toString());
+        } else {
+            refresh();
+        }
+        return equal;
+    }
+
+    /**
+     * Converts the given text to the boolean it represents if applicable.
+     *
+     * @return The boolean the given text represents if applicable,
+     *         <code>null</code> otherwise.
+     */
+    private Boolean toBoolean(String text) {
+        Boolean booleanValue = null;
+        if (text.toLowerCase().matches("true|false")) {
+            booleanValue = Boolean.parseBoolean(text);
+        }
+        return booleanValue;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public void createControls(Composite parent, TabbedPropertySheetPage tabbedPropertySheetPage) {
+        super.createControls(parent, tabbedPropertySheetPage);
+    }
+}
diff --git a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/singlereferencedescription/SingleReferenceDescriptionValueExpressionPropertySection.java b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/referencedescription/ReferenceDescriptionValueExpressionPropertySection.java
index 9772ae5d6d..0763341db2 100644
--- a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/singlereferencedescription/SingleReferenceDescriptionValueExpressionPropertySection.java
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/referencedescription/ReferenceDescriptionValueExpressionPropertySection.java
@@ -7,7 +7,7 @@
  * Contributors:
  *    Obeo - initial API and implementation
  *******************************************************************************/
-package org.eclipse.sirius.properties.editor.properties.sections.properties.singlereferencedescription;
+package org.eclipse.sirius.properties.editor.properties.sections.properties.referencedescription;
 
 import org.eclipse.emf.ecore.EAttribute;
 import org.eclipse.sirius.editor.editorPlugin.SiriusEditor;
@@ -25,10 +25,9 @@ import org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage;
 // End of user code imports
 
 /**
- * A section for the valueExpression property of a SingleReferenceDescription
- * object.
+ * A section for the valueExpression property of a ReferenceDescription object.
  */
-public class SingleReferenceDescriptionValueExpressionPropertySection extends AbstractTextWithButtonPropertySection implements ContentProposalClient {
+public class ReferenceDescriptionValueExpressionPropertySection extends AbstractTextWithButtonPropertySection implements ContentProposalClient {
 
     /**
      * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getDefaultLabelText()
@@ -56,7 +55,7 @@ public class SingleReferenceDescriptionValueExpressionPropertySection extends Ab
      */
     @Override
     public EAttribute getFeature() {
-        return PropertiesPackage.eINSTANCE.getSingleReferenceDescription_ValueExpression();
+        return PropertiesPackage.eINSTANCE.getReferenceDescription_ValueExpression();
     }
 
     /**
@@ -99,7 +98,7 @@ public class SingleReferenceDescriptionValueExpressionPropertySection extends Ab
         return new SelectionAdapter() {
             @Override
             public void widgetSelected(SelectionEvent e) {
-                TextWithContentProposalDialog dialog = new TextWithContentProposalDialog(composite.getShell(), SingleReferenceDescriptionValueExpressionPropertySection.this, text.getText());
+                TextWithContentProposalDialog dialog = new TextWithContentProposalDialog(composite.getShell(), ReferenceDescriptionValueExpressionPropertySection.this, text.getText());
                 dialog.open();
                 text.setText(dialog.getResult());
                 handleTextModified();
diff --git a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/multiplereferencesdescription/MultipleReferencesDescriptionValueExpressionPropertySection.java b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/widgetaction/WidgetActionLabelExpressionPropertySection.java
index 6cfd232630..0ce09d8ecf 100644
--- a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/multiplereferencesdescription/MultipleReferencesDescriptionValueExpressionPropertySection.java
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/widgetaction/WidgetActionLabelExpressionPropertySection.java
@@ -7,7 +7,7 @@
  * Contributors:
  *    Obeo - initial API and implementation
  *******************************************************************************/
-package org.eclipse.sirius.properties.editor.properties.sections.properties.multiplereferencesdescription;
+package org.eclipse.sirius.properties.editor.properties.sections.properties.widgetaction;
 
 import org.eclipse.emf.ecore.EAttribute;
 import org.eclipse.sirius.editor.editorPlugin.SiriusEditor;
@@ -25,17 +25,16 @@ import org.eclipse.ui.views.properties.tabbed.TabbedPropertySheetPage;
 // End of user code imports
 
 /**
- * A section for the valueExpression property of a MultipleReferencesDescription
- * object.
+ * A section for the labelExpression property of a WidgetAction object.
  */
-public class MultipleReferencesDescriptionValueExpressionPropertySection extends AbstractTextWithButtonPropertySection implements ContentProposalClient {
+public class WidgetActionLabelExpressionPropertySection extends AbstractTextWithButtonPropertySection implements ContentProposalClient {
 
     /**
      * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getDefaultLabelText()
      */
     @Override
     protected String getDefaultLabelText() {
-        return "ValueExpression"; //$NON-NLS-1$
+        return "LabelExpression"; //$NON-NLS-1$
     }
 
     /**
@@ -56,7 +55,7 @@ public class MultipleReferencesDescriptionValueExpressionPropertySection extends
      */
     @Override
     public EAttribute getFeature() {
-        return PropertiesPackage.eINSTANCE.getMultipleReferencesDescription_ValueExpression();
+        return PropertiesPackage.eINSTANCE.getWidgetAction_LabelExpression();
     }
 
     /**
@@ -99,7 +98,7 @@ public class MultipleReferencesDescriptionValueExpressionPropertySection extends
         return new SelectionAdapter() {
             @Override
             public void widgetSelected(SelectionEvent e) {
-                TextWithContentProposalDialog dialog = new TextWithContentProposalDialog(composite.getShell(), MultipleReferencesDescriptionValueExpressionPropertySection.this, text.getText());
+                TextWithContentProposalDialog dialog = new TextWithContentProposalDialog(composite.getShell(), WidgetActionLabelExpressionPropertySection.this, text.getText());
                 dialog.open();
                 text.setText(dialog.getResult());
                 handleTextModified();
diff --git a/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/ReferenceDescription.gif b/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/ReferenceDescription.gif
new file mode 100644
index 0000000000..94c953e013
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/ReferenceDescription.gif
diff --git a/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/ReferenceWidgetConditionalStyle.gif b/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/ReferenceWidgetConditionalStyle.gif
new file mode 100644
index 0000000000..b3643da048
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/ReferenceWidgetConditionalStyle.gif
diff --git a/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/ReferenceWidgetStyle.gif b/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/ReferenceWidgetStyle.gif
new file mode 100644
index 0000000000..db7414e937
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/ReferenceWidgetStyle.gif
diff --git a/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/WidgetAction.gif b/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/WidgetAction.gif
new file mode 100644
index 0000000000..ed87474740
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/WidgetAction.gif
diff --git a/incubation/org.eclipse.sirius.properties.edit/plugin.properties b/incubation/org.eclipse.sirius.properties.edit/plugin.properties
index 9a5781a7b7..5296033f97 100644
--- a/incubation/org.eclipse.sirius.properties.edit/plugin.properties
+++ b/incubation/org.eclipse.sirius.properties.edit/plugin.properties
@@ -86,10 +86,6 @@ _UI_SingleReferenceDescription_addButton_feature = Add Button
 _UI_AddButtonDescription_type = Add Button Description
 _UI_AddButtonDescription_initialOperation_feature = Initial Operation
 _UI_OperationDescription_type = Operation Description
-_UI_SingleReferenceDescription_createOperation_feature = Create Operation
-_UI_SingleReferenceDescription_searchOperation_feature = Search Operation
-_UI_SingleReferenceDescription_unsetOperation_feature = Unset Operation
-_UI_SingleReferenceDescription_onClickOperation_feature = On Click Operation
 _UI_CustomDescription_type = Custom Description
 _UI_CustomExpression_type = Custom Expression
 _UI_CustomDescription_customExpressions_feature = Custom Expressions
@@ -103,18 +99,6 @@ _UI_CustomDescription_customOperations_feature = Custom Operations
 _UI_CustomOperation_identifier_feature = Identifier
 _UI_CustomOperation_initialOperation_feature = Initial Operation
 _UI_OperationDescription_initialOperation_feature = Initial Operation
-_UI_MultipleReferencesDescription_type = Multiple References Description
-_UI_MultipleReferencesDescription_valueExpression_feature = Value Expression
-_UI_MultipleReferencesDescription_candidatesExpression_feature = Candidates Expression
-_UI_MultipleReferencesDescription_candidateDisplayExpression_feature = Candidate Display Expression
-_UI_MultipleReferencesDescription_createOperation_feature = Create Operation
-_UI_MultipleReferencesDescription_searchOperation_feature = Search Operation
-_UI_MultipleReferencesDescription_unsetOperation_feature = Unset Operation
-_UI_MultipleReferencesDescription_onClickOperation_feature = On Click Operation
-_UI_MultipleReferencesDescription_upOperation_feature = Up Operation
-_UI_MultipleReferencesDescription_downOperation_feature = Down Operation
-_UI_SingleReferenceDescription_displayExpression_feature = Display Expression
-_UI_MultipleReferencesDescription_displayExpression_feature = Display Expression
 _UI_ValidationSetDescription_type = Validation
 _UI_PropertyValidationRule_type = Property Validation Rule
 _UI_PageDescription_validationSet_feature = Validation
@@ -214,3 +198,17 @@ _UI_GridLayoutDescription_numberOfColumns_feature = Number Of Columns
 _UI_GridLayoutDescription_makeColumnsWithEqualWidth_feature = Make Columns With Equal Width
 _UI_FILL_LAYOUT_ORIENTATION_VERTICAL_literal = VERTICAL
 _UI_FILL_LAYOUT_ORIENTATION_HORIZONTAL_literal = HORIZONTAL
+_UI_ReferenceDescription_type = Reference Description
+_UI_WidgetAction_type = Widget Action
+_UI_ReferenceWidgetStyle_type = Reference Widget Style
+_UI_ReferenceDescription_multiple_feature = Multiple
+_UI_ReferenceDescription_valueExpression_feature = Value Expression
+_UI_ReferenceDescription_displayExpression_feature = Display Expression
+_UI_ReferenceDescription_onClickOperation_feature = On Click Operation
+_UI_ReferenceDescription_actions_feature = Actions
+_UI_ReferenceDescription_style_feature = Style
+_UI_WidgetAction_labelExpression_feature = Label Expression
+_UI_WidgetAction_initialOperation_feature = Initial Operation
+_UI_ReferenceWidgetConditionalStyle_type = Reference Widget Conditional Style
+_UI_ReferenceDescription_conditionalStyles_feature = Conditional Styles
+_UI_ReferenceWidgetConditionalStyle_style_feature = Style
diff --git a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/ContainerDescriptionItemProvider.java b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/ContainerDescriptionItemProvider.java
index e3df120420..51f010cb09 100644
--- a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/ContainerDescriptionItemProvider.java
+++ b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/ContainerDescriptionItemProvider.java
@@ -163,9 +163,7 @@ public class ContainerDescriptionItemProvider extends ControlDescriptionItemProv
 
         newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.CONTAINER_DESCRIPTION__CONTROLS, PropertiesFactory.eINSTANCE.createRadioDescription()));
 
-        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.CONTAINER_DESCRIPTION__CONTROLS, PropertiesFactory.eINSTANCE.createSingleReferenceDescription()));
-
-        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.CONTAINER_DESCRIPTION__CONTROLS, PropertiesFactory.eINSTANCE.createMultipleReferencesDescription()));
+        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.CONTAINER_DESCRIPTION__CONTROLS, PropertiesFactory.eINSTANCE.createReferenceDescription()));
 
         newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.CONTAINER_DESCRIPTION__CONTROLS, PropertiesFactory.eINSTANCE.createCustomDescription()));
 
diff --git a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/DynamicMappingIfItemProvider.java b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/DynamicMappingIfItemProvider.java
index 3d1f7eb0e8..494b88586e 100644
--- a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/DynamicMappingIfItemProvider.java
+++ b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/DynamicMappingIfItemProvider.java
@@ -184,9 +184,7 @@ public class DynamicMappingIfItemProvider extends ItemProviderAdapter
 
         newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.DYNAMIC_MAPPING_IF__WIDGET, PropertiesFactory.eINSTANCE.createRadioDescription()));
 
-        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.DYNAMIC_MAPPING_IF__WIDGET, PropertiesFactory.eINSTANCE.createSingleReferenceDescription()));
-
-        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.DYNAMIC_MAPPING_IF__WIDGET, PropertiesFactory.eINSTANCE.createMultipleReferencesDescription()));
+        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.DYNAMIC_MAPPING_IF__WIDGET, PropertiesFactory.eINSTANCE.createReferenceDescription()));
 
         newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.DYNAMIC_MAPPING_IF__WIDGET, PropertiesFactory.eINSTANCE.createCustomDescription()));
     }
diff --git a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/GroupDescriptionItemProvider.java b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/GroupDescriptionItemProvider.java
index 40234ff000..35453c8c9a 100644
--- a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/GroupDescriptionItemProvider.java
+++ b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/GroupDescriptionItemProvider.java
@@ -247,9 +247,7 @@ public class GroupDescriptionItemProvider extends ItemProviderAdapter
 
         newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.GROUP_DESCRIPTION__CONTROLS, PropertiesFactory.eINSTANCE.createRadioDescription()));
 
-        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.GROUP_DESCRIPTION__CONTROLS, PropertiesFactory.eINSTANCE.createSingleReferenceDescription()));
-
-        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.GROUP_DESCRIPTION__CONTROLS, PropertiesFactory.eINSTANCE.createMultipleReferencesDescription()));
+        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.GROUP_DESCRIPTION__CONTROLS, PropertiesFactory.eINSTANCE.createReferenceDescription()));
 
         newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.GROUP_DESCRIPTION__CONTROLS, PropertiesFactory.eINSTANCE.createCustomDescription()));
 
diff --git a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/MultipleReferencesDescriptionItemProvider.java b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/MultipleReferencesDescriptionItemProvider.java
deleted file mode 100644
index 78199cfeb1..0000000000
--- a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/MultipleReferencesDescriptionItemProvider.java
+++ /dev/null
@@ -1,228 +0,0 @@
-/**
- * Copyright (c) 2016 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.properties.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.ComposeableAdapterFactory;
-import org.eclipse.emf.edit.provider.IItemPropertyDescriptor;
-import org.eclipse.emf.edit.provider.ItemPropertyDescriptor;
-import org.eclipse.emf.edit.provider.ViewerNotification;
-import org.eclipse.sirius.properties.MultipleReferencesDescription;
-import org.eclipse.sirius.properties.PropertiesFactory;
-import org.eclipse.sirius.properties.PropertiesPackage;
-
-/**
- * This is the item provider adapter for a
- * {@link org.eclipse.sirius.properties.MultipleReferencesDescription} object.
- * <!-- begin-user-doc --> <!-- end-user-doc -->
- *
- * @generated
- */
-public class MultipleReferencesDescriptionItemProvider extends WidgetDescriptionItemProvider {
-    /**
-     * This constructs an instance from a factory and a notifier. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    public MultipleReferencesDescriptionItemProvider(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);
-
-            addValueExpressionPropertyDescriptor(object);
-            addDisplayExpressionPropertyDescriptor(object);
-        }
-        return itemPropertyDescriptors;
-    }
-
-    /**
-     * This adds a property descriptor for the Value Expression feature. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    protected void addValueExpressionPropertyDescriptor(Object object) {
-        itemPropertyDescriptors.add(createItemPropertyDescriptor(((ComposeableAdapterFactory) adapterFactory).getRootAdapterFactory(), getResourceLocator(),
-                getString("_UI_MultipleReferencesDescription_valueExpression_feature"),
-                getString("_UI_PropertyDescriptor_description", "_UI_MultipleReferencesDescription_valueExpression_feature", "_UI_MultipleReferencesDescription_type"),
-                PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__VALUE_EXPRESSION, true, false, false, ItemPropertyDescriptor.GENERIC_VALUE_IMAGE, null, null));
-    }
-
-    /**
-     * This adds a property descriptor for the Display Expression feature. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    protected void addDisplayExpressionPropertyDescriptor(Object object) {
-        itemPropertyDescriptors.add(createItemPropertyDescriptor(((ComposeableAdapterFactory) adapterFactory).getRootAdapterFactory(), getResourceLocator(),
-                getString("_UI_MultipleReferencesDescription_displayExpression_feature"),
-                getString("_UI_PropertyDescriptor_description", "_UI_MultipleReferencesDescription_displayExpression_feature", "_UI_MultipleReferencesDescription_type"),
-                PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__DISPLAY_EXPRESSION, true, false, false, ItemPropertyDescriptor.GENERIC_VALUE_IMAGE, null, null));
-    }
-
-    /**
-     * 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(PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__CREATE_OPERATION);
-            childrenFeatures.add(PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__SEARCH_OPERATION);
-            childrenFeatures.add(PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__UNSET_OPERATION);
-            childrenFeatures.add(PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__ON_CLICK_OPERATION);
-            childrenFeatures.add(PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__UP_OPERATION);
-            childrenFeatures.add(PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__DOWN_OPERATION);
-        }
-        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 MultipleReferencesDescription.gif. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public Object getImage(Object object) {
-        return overlayImage(object, getResourceLocator().getImage("full/obj16/MultipleReferencesDescription"));
-    }
-
-    /**
-     * This returns the label text for the adapted class. <!-- begin-user-doc
-     * --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public String getText(Object object) {
-        String label = ((MultipleReferencesDescription) object).getIdentifier();
-        return label == null || label.length() == 0 ? getString("_UI_MultipleReferencesDescription_type") : getString("_UI_MultipleReferencesDescription_type") + " " + label;
-    }
-
-    /**
-     * 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(MultipleReferencesDescription.class)) {
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__VALUE_EXPRESSION:
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DISPLAY_EXPRESSION:
-            fireNotifyChanged(new ViewerNotification(notification, notification.getNotifier(), false, true));
-            return;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__CREATE_OPERATION:
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__SEARCH_OPERATION:
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UNSET_OPERATION:
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__ON_CLICK_OPERATION:
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UP_OPERATION:
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DOWN_OPERATION:
-            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(PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__CREATE_OPERATION, PropertiesFactory.eINSTANCE.createOperationDescription()));
-
-        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__SEARCH_OPERATION, PropertiesFactory.eINSTANCE.createOperationDescription()));
-
-        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__UNSET_OPERATION, PropertiesFactory.eINSTANCE.createOperationDescription()));
-
-        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__ON_CLICK_OPERATION, PropertiesFactory.eINSTANCE.createOperationDescription()));
-
-        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__UP_OPERATION, PropertiesFactory.eINSTANCE.createOperationDescription()));
-
-        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__DOWN_OPERATION, PropertiesFactory.eINSTANCE.createOperationDescription()));
-    }
-
-    /**
-     * 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 == PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__CREATE_OPERATION
-                || childFeature == PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__SEARCH_OPERATION
-                || childFeature == PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__UNSET_OPERATION
-                || childFeature == PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__ON_CLICK_OPERATION
-                || childFeature == PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__UP_OPERATION
-                || childFeature == PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION__DOWN_OPERATION;
-
-        if (qualify) {
-            return getString("_UI_CreateChild_text2", new Object[] { getTypeText(childObject), getFeatureText(childFeature), getTypeText(owner) });
-        }
-        return super.getCreateChildText(owner, feature, child, selection);
-    }
-
-}
diff --git a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/PropertiesItemProviderAdapterFactory.java b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/PropertiesItemProviderAdapterFactory.java
index 6c2c72883e..7712d972e3 100644
--- a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/PropertiesItemProviderAdapterFactory.java
+++ b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/PropertiesItemProviderAdapterFactory.java
@@ -546,27 +546,27 @@ public class PropertiesItemProviderAdapterFactory extends PropertiesAdapterFacto
 
     /**
      * This keeps track of the one adapter used for all
-     * {@link org.eclipse.sirius.properties.SingleReferenceDescription}
-     * instances. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * {@link org.eclipse.sirius.properties.ReferenceDescription} instances.
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      */
-    protected SingleReferenceDescriptionItemProvider singleReferenceDescriptionItemProvider;
+    protected ReferenceDescriptionItemProvider referenceDescriptionItemProvider;
 
     /**
      * This creates an adapter for a
-     * {@link org.eclipse.sirius.properties.SingleReferenceDescription}. <!--
+     * {@link org.eclipse.sirius.properties.ReferenceDescription}. <!--
      * begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      */
     @Override
-    public Adapter createSingleReferenceDescriptionAdapter() {
-        if (singleReferenceDescriptionItemProvider == null) {
-            singleReferenceDescriptionItemProvider = new SingleReferenceDescriptionItemProvider(this);
+    public Adapter createReferenceDescriptionAdapter() {
+        if (referenceDescriptionItemProvider == null) {
+            referenceDescriptionItemProvider = new ReferenceDescriptionItemProvider(this);
         }
 
-        return singleReferenceDescriptionItemProvider;
+        return referenceDescriptionItemProvider;
     }
 
     /**
@@ -596,31 +596,6 @@ public class PropertiesItemProviderAdapterFactory extends PropertiesAdapterFacto
 
     /**
      * This keeps track of the one adapter used for all
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription}
-     * instances. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    protected MultipleReferencesDescriptionItemProvider multipleReferencesDescriptionItemProvider;
-
-    /**
-     * This creates an adapter for a
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription}. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public Adapter createMultipleReferencesDescriptionAdapter() {
-        if (multipleReferencesDescriptionItemProvider == null) {
-            multipleReferencesDescriptionItemProvider = new MultipleReferencesDescriptionItemProvider(this);
-        }
-
-        return multipleReferencesDescriptionItemProvider;
-    }
-
-    /**
-     * This keeps track of the one adapter used for all
      * {@link org.eclipse.sirius.properties.CustomDescription} instances. <!--
      * begin-user-doc --> <!-- end-user-doc -->
      *
@@ -1070,6 +1045,81 @@ public class PropertiesItemProviderAdapterFactory extends PropertiesAdapterFacto
     }
 
     /**
+     * This keeps track of the one adapter used for all
+     * {@link org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle}
+     * instances. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    protected ReferenceWidgetConditionalStyleItemProvider referenceWidgetConditionalStyleItemProvider;
+
+    /**
+     * This creates an adapter for a
+     * {@link org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle}.
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public Adapter createReferenceWidgetConditionalStyleAdapter() {
+        if (referenceWidgetConditionalStyleItemProvider == null) {
+            referenceWidgetConditionalStyleItemProvider = new ReferenceWidgetConditionalStyleItemProvider(this);
+        }
+
+        return referenceWidgetConditionalStyleItemProvider;
+    }
+
+    /**
+     * This keeps track of the one adapter used for all
+     * {@link org.eclipse.sirius.properties.WidgetAction} instances. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    protected WidgetActionItemProvider widgetActionItemProvider;
+
+    /**
+     * This creates an adapter for a
+     * {@link org.eclipse.sirius.properties.WidgetAction}. <!-- begin-user-doc
+     * --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public Adapter createWidgetActionAdapter() {
+        if (widgetActionItemProvider == null) {
+            widgetActionItemProvider = new WidgetActionItemProvider(this);
+        }
+
+        return widgetActionItemProvider;
+    }
+
+    /**
+     * This keeps track of the one adapter used for all
+     * {@link org.eclipse.sirius.properties.ReferenceWidgetStyle} instances.
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    protected ReferenceWidgetStyleItemProvider referenceWidgetStyleItemProvider;
+
+    /**
+     * This creates an adapter for a
+     * {@link org.eclipse.sirius.properties.ReferenceWidgetStyle}. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public Adapter createReferenceWidgetStyleAdapter() {
+        if (referenceWidgetStyleItemProvider == null) {
+            referenceWidgetStyleItemProvider = new ReferenceWidgetStyleItemProvider(this);
+        }
+
+        return referenceWidgetStyleItemProvider;
+    }
+
+    /**
      * This returns the root adapter factory that contains this factory. <!--
      * begin-user-doc --> <!-- end-user-doc -->
      *
@@ -1227,15 +1277,12 @@ public class PropertiesItemProviderAdapterFactory extends PropertiesAdapterFacto
         if (radioDescriptionItemProvider != null) {
             radioDescriptionItemProvider.dispose();
         }
-        if (singleReferenceDescriptionItemProvider != null) {
-            singleReferenceDescriptionItemProvider.dispose();
+        if (referenceDescriptionItemProvider != null) {
+            referenceDescriptionItemProvider.dispose();
         }
         if (operationDescriptionItemProvider != null) {
             operationDescriptionItemProvider.dispose();
         }
-        if (multipleReferencesDescriptionItemProvider != null) {
-            multipleReferencesDescriptionItemProvider.dispose();
-        }
         if (customDescriptionItemProvider != null) {
             customDescriptionItemProvider.dispose();
         }
@@ -1269,6 +1316,9 @@ public class PropertiesItemProviderAdapterFactory extends PropertiesAdapterFacto
         if (customWidgetStyleItemProvider != null) {
             customWidgetStyleItemProvider.dispose();
         }
+        if (referenceWidgetStyleItemProvider != null) {
+            referenceWidgetStyleItemProvider.dispose();
+        }
         if (textWidgetConditionalStyleItemProvider != null) {
             textWidgetConditionalStyleItemProvider.dispose();
         }
@@ -1290,6 +1340,12 @@ public class PropertiesItemProviderAdapterFactory extends PropertiesAdapterFacto
         if (customWidgetConditionalStyleItemProvider != null) {
             customWidgetConditionalStyleItemProvider.dispose();
         }
+        if (referenceWidgetConditionalStyleItemProvider != null) {
+            referenceWidgetConditionalStyleItemProvider.dispose();
+        }
+        if (widgetActionItemProvider != null) {
+            widgetActionItemProvider.dispose();
+        }
     }
 
     /**
diff --git a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/SingleReferenceDescriptionItemProvider.java b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/ReferenceDescriptionItemProvider.java
index bfca101561..a94faffd98 100644
--- a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/SingleReferenceDescriptionItemProvider.java
+++ b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/ReferenceDescriptionItemProvider.java
@@ -23,23 +23,24 @@ import org.eclipse.emf.edit.provider.ItemPropertyDescriptor;
 import org.eclipse.emf.edit.provider.ViewerNotification;
 import org.eclipse.sirius.properties.PropertiesFactory;
 import org.eclipse.sirius.properties.PropertiesPackage;
-import org.eclipse.sirius.properties.SingleReferenceDescription;
+import org.eclipse.sirius.properties.ReferenceDescription;
+import org.eclipse.sirius.viewpoint.description.tool.ToolFactory;
 
 /**
  * This is the item provider adapter for a
- * {@link org.eclipse.sirius.properties.SingleReferenceDescription} object. <!--
+ * {@link org.eclipse.sirius.properties.ReferenceDescription} object. <!--
  * begin-user-doc --> <!-- end-user-doc -->
  *
  * @generated
  */
-public class SingleReferenceDescriptionItemProvider extends WidgetDescriptionItemProvider {
+public class ReferenceDescriptionItemProvider extends WidgetDescriptionItemProvider {
     /**
      * This constructs an instance from a factory and a notifier. <!--
      * begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      */
-    public SingleReferenceDescriptionItemProvider(AdapterFactory adapterFactory) {
+    public ReferenceDescriptionItemProvider(AdapterFactory adapterFactory) {
         super(adapterFactory);
     }
 
@@ -54,6 +55,7 @@ public class SingleReferenceDescriptionItemProvider extends WidgetDescriptionIte
         if (itemPropertyDescriptors == null) {
             super.getPropertyDescriptors(object);
 
+            addMultiplePropertyDescriptor(object);
             addValueExpressionPropertyDescriptor(object);
             addDisplayExpressionPropertyDescriptor(object);
         }
@@ -61,16 +63,28 @@ public class SingleReferenceDescriptionItemProvider extends WidgetDescriptionIte
     }
 
     /**
+     * This adds a property descriptor for the Multiple feature. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    protected void addMultiplePropertyDescriptor(Object object) {
+        itemPropertyDescriptors.add(createItemPropertyDescriptor(((ComposeableAdapterFactory) adapterFactory).getRootAdapterFactory(), getResourceLocator(),
+                getString("_UI_ReferenceDescription_multiple_feature"), getString("_UI_PropertyDescriptor_description", "_UI_ReferenceDescription_multiple_feature", "_UI_ReferenceDescription_type"),
+                PropertiesPackage.Literals.REFERENCE_DESCRIPTION__MULTIPLE, true, false, false, ItemPropertyDescriptor.BOOLEAN_VALUE_IMAGE, null, null));
+    }
+
+    /**
      * This adds a property descriptor for the Value Expression feature. <!--
      * begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      */
     protected void addValueExpressionPropertyDescriptor(Object object) {
-        itemPropertyDescriptors.add(createItemPropertyDescriptor(((ComposeableAdapterFactory) adapterFactory).getRootAdapterFactory(), getResourceLocator(),
-                getString("_UI_SingleReferenceDescription_valueExpression_feature"),
-                getString("_UI_PropertyDescriptor_description", "_UI_SingleReferenceDescription_valueExpression_feature", "_UI_SingleReferenceDescription_type"),
-                PropertiesPackage.Literals.SINGLE_REFERENCE_DESCRIPTION__VALUE_EXPRESSION, true, false, false, ItemPropertyDescriptor.GENERIC_VALUE_IMAGE, null, null));
+        itemPropertyDescriptors.add(
+                createItemPropertyDescriptor(((ComposeableAdapterFactory) adapterFactory).getRootAdapterFactory(), getResourceLocator(), getString("_UI_ReferenceDescription_valueExpression_feature"),
+                        getString("_UI_PropertyDescriptor_description", "_UI_ReferenceDescription_valueExpression_feature", "_UI_ReferenceDescription_type"),
+                        PropertiesPackage.Literals.REFERENCE_DESCRIPTION__VALUE_EXPRESSION, true, false, false, ItemPropertyDescriptor.GENERIC_VALUE_IMAGE, null, null));
     }
 
     /**
@@ -81,9 +95,9 @@ public class SingleReferenceDescriptionItemProvider extends WidgetDescriptionIte
      */
     protected void addDisplayExpressionPropertyDescriptor(Object object) {
         itemPropertyDescriptors.add(createItemPropertyDescriptor(((ComposeableAdapterFactory) adapterFactory).getRootAdapterFactory(), getResourceLocator(),
-                getString("_UI_SingleReferenceDescription_displayExpression_feature"),
-                getString("_UI_PropertyDescriptor_description", "_UI_SingleReferenceDescription_displayExpression_feature", "_UI_SingleReferenceDescription_type"),
-                PropertiesPackage.Literals.SINGLE_REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION, true, false, false, ItemPropertyDescriptor.GENERIC_VALUE_IMAGE, null, null));
+                getString("_UI_ReferenceDescription_displayExpression_feature"),
+                getString("_UI_PropertyDescriptor_description", "_UI_ReferenceDescription_displayExpression_feature", "_UI_ReferenceDescription_type"),
+                PropertiesPackage.Literals.REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION, true, false, false, ItemPropertyDescriptor.GENERIC_VALUE_IMAGE, null, null));
     }
 
     /**
@@ -100,10 +114,10 @@ public class SingleReferenceDescriptionItemProvider extends WidgetDescriptionIte
     public Collection<? extends EStructuralFeature> getChildrenFeatures(Object object) {
         if (childrenFeatures == null) {
             super.getChildrenFeatures(object);
-            childrenFeatures.add(PropertiesPackage.Literals.SINGLE_REFERENCE_DESCRIPTION__CREATE_OPERATION);
-            childrenFeatures.add(PropertiesPackage.Literals.SINGLE_REFERENCE_DESCRIPTION__SEARCH_OPERATION);
-            childrenFeatures.add(PropertiesPackage.Literals.SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION);
-            childrenFeatures.add(PropertiesPackage.Literals.SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION);
+            childrenFeatures.add(PropertiesPackage.Literals.REFERENCE_DESCRIPTION__ON_CLICK_OPERATION);
+            childrenFeatures.add(PropertiesPackage.Literals.REFERENCE_DESCRIPTION__ACTIONS);
+            childrenFeatures.add(PropertiesPackage.Literals.REFERENCE_DESCRIPTION__STYLE);
+            childrenFeatures.add(PropertiesPackage.Literals.REFERENCE_DESCRIPTION__CONDITIONAL_STYLES);
         }
         return childrenFeatures;
     }
@@ -123,14 +137,14 @@ public class SingleReferenceDescriptionItemProvider extends WidgetDescriptionIte
     }
 
     /**
-     * This returns SingleReferenceDescription.gif. <!-- begin-user-doc --> <!--
+     * This returns ReferenceDescription.gif. <!-- begin-user-doc --> <!--
      * end-user-doc -->
      *
      * @generated
      */
     @Override
     public Object getImage(Object object) {
-        return overlayImage(object, getResourceLocator().getImage("full/obj16/SingleReferenceDescription"));
+        return overlayImage(object, getResourceLocator().getImage("full/obj16/ReferenceDescription"));
     }
 
     /**
@@ -141,8 +155,8 @@ public class SingleReferenceDescriptionItemProvider extends WidgetDescriptionIte
      */
     @Override
     public String getText(Object object) {
-        String label = ((SingleReferenceDescription) object).getIdentifier();
-        return label == null || label.length() == 0 ? getString("_UI_SingleReferenceDescription_type") : getString("_UI_SingleReferenceDescription_type") + " " + label;
+        String label = ((ReferenceDescription) object).getIdentifier();
+        return label == null || label.length() == 0 ? getString("_UI_ReferenceDescription_type") : getString("_UI_ReferenceDescription_type") + " " + label;
     }
 
     /**
@@ -157,15 +171,16 @@ public class SingleReferenceDescriptionItemProvider extends WidgetDescriptionIte
     public void notifyChanged(Notification notification) {
         updateChildren(notification);
 
-        switch (notification.getFeatureID(SingleReferenceDescription.class)) {
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__VALUE_EXPRESSION:
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION:
+        switch (notification.getFeatureID(ReferenceDescription.class)) {
+        case PropertiesPackage.REFERENCE_DESCRIPTION__MULTIPLE:
+        case PropertiesPackage.REFERENCE_DESCRIPTION__VALUE_EXPRESSION:
+        case PropertiesPackage.REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION:
             fireNotifyChanged(new ViewerNotification(notification, notification.getNotifier(), false, true));
             return;
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__CREATE_OPERATION:
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__SEARCH_OPERATION:
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION:
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION:
+        case PropertiesPackage.REFERENCE_DESCRIPTION__ON_CLICK_OPERATION:
+        case PropertiesPackage.REFERENCE_DESCRIPTION__ACTIONS:
+        case PropertiesPackage.REFERENCE_DESCRIPTION__STYLE:
+        case PropertiesPackage.REFERENCE_DESCRIPTION__CONDITIONAL_STYLES:
             fireNotifyChanged(new ViewerNotification(notification, notification.getNotifier(), true, false));
             return;
         }
@@ -183,35 +198,13 @@ public class SingleReferenceDescriptionItemProvider extends WidgetDescriptionIte
     protected void collectNewChildDescriptors(Collection<Object> newChildDescriptors, Object object) {
         super.collectNewChildDescriptors(newChildDescriptors, object);
 
-        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.SINGLE_REFERENCE_DESCRIPTION__CREATE_OPERATION, PropertiesFactory.eINSTANCE.createOperationDescription()));
-
-        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.SINGLE_REFERENCE_DESCRIPTION__SEARCH_OPERATION, PropertiesFactory.eINSTANCE.createOperationDescription()));
+        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.REFERENCE_DESCRIPTION__ON_CLICK_OPERATION, ToolFactory.eINSTANCE.createInitialOperation()));
 
-        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION, PropertiesFactory.eINSTANCE.createOperationDescription()));
+        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.REFERENCE_DESCRIPTION__ACTIONS, PropertiesFactory.eINSTANCE.createWidgetAction()));
 
-        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION, PropertiesFactory.eINSTANCE.createOperationDescription()));
-    }
-
-    /**
-     * 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;
+        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.REFERENCE_DESCRIPTION__STYLE, PropertiesFactory.eINSTANCE.createReferenceWidgetStyle()));
 
-        boolean qualify = childFeature == PropertiesPackage.Literals.SINGLE_REFERENCE_DESCRIPTION__CREATE_OPERATION
-                || childFeature == PropertiesPackage.Literals.SINGLE_REFERENCE_DESCRIPTION__SEARCH_OPERATION || childFeature == PropertiesPackage.Literals.SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION
-                || childFeature == PropertiesPackage.Literals.SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION;
-
-        if (qualify) {
-            return getString("_UI_CreateChild_text2", new Object[] { getTypeText(childObject), getFeatureText(childFeature), getTypeText(owner) });
-        }
-        return super.getCreateChildText(owner, feature, child, selection);
+        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.REFERENCE_DESCRIPTION__CONDITIONAL_STYLES, PropertiesFactory.eINSTANCE.createReferenceWidgetConditionalStyle()));
     }
 
 }
diff --git a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/ReferenceWidgetConditionalStyleItemProvider.java b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/ReferenceWidgetConditionalStyleItemProvider.java
new file mode 100644
index 0000000000..574e928b82
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/ReferenceWidgetConditionalStyleItemProvider.java
@@ -0,0 +1,149 @@
+/**
+ * Copyright (c) 2016 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.properties.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.properties.PropertiesFactory;
+import org.eclipse.sirius.properties.PropertiesPackage;
+import org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle;
+
+/**
+ * This is the item provider adapter for a
+ * {@link org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle} object.
+ * <!-- begin-user-doc --> <!-- end-user-doc -->
+ *
+ * @generated
+ */
+public class ReferenceWidgetConditionalStyleItemProvider extends WidgetConditionalStyleItemProvider {
+    /**
+     * This constructs an instance from a factory and a notifier. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    public ReferenceWidgetConditionalStyleItemProvider(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(PropertiesPackage.Literals.REFERENCE_WIDGET_CONDITIONAL_STYLE__STYLE);
+        }
+        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 ReferenceWidgetConditionalStyle.gif. <!-- begin-user-doc -->
+     * <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public Object getImage(Object object) {
+        return overlayImage(object, getResourceLocator().getImage("full/obj16/ReferenceWidgetConditionalStyle"));
+    }
+
+    /**
+     * This returns the label text for the adapted class. <!-- begin-user-doc
+     * --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public String getText(Object object) {
+        String label = ((ReferenceWidgetConditionalStyle) object).getPreconditionExpression();
+        return label == null || label.length() == 0 ? getString("_UI_ReferenceWidgetConditionalStyle_type") : getString("_UI_ReferenceWidgetConditionalStyle_type") + " " + label;
+    }
+
+    /**
+     * 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(ReferenceWidgetConditionalStyle.class)) {
+        case PropertiesPackage.REFERENCE_WIDGET_CONDITIONAL_STYLE__STYLE:
+            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(PropertiesPackage.Literals.REFERENCE_WIDGET_CONDITIONAL_STYLE__STYLE, PropertiesFactory.eINSTANCE.createReferenceWidgetStyle()));
+    }
+
+}
diff --git a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/ReferenceWidgetStyleItemProvider.java b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/ReferenceWidgetStyleItemProvider.java
new file mode 100644
index 0000000000..39d89cb51e
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/ReferenceWidgetStyleItemProvider.java
@@ -0,0 +1,104 @@
+/**
+ * Copyright (c) 2016 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.properties.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.edit.provider.IItemPropertyDescriptor;
+import org.eclipse.sirius.properties.ReferenceWidgetStyle;
+
+/**
+ * This is the item provider adapter for a
+ * {@link org.eclipse.sirius.properties.ReferenceWidgetStyle} object. <!--
+ * begin-user-doc --> <!-- end-user-doc -->
+ *
+ * @generated
+ */
+public class ReferenceWidgetStyleItemProvider extends WidgetStyleItemProvider {
+    /**
+     * This constructs an instance from a factory and a notifier. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    public ReferenceWidgetStyleItemProvider(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 returns ReferenceWidgetStyle.gif. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public Object getImage(Object object) {
+        return overlayImage(object, getResourceLocator().getImage("full/obj16/ReferenceWidgetStyle"));
+    }
+
+    /**
+     * This returns the label text for the adapted class. <!-- begin-user-doc
+     * --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public String getText(Object object) {
+        String label = ((ReferenceWidgetStyle) object).getLabelFontNameExpression();
+        return label == null || label.length() == 0 ? getString("_UI_ReferenceWidgetStyle_type") : getString("_UI_ReferenceWidgetStyle_type") + " " + label;
+    }
+
+    /**
+     * 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);
+        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);
+    }
+
+}
diff --git a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/WidgetActionItemProvider.java b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/WidgetActionItemProvider.java
new file mode 100644
index 0000000000..ab7c29a754
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/WidgetActionItemProvider.java
@@ -0,0 +1,186 @@
+/**
+ * Copyright (c) 2016 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.properties.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.common.util.ResourceLocator;
+import org.eclipse.emf.ecore.EStructuralFeature;
+import org.eclipse.emf.edit.provider.ComposeableAdapterFactory;
+import org.eclipse.emf.edit.provider.IEditingDomainItemProvider;
+import org.eclipse.emf.edit.provider.IItemLabelProvider;
+import org.eclipse.emf.edit.provider.IItemPropertyDescriptor;
+import org.eclipse.emf.edit.provider.IItemPropertySource;
+import org.eclipse.emf.edit.provider.IStructuredItemContentProvider;
+import org.eclipse.emf.edit.provider.ITreeItemContentProvider;
+import org.eclipse.emf.edit.provider.ItemPropertyDescriptor;
+import org.eclipse.emf.edit.provider.ItemProviderAdapter;
+import org.eclipse.emf.edit.provider.ViewerNotification;
+import org.eclipse.sirius.properties.PropertiesPackage;
+import org.eclipse.sirius.properties.WidgetAction;
+import org.eclipse.sirius.viewpoint.description.tool.ToolFactory;
+
+/**
+ * This is the item provider adapter for a
+ * {@link org.eclipse.sirius.properties.WidgetAction} object. <!--
+ * begin-user-doc --> <!-- end-user-doc -->
+ *
+ * @generated
+ */
+public class WidgetActionItemProvider extends ItemProviderAdapter
+        implements IEditingDomainItemProvider, IStructuredItemContentProvider, ITreeItemContentProvider, IItemLabelProvider, IItemPropertySource {
+    /**
+     * This constructs an instance from a factory and a notifier. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    public WidgetActionItemProvider(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);
+
+            addLabelExpressionPropertyDescriptor(object);
+        }
+        return itemPropertyDescriptors;
+    }
+
+    /**
+     * This adds a property descriptor for the Label Expression feature. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    protected void addLabelExpressionPropertyDescriptor(Object object) {
+        itemPropertyDescriptors.add(createItemPropertyDescriptor(((ComposeableAdapterFactory) adapterFactory).getRootAdapterFactory(), getResourceLocator(),
+                getString("_UI_WidgetAction_labelExpression_feature"), getString("_UI_PropertyDescriptor_description", "_UI_WidgetAction_labelExpression_feature", "_UI_WidgetAction_type"),
+                PropertiesPackage.Literals.WIDGET_ACTION__LABEL_EXPRESSION, true, false, false, ItemPropertyDescriptor.GENERIC_VALUE_IMAGE, null, null));
+    }
+
+    /**
+     * 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(PropertiesPackage.Literals.WIDGET_ACTION__INITIAL_OPERATION);
+        }
+        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 WidgetAction.gif. <!-- begin-user-doc --> <!-- end-user-doc
+     * -->
+     *
+     * @generated
+     */
+    @Override
+    public Object getImage(Object object) {
+        return overlayImage(object, getResourceLocator().getImage("full/obj16/WidgetAction"));
+    }
+
+    /**
+     * This returns the label text for the adapted class. <!-- begin-user-doc
+     * --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public String getText(Object object) {
+        String label = ((WidgetAction) object).getLabelExpression();
+        return label == null || label.length() == 0 ? getString("_UI_WidgetAction_type") : getString("_UI_WidgetAction_type") + " " + label;
+    }
+
+    /**
+     * 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(WidgetAction.class)) {
+        case PropertiesPackage.WIDGET_ACTION__LABEL_EXPRESSION:
+            fireNotifyChanged(new ViewerNotification(notification, notification.getNotifier(), false, true));
+            return;
+        case PropertiesPackage.WIDGET_ACTION__INITIAL_OPERATION:
+            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(PropertiesPackage.Literals.WIDGET_ACTION__INITIAL_OPERATION, ToolFactory.eINSTANCE.createInitialOperation()));
+    }
+
+    /**
+     * Return the resource locator for this item provider's resources. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public ResourceLocator getResourceLocator() {
+        return PropertiesEditPlugin.INSTANCE;
+    }
+
+}
diff --git a/incubation/org.eclipse.sirius.properties/model/properties.ecore b/incubation/org.eclipse.sirius.properties/model/properties.ecore
index 07ca4be00b..6a7090ad55 100644
--- a/incubation/org.eclipse.sirius.properties/model/properties.ecore
+++ b/incubation/org.eclipse.sirius.properties/model/properties.ecore
@@ -213,10 +213,11 @@
     <eStructuralFeatures xsi:type="ecore:EReference" name="conditionalStyles" upperBound="-1"
         eType="#//RadioWidgetConditionalStyle" containment="true"/>
   </eClassifiers>
-  <eClassifiers xsi:type="ecore:EClass" name="SingleReferenceDescription" eSuperTypes="#//WidgetDescription">
+  <eClassifiers xsi:type="ecore:EClass" name="ReferenceDescription" eSuperTypes="#//WidgetDescription">
     <eAnnotations source="http://www.eclipse.org/emf/2002/GenModel">
-      <details key="documentation" value="Represents a single reference in the user interface."/>
+      <details key="documentation" value="Represents a reference in the user interface."/>
     </eAnnotations>
+    <eStructuralFeatures xsi:type="ecore:EAttribute" name="multiple" eType="ecore:EDataType http://www.eclipse.org/emf/2002/Ecore#//EBoolean"/>
     <eStructuralFeatures xsi:type="ecore:EAttribute" name="valueExpression" eType="ecore:EDataType ../../org.eclipse.sirius/model/viewpoint.ecore#//description/InterpretedExpression">
       <eAnnotations source="http://www.eclipse.org/emf/2002/GenModel">
         <details key="documentation" value="The initial value."/>
@@ -227,63 +228,24 @@
         <details key="documentation" value="Represents how to display the value."/>
       </eAnnotations>
     </eStructuralFeatures>
-    <eStructuralFeatures xsi:type="ecore:EReference" name="createOperation" eType="#//OperationDescription"
-        containment="true">
-      <eAnnotations source="http://www.eclipse.org/emf/2002/GenModel">
-        <details key="documentation" value="Defines the expected behavior  when the user clicks on the create button."/>
-      </eAnnotations>
-    </eStructuralFeatures>
-    <eStructuralFeatures xsi:type="ecore:EReference" name="searchOperation" eType="#//OperationDescription"
-        containment="true">
-      <eAnnotations source="http://www.eclipse.org/emf/2002/GenModel">
-        <details key="documentation" value="Defines the expected behavior  when the user clicks on the search button."/>
-      </eAnnotations>
-    </eStructuralFeatures>
-    <eStructuralFeatures xsi:type="ecore:EReference" name="unsetOperation" eType="#//OperationDescription"
-        containment="true">
-      <eAnnotations source="http://www.eclipse.org/emf/2002/GenModel">
-        <details key="documentation" value="Defines the expected behavior  when the user clicks on the unset button."/>
-      </eAnnotations>
-    </eStructuralFeatures>
-    <eStructuralFeatures xsi:type="ecore:EReference" name="onClickOperation" eType="#//OperationDescription"
+    <eStructuralFeatures xsi:type="ecore:EReference" name="onClickOperation" eType="ecore:EClass ../../org.eclipse.sirius/model/viewpoint.ecore#//description/tool/InitialOperation"
         containment="true">
       <eAnnotations source="http://www.eclipse.org/emf/2002/GenModel">
         <details key="documentation" value="Defines the expected behavior  when the user clicks on the hyperlink."/>
       </eAnnotations>
     </eStructuralFeatures>
+    <eStructuralFeatures xsi:type="ecore:EReference" name="actions" upperBound="-1"
+        eType="#//WidgetAction" containment="true"/>
+    <eStructuralFeatures xsi:type="ecore:EReference" name="style" eType="#//ReferenceWidgetStyle"
+        containment="true"/>
+    <eStructuralFeatures xsi:type="ecore:EReference" name="conditionalStyles" upperBound="-1"
+        eType="#//ReferenceWidgetConditionalStyle" containment="true"/>
   </eClassifiers>
   <eClassifiers xsi:type="ecore:EClass" name="OperationDescription">
     <eStructuralFeatures xsi:type="ecore:EReference" name="initialOperation" lowerBound="1"
         eType="ecore:EClass ../../org.eclipse.sirius/model/viewpoint.ecore#//description/tool/InitialOperation"
         containment="true"/>
   </eClassifiers>
-  <eClassifiers xsi:type="ecore:EClass" name="MultipleReferencesDescription" eSuperTypes="#//WidgetDescription">
-    <eAnnotations source="http://www.eclipse.org/emf/2002/GenModel">
-      <details key="documentation" value="Represents a radio button in the user interface."/>
-    </eAnnotations>
-    <eStructuralFeatures xsi:type="ecore:EAttribute" name="valueExpression" eType="ecore:EDataType ../../org.eclipse.sirius/model/viewpoint.ecore#//description/InterpretedExpression">
-      <eAnnotations source="http://www.eclipse.org/emf/2002/GenModel">
-        <details key="documentation" value="The initial values."/>
-      </eAnnotations>
-    </eStructuralFeatures>
-    <eStructuralFeatures xsi:type="ecore:EAttribute" name="displayExpression" eType="ecore:EDataType ../../org.eclipse.sirius/model/viewpoint.ecore#//description/InterpretedExpression">
-      <eAnnotations source="http://www.eclipse.org/emf/2002/GenModel">
-        <details key="documentation" value="Indicates how to display the input value."/>
-      </eAnnotations>
-    </eStructuralFeatures>
-    <eStructuralFeatures xsi:type="ecore:EReference" name="createOperation" eType="#//OperationDescription"
-        containment="true"/>
-    <eStructuralFeatures xsi:type="ecore:EReference" name="searchOperation" eType="#//OperationDescription"
-        containment="true"/>
-    <eStructuralFeatures xsi:type="ecore:EReference" name="unsetOperation" eType="#//OperationDescription"
-        containment="true"/>
-    <eStructuralFeatures xsi:type="ecore:EReference" name="onClickOperation" eType="#//OperationDescription"
-        containment="true"/>
-    <eStructuralFeatures xsi:type="ecore:EReference" name="upOperation" eType="#//OperationDescription"
-        containment="true"/>
-    <eStructuralFeatures xsi:type="ecore:EReference" name="downOperation" eType="#//OperationDescription"
-        containment="true"/>
-  </eClassifiers>
   <eClassifiers xsi:type="ecore:EClass" name="CustomDescription" eSuperTypes="#//WidgetDescription">
     <eStructuralFeatures xsi:type="ecore:EReference" name="customExpressions" upperBound="-1"
         eType="#//CustomExpression" containment="true"/>
@@ -336,6 +298,7 @@
   <eClassifiers xsi:type="ecore:EClass" name="ButtonWidgetStyle" eSuperTypes="#//WidgetStyle"/>
   <eClassifiers xsi:type="ecore:EClass" name="SelectWidgetStyle" eSuperTypes="#//WidgetStyle"/>
   <eClassifiers xsi:type="ecore:EClass" name="CustomWidgetStyle" eSuperTypes="#//WidgetStyle"/>
+  <eClassifiers xsi:type="ecore:EClass" name="ReferenceWidgetStyle" eSuperTypes="#//WidgetStyle"/>
   <eClassifiers xsi:type="ecore:EClass" name="WidgetConditionalStyle" abstract="true">
     <eStructuralFeatures xsi:type="ecore:EAttribute" name="preconditionExpression"
         eType="ecore:EDataType ../../org.eclipse.sirius/model/viewpoint.ecore#//description/InterpretedExpression"/>
@@ -368,4 +331,18 @@
     <eStructuralFeatures xsi:type="ecore:EReference" name="style" eType="#//CustomWidgetStyle"
         containment="true"/>
   </eClassifiers>
+  <eClassifiers xsi:type="ecore:EClass" name="ReferenceWidgetConditionalStyle" eSuperTypes="#//WidgetConditionalStyle">
+    <eStructuralFeatures xsi:type="ecore:EReference" name="style" eType="#//ReferenceWidgetStyle"
+        containment="true"/>
+  </eClassifiers>
+  <eClassifiers xsi:type="ecore:EClass" name="WidgetAction">
+    <eStructuralFeatures xsi:type="ecore:EAttribute" name="labelExpression" eType="ecore:EDataType ../../org.eclipse.sirius/model/viewpoint.ecore#//description/InterpretedExpression"/>
+    <eStructuralFeatures xsi:type="ecore:EReference" name="initialOperation" lowerBound="1"
+        eType="ecore:EClass ../../org.eclipse.sirius/model/viewpoint.ecore#//description/tool/InitialOperation"
+        containment="true">
+      <eAnnotations source="http://www.eclipse.org/emf/2002/GenModel">
+        <details key="documentation" value="Defines the behavior executed when the end-user updates the value of the radio."/>
+      </eAnnotations>
+    </eStructuralFeatures>
+  </eClassifiers>
 </ecore:EPackage>
diff --git a/incubation/org.eclipse.sirius.properties/model/properties.genmodel b/incubation/org.eclipse.sirius.properties/model/properties.genmodel
index e9bc4412d6..cc4bc6adaf 100644
--- a/incubation/org.eclipse.sirius.properties/model/properties.genmodel
+++ b/incubation/org.eclipse.sirius.properties/model/properties.genmodel
@@ -122,27 +122,18 @@
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//RadioDescription/numberOfColumns"/>
       <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//RadioDescription/conditionalStyles"/>
     </genClasses>
-    <genClasses ecoreClass="properties.ecore#//SingleReferenceDescription">
-      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//SingleReferenceDescription/valueExpression"/>
-      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//SingleReferenceDescription/displayExpression"/>
-      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//SingleReferenceDescription/createOperation"/>
-      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//SingleReferenceDescription/searchOperation"/>
-      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//SingleReferenceDescription/unsetOperation"/>
-      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//SingleReferenceDescription/onClickOperation"/>
+    <genClasses ecoreClass="properties.ecore#//ReferenceDescription">
+      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//ReferenceDescription/multiple"/>
+      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//ReferenceDescription/valueExpression"/>
+      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//ReferenceDescription/displayExpression"/>
+      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//ReferenceDescription/onClickOperation"/>
+      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//ReferenceDescription/actions"/>
+      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//ReferenceDescription/style"/>
+      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//ReferenceDescription/conditionalStyles"/>
     </genClasses>
     <genClasses ecoreClass="properties.ecore#//OperationDescription">
       <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//OperationDescription/initialOperation"/>
     </genClasses>
-    <genClasses ecoreClass="properties.ecore#//MultipleReferencesDescription">
-      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//MultipleReferencesDescription/valueExpression"/>
-      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//MultipleReferencesDescription/displayExpression"/>
-      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//MultipleReferencesDescription/createOperation"/>
-      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//MultipleReferencesDescription/searchOperation"/>
-      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//MultipleReferencesDescription/unsetOperation"/>
-      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//MultipleReferencesDescription/onClickOperation"/>
-      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//MultipleReferencesDescription/upOperation"/>
-      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//MultipleReferencesDescription/downOperation"/>
-    </genClasses>
     <genClasses ecoreClass="properties.ecore#//CustomDescription">
       <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//CustomDescription/customExpressions"/>
       <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//CustomDescription/customOperations"/>
@@ -183,6 +174,7 @@
     <genClasses ecoreClass="properties.ecore#//ButtonWidgetStyle"/>
     <genClasses ecoreClass="properties.ecore#//SelectWidgetStyle"/>
     <genClasses ecoreClass="properties.ecore#//CustomWidgetStyle"/>
+    <genClasses ecoreClass="properties.ecore#//ReferenceWidgetStyle"/>
     <genClasses image="false" ecoreClass="properties.ecore#//WidgetConditionalStyle">
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//WidgetConditionalStyle/preconditionExpression"/>
     </genClasses>
@@ -207,5 +199,12 @@
     <genClasses ecoreClass="properties.ecore#//CustomWidgetConditionalStyle">
       <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//CustomWidgetConditionalStyle/style"/>
     </genClasses>
+    <genClasses ecoreClass="properties.ecore#//ReferenceWidgetConditionalStyle">
+      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//ReferenceWidgetConditionalStyle/style"/>
+    </genClasses>
+    <genClasses ecoreClass="properties.ecore#//WidgetAction">
+      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//WidgetAction/labelExpression"/>
+      <genFeatures property="None" children="true" createChild="true" ecoreFeature="ecore:EReference properties.ecore#//WidgetAction/initialOperation"/>
+    </genClasses>
   </genPackages>
 </genmodel:GenModel>
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/MultipleReferencesDescription.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/MultipleReferencesDescription.java
deleted file mode 100644
index e9deda0b9c..0000000000
--- a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/MultipleReferencesDescription.java
+++ /dev/null
@@ -1,300 +0,0 @@
-/**
- * Copyright (c) 2016 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.properties;
-
-/**
- * <!-- begin-user-doc --> A representation of the model object '
- * <em><b>Multiple References Description</b></em>'. <!-- end-user-doc -->
- *
- * <!-- begin-model-doc --> Represents a radio button in the user interface.
- * <!-- end-model-doc -->
- *
- * <p>
- * The following features are supported:
- * </p>
- * <ul>
- * <li>
- * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getValueExpression
- * <em>Value Expression</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getDisplayExpression
- * <em>Display Expression</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getCreateOperation
- * <em>Create Operation</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getSearchOperation
- * <em>Search Operation</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getUnsetOperation
- * <em>Unset Operation</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getOnClickOperation
- * <em>On Click Operation</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getUpOperation
- * <em>Up Operation</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getDownOperation
- * <em>Down Operation</em>}</li>
- * </ul>
- *
- * @see org.eclipse.sirius.properties.PropertiesPackage#getMultipleReferencesDescription()
- * @model
- * @generated
- */
-public interface MultipleReferencesDescription extends WidgetDescription {
-    /**
-     * Returns the value of the '<em><b>Value Expression</b></em>' attribute.
-     * <!-- begin-user-doc --> <!-- end-user-doc --> <!-- begin-model-doc -->
-     * The initial values. <!-- end-model-doc -->
-     *
-     * @return the value of the '<em>Value Expression</em>' attribute.
-     * @see #setValueExpression(String)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getMultipleReferencesDescription_ValueExpression()
-     * @model dataType=
-     *        "org.eclipse.sirius.viewpoint.description.InterpretedExpression"
-     * @generated
-     */
-    String getValueExpression();
-
-    /**
-     * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getValueExpression
-     * <em>Value Expression</em>}' attribute. <!-- begin-user-doc --> <!--
-     * end-user-doc -->
-     *
-     * @param value
-     *            the new value of the '<em>Value Expression</em>' attribute.
-     * @see #getValueExpression()
-     * @generated
-     */
-    void setValueExpression(String value);
-
-    /**
-     * Returns the value of the '<em><b>Display Expression</b></em>' attribute.
-     * <!-- begin-user-doc --> <!-- end-user-doc --> <!-- begin-model-doc -->
-     * Indicates how to display the input value. <!-- end-model-doc -->
-     *
-     * @return the value of the '<em>Display Expression</em>' attribute.
-     * @see #setDisplayExpression(String)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getMultipleReferencesDescription_DisplayExpression()
-     * @model dataType=
-     *        "org.eclipse.sirius.viewpoint.description.InterpretedExpression"
-     * @generated
-     */
-    String getDisplayExpression();
-
-    /**
-     * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getDisplayExpression
-     * <em>Display Expression</em>}' attribute. <!-- begin-user-doc --> <!--
-     * end-user-doc -->
-     *
-     * @param value
-     *            the new value of the '<em>Display Expression</em>' attribute.
-     * @see #getDisplayExpression()
-     * @generated
-     */
-    void setDisplayExpression(String value);
-
-    /**
-     * Returns the value of the '<em><b>Create Operation</b></em>' containment
-     * reference. <!-- begin-user-doc -->
-     * <p>
-     * If the meaning of the '<em>Create Operation</em>' containment reference
-     * isn't clear, there really should be more of a description here...
-     * </p>
-     * <!-- end-user-doc -->
-     *
-     * @return the value of the '<em>Create Operation</em>' containment
-     *         reference.
-     * @see #setCreateOperation(OperationDescription)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getMultipleReferencesDescription_CreateOperation()
-     * @model containment="true"
-     * @generated
-     */
-    OperationDescription getCreateOperation();
-
-    /**
-     * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getCreateOperation
-     * <em>Create Operation</em>}' containment reference. <!-- begin-user-doc
-     * --> <!-- end-user-doc -->
-     *
-     * @param value
-     *            the new value of the '<em>Create Operation</em>' containment
-     *            reference.
-     * @see #getCreateOperation()
-     * @generated
-     */
-    void setCreateOperation(OperationDescription value);
-
-    /**
-     * Returns the value of the '<em><b>Search Operation</b></em>' containment
-     * reference. <!-- begin-user-doc -->
-     * <p>
-     * If the meaning of the '<em>Search Operation</em>' containment reference
-     * isn't clear, there really should be more of a description here...
-     * </p>
-     * <!-- end-user-doc -->
-     *
-     * @return the value of the '<em>Search Operation</em>' containment
-     *         reference.
-     * @see #setSearchOperation(OperationDescription)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getMultipleReferencesDescription_SearchOperation()
-     * @model containment="true"
-     * @generated
-     */
-    OperationDescription getSearchOperation();
-
-    /**
-     * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getSearchOperation
-     * <em>Search Operation</em>}' containment reference. <!-- begin-user-doc
-     * --> <!-- end-user-doc -->
-     *
-     * @param value
-     *            the new value of the '<em>Search Operation</em>' containment
-     *            reference.
-     * @see #getSearchOperation()
-     * @generated
-     */
-    void setSearchOperation(OperationDescription value);
-
-    /**
-     * Returns the value of the '<em><b>Unset Operation</b></em>' containment
-     * reference. <!-- begin-user-doc -->
-     * <p>
-     * If the meaning of the '<em>Unset Operation</em>' containment reference
-     * isn't clear, there really should be more of a description here...
-     * </p>
-     * <!-- end-user-doc -->
-     *
-     * @return the value of the '<em>Unset Operation</em>' containment
-     *         reference.
-     * @see #setUnsetOperation(OperationDescription)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getMultipleReferencesDescription_UnsetOperation()
-     * @model containment="true"
-     * @generated
-     */
-    OperationDescription getUnsetOperation();
-
-    /**
-     * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getUnsetOperation
-     * <em>Unset Operation</em>}' containment reference. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
-     *
-     * @param value
-     *            the new value of the '<em>Unset Operation</em>' containment
-     *            reference.
-     * @see #getUnsetOperation()
-     * @generated
-     */
-    void setUnsetOperation(OperationDescription value);
-
-    /**
-     * Returns the value of the '<em><b>On Click Operation</b></em>' containment
-     * reference. <!-- begin-user-doc -->
-     * <p>
-     * If the meaning of the '<em>On Click Operation</em>' containment reference
-     * isn't clear, there really should be more of a description here...
-     * </p>
-     * <!-- end-user-doc -->
-     *
-     * @return the value of the '<em>On Click Operation</em>' containment
-     *         reference.
-     * @see #setOnClickOperation(OperationDescription)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getMultipleReferencesDescription_OnClickOperation()
-     * @model containment="true"
-     * @generated
-     */
-    OperationDescription getOnClickOperation();
-
-    /**
-     * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getOnClickOperation
-     * <em>On Click Operation</em>}' containment reference. <!-- begin-user-doc
-     * --> <!-- end-user-doc -->
-     *
-     * @param value
-     *            the new value of the '<em>On Click Operation</em>' containment
-     *            reference.
-     * @see #getOnClickOperation()
-     * @generated
-     */
-    void setOnClickOperation(OperationDescription value);
-
-    /**
-     * Returns the value of the '<em><b>Up Operation</b></em>' containment
-     * reference. <!-- begin-user-doc -->
-     * <p>
-     * If the meaning of the '<em>Up Operation</em>' containment reference isn't
-     * clear, there really should be more of a description here...
-     * </p>
-     * <!-- end-user-doc -->
-     *
-     * @return the value of the '<em>Up Operation</em>' containment reference.
-     * @see #setUpOperation(OperationDescription)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getMultipleReferencesDescription_UpOperation()
-     * @model containment="true"
-     * @generated
-     */
-    OperationDescription getUpOperation();
-
-    /**
-     * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getUpOperation
-     * <em>Up Operation</em>}' containment reference. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
-     *
-     * @param value
-     *            the new value of the '<em>Up Operation</em>' containment
-     *            reference.
-     * @see #getUpOperation()
-     * @generated
-     */
-    void setUpOperation(OperationDescription value);
-
-    /**
-     * Returns the value of the '<em><b>Down Operation</b></em>' containment
-     * reference. <!-- begin-user-doc -->
-     * <p>
-     * If the meaning of the '<em>Down Operation</em>' containment reference
-     * isn't clear, there really should be more of a description here...
-     * </p>
-     * <!-- end-user-doc -->
-     *
-     * @return the value of the '<em>Down Operation</em>' containment reference.
-     * @see #setDownOperation(OperationDescription)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getMultipleReferencesDescription_DownOperation()
-     * @model containment="true"
-     * @generated
-     */
-    OperationDescription getDownOperation();
-
-    /**
-     * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getDownOperation
-     * <em>Down Operation</em>}' containment reference. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
-     *
-     * @param value
-     *            the new value of the '<em>Down Operation</em>' containment
-     *            reference.
-     * @see #getDownOperation()
-     * @generated
-     */
-    void setDownOperation(OperationDescription value);
-
-} // MultipleReferencesDescription
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/PropertiesFactory.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/PropertiesFactory.java
index c39012a6df..c910d628d4 100644
--- a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/PropertiesFactory.java
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/PropertiesFactory.java
@@ -193,13 +193,13 @@ public interface PropertiesFactory extends EFactory {
     RadioDescription createRadioDescription();
 
     /**
-     * Returns a new object of class '<em>Single Reference Description</em>'.
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * Returns a new object of class '<em>Reference Description</em>'. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
      *
-     * @return a new object of class '<em>Single Reference Description</em>'.
+     * @return a new object of class '<em>Reference Description</em>'.
      * @generated
      */
-    SingleReferenceDescription createSingleReferenceDescription();
+    ReferenceDescription createReferenceDescription();
 
     /**
      * Returns a new object of class '<em>Operation Description</em>'. <!--
@@ -211,15 +211,6 @@ public interface PropertiesFactory extends EFactory {
     OperationDescription createOperationDescription();
 
     /**
-     * Returns a new object of class '<em>Multiple References Description</em>'.
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @return a new object of class '<em>Multiple References Description</em>'.
-     * @generated
-     */
-    MultipleReferencesDescription createMultipleReferencesDescription();
-
-    /**
      * Returns a new object of class '<em>Custom Description</em>'. <!--
      * begin-user-doc --> <!-- end-user-doc -->
      *
@@ -383,6 +374,35 @@ public interface PropertiesFactory extends EFactory {
     CustomWidgetConditionalStyle createCustomWidgetConditionalStyle();
 
     /**
+     * Returns a new object of class '
+     * <em>Reference Widget Conditional Style</em>'. <!-- begin-user-doc -->
+     * <!-- end-user-doc -->
+     *
+     * @return a new object of class '
+     *         <em>Reference Widget Conditional Style</em>'.
+     * @generated
+     */
+    ReferenceWidgetConditionalStyle createReferenceWidgetConditionalStyle();
+
+    /**
+     * Returns a new object of class '<em>Widget Action</em>'. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @return a new object of class '<em>Widget Action</em>'.
+     * @generated
+     */
+    WidgetAction createWidgetAction();
+
+    /**
+     * Returns a new object of class '<em>Reference Widget Style</em>'. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @return a new object of class '<em>Reference Widget Style</em>'.
+     * @generated
+     */
+    ReferenceWidgetStyle createReferenceWidgetStyle();
+
+    /**
      * Returns the package supported by this factory. <!-- begin-user-doc -->
      * <!-- end-user-doc -->
      *
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/PropertiesPackage.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/PropertiesPackage.java
index dba4c61c0b..66de9c5d7e 100644
--- a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/PropertiesPackage.java
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/PropertiesPackage.java
@@ -1395,15 +1395,15 @@ public interface PropertiesPackage extends EPackage {
 
     /**
      * The meta object id for the '
-     * {@link org.eclipse.sirius.properties.impl.SingleReferenceDescriptionImpl
-     * <em>Single Reference Description</em>}' class. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
+     * {@link org.eclipse.sirius.properties.impl.ReferenceDescriptionImpl
+     * <em>Reference Description</em>}' class. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
      *
-     * @see org.eclipse.sirius.properties.impl.SingleReferenceDescriptionImpl
-     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getSingleReferenceDescription()
+     * @see org.eclipse.sirius.properties.impl.ReferenceDescriptionImpl
+     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getReferenceDescription()
      * @generated
      */
-    int SINGLE_REFERENCE_DESCRIPTION = 21;
+    int REFERENCE_DESCRIPTION = 21;
 
     /**
      * The feature id for the '<em><b>Identifier</b></em>' attribute. <!--
@@ -1412,7 +1412,7 @@ public interface PropertiesPackage extends EPackage {
      * @generated
      * @ordered
      */
-    int SINGLE_REFERENCE_DESCRIPTION__IDENTIFIER = PropertiesPackage.WIDGET_DESCRIPTION__IDENTIFIER;
+    int REFERENCE_DESCRIPTION__IDENTIFIER = PropertiesPackage.WIDGET_DESCRIPTION__IDENTIFIER;
 
     /**
      * The feature id for the '<em><b>Label Expression</b></em>' attribute. <!--
@@ -1421,7 +1421,7 @@ public interface PropertiesPackage extends EPackage {
      * @generated
      * @ordered
      */
-    int SINGLE_REFERENCE_DESCRIPTION__LABEL_EXPRESSION = PropertiesPackage.WIDGET_DESCRIPTION__LABEL_EXPRESSION;
+    int REFERENCE_DESCRIPTION__LABEL_EXPRESSION = PropertiesPackage.WIDGET_DESCRIPTION__LABEL_EXPRESSION;
 
     /**
      * The feature id for the '<em><b>Help Expression</b></em>' attribute. <!--
@@ -1430,7 +1430,16 @@ public interface PropertiesPackage extends EPackage {
      * @generated
      * @ordered
      */
-    int SINGLE_REFERENCE_DESCRIPTION__HELP_EXPRESSION = PropertiesPackage.WIDGET_DESCRIPTION__HELP_EXPRESSION;
+    int REFERENCE_DESCRIPTION__HELP_EXPRESSION = PropertiesPackage.WIDGET_DESCRIPTION__HELP_EXPRESSION;
+
+    /**
+     * The feature id for the '<em><b>Multiple</b></em>' attribute. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int REFERENCE_DESCRIPTION__MULTIPLE = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 0;
 
     /**
      * The feature id for the '<em><b>Value Expression</b></em>' attribute. <!--
@@ -1439,7 +1448,7 @@ public interface PropertiesPackage extends EPackage {
      * @generated
      * @ordered
      */
-    int SINGLE_REFERENCE_DESCRIPTION__VALUE_EXPRESSION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 0;
+    int REFERENCE_DESCRIPTION__VALUE_EXPRESSION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 1;
 
     /**
      * The feature id for the '<em><b>Display Expression</b></em>' attribute.
@@ -1448,53 +1457,52 @@ public interface PropertiesPackage extends EPackage {
      * @generated
      * @ordered
      */
-    int SINGLE_REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 1;
+    int REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 2;
 
     /**
-     * The feature id for the '<em><b>Create Operation</b></em>' containment
+     * The feature id for the '<em><b>On Click Operation</b></em>' containment
      * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int SINGLE_REFERENCE_DESCRIPTION__CREATE_OPERATION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 2;
+    int REFERENCE_DESCRIPTION__ON_CLICK_OPERATION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 3;
 
     /**
-     * The feature id for the '<em><b>Search Operation</b></em>' containment
-     * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * The feature id for the '<em><b>Actions</b></em>' containment reference
+     * list. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int SINGLE_REFERENCE_DESCRIPTION__SEARCH_OPERATION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 3;
+    int REFERENCE_DESCRIPTION__ACTIONS = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 4;
 
     /**
-     * The feature id for the '<em><b>Unset Operation</b></em>' containment
-     * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * The feature id for the '<em><b>Style</b></em>' containment reference.
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 4;
+    int REFERENCE_DESCRIPTION__STYLE = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 5;
 
     /**
-     * The feature id for the '<em><b>On Click Operation</b></em>' containment
-     * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * The feature id for the '<em><b>Conditional Styles</b></em>' containment
+     * reference list. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 5;
+    int REFERENCE_DESCRIPTION__CONDITIONAL_STYLES = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 6;
 
     /**
-     * The number of structural features of the '
-     * <em>Single Reference Description</em>' class. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
+     * The number of structural features of the '<em>Reference Description</em>'
+     * class. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int SINGLE_REFERENCE_DESCRIPTION_FEATURE_COUNT = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 6;
+    int REFERENCE_DESCRIPTION_FEATURE_COUNT = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 7;
 
     /**
      * The meta object id for the '
@@ -1528,127 +1536,6 @@ public interface PropertiesPackage extends EPackage {
 
     /**
      * The meta object id for the '
-     * {@link org.eclipse.sirius.properties.impl.MultipleReferencesDescriptionImpl
-     * <em>Multiple References Description</em>}' class. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
-     *
-     * @see org.eclipse.sirius.properties.impl.MultipleReferencesDescriptionImpl
-     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getMultipleReferencesDescription()
-     * @generated
-     */
-    int MULTIPLE_REFERENCES_DESCRIPTION = 23;
-
-    /**
-     * The feature id for the '<em><b>Identifier</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     * @ordered
-     */
-    int MULTIPLE_REFERENCES_DESCRIPTION__IDENTIFIER = PropertiesPackage.WIDGET_DESCRIPTION__IDENTIFIER;
-
-    /**
-     * The feature id for the '<em><b>Label Expression</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     * @ordered
-     */
-    int MULTIPLE_REFERENCES_DESCRIPTION__LABEL_EXPRESSION = PropertiesPackage.WIDGET_DESCRIPTION__LABEL_EXPRESSION;
-
-    /**
-     * The feature id for the '<em><b>Help Expression</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     * @ordered
-     */
-    int MULTIPLE_REFERENCES_DESCRIPTION__HELP_EXPRESSION = PropertiesPackage.WIDGET_DESCRIPTION__HELP_EXPRESSION;
-
-    /**
-     * The feature id for the '<em><b>Value Expression</b></em>' attribute. <!--
-     * begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     * @ordered
-     */
-    int MULTIPLE_REFERENCES_DESCRIPTION__VALUE_EXPRESSION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 0;
-
-    /**
-     * The feature id for the '<em><b>Display Expression</b></em>' attribute.
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     * @ordered
-     */
-    int MULTIPLE_REFERENCES_DESCRIPTION__DISPLAY_EXPRESSION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 1;
-
-    /**
-     * The feature id for the '<em><b>Create Operation</b></em>' containment
-     * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     * @ordered
-     */
-    int MULTIPLE_REFERENCES_DESCRIPTION__CREATE_OPERATION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 2;
-
-    /**
-     * The feature id for the '<em><b>Search Operation</b></em>' containment
-     * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     * @ordered
-     */
-    int MULTIPLE_REFERENCES_DESCRIPTION__SEARCH_OPERATION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 3;
-
-    /**
-     * The feature id for the '<em><b>Unset Operation</b></em>' containment
-     * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     * @ordered
-     */
-    int MULTIPLE_REFERENCES_DESCRIPTION__UNSET_OPERATION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 4;
-
-    /**
-     * The feature id for the '<em><b>On Click Operation</b></em>' containment
-     * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     * @ordered
-     */
-    int MULTIPLE_REFERENCES_DESCRIPTION__ON_CLICK_OPERATION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 5;
-
-    /**
-     * The feature id for the '<em><b>Up Operation</b></em>' containment
-     * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     * @ordered
-     */
-    int MULTIPLE_REFERENCES_DESCRIPTION__UP_OPERATION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 6;
-
-    /**
-     * The feature id for the '<em><b>Down Operation</b></em>' containment
-     * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     * @ordered
-     */
-    int MULTIPLE_REFERENCES_DESCRIPTION__DOWN_OPERATION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 7;
-
-    /**
-     * The number of structural features of the '
-     * <em>Multiple References Description</em>' class. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
-     *
-     * @generated
-     * @ordered
-     */
-    int MULTIPLE_REFERENCES_DESCRIPTION_FEATURE_COUNT = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 8;
-
-    /**
-     * The meta object id for the '
      * {@link org.eclipse.sirius.properties.impl.CustomDescriptionImpl
      * <em>Custom Description</em>}' class. <!-- begin-user-doc --> <!--
      * end-user-doc -->
@@ -1657,7 +1544,7 @@ public interface PropertiesPackage extends EPackage {
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getCustomDescription()
      * @generated
      */
-    int CUSTOM_DESCRIPTION = 24;
+    int CUSTOM_DESCRIPTION = 23;
 
     /**
      * The feature id for the '<em><b>Identifier</b></em>' attribute. <!--
@@ -1741,7 +1628,7 @@ public interface PropertiesPackage extends EPackage {
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getCustomExpression()
      * @generated
      */
-    int CUSTOM_EXPRESSION = 25;
+    int CUSTOM_EXPRESSION = 24;
 
     /**
      * The feature id for the '<em><b>Identifier</b></em>' attribute. <!--
@@ -1780,7 +1667,7 @@ public interface PropertiesPackage extends EPackage {
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getCustomOperation()
      * @generated
      */
-    int CUSTOM_OPERATION = 26;
+    int CUSTOM_OPERATION = 25;
 
     /**
      * The feature id for the '<em><b>Identifier</b></em>' attribute. <!--
@@ -1819,7 +1706,7 @@ public interface PropertiesPackage extends EPackage {
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getWidgetStyle()
      * @generated
      */
-    int WIDGET_STYLE = 27;
+    int WIDGET_STYLE = 26;
 
     /**
      * The feature id for the '<em><b>Label Font Name Expression</b></em>'
@@ -1885,7 +1772,7 @@ public interface PropertiesPackage extends EPackage {
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getTextWidgetStyle()
      * @generated
      */
-    int TEXT_WIDGET_STYLE = 28;
+    int TEXT_WIDGET_STYLE = 27;
 
     /**
      * The feature id for the '<em><b>Label Font Name Expression</b></em>'
@@ -1996,7 +1883,7 @@ public interface PropertiesPackage extends EPackage {
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getLabelWidgetStyle()
      * @generated
      */
-    int LABEL_WIDGET_STYLE = 29;
+    int LABEL_WIDGET_STYLE = 28;
 
     /**
      * The feature id for the '<em><b>Label Font Name Expression</b></em>'
@@ -2107,7 +1994,7 @@ public interface PropertiesPackage extends EPackage {
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getCheckboxWidgetStyle()
      * @generated
      */
-    int CHECKBOX_WIDGET_STYLE = 30;
+    int CHECKBOX_WIDGET_STYLE = 29;
 
     /**
      * The feature id for the '<em><b>Label Font Name Expression</b></em>'
@@ -2173,7 +2060,7 @@ public interface PropertiesPackage extends EPackage {
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getRadioWidgetStyle()
      * @generated
      */
-    int RADIO_WIDGET_STYLE = 31;
+    int RADIO_WIDGET_STYLE = 30;
 
     /**
      * The feature id for the '<em><b>Label Font Name Expression</b></em>'
@@ -2239,7 +2126,7 @@ public interface PropertiesPackage extends EPackage {
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getButtonWidgetStyle()
      * @generated
      */
-    int BUTTON_WIDGET_STYLE = 32;
+    int BUTTON_WIDGET_STYLE = 31;
 
     /**
      * The feature id for the '<em><b>Label Font Name Expression</b></em>'
@@ -2305,7 +2192,7 @@ public interface PropertiesPackage extends EPackage {
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getSelectWidgetStyle()
      * @generated
      */
-    int SELECT_WIDGET_STYLE = 33;
+    int SELECT_WIDGET_STYLE = 32;
 
     /**
      * The feature id for the '<em><b>Label Font Name Expression</b></em>'
@@ -2371,7 +2258,7 @@ public interface PropertiesPackage extends EPackage {
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getCustomWidgetStyle()
      * @generated
      */
-    int CUSTOM_WIDGET_STYLE = 34;
+    int CUSTOM_WIDGET_STYLE = 33;
 
     /**
      * The feature id for the '<em><b>Label Font Name Expression</b></em>'
@@ -2440,6 +2327,180 @@ public interface PropertiesPackage extends EPackage {
     int WIDGET_CONDITIONAL_STYLE = 35;
 
     /**
+     * The meta object id for the '
+     * {@link org.eclipse.sirius.properties.impl.TextWidgetConditionalStyleImpl
+     * <em>Text Widget Conditional Style</em>}' class. <!-- begin-user-doc -->
+     * <!-- end-user-doc -->
+     *
+     * @see org.eclipse.sirius.properties.impl.TextWidgetConditionalStyleImpl
+     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getTextWidgetConditionalStyle()
+     * @generated
+     */
+    int TEXT_WIDGET_CONDITIONAL_STYLE = 36;
+
+    /**
+     * The meta object id for the '
+     * {@link org.eclipse.sirius.properties.impl.LabelWidgetConditionalStyleImpl
+     * <em>Label Widget Conditional Style</em>}' class. <!-- begin-user-doc -->
+     * <!-- end-user-doc -->
+     *
+     * @see org.eclipse.sirius.properties.impl.LabelWidgetConditionalStyleImpl
+     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getLabelWidgetConditionalStyle()
+     * @generated
+     */
+    int LABEL_WIDGET_CONDITIONAL_STYLE = 37;
+
+    /**
+     * The meta object id for the '
+     * {@link org.eclipse.sirius.properties.impl.CheckboxWidgetConditionalStyleImpl
+     * <em>Checkbox Widget Conditional Style</em>}' class. <!-- begin-user-doc
+     * --> <!-- end-user-doc -->
+     *
+     * @see org.eclipse.sirius.properties.impl.CheckboxWidgetConditionalStyleImpl
+     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getCheckboxWidgetConditionalStyle()
+     * @generated
+     */
+    int CHECKBOX_WIDGET_CONDITIONAL_STYLE = 38;
+
+    /**
+     * The meta object id for the '
+     * {@link org.eclipse.sirius.properties.impl.RadioWidgetConditionalStyleImpl
+     * <em>Radio Widget Conditional Style</em>}' class. <!-- begin-user-doc -->
+     * <!-- end-user-doc -->
+     *
+     * @see org.eclipse.sirius.properties.impl.RadioWidgetConditionalStyleImpl
+     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getRadioWidgetConditionalStyle()
+     * @generated
+     */
+    int RADIO_WIDGET_CONDITIONAL_STYLE = 39;
+
+    /**
+     * The meta object id for the '
+     * {@link org.eclipse.sirius.properties.impl.ButtonWidgetConditionalStyleImpl
+     * <em>Button Widget Conditional Style</em>}' class. <!-- begin-user-doc -->
+     * <!-- end-user-doc -->
+     *
+     * @see org.eclipse.sirius.properties.impl.ButtonWidgetConditionalStyleImpl
+     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getButtonWidgetConditionalStyle()
+     * @generated
+     */
+    int BUTTON_WIDGET_CONDITIONAL_STYLE = 40;
+
+    /**
+     * The meta object id for the '
+     * {@link org.eclipse.sirius.properties.impl.SelectWidgetConditionalStyleImpl
+     * <em>Select Widget Conditional Style</em>}' class. <!-- begin-user-doc -->
+     * <!-- end-user-doc -->
+     *
+     * @see org.eclipse.sirius.properties.impl.SelectWidgetConditionalStyleImpl
+     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getSelectWidgetConditionalStyle()
+     * @generated
+     */
+    int SELECT_WIDGET_CONDITIONAL_STYLE = 41;
+
+    /**
+     * The meta object id for the '
+     * {@link org.eclipse.sirius.properties.impl.CustomWidgetConditionalStyleImpl
+     * <em>Custom Widget Conditional Style</em>}' class. <!-- begin-user-doc -->
+     * <!-- end-user-doc -->
+     *
+     * @see org.eclipse.sirius.properties.impl.CustomWidgetConditionalStyleImpl
+     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getCustomWidgetConditionalStyle()
+     * @generated
+     */
+    int CUSTOM_WIDGET_CONDITIONAL_STYLE = 42;
+
+    /**
+     * The meta object id for the '
+     * {@link org.eclipse.sirius.properties.impl.ReferenceWidgetConditionalStyleImpl
+     * <em>Reference Widget Conditional Style</em>}' class. <!-- begin-user-doc
+     * --> <!-- end-user-doc -->
+     *
+     * @see org.eclipse.sirius.properties.impl.ReferenceWidgetConditionalStyleImpl
+     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getReferenceWidgetConditionalStyle()
+     * @generated
+     */
+    int REFERENCE_WIDGET_CONDITIONAL_STYLE = 43;
+
+    /**
+     * The meta object id for the '
+     * {@link org.eclipse.sirius.properties.impl.WidgetActionImpl
+     * <em>Widget Action</em>}' class. <!-- begin-user-doc --> <!-- end-user-doc
+     * -->
+     *
+     * @see org.eclipse.sirius.properties.impl.WidgetActionImpl
+     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getWidgetAction()
+     * @generated
+     */
+    int WIDGET_ACTION = 44;
+
+    /**
+     * The meta object id for the '
+     * {@link org.eclipse.sirius.properties.impl.ReferenceWidgetStyleImpl
+     * <em>Reference Widget Style</em>}' class. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @see org.eclipse.sirius.properties.impl.ReferenceWidgetStyleImpl
+     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getReferenceWidgetStyle()
+     * @generated
+     */
+    int REFERENCE_WIDGET_STYLE = 34;
+
+    /**
+     * The feature id for the '<em><b>Label Font Name Expression</b></em>'
+     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int REFERENCE_WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_NAME_EXPRESSION;
+
+    /**
+     * The feature id for the '<em><b>Label Font Size</b></em>' attribute. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int REFERENCE_WIDGET_STYLE__LABEL_FONT_SIZE = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_SIZE;
+
+    /**
+     * The feature id for the '<em><b>Label Background Color</b></em>'
+     * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int REFERENCE_WIDGET_STYLE__LABEL_BACKGROUND_COLOR = PropertiesPackage.WIDGET_STYLE__LABEL_BACKGROUND_COLOR;
+
+    /**
+     * The feature id for the '<em><b>Label Foreground Color</b></em>'
+     * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int REFERENCE_WIDGET_STYLE__LABEL_FOREGROUND_COLOR = PropertiesPackage.WIDGET_STYLE__LABEL_FOREGROUND_COLOR;
+
+    /**
+     * The feature id for the '<em><b>Label Font Format</b></em>' attribute
+     * list. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int REFERENCE_WIDGET_STYLE__LABEL_FONT_FORMAT = PropertiesPackage.WIDGET_STYLE__LABEL_FONT_FORMAT;
+
+    /**
+     * The number of structural features of the '<em>Reference Widget Style</em>
+     * ' class. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int REFERENCE_WIDGET_STYLE_FEATURE_COUNT = PropertiesPackage.WIDGET_STYLE_FEATURE_COUNT + 0;
+
+    /**
      * The feature id for the '<em><b>Precondition Expression</b></em>'
      * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
@@ -2459,18 +2520,6 @@ public interface PropertiesPackage extends EPackage {
     int WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT = 1;
 
     /**
-     * The meta object id for the '
-     * {@link org.eclipse.sirius.properties.impl.TextWidgetConditionalStyleImpl
-     * <em>Text Widget Conditional Style</em>}' class. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
-     *
-     * @see org.eclipse.sirius.properties.impl.TextWidgetConditionalStyleImpl
-     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getTextWidgetConditionalStyle()
-     * @generated
-     */
-    int TEXT_WIDGET_CONDITIONAL_STYLE = 36;
-
-    /**
      * The feature id for the '<em><b>Precondition Expression</b></em>'
      * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
@@ -2499,18 +2548,6 @@ public interface PropertiesPackage extends EPackage {
     int TEXT_WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT = PropertiesPackage.WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT + 1;
 
     /**
-     * The meta object id for the '
-     * {@link org.eclipse.sirius.properties.impl.LabelWidgetConditionalStyleImpl
-     * <em>Label Widget Conditional Style</em>}' class. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
-     *
-     * @see org.eclipse.sirius.properties.impl.LabelWidgetConditionalStyleImpl
-     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getLabelWidgetConditionalStyle()
-     * @generated
-     */
-    int LABEL_WIDGET_CONDITIONAL_STYLE = 37;
-
-    /**
      * The feature id for the '<em><b>Precondition Expression</b></em>'
      * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
@@ -2539,18 +2576,6 @@ public interface PropertiesPackage extends EPackage {
     int LABEL_WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT = PropertiesPackage.WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT + 1;
 
     /**
-     * The meta object id for the '
-     * {@link org.eclipse.sirius.properties.impl.CheckboxWidgetConditionalStyleImpl
-     * <em>Checkbox Widget Conditional Style</em>}' class. <!-- begin-user-doc
-     * --> <!-- end-user-doc -->
-     *
-     * @see org.eclipse.sirius.properties.impl.CheckboxWidgetConditionalStyleImpl
-     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getCheckboxWidgetConditionalStyle()
-     * @generated
-     */
-    int CHECKBOX_WIDGET_CONDITIONAL_STYLE = 38;
-
-    /**
      * The feature id for the '<em><b>Precondition Expression</b></em>'
      * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
@@ -2579,18 +2604,6 @@ public interface PropertiesPackage extends EPackage {
     int CHECKBOX_WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT = PropertiesPackage.WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT + 1;
 
     /**
-     * The meta object id for the '
-     * {@link org.eclipse.sirius.properties.impl.RadioWidgetConditionalStyleImpl
-     * <em>Radio Widget Conditional Style</em>}' class. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
-     *
-     * @see org.eclipse.sirius.properties.impl.RadioWidgetConditionalStyleImpl
-     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getRadioWidgetConditionalStyle()
-     * @generated
-     */
-    int RADIO_WIDGET_CONDITIONAL_STYLE = 39;
-
-    /**
      * The feature id for the '<em><b>Precondition Expression</b></em>'
      * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
@@ -2619,18 +2632,6 @@ public interface PropertiesPackage extends EPackage {
     int RADIO_WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT = PropertiesPackage.WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT + 1;
 
     /**
-     * The meta object id for the '
-     * {@link org.eclipse.sirius.properties.impl.ButtonWidgetConditionalStyleImpl
-     * <em>Button Widget Conditional Style</em>}' class. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
-     *
-     * @see org.eclipse.sirius.properties.impl.ButtonWidgetConditionalStyleImpl
-     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getButtonWidgetConditionalStyle()
-     * @generated
-     */
-    int BUTTON_WIDGET_CONDITIONAL_STYLE = 40;
-
-    /**
      * The feature id for the '<em><b>Precondition Expression</b></em>'
      * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
@@ -2659,18 +2660,6 @@ public interface PropertiesPackage extends EPackage {
     int BUTTON_WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT = PropertiesPackage.WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT + 1;
 
     /**
-     * The meta object id for the '
-     * {@link org.eclipse.sirius.properties.impl.SelectWidgetConditionalStyleImpl
-     * <em>Select Widget Conditional Style</em>}' class. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
-     *
-     * @see org.eclipse.sirius.properties.impl.SelectWidgetConditionalStyleImpl
-     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getSelectWidgetConditionalStyle()
-     * @generated
-     */
-    int SELECT_WIDGET_CONDITIONAL_STYLE = 41;
-
-    /**
      * The feature id for the '<em><b>Precondition Expression</b></em>'
      * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
@@ -2699,16 +2688,32 @@ public interface PropertiesPackage extends EPackage {
     int SELECT_WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT = PropertiesPackage.WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT + 1;
 
     /**
-     * The meta object id for the '
-     * {@link org.eclipse.sirius.properties.impl.CustomWidgetConditionalStyleImpl
-     * <em>Custom Widget Conditional Style</em>}' class. <!-- begin-user-doc -->
+     * The feature id for the '<em><b>Precondition Expression</b></em>'
+     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int CUSTOM_WIDGET_CONDITIONAL_STYLE__PRECONDITION_EXPRESSION = PropertiesPackage.WIDGET_CONDITIONAL_STYLE__PRECONDITION_EXPRESSION;
+
+    /**
+     * The feature id for the '<em><b>Style</b></em>' containment reference.
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int CUSTOM_WIDGET_CONDITIONAL_STYLE__STYLE = PropertiesPackage.WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT + 0;
+
+    /**
+     * The number of structural features of the '
+     * <em>Custom Widget Conditional Style</em>' class. <!-- begin-user-doc -->
      * <!-- end-user-doc -->
      *
-     * @see org.eclipse.sirius.properties.impl.CustomWidgetConditionalStyleImpl
-     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getCustomWidgetConditionalStyle()
      * @generated
+     * @ordered
      */
-    int CUSTOM_WIDGET_CONDITIONAL_STYLE = 42;
+    int CUSTOM_WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT = PropertiesPackage.WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT + 1;
 
     /**
      * The feature id for the '<em><b>Precondition Expression</b></em>'
@@ -2717,7 +2722,7 @@ public interface PropertiesPackage extends EPackage {
      * @generated
      * @ordered
      */
-    int CUSTOM_WIDGET_CONDITIONAL_STYLE__PRECONDITION_EXPRESSION = PropertiesPackage.WIDGET_CONDITIONAL_STYLE__PRECONDITION_EXPRESSION;
+    int REFERENCE_WIDGET_CONDITIONAL_STYLE__PRECONDITION_EXPRESSION = PropertiesPackage.WIDGET_CONDITIONAL_STYLE__PRECONDITION_EXPRESSION;
 
     /**
      * The feature id for the '<em><b>Style</b></em>' containment reference.
@@ -2726,17 +2731,44 @@ public interface PropertiesPackage extends EPackage {
      * @generated
      * @ordered
      */
-    int CUSTOM_WIDGET_CONDITIONAL_STYLE__STYLE = PropertiesPackage.WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT + 0;
+    int REFERENCE_WIDGET_CONDITIONAL_STYLE__STYLE = PropertiesPackage.WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT + 0;
 
     /**
      * The number of structural features of the '
-     * <em>Custom Widget Conditional Style</em>' class. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
+     * <em>Reference Widget Conditional Style</em>' class. <!-- begin-user-doc
+     * --> <!-- end-user-doc -->
      *
      * @generated
      * @ordered
      */
-    int CUSTOM_WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT = PropertiesPackage.WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT + 1;
+    int REFERENCE_WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT = PropertiesPackage.WIDGET_CONDITIONAL_STYLE_FEATURE_COUNT + 1;
+
+    /**
+     * The feature id for the '<em><b>Label Expression</b></em>' attribute. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int WIDGET_ACTION__LABEL_EXPRESSION = 0;
+
+    /**
+     * The feature id for the '<em><b>Initial Operation</b></em>' containment
+     * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int WIDGET_ACTION__INITIAL_OPERATION = 1;
+
+    /**
+     * The number of structural features of the '<em>Widget Action</em>' class.
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int WIDGET_ACTION_FEATURE_COUNT = 2;
 
     /**
      * The meta object id for the '
@@ -2748,7 +2780,7 @@ public interface PropertiesPackage extends EPackage {
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getFILL_LAYOUT_ORIENTATION()
      * @generated
      */
-    int FILL_LAYOUT_ORIENTATION = 43;
+    int FILL_LAYOUT_ORIENTATION = 45;
 
     /**
      * Returns the meta object for class '
@@ -3842,97 +3874,106 @@ public interface PropertiesPackage extends EPackage {
 
     /**
      * Returns the meta object for class '
-     * {@link org.eclipse.sirius.properties.SingleReferenceDescription
-     * <em>Single Reference Description</em>}'. <!-- begin-user-doc --> <!--
+     * {@link org.eclipse.sirius.properties.ReferenceDescription
+     * <em>Reference Description</em>}'. <!-- begin-user-doc --> <!--
      * end-user-doc -->
      *
-     * @return the meta object for class '<em>Single Reference Description</em>
-     *         '.
-     * @see org.eclipse.sirius.properties.SingleReferenceDescription
+     * @return the meta object for class '<em>Reference Description</em>'.
+     * @see org.eclipse.sirius.properties.ReferenceDescription
      * @generated
      */
-    EClass getSingleReferenceDescription();
+    EClass getReferenceDescription();
 
     /**
      * Returns the meta object for the attribute '
-     * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getValueExpression
+     * {@link org.eclipse.sirius.properties.ReferenceDescription#isMultiple
+     * <em>Multiple</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @return the meta object for the attribute '<em>Multiple</em>'.
+     * @see org.eclipse.sirius.properties.ReferenceDescription#isMultiple()
+     * @see #getReferenceDescription()
+     * @generated
+     */
+    EAttribute getReferenceDescription_Multiple();
+
+    /**
+     * Returns the meta object for the attribute '
+     * {@link org.eclipse.sirius.properties.ReferenceDescription#getValueExpression
      * <em>Value Expression</em>}'. <!-- begin-user-doc --> <!-- end-user-doc
      * -->
      *
      * @return the meta object for the attribute '<em>Value Expression</em>'.
-     * @see org.eclipse.sirius.properties.SingleReferenceDescription#getValueExpression()
-     * @see #getSingleReferenceDescription()
+     * @see org.eclipse.sirius.properties.ReferenceDescription#getValueExpression()
+     * @see #getReferenceDescription()
      * @generated
      */
-    EAttribute getSingleReferenceDescription_ValueExpression();
+    EAttribute getReferenceDescription_ValueExpression();
 
     /**
      * Returns the meta object for the attribute '
-     * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getDisplayExpression
+     * {@link org.eclipse.sirius.properties.ReferenceDescription#getDisplayExpression
      * <em>Display Expression</em>}'. <!-- begin-user-doc --> <!-- end-user-doc
      * -->
      *
      * @return the meta object for the attribute '<em>Display Expression</em>'.
-     * @see org.eclipse.sirius.properties.SingleReferenceDescription#getDisplayExpression()
-     * @see #getSingleReferenceDescription()
+     * @see org.eclipse.sirius.properties.ReferenceDescription#getDisplayExpression()
+     * @see #getReferenceDescription()
      * @generated
      */
-    EAttribute getSingleReferenceDescription_DisplayExpression();
+    EAttribute getReferenceDescription_DisplayExpression();
 
     /**
      * Returns the meta object for the containment reference '
-     * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getCreateOperation
-     * <em>Create Operation</em>}'. <!-- begin-user-doc --> <!-- end-user-doc
+     * {@link org.eclipse.sirius.properties.ReferenceDescription#getOnClickOperation
+     * <em>On Click Operation</em>}'. <!-- begin-user-doc --> <!-- end-user-doc
      * -->
      *
      * @return the meta object for the containment reference '
-     *         <em>Create Operation</em>'.
-     * @see org.eclipse.sirius.properties.SingleReferenceDescription#getCreateOperation()
-     * @see #getSingleReferenceDescription()
+     *         <em>On Click Operation</em>'.
+     * @see org.eclipse.sirius.properties.ReferenceDescription#getOnClickOperation()
+     * @see #getReferenceDescription()
      * @generated
      */
-    EReference getSingleReferenceDescription_CreateOperation();
+    EReference getReferenceDescription_OnClickOperation();
 
     /**
-     * Returns the meta object for the containment reference '
-     * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getSearchOperation
-     * <em>Search Operation</em>}'. <!-- begin-user-doc --> <!-- end-user-doc
-     * -->
+     * Returns the meta object for the containment reference list '
+     * {@link org.eclipse.sirius.properties.ReferenceDescription#getActions
+     * <em>Actions</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
-     * @return the meta object for the containment reference '
-     *         <em>Search Operation</em>'.
-     * @see org.eclipse.sirius.properties.SingleReferenceDescription#getSearchOperation()
-     * @see #getSingleReferenceDescription()
+     * @return the meta object for the containment reference list '
+     *         <em>Actions</em>'.
+     * @see org.eclipse.sirius.properties.ReferenceDescription#getActions()
+     * @see #getReferenceDescription()
      * @generated
      */
-    EReference getSingleReferenceDescription_SearchOperation();
+    EReference getReferenceDescription_Actions();
 
     /**
      * Returns the meta object for the containment reference '
-     * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getUnsetOperation
-     * <em>Unset Operation</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * {@link org.eclipse.sirius.properties.ReferenceDescription#getStyle
+     * <em>Style</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
      *
-     * @return the meta object for the containment reference '
-     *         <em>Unset Operation</em>'.
-     * @see org.eclipse.sirius.properties.SingleReferenceDescription#getUnsetOperation()
-     * @see #getSingleReferenceDescription()
+     * @return the meta object for the containment reference '<em>Style</em>'.
+     * @see org.eclipse.sirius.properties.ReferenceDescription#getStyle()
+     * @see #getReferenceDescription()
      * @generated
      */
-    EReference getSingleReferenceDescription_UnsetOperation();
+    EReference getReferenceDescription_Style();
 
     /**
-     * Returns the meta object for the containment reference '
-     * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getOnClickOperation
-     * <em>On Click Operation</em>}'. <!-- begin-user-doc --> <!-- end-user-doc
+     * Returns the meta object for the containment reference list '
+     * {@link org.eclipse.sirius.properties.ReferenceDescription#getConditionalStyles
+     * <em>Conditional Styles</em>}'. <!-- begin-user-doc --> <!-- end-user-doc
      * -->
      *
-     * @return the meta object for the containment reference '
-     *         <em>On Click Operation</em>'.
-     * @see org.eclipse.sirius.properties.SingleReferenceDescription#getOnClickOperation()
-     * @see #getSingleReferenceDescription()
+     * @return the meta object for the containment reference list '
+     *         <em>Conditional Styles</em>'.
+     * @see org.eclipse.sirius.properties.ReferenceDescription#getConditionalStyles()
+     * @see #getReferenceDescription()
      * @generated
      */
-    EReference getSingleReferenceDescription_OnClickOperation();
+    EReference getReferenceDescription_ConditionalStyles();
 
     /**
      * Returns the meta object for class '
@@ -3962,126 +4003,6 @@ public interface PropertiesPackage extends EPackage {
 
     /**
      * Returns the meta object for class '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription
-     * <em>Multiple References Description</em>}'. <!-- begin-user-doc --> <!--
-     * end-user-doc -->
-     *
-     * @return the meta object for class '
-     *         <em>Multiple References Description</em>'.
-     * @see org.eclipse.sirius.properties.MultipleReferencesDescription
-     * @generated
-     */
-    EClass getMultipleReferencesDescription();
-
-    /**
-     * Returns the meta object for the attribute '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getValueExpression
-     * <em>Value Expression</em>}'. <!-- begin-user-doc --> <!-- end-user-doc
-     * -->
-     *
-     * @return the meta object for the attribute '<em>Value Expression</em>'.
-     * @see org.eclipse.sirius.properties.MultipleReferencesDescription#getValueExpression()
-     * @see #getMultipleReferencesDescription()
-     * @generated
-     */
-    EAttribute getMultipleReferencesDescription_ValueExpression();
-
-    /**
-     * Returns the meta object for the attribute '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getDisplayExpression
-     * <em>Display Expression</em>}'. <!-- begin-user-doc --> <!-- end-user-doc
-     * -->
-     *
-     * @return the meta object for the attribute '<em>Display Expression</em>'.
-     * @see org.eclipse.sirius.properties.MultipleReferencesDescription#getDisplayExpression()
-     * @see #getMultipleReferencesDescription()
-     * @generated
-     */
-    EAttribute getMultipleReferencesDescription_DisplayExpression();
-
-    /**
-     * Returns the meta object for the containment reference '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getCreateOperation
-     * <em>Create Operation</em>}'. <!-- begin-user-doc --> <!-- end-user-doc
-     * -->
-     *
-     * @return the meta object for the containment reference '
-     *         <em>Create Operation</em>'.
-     * @see org.eclipse.sirius.properties.MultipleReferencesDescription#getCreateOperation()
-     * @see #getMultipleReferencesDescription()
-     * @generated
-     */
-    EReference getMultipleReferencesDescription_CreateOperation();
-
-    /**
-     * Returns the meta object for the containment reference '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getSearchOperation
-     * <em>Search Operation</em>}'. <!-- begin-user-doc --> <!-- end-user-doc
-     * -->
-     *
-     * @return the meta object for the containment reference '
-     *         <em>Search Operation</em>'.
-     * @see org.eclipse.sirius.properties.MultipleReferencesDescription#getSearchOperation()
-     * @see #getMultipleReferencesDescription()
-     * @generated
-     */
-    EReference getMultipleReferencesDescription_SearchOperation();
-
-    /**
-     * Returns the meta object for the containment reference '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getUnsetOperation
-     * <em>Unset Operation</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @return the meta object for the containment reference '
-     *         <em>Unset Operation</em>'.
-     * @see org.eclipse.sirius.properties.MultipleReferencesDescription#getUnsetOperation()
-     * @see #getMultipleReferencesDescription()
-     * @generated
-     */
-    EReference getMultipleReferencesDescription_UnsetOperation();
-
-    /**
-     * Returns the meta object for the containment reference '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getOnClickOperation
-     * <em>On Click Operation</em>}'. <!-- begin-user-doc --> <!-- end-user-doc
-     * -->
-     *
-     * @return the meta object for the containment reference '
-     *         <em>On Click Operation</em>'.
-     * @see org.eclipse.sirius.properties.MultipleReferencesDescription#getOnClickOperation()
-     * @see #getMultipleReferencesDescription()
-     * @generated
-     */
-    EReference getMultipleReferencesDescription_OnClickOperation();
-
-    /**
-     * Returns the meta object for the containment reference '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getUpOperation
-     * <em>Up Operation</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @return the meta object for the containment reference '
-     *         <em>Up Operation</em>'.
-     * @see org.eclipse.sirius.properties.MultipleReferencesDescription#getUpOperation()
-     * @see #getMultipleReferencesDescription()
-     * @generated
-     */
-    EReference getMultipleReferencesDescription_UpOperation();
-
-    /**
-     * Returns the meta object for the containment reference '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription#getDownOperation
-     * <em>Down Operation</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @return the meta object for the containment reference '
-     *         <em>Down Operation</em>'.
-     * @see org.eclipse.sirius.properties.MultipleReferencesDescription#getDownOperation()
-     * @see #getMultipleReferencesDescription()
-     * @generated
-     */
-    EReference getMultipleReferencesDescription_DownOperation();
-
-    /**
-     * Returns the meta object for class '
      * {@link org.eclipse.sirius.properties.CustomDescription
      * <em>Custom Description</em>}'. <!-- begin-user-doc --> <!-- end-user-doc
      * -->
@@ -4714,6 +4635,81 @@ public interface PropertiesPackage extends EPackage {
     EReference getCustomWidgetConditionalStyle_Style();
 
     /**
+     * Returns the meta object for class '
+     * {@link org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle
+     * <em>Reference Widget Conditional Style</em>}'. <!-- begin-user-doc -->
+     * <!-- end-user-doc -->
+     *
+     * @return the meta object for class '
+     *         <em>Reference Widget Conditional Style</em>'.
+     * @see org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle
+     * @generated
+     */
+    EClass getReferenceWidgetConditionalStyle();
+
+    /**
+     * Returns the meta object for the containment reference '
+     * {@link org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle#getStyle
+     * <em>Style</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @return the meta object for the containment reference '<em>Style</em>'.
+     * @see org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle#getStyle()
+     * @see #getReferenceWidgetConditionalStyle()
+     * @generated
+     */
+    EReference getReferenceWidgetConditionalStyle_Style();
+
+    /**
+     * Returns the meta object for class '
+     * {@link org.eclipse.sirius.properties.WidgetAction <em>Widget Action</em>}
+     * '. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @return the meta object for class '<em>Widget Action</em>'.
+     * @see org.eclipse.sirius.properties.WidgetAction
+     * @generated
+     */
+    EClass getWidgetAction();
+
+    /**
+     * Returns the meta object for the attribute '
+     * {@link org.eclipse.sirius.properties.WidgetAction#getLabelExpression
+     * <em>Label Expression</em>}'. <!-- begin-user-doc --> <!-- end-user-doc
+     * -->
+     *
+     * @return the meta object for the attribute '<em>Label Expression</em>'.
+     * @see org.eclipse.sirius.properties.WidgetAction#getLabelExpression()
+     * @see #getWidgetAction()
+     * @generated
+     */
+    EAttribute getWidgetAction_LabelExpression();
+
+    /**
+     * Returns the meta object for the containment reference '
+     * {@link org.eclipse.sirius.properties.WidgetAction#getInitialOperation
+     * <em>Initial Operation</em>}'. <!-- begin-user-doc --> <!-- end-user-doc
+     * -->
+     *
+     * @return the meta object for the containment reference '
+     *         <em>Initial Operation</em>'.
+     * @see org.eclipse.sirius.properties.WidgetAction#getInitialOperation()
+     * @see #getWidgetAction()
+     * @generated
+     */
+    EReference getWidgetAction_InitialOperation();
+
+    /**
+     * Returns the meta object for class '
+     * {@link org.eclipse.sirius.properties.ReferenceWidgetStyle
+     * <em>Reference Widget Style</em>}'. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @return the meta object for class '<em>Reference Widget Style</em>'.
+     * @see org.eclipse.sirius.properties.ReferenceWidgetStyle
+     * @generated
+     */
+    EClass getReferenceWidgetStyle();
+
+    /**
      * Returns the meta object for enum '
      * {@link org.eclipse.sirius.properties.FILL_LAYOUT_ORIENTATION
      * <em>FILL LAYOUT ORIENTATION</em>}'. <!-- begin-user-doc --> <!--
@@ -5543,15 +5539,23 @@ public interface PropertiesPackage extends EPackage {
 
         /**
          * The meta object literal for the '
-         * {@link org.eclipse.sirius.properties.impl.SingleReferenceDescriptionImpl
-         * <em>Single Reference Description</em>}' class. <!-- begin-user-doc
-         * --> <!-- end-user-doc -->
+         * {@link org.eclipse.sirius.properties.impl.ReferenceDescriptionImpl
+         * <em>Reference Description</em>}' class. <!-- begin-user-doc --> <!--
+         * end-user-doc -->
          *
-         * @see org.eclipse.sirius.properties.impl.SingleReferenceDescriptionImpl
-         * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getSingleReferenceDescription()
+         * @see org.eclipse.sirius.properties.impl.ReferenceDescriptionImpl
+         * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getReferenceDescription()
          * @generated
          */
-        EClass SINGLE_REFERENCE_DESCRIPTION = PropertiesPackage.eINSTANCE.getSingleReferenceDescription();
+        EClass REFERENCE_DESCRIPTION = PropertiesPackage.eINSTANCE.getReferenceDescription();
+
+        /**
+         * The meta object literal for the '<em><b>Multiple</b></em>' attribute
+         * feature. <!-- begin-user-doc --> <!-- end-user-doc -->
+         *
+         * @generated
+         */
+        EAttribute REFERENCE_DESCRIPTION__MULTIPLE = PropertiesPackage.eINSTANCE.getReferenceDescription_Multiple();
 
         /**
          * The meta object literal for the '<em><b>Value Expression</b></em>'
@@ -5559,7 +5563,7 @@ public interface PropertiesPackage extends EPackage {
          *
          * @generated
          */
-        EAttribute SINGLE_REFERENCE_DESCRIPTION__VALUE_EXPRESSION = PropertiesPackage.eINSTANCE.getSingleReferenceDescription_ValueExpression();
+        EAttribute REFERENCE_DESCRIPTION__VALUE_EXPRESSION = PropertiesPackage.eINSTANCE.getReferenceDescription_ValueExpression();
 
         /**
          * The meta object literal for the '<em><b>Display Expression</b></em>'
@@ -5567,43 +5571,41 @@ public interface PropertiesPackage extends EPackage {
          *
          * @generated
          */
-        EAttribute SINGLE_REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION = PropertiesPackage.eINSTANCE.getSingleReferenceDescription_DisplayExpression();
+        EAttribute REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION = PropertiesPackage.eINSTANCE.getReferenceDescription_DisplayExpression();
 
         /**
-         * The meta object literal for the '<em><b>Create Operation</b></em>'
+         * The meta object literal for the '<em><b>On Click Operation</b></em>'
          * containment reference feature. <!-- begin-user-doc --> <!--
          * end-user-doc -->
          *
          * @generated
          */
-        EReference SINGLE_REFERENCE_DESCRIPTION__CREATE_OPERATION = PropertiesPackage.eINSTANCE.getSingleReferenceDescription_CreateOperation();
+        EReference REFERENCE_DESCRIPTION__ON_CLICK_OPERATION = PropertiesPackage.eINSTANCE.getReferenceDescription_OnClickOperation();
 
         /**
-         * The meta object literal for the '<em><b>Search Operation</b></em>'
-         * containment reference feature. <!-- begin-user-doc --> <!--
-         * end-user-doc -->
+         * The meta object literal for the '<em><b>Actions</b></em>' containment
+         * reference list feature. <!-- begin-user-doc --> <!-- end-user-doc -->
          *
          * @generated
          */
-        EReference SINGLE_REFERENCE_DESCRIPTION__SEARCH_OPERATION = PropertiesPackage.eINSTANCE.getSingleReferenceDescription_SearchOperation();
+        EReference REFERENCE_DESCRIPTION__ACTIONS = PropertiesPackage.eINSTANCE.getReferenceDescription_Actions();
 
         /**
-         * The meta object literal for the '<em><b>Unset Operation</b></em>'
-         * containment reference feature. <!-- begin-user-doc --> <!--
-         * end-user-doc -->
+         * The meta object literal for the '<em><b>Style</b></em>' containment
+         * reference feature. <!-- begin-user-doc --> <!-- end-user-doc -->
          *
          * @generated
          */
-        EReference SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION = PropertiesPackage.eINSTANCE.getSingleReferenceDescription_UnsetOperation();
+        EReference REFERENCE_DESCRIPTION__STYLE = PropertiesPackage.eINSTANCE.getReferenceDescription_Style();
 
         /**
-         * The meta object literal for the '<em><b>On Click Operation</b></em>'
-         * containment reference feature. <!-- begin-user-doc --> <!--
+         * The meta object literal for the '<em><b>Conditional Styles</b></em>'
+         * containment reference list feature. <!-- begin-user-doc --> <!--
          * end-user-doc -->
          *
          * @generated
          */
-        EReference SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION = PropertiesPackage.eINSTANCE.getSingleReferenceDescription_OnClickOperation();
+        EReference REFERENCE_DESCRIPTION__CONDITIONAL_STYLES = PropertiesPackage.eINSTANCE.getReferenceDescription_ConditionalStyles();
 
         /**
          * The meta object literal for the '
@@ -5628,88 +5630,6 @@ public interface PropertiesPackage extends EPackage {
 
         /**
          * The meta object literal for the '
-         * {@link org.eclipse.sirius.properties.impl.MultipleReferencesDescriptionImpl
-         * <em>Multiple References Description</em>}' class. <!-- begin-user-doc
-         * --> <!-- end-user-doc -->
-         *
-         * @see org.eclipse.sirius.properties.impl.MultipleReferencesDescriptionImpl
-         * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getMultipleReferencesDescription()
-         * @generated
-         */
-        EClass MULTIPLE_REFERENCES_DESCRIPTION = PropertiesPackage.eINSTANCE.getMultipleReferencesDescription();
-
-        /**
-         * The meta object literal for the '<em><b>Value Expression</b></em>'
-         * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
-         * @generated
-         */
-        EAttribute MULTIPLE_REFERENCES_DESCRIPTION__VALUE_EXPRESSION = PropertiesPackage.eINSTANCE.getMultipleReferencesDescription_ValueExpression();
-
-        /**
-         * The meta object literal for the '<em><b>Display Expression</b></em>'
-         * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
-         * @generated
-         */
-        EAttribute MULTIPLE_REFERENCES_DESCRIPTION__DISPLAY_EXPRESSION = PropertiesPackage.eINSTANCE.getMultipleReferencesDescription_DisplayExpression();
-
-        /**
-         * The meta object literal for the '<em><b>Create Operation</b></em>'
-         * containment reference feature. <!-- begin-user-doc --> <!--
-         * end-user-doc -->
-         *
-         * @generated
-         */
-        EReference MULTIPLE_REFERENCES_DESCRIPTION__CREATE_OPERATION = PropertiesPackage.eINSTANCE.getMultipleReferencesDescription_CreateOperation();
-
-        /**
-         * The meta object literal for the '<em><b>Search Operation</b></em>'
-         * containment reference feature. <!-- begin-user-doc --> <!--
-         * end-user-doc -->
-         *
-         * @generated
-         */
-        EReference MULTIPLE_REFERENCES_DESCRIPTION__SEARCH_OPERATION = PropertiesPackage.eINSTANCE.getMultipleReferencesDescription_SearchOperation();
-
-        /**
-         * The meta object literal for the '<em><b>Unset Operation</b></em>'
-         * containment reference feature. <!-- begin-user-doc --> <!--
-         * end-user-doc -->
-         *
-         * @generated
-         */
-        EReference MULTIPLE_REFERENCES_DESCRIPTION__UNSET_OPERATION = PropertiesPackage.eINSTANCE.getMultipleReferencesDescription_UnsetOperation();
-
-        /**
-         * The meta object literal for the '<em><b>On Click Operation</b></em>'
-         * containment reference feature. <!-- begin-user-doc --> <!--
-         * end-user-doc -->
-         *
-         * @generated
-         */
-        EReference MULTIPLE_REFERENCES_DESCRIPTION__ON_CLICK_OPERATION = PropertiesPackage.eINSTANCE.getMultipleReferencesDescription_OnClickOperation();
-
-        /**
-         * The meta object literal for the '<em><b>Up Operation</b></em>'
-         * containment reference feature. <!-- begin-user-doc --> <!--
-         * end-user-doc -->
-         *
-         * @generated
-         */
-        EReference MULTIPLE_REFERENCES_DESCRIPTION__UP_OPERATION = PropertiesPackage.eINSTANCE.getMultipleReferencesDescription_UpOperation();
-
-        /**
-         * The meta object literal for the '<em><b>Down Operation</b></em>'
-         * containment reference feature. <!-- begin-user-doc --> <!--
-         * end-user-doc -->
-         *
-         * @generated
-         */
-        EReference MULTIPLE_REFERENCES_DESCRIPTION__DOWN_OPERATION = PropertiesPackage.eINSTANCE.getMultipleReferencesDescription_DownOperation();
-
-        /**
-         * The meta object literal for the '
          * {@link org.eclipse.sirius.properties.impl.CustomDescriptionImpl
          * <em>Custom Description</em>}' class. <!-- begin-user-doc --> <!--
          * end-user-doc -->
@@ -6194,6 +6114,67 @@ public interface PropertiesPackage extends EPackage {
 
         /**
          * The meta object literal for the '
+         * {@link org.eclipse.sirius.properties.impl.ReferenceWidgetConditionalStyleImpl
+         * <em>Reference Widget Conditional Style</em>}' class. <!--
+         * begin-user-doc --> <!-- end-user-doc -->
+         *
+         * @see org.eclipse.sirius.properties.impl.ReferenceWidgetConditionalStyleImpl
+         * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getReferenceWidgetConditionalStyle()
+         * @generated
+         */
+        EClass REFERENCE_WIDGET_CONDITIONAL_STYLE = PropertiesPackage.eINSTANCE.getReferenceWidgetConditionalStyle();
+
+        /**
+         * The meta object literal for the '<em><b>Style</b></em>' containment
+         * reference feature. <!-- begin-user-doc --> <!-- end-user-doc -->
+         *
+         * @generated
+         */
+        EReference REFERENCE_WIDGET_CONDITIONAL_STYLE__STYLE = PropertiesPackage.eINSTANCE.getReferenceWidgetConditionalStyle_Style();
+
+        /**
+         * The meta object literal for the '
+         * {@link org.eclipse.sirius.properties.impl.WidgetActionImpl
+         * <em>Widget Action</em>}' class. <!-- begin-user-doc --> <!--
+         * end-user-doc -->
+         *
+         * @see org.eclipse.sirius.properties.impl.WidgetActionImpl
+         * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getWidgetAction()
+         * @generated
+         */
+        EClass WIDGET_ACTION = PropertiesPackage.eINSTANCE.getWidgetAction();
+
+        /**
+         * The meta object literal for the '<em><b>Label Expression</b></em>'
+         * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
+         *
+         * @generated
+         */
+        EAttribute WIDGET_ACTION__LABEL_EXPRESSION = PropertiesPackage.eINSTANCE.getWidgetAction_LabelExpression();
+
+        /**
+         * The meta object literal for the '<em><b>Initial Operation</b></em>'
+         * containment reference feature. <!-- begin-user-doc --> <!--
+         * end-user-doc -->
+         *
+         * @generated
+         */
+        EReference WIDGET_ACTION__INITIAL_OPERATION = PropertiesPackage.eINSTANCE.getWidgetAction_InitialOperation();
+
+        /**
+         * The meta object literal for the '
+         * {@link org.eclipse.sirius.properties.impl.ReferenceWidgetStyleImpl
+         * <em>Reference Widget Style</em>}' class. <!-- begin-user-doc --> <!--
+         * end-user-doc -->
+         *
+         * @see org.eclipse.sirius.properties.impl.ReferenceWidgetStyleImpl
+         * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getReferenceWidgetStyle()
+         * @generated
+         */
+        EClass REFERENCE_WIDGET_STYLE = PropertiesPackage.eINSTANCE.getReferenceWidgetStyle();
+
+        /**
+         * The meta object literal for the '
          * {@link org.eclipse.sirius.properties.FILL_LAYOUT_ORIENTATION
          * <em>FILL LAYOUT ORIENTATION</em>}' enum. <!-- begin-user-doc --> <!--
          * end-user-doc -->
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/ReferenceDescription.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/ReferenceDescription.java
new file mode 100644
index 0000000000..252b9f7625
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/ReferenceDescription.java
@@ -0,0 +1,233 @@
+/**
+ * Copyright (c) 2016 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.properties;
+
+import org.eclipse.emf.common.util.EList;
+import org.eclipse.sirius.viewpoint.description.tool.InitialOperation;
+
+/**
+ * <!-- begin-user-doc --> A representation of the model object '
+ * <em><b>Reference Description</b></em>'. <!-- end-user-doc -->
+ *
+ * <!-- begin-model-doc --> Represents a reference in the user interface. <!--
+ * end-model-doc -->
+ *
+ * <p>
+ * The following features are supported:
+ * </p>
+ * <ul>
+ * <li>{@link org.eclipse.sirius.properties.ReferenceDescription#isMultiple
+ * <em>Multiple</em>}</li>
+ * <li>
+ * {@link org.eclipse.sirius.properties.ReferenceDescription#getValueExpression
+ * <em>Value Expression</em>}</li>
+ * <li>
+ * {@link org.eclipse.sirius.properties.ReferenceDescription#getDisplayExpression
+ * <em>Display Expression</em>}</li>
+ * <li>
+ * {@link org.eclipse.sirius.properties.ReferenceDescription#getOnClickOperation
+ * <em>On Click Operation</em>}</li>
+ * <li>{@link org.eclipse.sirius.properties.ReferenceDescription#getActions
+ * <em>Actions</em>}</li>
+ * <li>{@link org.eclipse.sirius.properties.ReferenceDescription#getStyle
+ * <em>Style</em>}</li>
+ * <li>
+ * {@link org.eclipse.sirius.properties.ReferenceDescription#getConditionalStyles
+ * <em>Conditional Styles</em>}</li>
+ * </ul>
+ *
+ * @see org.eclipse.sirius.properties.PropertiesPackage#getReferenceDescription()
+ * @model
+ * @generated
+ */
+public interface ReferenceDescription extends WidgetDescription {
+    /**
+     * Returns the value of the '<em><b>Multiple</b></em>' attribute. <!--
+     * begin-user-doc -->
+     * <p>
+     * If the meaning of the '<em>Multiple</em>' attribute isn't clear, there
+     * really should be more of a description here...
+     * </p>
+     * <!-- end-user-doc -->
+     *
+     * @return the value of the '<em>Multiple</em>' attribute.
+     * @see #setMultiple(boolean)
+     * @see org.eclipse.sirius.properties.PropertiesPackage#getReferenceDescription_Multiple()
+     * @model
+     * @generated
+     */
+    boolean isMultiple();
+
+    /**
+     * Sets the value of the '
+     * {@link org.eclipse.sirius.properties.ReferenceDescription#isMultiple
+     * <em>Multiple</em>}' attribute. <!-- begin-user-doc --> <!-- end-user-doc
+     * -->
+     *
+     * @param value
+     *            the new value of the '<em>Multiple</em>' attribute.
+     * @see #isMultiple()
+     * @generated
+     */
+    void setMultiple(boolean value);
+
+    /**
+     * Returns the value of the '<em><b>Value Expression</b></em>' attribute.
+     * <!-- begin-user-doc --> <!-- end-user-doc --> <!-- begin-model-doc -->
+     * The initial value. <!-- end-model-doc -->
+     *
+     * @return the value of the '<em>Value Expression</em>' attribute.
+     * @see #setValueExpression(String)
+     * @see org.eclipse.sirius.properties.PropertiesPackage#getReferenceDescription_ValueExpression()
+     * @model dataType=
+     *        "org.eclipse.sirius.viewpoint.description.InterpretedExpression"
+     * @generated
+     */
+    String getValueExpression();
+
+    /**
+     * Sets the value of the '
+     * {@link org.eclipse.sirius.properties.ReferenceDescription#getValueExpression
+     * <em>Value Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @param value
+     *            the new value of the '<em>Value Expression</em>' attribute.
+     * @see #getValueExpression()
+     * @generated
+     */
+    void setValueExpression(String value);
+
+    /**
+     * Returns the value of the '<em><b>Display Expression</b></em>' attribute.
+     * <!-- begin-user-doc --> <!-- end-user-doc --> <!-- begin-model-doc -->
+     * Represents how to display the value. <!-- end-model-doc -->
+     *
+     * @return the value of the '<em>Display Expression</em>' attribute.
+     * @see #setDisplayExpression(String)
+     * @see org.eclipse.sirius.properties.PropertiesPackage#getReferenceDescription_DisplayExpression()
+     * @model dataType=
+     *        "org.eclipse.sirius.viewpoint.description.InterpretedExpression"
+     * @generated
+     */
+    String getDisplayExpression();
+
+    /**
+     * Sets the value of the '
+     * {@link org.eclipse.sirius.properties.ReferenceDescription#getDisplayExpression
+     * <em>Display Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @param value
+     *            the new value of the '<em>Display Expression</em>' attribute.
+     * @see #getDisplayExpression()
+     * @generated
+     */
+    void setDisplayExpression(String value);
+
+    /**
+     * Returns the value of the '<em><b>On Click Operation</b></em>' containment
+     * reference. <!-- begin-user-doc --> <!-- end-user-doc --> <!--
+     * begin-model-doc --> Defines the expected behavior when the user clicks on
+     * the hyperlink. <!-- end-model-doc -->
+     *
+     * @return the value of the '<em>On Click Operation</em>' containment
+     *         reference.
+     * @see #setOnClickOperation(OperationDescription)
+     * @see org.eclipse.sirius.properties.PropertiesPackage#getReferenceDescription_OnClickOperation()
+     * @model containment="true"
+     * @generated
+     */
+    InitialOperation getOnClickOperation();
+
+    /**
+     * Sets the value of the '
+     * {@link org.eclipse.sirius.properties.ReferenceDescription#getOnClickOperation
+     * <em>On Click Operation</em>}' containment reference. <!-- begin-user-doc
+     * --> <!-- end-user-doc -->
+     *
+     * @param value
+     *            the new value of the '<em>On Click Operation</em>' containment
+     *            reference.
+     * @see #getOnClickOperation()
+     * @generated
+     */
+    void setOnClickOperation(InitialOperation value);
+
+    /**
+     * Returns the value of the '<em><b>Actions</b></em>' containment reference
+     * list. The list contents are of type
+     * {@link org.eclipse.sirius.properties.WidgetAction}. <!-- begin-user-doc
+     * -->
+     * <p>
+     * If the meaning of the '<em>Actions</em>' containment reference isn't
+     * clear, there really should be more of a description here...
+     * </p>
+     * <!-- end-user-doc -->
+     *
+     * @return the value of the '<em>Actions</em>' containment reference list.
+     * @see org.eclipse.sirius.properties.PropertiesPackage#getReferenceDescription_Actions()
+     * @model containment="true"
+     * @generated
+     */
+    EList<WidgetAction> getActions();
+
+    /**
+     * Returns the value of the '<em><b>Style</b></em>' containment reference.
+     * <!-- begin-user-doc -->
+     * <p>
+     * If the meaning of the '<em>Style</em>' containment reference isn't clear,
+     * there really should be more of a description here...
+     * </p>
+     * <!-- end-user-doc -->
+     *
+     * @return the value of the '<em>Style</em>' containment reference.
+     * @see #setStyle(ReferenceWidgetStyle)
+     * @see org.eclipse.sirius.properties.PropertiesPackage#getReferenceDescription_Style()
+     * @model containment="true"
+     * @generated
+     */
+    ReferenceWidgetStyle getStyle();
+
+    /**
+     * Sets the value of the '
+     * {@link org.eclipse.sirius.properties.ReferenceDescription#getStyle
+     * <em>Style</em>}' containment reference. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @param value
+     *            the new value of the '<em>Style</em>' containment reference.
+     * @see #getStyle()
+     * @generated
+     */
+    void setStyle(ReferenceWidgetStyle value);
+
+    /**
+     * Returns the value of the '<em><b>Conditional Styles</b></em>' containment
+     * reference list. The list contents are of type
+     * {@link org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle}.
+     * <!-- begin-user-doc -->
+     * <p>
+     * If the meaning of the '<em>Conditional Styles</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>Conditional Styles</em>' containment
+     *         reference list.
+     * @see org.eclipse.sirius.properties.PropertiesPackage#getReferenceDescription_ConditionalStyles()
+     * @model containment="true"
+     * @generated
+     */
+    EList<ReferenceWidgetConditionalStyle> getConditionalStyles();
+
+} // ReferenceDescription
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/ReferenceWidgetConditionalStyle.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/ReferenceWidgetConditionalStyle.java
new file mode 100644
index 0000000000..755337ad89
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/ReferenceWidgetConditionalStyle.java
@@ -0,0 +1,62 @@
+/**
+ * Copyright (c) 2016 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.properties;
+
+/**
+ * <!-- begin-user-doc --> A representation of the model object '
+ * <em><b>Reference Widget Conditional Style</b></em>'. <!-- end-user-doc -->
+ *
+ * <p>
+ * The following features are supported:
+ * </p>
+ * <ul>
+ * <li>
+ * {@link org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle#getStyle
+ * <em>Style</em>}</li>
+ * </ul>
+ *
+ * @see org.eclipse.sirius.properties.PropertiesPackage#getReferenceWidgetConditionalStyle()
+ * @model
+ * @generated
+ */
+public interface ReferenceWidgetConditionalStyle extends WidgetConditionalStyle {
+    /**
+     * Returns the value of the '<em><b>Style</b></em>' containment reference.
+     * <!-- begin-user-doc -->
+     * <p>
+     * If the meaning of the '<em>Style</em>' containment reference isn't clear,
+     * there really should be more of a description here...
+     * </p>
+     * <!-- end-user-doc -->
+     *
+     * @return the value of the '<em>Style</em>' containment reference.
+     * @see #setStyle(ReferenceWidgetStyle)
+     * @see org.eclipse.sirius.properties.PropertiesPackage#getReferenceWidgetConditionalStyle_Style()
+     * @model containment="true"
+     * @generated
+     */
+    ReferenceWidgetStyle getStyle();
+
+    /**
+     * Sets the value of the '
+     * {@link org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle#getStyle
+     * <em>Style</em>}' containment reference. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @param value
+     *            the new value of the '<em>Style</em>' containment reference.
+     * @see #getStyle()
+     * @generated
+     */
+    void setStyle(ReferenceWidgetStyle value);
+
+} // ReferenceWidgetConditionalStyle
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/ReferenceWidgetStyle.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/ReferenceWidgetStyle.java
new file mode 100644
index 0000000000..852648a7e7
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/ReferenceWidgetStyle.java
@@ -0,0 +1,24 @@
+/**
+ * Copyright (c) 2016 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.properties;
+
+/**
+ * <!-- begin-user-doc --> A representation of the model object '
+ * <em><b>Reference Widget Style</b></em>'. <!-- end-user-doc -->
+ *
+ *
+ * @see org.eclipse.sirius.properties.PropertiesPackage#getReferenceWidgetStyle()
+ * @model
+ * @generated
+ */
+public interface ReferenceWidgetStyle extends WidgetStyle {
+} // ReferenceWidgetStyle
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/SingleReferenceDescription.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/SingleReferenceDescription.java
deleted file mode 100644
index 11ef8af305..0000000000
--- a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/SingleReferenceDescription.java
+++ /dev/null
@@ -1,220 +0,0 @@
-/**
- * Copyright (c) 2016 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.properties;
-
-/**
- * <!-- begin-user-doc --> A representation of the model object '
- * <em><b>Single Reference Description</b></em>'. <!-- end-user-doc -->
- *
- * <!-- begin-model-doc --> Represents a single reference in the user interface.
- * <!-- end-model-doc -->
- *
- * <p>
- * The following features are supported:
- * </p>
- * <ul>
- * <li>
- * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getValueExpression
- * <em>Value Expression</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getDisplayExpression
- * <em>Display Expression</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getCreateOperation
- * <em>Create Operation</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getSearchOperation
- * <em>Search Operation</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getUnsetOperation
- * <em>Unset Operation</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getOnClickOperation
- * <em>On Click Operation</em>}</li>
- * </ul>
- *
- * @see org.eclipse.sirius.properties.PropertiesPackage#getSingleReferenceDescription()
- * @model
- * @generated
- */
-public interface SingleReferenceDescription extends WidgetDescription {
-    /**
-     * Returns the value of the '<em><b>Value Expression</b></em>' attribute.
-     * <!-- begin-user-doc --> <!-- end-user-doc --> <!-- begin-model-doc -->
-     * The initial value. <!-- end-model-doc -->
-     *
-     * @return the value of the '<em>Value Expression</em>' attribute.
-     * @see #setValueExpression(String)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getSingleReferenceDescription_ValueExpression()
-     * @model dataType=
-     *        "org.eclipse.sirius.viewpoint.description.InterpretedExpression"
-     * @generated
-     */
-    String getValueExpression();
-
-    /**
-     * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getValueExpression
-     * <em>Value Expression</em>}' attribute. <!-- begin-user-doc --> <!--
-     * end-user-doc -->
-     *
-     * @param value
-     *            the new value of the '<em>Value Expression</em>' attribute.
-     * @see #getValueExpression()
-     * @generated
-     */
-    void setValueExpression(String value);
-
-    /**
-     * Returns the value of the '<em><b>Display Expression</b></em>' attribute.
-     * <!-- begin-user-doc --> <!-- end-user-doc --> <!-- begin-model-doc -->
-     * Represents how to display the value. <!-- end-model-doc -->
-     *
-     * @return the value of the '<em>Display Expression</em>' attribute.
-     * @see #setDisplayExpression(String)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getSingleReferenceDescription_DisplayExpression()
-     * @model dataType=
-     *        "org.eclipse.sirius.viewpoint.description.InterpretedExpression"
-     * @generated
-     */
-    String getDisplayExpression();
-
-    /**
-     * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getDisplayExpression
-     * <em>Display Expression</em>}' attribute. <!-- begin-user-doc --> <!--
-     * end-user-doc -->
-     *
-     * @param value
-     *            the new value of the '<em>Display Expression</em>' attribute.
-     * @see #getDisplayExpression()
-     * @generated
-     */
-    void setDisplayExpression(String value);
-
-    /**
-     * Returns the value of the '<em><b>Create Operation</b></em>' containment
-     * reference. <!-- begin-user-doc --> <!-- end-user-doc --> <!--
-     * begin-model-doc --> Defines the expected behavior when the user clicks on
-     * the create button. <!-- end-model-doc -->
-     *
-     * @return the value of the '<em>Create Operation</em>' containment
-     *         reference.
-     * @see #setCreateOperation(OperationDescription)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getSingleReferenceDescription_CreateOperation()
-     * @model containment="true"
-     * @generated
-     */
-    OperationDescription getCreateOperation();
-
-    /**
-     * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getCreateOperation
-     * <em>Create Operation</em>}' containment reference. <!-- begin-user-doc
-     * --> <!-- end-user-doc -->
-     *
-     * @param value
-     *            the new value of the '<em>Create Operation</em>' containment
-     *            reference.
-     * @see #getCreateOperation()
-     * @generated
-     */
-    void setCreateOperation(OperationDescription value);
-
-    /**
-     * Returns the value of the '<em><b>Search Operation</b></em>' containment
-     * reference. <!-- begin-user-doc --> <!-- end-user-doc --> <!--
-     * begin-model-doc --> Defines the expected behavior when the user clicks on
-     * the search button. <!-- end-model-doc -->
-     *
-     * @return the value of the '<em>Search Operation</em>' containment
-     *         reference.
-     * @see #setSearchOperation(OperationDescription)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getSingleReferenceDescription_SearchOperation()
-     * @model containment="true"
-     * @generated
-     */
-    OperationDescription getSearchOperation();
-
-    /**
-     * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getSearchOperation
-     * <em>Search Operation</em>}' containment reference. <!-- begin-user-doc
-     * --> <!-- end-user-doc -->
-     *
-     * @param value
-     *            the new value of the '<em>Search Operation</em>' containment
-     *            reference.
-     * @see #getSearchOperation()
-     * @generated
-     */
-    void setSearchOperation(OperationDescription value);
-
-    /**
-     * Returns the value of the '<em><b>Unset Operation</b></em>' containment
-     * reference. <!-- begin-user-doc --> <!-- end-user-doc --> <!--
-     * begin-model-doc --> Defines the expected behavior when the user clicks on
-     * the unset button. <!-- end-model-doc -->
-     *
-     * @return the value of the '<em>Unset Operation</em>' containment
-     *         reference.
-     * @see #setUnsetOperation(OperationDescription)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getSingleReferenceDescription_UnsetOperation()
-     * @model containment="true"
-     * @generated
-     */
-    OperationDescription getUnsetOperation();
-
-    /**
-     * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getUnsetOperation
-     * <em>Unset Operation</em>}' containment reference. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
-     *
-     * @param value
-     *            the new value of the '<em>Unset Operation</em>' containment
-     *            reference.
-     * @see #getUnsetOperation()
-     * @generated
-     */
-    void setUnsetOperation(OperationDescription value);
-
-    /**
-     * Returns the value of the '<em><b>On Click Operation</b></em>' containment
-     * reference. <!-- begin-user-doc --> <!-- end-user-doc --> <!--
-     * begin-model-doc --> Defines the expected behavior when the user clicks on
-     * the hyperlink. <!-- end-model-doc -->
-     *
-     * @return the value of the '<em>On Click Operation</em>' containment
-     *         reference.
-     * @see #setOnClickOperation(OperationDescription)
-     * @see org.eclipse.sirius.properties.PropertiesPackage#getSingleReferenceDescription_OnClickOperation()
-     * @model containment="true"
-     * @generated
-     */
-    OperationDescription getOnClickOperation();
-
-    /**
-     * Sets the value of the '
-     * {@link org.eclipse.sirius.properties.SingleReferenceDescription#getOnClickOperation
-     * <em>On Click Operation</em>}' containment reference. <!-- begin-user-doc
-     * --> <!-- end-user-doc -->
-     *
-     * @param value
-     *            the new value of the '<em>On Click Operation</em>' containment
-     *            reference.
-     * @see #getOnClickOperation()
-     * @generated
-     */
-    void setOnClickOperation(OperationDescription value);
-
-} // SingleReferenceDescription
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/WidgetAction.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/WidgetAction.java
new file mode 100644
index 0000000000..bb2895e69d
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/WidgetAction.java
@@ -0,0 +1,96 @@
+/**
+ * Copyright (c) 2016 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.properties;
+
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.sirius.viewpoint.description.tool.InitialOperation;
+
+/**
+ * <!-- begin-user-doc --> A representation of the model object '
+ * <em><b>Widget Action</b></em>'. <!-- end-user-doc -->
+ *
+ * <p>
+ * The following features are supported:
+ * </p>
+ * <ul>
+ * <li>{@link org.eclipse.sirius.properties.WidgetAction#getLabelExpression
+ * <em>Label Expression</em>}</li>
+ * <li>{@link org.eclipse.sirius.properties.WidgetAction#getInitialOperation
+ * <em>Initial Operation</em>}</li>
+ * </ul>
+ *
+ * @see org.eclipse.sirius.properties.PropertiesPackage#getWidgetAction()
+ * @model
+ * @generated
+ */
+public interface WidgetAction extends EObject {
+    /**
+     * Returns the value of the '<em><b>Label Expression</b></em>' attribute.
+     * <!-- begin-user-doc -->
+     * <p>
+     * If the meaning of the '<em>Label Expression</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 Expression</em>' attribute.
+     * @see #setLabelExpression(String)
+     * @see org.eclipse.sirius.properties.PropertiesPackage#getWidgetAction_LabelExpression()
+     * @model dataType=
+     *        "org.eclipse.sirius.viewpoint.description.InterpretedExpression"
+     * @generated
+     */
+    String getLabelExpression();
+
+    /**
+     * Sets the value of the '
+     * {@link org.eclipse.sirius.properties.WidgetAction#getLabelExpression
+     * <em>Label Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @param value
+     *            the new value of the '<em>Label Expression</em>' attribute.
+     * @see #getLabelExpression()
+     * @generated
+     */
+    void setLabelExpression(String value);
+
+    /**
+     * Returns the value of the '<em><b>Initial Operation</b></em>' containment
+     * reference. <!-- begin-user-doc --> <!-- end-user-doc --> <!--
+     * begin-model-doc --> Defines the behavior executed when the end-user
+     * updates the value of the radio. <!-- end-model-doc -->
+     *
+     * @return the value of the '<em>Initial Operation</em>' containment
+     *         reference.
+     * @see #setInitialOperation(InitialOperation)
+     * @see org.eclipse.sirius.properties.PropertiesPackage#getWidgetAction_InitialOperation()
+     * @model containment="true" required="true"
+     * @generated
+     */
+    InitialOperation getInitialOperation();
+
+    /**
+     * Sets the value of the '
+     * {@link org.eclipse.sirius.properties.WidgetAction#getInitialOperation
+     * <em>Initial Operation</em>}' containment reference. <!-- begin-user-doc
+     * --> <!-- end-user-doc -->
+     *
+     * @param value
+     *            the new value of the '<em>Initial Operation</em>' containment
+     *            reference.
+     * @see #getInitialOperation()
+     * @generated
+     */
+    void setInitialOperation(InitialOperation value);
+
+} // WidgetAction
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/MultipleReferencesDescriptionImpl.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/MultipleReferencesDescriptionImpl.java
deleted file mode 100644
index 836eb2244b..0000000000
--- a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/MultipleReferencesDescriptionImpl.java
+++ /dev/null
@@ -1,733 +0,0 @@
-/**
- * Copyright (c) 2016 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.properties.impl;
-
-import org.eclipse.emf.common.notify.Notification;
-import org.eclipse.emf.common.notify.NotificationChain;
-import org.eclipse.emf.ecore.EClass;
-import org.eclipse.emf.ecore.InternalEObject;
-import org.eclipse.emf.ecore.impl.ENotificationImpl;
-import org.eclipse.sirius.properties.MultipleReferencesDescription;
-import org.eclipse.sirius.properties.OperationDescription;
-import org.eclipse.sirius.properties.PropertiesPackage;
-
-/**
- * <!-- begin-user-doc --> An implementation of the model object '
- * <em><b>Multiple References Description</b></em>'. <!-- end-user-doc -->
- * <p>
- * The following features are implemented:
- * </p>
- * <ul>
- * <li>
- * {@link org.eclipse.sirius.properties.impl.MultipleReferencesDescriptionImpl#getValueExpression
- * <em>Value Expression</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.impl.MultipleReferencesDescriptionImpl#getDisplayExpression
- * <em>Display Expression</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.impl.MultipleReferencesDescriptionImpl#getCreateOperation
- * <em>Create Operation</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.impl.MultipleReferencesDescriptionImpl#getSearchOperation
- * <em>Search Operation</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.impl.MultipleReferencesDescriptionImpl#getUnsetOperation
- * <em>Unset Operation</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.impl.MultipleReferencesDescriptionImpl#getOnClickOperation
- * <em>On Click Operation</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.impl.MultipleReferencesDescriptionImpl#getUpOperation
- * <em>Up Operation</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.impl.MultipleReferencesDescriptionImpl#getDownOperation
- * <em>Down Operation</em>}</li>
- * </ul>
- *
- * @generated
- */
-public class MultipleReferencesDescriptionImpl extends WidgetDescriptionImpl implements MultipleReferencesDescription {
-    /**
-     * The default value of the '{@link #getValueExpression()
-     * <em>Value Expression</em>}' attribute. <!-- begin-user-doc --> <!--
-     * end-user-doc -->
-     *
-     * @see #getValueExpression()
-     * @generated
-     * @ordered
-     */
-    protected static final String VALUE_EXPRESSION_EDEFAULT = null;
-
-    /**
-     * The cached value of the '{@link #getValueExpression()
-     * <em>Value Expression</em>}' attribute. <!-- begin-user-doc --> <!--
-     * end-user-doc -->
-     *
-     * @see #getValueExpression()
-     * @generated
-     * @ordered
-     */
-    protected String valueExpression = MultipleReferencesDescriptionImpl.VALUE_EXPRESSION_EDEFAULT;
-
-    /**
-     * The default value of the '{@link #getDisplayExpression()
-     * <em>Display Expression</em>}' attribute. <!-- begin-user-doc --> <!--
-     * end-user-doc -->
-     *
-     * @see #getDisplayExpression()
-     * @generated
-     * @ordered
-     */
-    protected static final String DISPLAY_EXPRESSION_EDEFAULT = null;
-
-    /**
-     * The cached value of the '{@link #getDisplayExpression()
-     * <em>Display Expression</em>}' attribute. <!-- begin-user-doc --> <!--
-     * end-user-doc -->
-     *
-     * @see #getDisplayExpression()
-     * @generated
-     * @ordered
-     */
-    protected String displayExpression = MultipleReferencesDescriptionImpl.DISPLAY_EXPRESSION_EDEFAULT;
-
-    /**
-     * The cached value of the '{@link #getCreateOperation()
-     * <em>Create Operation</em>}' containment reference. <!-- begin-user-doc
-     * --> <!-- end-user-doc -->
-     *
-     * @see #getCreateOperation()
-     * @generated
-     * @ordered
-     */
-    protected OperationDescription createOperation;
-
-    /**
-     * The cached value of the '{@link #getSearchOperation()
-     * <em>Search Operation</em>}' containment reference. <!-- begin-user-doc
-     * --> <!-- end-user-doc -->
-     *
-     * @see #getSearchOperation()
-     * @generated
-     * @ordered
-     */
-    protected OperationDescription searchOperation;
-
-    /**
-     * The cached value of the '{@link #getUnsetOperation()
-     * <em>Unset Operation</em>}' containment reference. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
-     *
-     * @see #getUnsetOperation()
-     * @generated
-     * @ordered
-     */
-    protected OperationDescription unsetOperation;
-
-    /**
-     * The cached value of the '{@link #getOnClickOperation()
-     * <em>On Click Operation</em>}' containment reference. <!-- begin-user-doc
-     * --> <!-- end-user-doc -->
-     *
-     * @see #getOnClickOperation()
-     * @generated
-     * @ordered
-     */
-    protected OperationDescription onClickOperation;
-
-    /**
-     * The cached value of the '{@link #getUpOperation() <em>Up Operation</em>}'
-     * containment reference. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @see #getUpOperation()
-     * @generated
-     * @ordered
-     */
-    protected OperationDescription upOperation;
-
-    /**
-     * The cached value of the '{@link #getDownOperation()
-     * <em>Down Operation</em>}' containment reference. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
-     *
-     * @see #getDownOperation()
-     * @generated
-     * @ordered
-     */
-    protected OperationDescription downOperation;
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    protected MultipleReferencesDescriptionImpl() {
-        super();
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    protected EClass eStaticClass() {
-        return PropertiesPackage.Literals.MULTIPLE_REFERENCES_DESCRIPTION;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public String getValueExpression() {
-        return valueExpression;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void setValueExpression(String newValueExpression) {
-        String oldValueExpression = valueExpression;
-        valueExpression = newValueExpression;
-        if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__VALUE_EXPRESSION, oldValueExpression, valueExpression));
-        }
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public String getDisplayExpression() {
-        return displayExpression;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void setDisplayExpression(String newDisplayExpression) {
-        String oldDisplayExpression = displayExpression;
-        displayExpression = newDisplayExpression;
-        if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DISPLAY_EXPRESSION, oldDisplayExpression, displayExpression));
-        }
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public OperationDescription getCreateOperation() {
-        return createOperation;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    public NotificationChain basicSetCreateOperation(OperationDescription newCreateOperation, NotificationChain msgs) {
-        OperationDescription oldCreateOperation = createOperation;
-        createOperation = newCreateOperation;
-        if (eNotificationRequired()) {
-            ENotificationImpl notification = new ENotificationImpl(this, Notification.SET, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__CREATE_OPERATION, oldCreateOperation, newCreateOperation);
-            if (msgs == null) {
-                msgs = notification;
-            } else {
-                msgs.add(notification);
-            }
-        }
-        return msgs;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void setCreateOperation(OperationDescription newCreateOperation) {
-        if (newCreateOperation != createOperation) {
-            NotificationChain msgs = null;
-            if (createOperation != null) {
-                msgs = ((InternalEObject) createOperation).eInverseRemove(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__CREATE_OPERATION, null,
-                        msgs);
-            }
-            if (newCreateOperation != null) {
-                msgs = ((InternalEObject) newCreateOperation).eInverseAdd(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__CREATE_OPERATION, null,
-                        msgs);
-            }
-            msgs = basicSetCreateOperation(newCreateOperation, msgs);
-            if (msgs != null) {
-                msgs.dispatch();
-            }
-        } else if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__CREATE_OPERATION, newCreateOperation, newCreateOperation));
-        }
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public OperationDescription getSearchOperation() {
-        return searchOperation;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    public NotificationChain basicSetSearchOperation(OperationDescription newSearchOperation, NotificationChain msgs) {
-        OperationDescription oldSearchOperation = searchOperation;
-        searchOperation = newSearchOperation;
-        if (eNotificationRequired()) {
-            ENotificationImpl notification = new ENotificationImpl(this, Notification.SET, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__SEARCH_OPERATION, oldSearchOperation, newSearchOperation);
-            if (msgs == null) {
-                msgs = notification;
-            } else {
-                msgs.add(notification);
-            }
-        }
-        return msgs;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void setSearchOperation(OperationDescription newSearchOperation) {
-        if (newSearchOperation != searchOperation) {
-            NotificationChain msgs = null;
-            if (searchOperation != null) {
-                msgs = ((InternalEObject) searchOperation).eInverseRemove(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__SEARCH_OPERATION, null,
-                        msgs);
-            }
-            if (newSearchOperation != null) {
-                msgs = ((InternalEObject) newSearchOperation).eInverseAdd(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__SEARCH_OPERATION, null,
-                        msgs);
-            }
-            msgs = basicSetSearchOperation(newSearchOperation, msgs);
-            if (msgs != null) {
-                msgs.dispatch();
-            }
-        } else if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__SEARCH_OPERATION, newSearchOperation, newSearchOperation));
-        }
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public OperationDescription getUnsetOperation() {
-        return unsetOperation;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    public NotificationChain basicSetUnsetOperation(OperationDescription newUnsetOperation, NotificationChain msgs) {
-        OperationDescription oldUnsetOperation = unsetOperation;
-        unsetOperation = newUnsetOperation;
-        if (eNotificationRequired()) {
-            ENotificationImpl notification = new ENotificationImpl(this, Notification.SET, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UNSET_OPERATION, oldUnsetOperation, newUnsetOperation);
-            if (msgs == null) {
-                msgs = notification;
-            } else {
-                msgs.add(notification);
-            }
-        }
-        return msgs;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void setUnsetOperation(OperationDescription newUnsetOperation) {
-        if (newUnsetOperation != unsetOperation) {
-            NotificationChain msgs = null;
-            if (unsetOperation != null) {
-                msgs = ((InternalEObject) unsetOperation).eInverseRemove(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UNSET_OPERATION, null, msgs);
-            }
-            if (newUnsetOperation != null) {
-                msgs = ((InternalEObject) newUnsetOperation).eInverseAdd(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UNSET_OPERATION, null, msgs);
-            }
-            msgs = basicSetUnsetOperation(newUnsetOperation, msgs);
-            if (msgs != null) {
-                msgs.dispatch();
-            }
-        } else if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UNSET_OPERATION, newUnsetOperation, newUnsetOperation));
-        }
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public OperationDescription getOnClickOperation() {
-        return onClickOperation;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    public NotificationChain basicSetOnClickOperation(OperationDescription newOnClickOperation, NotificationChain msgs) {
-        OperationDescription oldOnClickOperation = onClickOperation;
-        onClickOperation = newOnClickOperation;
-        if (eNotificationRequired()) {
-            ENotificationImpl notification = new ENotificationImpl(this, Notification.SET, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__ON_CLICK_OPERATION, oldOnClickOperation,
-                    newOnClickOperation);
-            if (msgs == null) {
-                msgs = notification;
-            } else {
-                msgs.add(notification);
-            }
-        }
-        return msgs;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void setOnClickOperation(OperationDescription newOnClickOperation) {
-        if (newOnClickOperation != onClickOperation) {
-            NotificationChain msgs = null;
-            if (onClickOperation != null) {
-                msgs = ((InternalEObject) onClickOperation).eInverseRemove(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__ON_CLICK_OPERATION, null,
-                        msgs);
-            }
-            if (newOnClickOperation != null) {
-                msgs = ((InternalEObject) newOnClickOperation).eInverseAdd(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__ON_CLICK_OPERATION, null,
-                        msgs);
-            }
-            msgs = basicSetOnClickOperation(newOnClickOperation, msgs);
-            if (msgs != null) {
-                msgs.dispatch();
-            }
-        } else if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__ON_CLICK_OPERATION, newOnClickOperation, newOnClickOperation));
-        }
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public OperationDescription getUpOperation() {
-        return upOperation;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    public NotificationChain basicSetUpOperation(OperationDescription newUpOperation, NotificationChain msgs) {
-        OperationDescription oldUpOperation = upOperation;
-        upOperation = newUpOperation;
-        if (eNotificationRequired()) {
-            ENotificationImpl notification = new ENotificationImpl(this, Notification.SET, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UP_OPERATION, oldUpOperation, newUpOperation);
-            if (msgs == null) {
-                msgs = notification;
-            } else {
-                msgs.add(notification);
-            }
-        }
-        return msgs;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void setUpOperation(OperationDescription newUpOperation) {
-        if (newUpOperation != upOperation) {
-            NotificationChain msgs = null;
-            if (upOperation != null) {
-                msgs = ((InternalEObject) upOperation).eInverseRemove(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UP_OPERATION, null, msgs);
-            }
-            if (newUpOperation != null) {
-                msgs = ((InternalEObject) newUpOperation).eInverseAdd(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UP_OPERATION, null, msgs);
-            }
-            msgs = basicSetUpOperation(newUpOperation, msgs);
-            if (msgs != null) {
-                msgs.dispatch();
-            }
-        } else if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UP_OPERATION, newUpOperation, newUpOperation));
-        }
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public OperationDescription getDownOperation() {
-        return downOperation;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    public NotificationChain basicSetDownOperation(OperationDescription newDownOperation, NotificationChain msgs) {
-        OperationDescription oldDownOperation = downOperation;
-        downOperation = newDownOperation;
-        if (eNotificationRequired()) {
-            ENotificationImpl notification = new ENotificationImpl(this, Notification.SET, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DOWN_OPERATION, oldDownOperation, newDownOperation);
-            if (msgs == null) {
-                msgs = notification;
-            } else {
-                msgs.add(notification);
-            }
-        }
-        return msgs;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void setDownOperation(OperationDescription newDownOperation) {
-        if (newDownOperation != downOperation) {
-            NotificationChain msgs = null;
-            if (downOperation != null) {
-                msgs = ((InternalEObject) downOperation).eInverseRemove(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DOWN_OPERATION, null, msgs);
-            }
-            if (newDownOperation != null) {
-                msgs = ((InternalEObject) newDownOperation).eInverseAdd(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DOWN_OPERATION, null, msgs);
-            }
-            msgs = basicSetDownOperation(newDownOperation, msgs);
-            if (msgs != null) {
-                msgs.dispatch();
-            }
-        } else if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DOWN_OPERATION, newDownOperation, newDownOperation));
-        }
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public NotificationChain eInverseRemove(InternalEObject otherEnd, int featureID, NotificationChain msgs) {
-        switch (featureID) {
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__CREATE_OPERATION:
-            return basicSetCreateOperation(null, msgs);
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__SEARCH_OPERATION:
-            return basicSetSearchOperation(null, msgs);
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UNSET_OPERATION:
-            return basicSetUnsetOperation(null, msgs);
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__ON_CLICK_OPERATION:
-            return basicSetOnClickOperation(null, msgs);
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UP_OPERATION:
-            return basicSetUpOperation(null, msgs);
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DOWN_OPERATION:
-            return basicSetDownOperation(null, 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 PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__VALUE_EXPRESSION:
-            return getValueExpression();
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DISPLAY_EXPRESSION:
-            return getDisplayExpression();
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__CREATE_OPERATION:
-            return getCreateOperation();
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__SEARCH_OPERATION:
-            return getSearchOperation();
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UNSET_OPERATION:
-            return getUnsetOperation();
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__ON_CLICK_OPERATION:
-            return getOnClickOperation();
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UP_OPERATION:
-            return getUpOperation();
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DOWN_OPERATION:
-            return getDownOperation();
-        }
-        return super.eGet(featureID, resolve, coreType);
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void eSet(int featureID, Object newValue) {
-        switch (featureID) {
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__VALUE_EXPRESSION:
-            setValueExpression((String) newValue);
-            return;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DISPLAY_EXPRESSION:
-            setDisplayExpression((String) newValue);
-            return;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__CREATE_OPERATION:
-            setCreateOperation((OperationDescription) newValue);
-            return;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__SEARCH_OPERATION:
-            setSearchOperation((OperationDescription) newValue);
-            return;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UNSET_OPERATION:
-            setUnsetOperation((OperationDescription) newValue);
-            return;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__ON_CLICK_OPERATION:
-            setOnClickOperation((OperationDescription) newValue);
-            return;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UP_OPERATION:
-            setUpOperation((OperationDescription) newValue);
-            return;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DOWN_OPERATION:
-            setDownOperation((OperationDescription) newValue);
-            return;
-        }
-        super.eSet(featureID, newValue);
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void eUnset(int featureID) {
-        switch (featureID) {
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__VALUE_EXPRESSION:
-            setValueExpression(MultipleReferencesDescriptionImpl.VALUE_EXPRESSION_EDEFAULT);
-            return;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DISPLAY_EXPRESSION:
-            setDisplayExpression(MultipleReferencesDescriptionImpl.DISPLAY_EXPRESSION_EDEFAULT);
-            return;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__CREATE_OPERATION:
-            setCreateOperation((OperationDescription) null);
-            return;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__SEARCH_OPERATION:
-            setSearchOperation((OperationDescription) null);
-            return;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UNSET_OPERATION:
-            setUnsetOperation((OperationDescription) null);
-            return;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__ON_CLICK_OPERATION:
-            setOnClickOperation((OperationDescription) null);
-            return;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UP_OPERATION:
-            setUpOperation((OperationDescription) null);
-            return;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DOWN_OPERATION:
-            setDownOperation((OperationDescription) null);
-            return;
-        }
-        super.eUnset(featureID);
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public boolean eIsSet(int featureID) {
-        switch (featureID) {
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__VALUE_EXPRESSION:
-            return MultipleReferencesDescriptionImpl.VALUE_EXPRESSION_EDEFAULT == null ? valueExpression != null : !MultipleReferencesDescriptionImpl.VALUE_EXPRESSION_EDEFAULT.equals(valueExpression);
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DISPLAY_EXPRESSION:
-            return MultipleReferencesDescriptionImpl.DISPLAY_EXPRESSION_EDEFAULT == null ? displayExpression != null
-                    : !MultipleReferencesDescriptionImpl.DISPLAY_EXPRESSION_EDEFAULT.equals(displayExpression);
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__CREATE_OPERATION:
-            return createOperation != null;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__SEARCH_OPERATION:
-            return searchOperation != null;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UNSET_OPERATION:
-            return unsetOperation != null;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__ON_CLICK_OPERATION:
-            return onClickOperation != null;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UP_OPERATION:
-            return upOperation != null;
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DOWN_OPERATION:
-            return downOperation != null;
-        }
-        return super.eIsSet(featureID);
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public String toString() {
-        if (eIsProxy()) {
-            return super.toString();
-        }
-
-        StringBuffer result = new StringBuffer(super.toString());
-        result.append(" (valueExpression: ");
-        result.append(valueExpression);
-        result.append(", displayExpression: ");
-        result.append(displayExpression);
-        result.append(')');
-        return result.toString();
-    }
-
-} // MultipleReferencesDescriptionImpl
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/PropertiesFactoryImpl.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/PropertiesFactoryImpl.java
index 1875055a01..b27dacfd5f 100644
--- a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/PropertiesFactoryImpl.java
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/PropertiesFactoryImpl.java
@@ -39,7 +39,6 @@ import org.eclipse.sirius.properties.GroupValidationSetDescription;
 import org.eclipse.sirius.properties.LabelDescription;
 import org.eclipse.sirius.properties.LabelWidgetConditionalStyle;
 import org.eclipse.sirius.properties.LabelWidgetStyle;
-import org.eclipse.sirius.properties.MultipleReferencesDescription;
 import org.eclipse.sirius.properties.OperationDescription;
 import org.eclipse.sirius.properties.PageDescription;
 import org.eclipse.sirius.properties.PageValidationSetDescription;
@@ -49,15 +48,18 @@ import org.eclipse.sirius.properties.PropertyValidationRule;
 import org.eclipse.sirius.properties.RadioDescription;
 import org.eclipse.sirius.properties.RadioWidgetConditionalStyle;
 import org.eclipse.sirius.properties.RadioWidgetStyle;
+import org.eclipse.sirius.properties.ReferenceDescription;
+import org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle;
+import org.eclipse.sirius.properties.ReferenceWidgetStyle;
 import org.eclipse.sirius.properties.SelectDescription;
 import org.eclipse.sirius.properties.SelectWidgetConditionalStyle;
 import org.eclipse.sirius.properties.SelectWidgetStyle;
-import org.eclipse.sirius.properties.SingleReferenceDescription;
 import org.eclipse.sirius.properties.TextAreaDescription;
 import org.eclipse.sirius.properties.TextDescription;
 import org.eclipse.sirius.properties.TextWidgetConditionalStyle;
 import org.eclipse.sirius.properties.TextWidgetStyle;
 import org.eclipse.sirius.properties.ViewExtensionDescription;
+import org.eclipse.sirius.properties.WidgetAction;
 import org.eclipse.sirius.properties.WidgetStyle;
 
 /**
@@ -139,12 +141,10 @@ public class PropertiesFactoryImpl extends EFactoryImpl implements PropertiesFac
             return createTextAreaDescription();
         case PropertiesPackage.RADIO_DESCRIPTION:
             return createRadioDescription();
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION:
-            return createSingleReferenceDescription();
+        case PropertiesPackage.REFERENCE_DESCRIPTION:
+            return createReferenceDescription();
         case PropertiesPackage.OPERATION_DESCRIPTION:
             return createOperationDescription();
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION:
-            return createMultipleReferencesDescription();
         case PropertiesPackage.CUSTOM_DESCRIPTION:
             return createCustomDescription();
         case PropertiesPackage.CUSTOM_EXPRESSION:
@@ -167,6 +167,8 @@ public class PropertiesFactoryImpl extends EFactoryImpl implements PropertiesFac
             return createSelectWidgetStyle();
         case PropertiesPackage.CUSTOM_WIDGET_STYLE:
             return createCustomWidgetStyle();
+        case PropertiesPackage.REFERENCE_WIDGET_STYLE:
+            return createReferenceWidgetStyle();
         case PropertiesPackage.TEXT_WIDGET_CONDITIONAL_STYLE:
             return createTextWidgetConditionalStyle();
         case PropertiesPackage.LABEL_WIDGET_CONDITIONAL_STYLE:
@@ -181,6 +183,10 @@ public class PropertiesFactoryImpl extends EFactoryImpl implements PropertiesFac
             return createSelectWidgetConditionalStyle();
         case PropertiesPackage.CUSTOM_WIDGET_CONDITIONAL_STYLE:
             return createCustomWidgetConditionalStyle();
+        case PropertiesPackage.REFERENCE_WIDGET_CONDITIONAL_STYLE:
+            return createReferenceWidgetConditionalStyle();
+        case PropertiesPackage.WIDGET_ACTION:
+            return createWidgetAction();
         default:
             throw new IllegalArgumentException("The class '" + eClass.getName() + "' is not a valid classifier");
         }
@@ -420,9 +426,9 @@ public class PropertiesFactoryImpl extends EFactoryImpl implements PropertiesFac
      * @generated
      */
     @Override
-    public SingleReferenceDescription createSingleReferenceDescription() {
-        SingleReferenceDescriptionImpl singleReferenceDescription = new SingleReferenceDescriptionImpl();
-        return singleReferenceDescription;
+    public ReferenceDescription createReferenceDescription() {
+        ReferenceDescriptionImpl referenceDescription = new ReferenceDescriptionImpl();
+        return referenceDescription;
     }
 
     /**
@@ -442,17 +448,6 @@ public class PropertiesFactoryImpl extends EFactoryImpl implements PropertiesFac
      * @generated
      */
     @Override
-    public MultipleReferencesDescription createMultipleReferencesDescription() {
-        MultipleReferencesDescriptionImpl multipleReferencesDescription = new MultipleReferencesDescriptionImpl();
-        return multipleReferencesDescription;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
     public CustomDescription createCustomDescription() {
         CustomDescriptionImpl customDescription = new CustomDescriptionImpl();
         return customDescription;
@@ -650,6 +645,39 @@ public class PropertiesFactoryImpl extends EFactoryImpl implements PropertiesFac
      *
      * @generated
      */
+    @Override
+    public ReferenceWidgetConditionalStyle createReferenceWidgetConditionalStyle() {
+        ReferenceWidgetConditionalStyleImpl referenceWidgetConditionalStyle = new ReferenceWidgetConditionalStyleImpl();
+        return referenceWidgetConditionalStyle;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public WidgetAction createWidgetAction() {
+        WidgetActionImpl widgetAction = new WidgetActionImpl();
+        return widgetAction;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public ReferenceWidgetStyle createReferenceWidgetStyle() {
+        ReferenceWidgetStyleImpl referenceWidgetStyle = new ReferenceWidgetStyleImpl();
+        return referenceWidgetStyle;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
     public FILL_LAYOUT_ORIENTATION createFILL_LAYOUT_ORIENTATIONFromString(EDataType eDataType, String initialValue) {
         FILL_LAYOUT_ORIENTATION result = FILL_LAYOUT_ORIENTATION.get(initialValue);
         if (result == null) {
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/PropertiesPackageImpl.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/PropertiesPackageImpl.java
index 66aadc5227..10ab83f4ed 100644
--- a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/PropertiesPackageImpl.java
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/PropertiesPackageImpl.java
@@ -41,7 +41,6 @@ import org.eclipse.sirius.properties.LabelDescription;
 import org.eclipse.sirius.properties.LabelWidgetConditionalStyle;
 import org.eclipse.sirius.properties.LabelWidgetStyle;
 import org.eclipse.sirius.properties.LayoutDescription;
-import org.eclipse.sirius.properties.MultipleReferencesDescription;
 import org.eclipse.sirius.properties.OperationDescription;
 import org.eclipse.sirius.properties.PageDescription;
 import org.eclipse.sirius.properties.PageValidationSetDescription;
@@ -51,15 +50,18 @@ import org.eclipse.sirius.properties.PropertyValidationRule;
 import org.eclipse.sirius.properties.RadioDescription;
 import org.eclipse.sirius.properties.RadioWidgetConditionalStyle;
 import org.eclipse.sirius.properties.RadioWidgetStyle;
+import org.eclipse.sirius.properties.ReferenceDescription;
+import org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle;
+import org.eclipse.sirius.properties.ReferenceWidgetStyle;
 import org.eclipse.sirius.properties.SelectDescription;
 import org.eclipse.sirius.properties.SelectWidgetConditionalStyle;
 import org.eclipse.sirius.properties.SelectWidgetStyle;
-import org.eclipse.sirius.properties.SingleReferenceDescription;
 import org.eclipse.sirius.properties.TextAreaDescription;
 import org.eclipse.sirius.properties.TextDescription;
 import org.eclipse.sirius.properties.TextWidgetConditionalStyle;
 import org.eclipse.sirius.properties.TextWidgetStyle;
 import org.eclipse.sirius.properties.ViewExtensionDescription;
+import org.eclipse.sirius.properties.WidgetAction;
 import org.eclipse.sirius.properties.WidgetConditionalStyle;
 import org.eclipse.sirius.properties.WidgetDescription;
 import org.eclipse.sirius.properties.WidgetStyle;
@@ -227,7 +229,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      *
      * @generated
      */
-    private EClass singleReferenceDescriptionEClass = null;
+    private EClass referenceDescriptionEClass = null;
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
@@ -241,13 +243,6 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      *
      * @generated
      */
-    private EClass multipleReferencesDescriptionEClass = null;
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
     private EClass customDescriptionEClass = null;
 
     /**
@@ -381,6 +376,27 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      *
      * @generated
      */
+    private EClass referenceWidgetConditionalStyleEClass = null;
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    private EClass widgetActionEClass = null;
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    private EClass referenceWidgetStyleEClass = null;
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
     private EEnum filL_LAYOUT_ORIENTATIONEEnum = null;
 
     /**
@@ -1308,8 +1324,8 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      * @generated
      */
     @Override
-    public EClass getSingleReferenceDescription() {
-        return singleReferenceDescriptionEClass;
+    public EClass getReferenceDescription() {
+        return referenceDescriptionEClass;
     }
 
     /**
@@ -1318,8 +1334,8 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      * @generated
      */
     @Override
-    public EAttribute getSingleReferenceDescription_ValueExpression() {
-        return (EAttribute) singleReferenceDescriptionEClass.getEStructuralFeatures().get(0);
+    public EAttribute getReferenceDescription_Multiple() {
+        return (EAttribute) referenceDescriptionEClass.getEStructuralFeatures().get(0);
     }
 
     /**
@@ -1328,8 +1344,8 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      * @generated
      */
     @Override
-    public EAttribute getSingleReferenceDescription_DisplayExpression() {
-        return (EAttribute) singleReferenceDescriptionEClass.getEStructuralFeatures().get(1);
+    public EAttribute getReferenceDescription_ValueExpression() {
+        return (EAttribute) referenceDescriptionEClass.getEStructuralFeatures().get(1);
     }
 
     /**
@@ -1338,8 +1354,8 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      * @generated
      */
     @Override
-    public EReference getSingleReferenceDescription_CreateOperation() {
-        return (EReference) singleReferenceDescriptionEClass.getEStructuralFeatures().get(2);
+    public EAttribute getReferenceDescription_DisplayExpression() {
+        return (EAttribute) referenceDescriptionEClass.getEStructuralFeatures().get(2);
     }
 
     /**
@@ -1348,8 +1364,8 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      * @generated
      */
     @Override
-    public EReference getSingleReferenceDescription_SearchOperation() {
-        return (EReference) singleReferenceDescriptionEClass.getEStructuralFeatures().get(3);
+    public EReference getReferenceDescription_OnClickOperation() {
+        return (EReference) referenceDescriptionEClass.getEStructuralFeatures().get(3);
     }
 
     /**
@@ -1358,8 +1374,8 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      * @generated
      */
     @Override
-    public EReference getSingleReferenceDescription_UnsetOperation() {
-        return (EReference) singleReferenceDescriptionEClass.getEStructuralFeatures().get(4);
+    public EReference getReferenceDescription_Actions() {
+        return (EReference) referenceDescriptionEClass.getEStructuralFeatures().get(4);
     }
 
     /**
@@ -1368,8 +1384,8 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      * @generated
      */
     @Override
-    public EReference getSingleReferenceDescription_OnClickOperation() {
-        return (EReference) singleReferenceDescriptionEClass.getEStructuralFeatures().get(5);
+    public EReference getReferenceDescription_Style() {
+        return (EReference) referenceDescriptionEClass.getEStructuralFeatures().get(5);
     }
 
     /**
@@ -1378,18 +1394,8 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      * @generated
      */
     @Override
-    public EClass getOperationDescription() {
-        return operationDescriptionEClass;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public EReference getOperationDescription_InitialOperation() {
-        return (EReference) operationDescriptionEClass.getEStructuralFeatures().get(0);
+    public EReference getReferenceDescription_ConditionalStyles() {
+        return (EReference) referenceDescriptionEClass.getEStructuralFeatures().get(6);
     }
 
     /**
@@ -1398,78 +1404,8 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      * @generated
      */
     @Override
-    public EClass getMultipleReferencesDescription() {
-        return multipleReferencesDescriptionEClass;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public EAttribute getMultipleReferencesDescription_ValueExpression() {
-        return (EAttribute) multipleReferencesDescriptionEClass.getEStructuralFeatures().get(0);
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public EAttribute getMultipleReferencesDescription_DisplayExpression() {
-        return (EAttribute) multipleReferencesDescriptionEClass.getEStructuralFeatures().get(1);
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public EReference getMultipleReferencesDescription_CreateOperation() {
-        return (EReference) multipleReferencesDescriptionEClass.getEStructuralFeatures().get(2);
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public EReference getMultipleReferencesDescription_SearchOperation() {
-        return (EReference) multipleReferencesDescriptionEClass.getEStructuralFeatures().get(3);
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public EReference getMultipleReferencesDescription_UnsetOperation() {
-        return (EReference) multipleReferencesDescriptionEClass.getEStructuralFeatures().get(4);
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public EReference getMultipleReferencesDescription_OnClickOperation() {
-        return (EReference) multipleReferencesDescriptionEClass.getEStructuralFeatures().get(5);
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public EReference getMultipleReferencesDescription_UpOperation() {
-        return (EReference) multipleReferencesDescriptionEClass.getEStructuralFeatures().get(6);
+    public EClass getOperationDescription() {
+        return operationDescriptionEClass;
     }
 
     /**
@@ -1478,8 +1414,8 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      * @generated
      */
     @Override
-    public EReference getMultipleReferencesDescription_DownOperation() {
-        return (EReference) multipleReferencesDescriptionEClass.getEStructuralFeatures().get(7);
+    public EReference getOperationDescription_InitialOperation() {
+        return (EReference) operationDescriptionEClass.getEStructuralFeatures().get(0);
     }
 
     /**
@@ -1988,6 +1924,66 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      * @generated
      */
     @Override
+    public EClass getReferenceWidgetConditionalStyle() {
+        return referenceWidgetConditionalStyleEClass;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public EReference getReferenceWidgetConditionalStyle_Style() {
+        return (EReference) referenceWidgetConditionalStyleEClass.getEStructuralFeatures().get(0);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public EClass getWidgetAction() {
+        return widgetActionEClass;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public EAttribute getWidgetAction_LabelExpression() {
+        return (EAttribute) widgetActionEClass.getEStructuralFeatures().get(0);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public EReference getWidgetAction_InitialOperation() {
+        return (EReference) widgetActionEClass.getEStructuralFeatures().get(1);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public EClass getReferenceWidgetStyle() {
+        return referenceWidgetStyleEClass;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
     public EEnum getFILL_LAYOUT_ORIENTATION() {
         return filL_LAYOUT_ORIENTATIONEEnum;
     }
@@ -2129,27 +2125,18 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
         createEAttribute(radioDescriptionEClass, PropertiesPackage.RADIO_DESCRIPTION__NUMBER_OF_COLUMNS);
         createEReference(radioDescriptionEClass, PropertiesPackage.RADIO_DESCRIPTION__CONDITIONAL_STYLES);
 
-        singleReferenceDescriptionEClass = createEClass(PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION);
-        createEAttribute(singleReferenceDescriptionEClass, PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__VALUE_EXPRESSION);
-        createEAttribute(singleReferenceDescriptionEClass, PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION);
-        createEReference(singleReferenceDescriptionEClass, PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__CREATE_OPERATION);
-        createEReference(singleReferenceDescriptionEClass, PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__SEARCH_OPERATION);
-        createEReference(singleReferenceDescriptionEClass, PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION);
-        createEReference(singleReferenceDescriptionEClass, PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION);
+        referenceDescriptionEClass = createEClass(PropertiesPackage.REFERENCE_DESCRIPTION);
+        createEAttribute(referenceDescriptionEClass, PropertiesPackage.REFERENCE_DESCRIPTION__MULTIPLE);
+        createEAttribute(referenceDescriptionEClass, PropertiesPackage.REFERENCE_DESCRIPTION__VALUE_EXPRESSION);
+        createEAttribute(referenceDescriptionEClass, PropertiesPackage.REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION);
+        createEReference(referenceDescriptionEClass, PropertiesPackage.REFERENCE_DESCRIPTION__ON_CLICK_OPERATION);
+        createEReference(referenceDescriptionEClass, PropertiesPackage.REFERENCE_DESCRIPTION__ACTIONS);
+        createEReference(referenceDescriptionEClass, PropertiesPackage.REFERENCE_DESCRIPTION__STYLE);
+        createEReference(referenceDescriptionEClass, PropertiesPackage.REFERENCE_DESCRIPTION__CONDITIONAL_STYLES);
 
         operationDescriptionEClass = createEClass(PropertiesPackage.OPERATION_DESCRIPTION);
         createEReference(operationDescriptionEClass, PropertiesPackage.OPERATION_DESCRIPTION__INITIAL_OPERATION);
 
-        multipleReferencesDescriptionEClass = createEClass(PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION);
-        createEAttribute(multipleReferencesDescriptionEClass, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__VALUE_EXPRESSION);
-        createEAttribute(multipleReferencesDescriptionEClass, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DISPLAY_EXPRESSION);
-        createEReference(multipleReferencesDescriptionEClass, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__CREATE_OPERATION);
-        createEReference(multipleReferencesDescriptionEClass, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__SEARCH_OPERATION);
-        createEReference(multipleReferencesDescriptionEClass, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UNSET_OPERATION);
-        createEReference(multipleReferencesDescriptionEClass, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__ON_CLICK_OPERATION);
-        createEReference(multipleReferencesDescriptionEClass, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__UP_OPERATION);
-        createEReference(multipleReferencesDescriptionEClass, PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION__DOWN_OPERATION);
-
         customDescriptionEClass = createEClass(PropertiesPackage.CUSTOM_DESCRIPTION);
         createEReference(customDescriptionEClass, PropertiesPackage.CUSTOM_DESCRIPTION__CUSTOM_EXPRESSIONS);
         createEReference(customDescriptionEClass, PropertiesPackage.CUSTOM_DESCRIPTION__CUSTOM_OPERATIONS);
@@ -2195,6 +2182,8 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
         customWidgetStyleEClass = createEClass(PropertiesPackage.CUSTOM_WIDGET_STYLE);
 
+        referenceWidgetStyleEClass = createEClass(PropertiesPackage.REFERENCE_WIDGET_STYLE);
+
         widgetConditionalStyleEClass = createEClass(PropertiesPackage.WIDGET_CONDITIONAL_STYLE);
         createEAttribute(widgetConditionalStyleEClass, PropertiesPackage.WIDGET_CONDITIONAL_STYLE__PRECONDITION_EXPRESSION);
 
@@ -2219,6 +2208,13 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
         customWidgetConditionalStyleEClass = createEClass(PropertiesPackage.CUSTOM_WIDGET_CONDITIONAL_STYLE);
         createEReference(customWidgetConditionalStyleEClass, PropertiesPackage.CUSTOM_WIDGET_CONDITIONAL_STYLE__STYLE);
 
+        referenceWidgetConditionalStyleEClass = createEClass(PropertiesPackage.REFERENCE_WIDGET_CONDITIONAL_STYLE);
+        createEReference(referenceWidgetConditionalStyleEClass, PropertiesPackage.REFERENCE_WIDGET_CONDITIONAL_STYLE__STYLE);
+
+        widgetActionEClass = createEClass(PropertiesPackage.WIDGET_ACTION);
+        createEAttribute(widgetActionEClass, PropertiesPackage.WIDGET_ACTION__LABEL_EXPRESSION);
+        createEReference(widgetActionEClass, PropertiesPackage.WIDGET_ACTION__INITIAL_OPERATION);
+
         // Create enums
         filL_LAYOUT_ORIENTATIONEEnum = createEEnum(PropertiesPackage.FILL_LAYOUT_ORIENTATION);
     }
@@ -2274,8 +2270,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
         dynamicMappingForEClass.getESuperTypes().add(this.getControlDescription());
         textAreaDescriptionEClass.getESuperTypes().add(this.getTextDescription());
         radioDescriptionEClass.getESuperTypes().add(this.getWidgetDescription());
-        singleReferenceDescriptionEClass.getESuperTypes().add(this.getWidgetDescription());
-        multipleReferencesDescriptionEClass.getESuperTypes().add(this.getWidgetDescription());
+        referenceDescriptionEClass.getESuperTypes().add(this.getWidgetDescription());
         customDescriptionEClass.getESuperTypes().add(this.getWidgetDescription());
         textWidgetStyleEClass.getESuperTypes().add(this.getWidgetStyle());
         labelWidgetStyleEClass.getESuperTypes().add(this.getWidgetStyle());
@@ -2284,6 +2279,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
         buttonWidgetStyleEClass.getESuperTypes().add(this.getWidgetStyle());
         selectWidgetStyleEClass.getESuperTypes().add(this.getWidgetStyle());
         customWidgetStyleEClass.getESuperTypes().add(this.getWidgetStyle());
+        referenceWidgetStyleEClass.getESuperTypes().add(this.getWidgetStyle());
         textWidgetConditionalStyleEClass.getESuperTypes().add(this.getWidgetConditionalStyle());
         labelWidgetConditionalStyleEClass.getESuperTypes().add(this.getWidgetConditionalStyle());
         checkboxWidgetConditionalStyleEClass.getESuperTypes().add(this.getWidgetConditionalStyle());
@@ -2291,6 +2287,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
         buttonWidgetConditionalStyleEClass.getESuperTypes().add(this.getWidgetConditionalStyle());
         selectWidgetConditionalStyleEClass.getESuperTypes().add(this.getWidgetConditionalStyle());
         customWidgetConditionalStyleEClass.getESuperTypes().add(this.getWidgetConditionalStyle());
+        referenceWidgetConditionalStyleEClass.getESuperTypes().add(this.getWidgetConditionalStyle());
 
         // Initialize classes and features; add operations and parameters
         initEClass(viewExtensionDescriptionEClass, ViewExtensionDescription.class, "ViewExtensionDescription", !EPackageImpl.IS_ABSTRACT, !EPackageImpl.IS_INTERFACE,
@@ -2509,24 +2506,25 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
                 !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE, EPackageImpl.IS_UNIQUE,
                 !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
 
-        initEClass(singleReferenceDescriptionEClass, SingleReferenceDescription.class, "SingleReferenceDescription", !EPackageImpl.IS_ABSTRACT, !EPackageImpl.IS_INTERFACE,
-                EPackageImpl.IS_GENERATED_INSTANCE_CLASS);
-        initEAttribute(getSingleReferenceDescription_ValueExpression(), theDescriptionPackage.getInterpretedExpression(), "valueExpression", null, 0, 1, SingleReferenceDescription.class,
+        initEClass(referenceDescriptionEClass, ReferenceDescription.class, "ReferenceDescription", !EPackageImpl.IS_ABSTRACT, !EPackageImpl.IS_INTERFACE, EPackageImpl.IS_GENERATED_INSTANCE_CLASS);
+        initEAttribute(getReferenceDescription_Multiple(), ecorePackage.getEBoolean(), "multiple", null, 0, 1, ReferenceDescription.class, !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE,
+                EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
+        initEAttribute(getReferenceDescription_ValueExpression(), theDescriptionPackage.getInterpretedExpression(), "valueExpression", null, 0, 1, ReferenceDescription.class,
                 !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED,
                 EPackageImpl.IS_ORDERED);
-        initEAttribute(getSingleReferenceDescription_DisplayExpression(), theDescriptionPackage.getInterpretedExpression(), "displayExpression", null, 0, 1, SingleReferenceDescription.class,
+        initEAttribute(getReferenceDescription_DisplayExpression(), theDescriptionPackage.getInterpretedExpression(), "displayExpression", null, 0, 1, ReferenceDescription.class,
                 !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED,
                 EPackageImpl.IS_ORDERED);
-        initEReference(getSingleReferenceDescription_CreateOperation(), this.getOperationDescription(), null, "createOperation", null, 0, 1, SingleReferenceDescription.class,
-                !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE,
-                EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
-        initEReference(getSingleReferenceDescription_SearchOperation(), this.getOperationDescription(), null, "searchOperation", null, 0, 1, SingleReferenceDescription.class,
-                !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE,
-                EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
-        initEReference(getSingleReferenceDescription_UnsetOperation(), this.getOperationDescription(), null, "unsetOperation", null, 0, 1, SingleReferenceDescription.class, !EPackageImpl.IS_TRANSIENT,
+        initEReference(getReferenceDescription_OnClickOperation(), theToolPackage.getInitialOperation(), null, "onClickOperation", null, 0, 1, ReferenceDescription.class, !EPackageImpl.IS_TRANSIENT,
                 !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE, EPackageImpl.IS_UNIQUE,
                 !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
-        initEReference(getSingleReferenceDescription_OnClickOperation(), this.getOperationDescription(), null, "onClickOperation", null, 0, 1, SingleReferenceDescription.class,
+        initEReference(getReferenceDescription_Actions(), this.getWidgetAction(), null, "actions", null, 0, -1, ReferenceDescription.class, !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE,
+                EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED,
+                EPackageImpl.IS_ORDERED);
+        initEReference(getReferenceDescription_Style(), this.getReferenceWidgetStyle(), null, "style", null, 0, 1, ReferenceDescription.class, !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE,
+                EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED,
+                EPackageImpl.IS_ORDERED);
+        initEReference(getReferenceDescription_ConditionalStyles(), this.getReferenceWidgetConditionalStyle(), null, "conditionalStyles", null, 0, -1, ReferenceDescription.class,
                 !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE,
                 EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
 
@@ -2535,33 +2533,6 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
                 !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE, EPackageImpl.IS_UNIQUE,
                 !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
 
-        initEClass(multipleReferencesDescriptionEClass, MultipleReferencesDescription.class, "MultipleReferencesDescription", !EPackageImpl.IS_ABSTRACT, !EPackageImpl.IS_INTERFACE,
-                EPackageImpl.IS_GENERATED_INSTANCE_CLASS);
-        initEAttribute(getMultipleReferencesDescription_ValueExpression(), theDescriptionPackage.getInterpretedExpression(), "valueExpression", null, 0, 1, MultipleReferencesDescription.class,
-                !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED,
-                EPackageImpl.IS_ORDERED);
-        initEAttribute(getMultipleReferencesDescription_DisplayExpression(), theDescriptionPackage.getInterpretedExpression(), "displayExpression", null, 0, 1, MultipleReferencesDescription.class,
-                !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED,
-                EPackageImpl.IS_ORDERED);
-        initEReference(getMultipleReferencesDescription_CreateOperation(), this.getOperationDescription(), null, "createOperation", null, 0, 1, MultipleReferencesDescription.class,
-                !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE,
-                EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
-        initEReference(getMultipleReferencesDescription_SearchOperation(), this.getOperationDescription(), null, "searchOperation", null, 0, 1, MultipleReferencesDescription.class,
-                !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE,
-                EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
-        initEReference(getMultipleReferencesDescription_UnsetOperation(), this.getOperationDescription(), null, "unsetOperation", null, 0, 1, MultipleReferencesDescription.class,
-                !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE,
-                EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
-        initEReference(getMultipleReferencesDescription_OnClickOperation(), this.getOperationDescription(), null, "onClickOperation", null, 0, 1, MultipleReferencesDescription.class,
-                !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE,
-                EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
-        initEReference(getMultipleReferencesDescription_UpOperation(), this.getOperationDescription(), null, "upOperation", null, 0, 1, MultipleReferencesDescription.class, !EPackageImpl.IS_TRANSIENT,
-                !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE, EPackageImpl.IS_UNIQUE,
-                !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
-        initEReference(getMultipleReferencesDescription_DownOperation(), this.getOperationDescription(), null, "downOperation", null, 0, 1, MultipleReferencesDescription.class,
-                !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE,
-                EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
-
         initEClass(customDescriptionEClass, CustomDescription.class, "CustomDescription", !EPackageImpl.IS_ABSTRACT, !EPackageImpl.IS_INTERFACE, EPackageImpl.IS_GENERATED_INSTANCE_CLASS);
         initEReference(getCustomDescription_CustomExpressions(), this.getCustomExpression(), null, "customExpressions", null, 0, -1, CustomDescription.class, !EPackageImpl.IS_TRANSIENT,
                 !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE, EPackageImpl.IS_UNIQUE,
@@ -2641,6 +2612,8 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
         initEClass(customWidgetStyleEClass, CustomWidgetStyle.class, "CustomWidgetStyle", !EPackageImpl.IS_ABSTRACT, !EPackageImpl.IS_INTERFACE, EPackageImpl.IS_GENERATED_INSTANCE_CLASS);
 
+        initEClass(referenceWidgetStyleEClass, ReferenceWidgetStyle.class, "ReferenceWidgetStyle", !EPackageImpl.IS_ABSTRACT, !EPackageImpl.IS_INTERFACE, EPackageImpl.IS_GENERATED_INSTANCE_CLASS);
+
         initEClass(widgetConditionalStyleEClass, WidgetConditionalStyle.class, "WidgetConditionalStyle", EPackageImpl.IS_ABSTRACT, !EPackageImpl.IS_INTERFACE,
                 EPackageImpl.IS_GENERATED_INSTANCE_CLASS);
         initEAttribute(getWidgetConditionalStyle_PreconditionExpression(), theDescriptionPackage.getInterpretedExpression(), "preconditionExpression", null, 0, 1, WidgetConditionalStyle.class,
@@ -2689,6 +2662,19 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
                 !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE, EPackageImpl.IS_UNIQUE,
                 !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
 
+        initEClass(referenceWidgetConditionalStyleEClass, ReferenceWidgetConditionalStyle.class, "ReferenceWidgetConditionalStyle", !EPackageImpl.IS_ABSTRACT, !EPackageImpl.IS_INTERFACE,
+                EPackageImpl.IS_GENERATED_INSTANCE_CLASS);
+        initEReference(getReferenceWidgetConditionalStyle_Style(), this.getReferenceWidgetStyle(), null, "style", null, 0, 1, ReferenceWidgetConditionalStyle.class, !EPackageImpl.IS_TRANSIENT,
+                !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE, EPackageImpl.IS_UNIQUE,
+                !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
+
+        initEClass(widgetActionEClass, WidgetAction.class, "WidgetAction", !EPackageImpl.IS_ABSTRACT, !EPackageImpl.IS_INTERFACE, EPackageImpl.IS_GENERATED_INSTANCE_CLASS);
+        initEAttribute(getWidgetAction_LabelExpression(), theDescriptionPackage.getInterpretedExpression(), "labelExpression", null, 0, 1, WidgetAction.class, !EPackageImpl.IS_TRANSIENT,
+                !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, EPackageImpl.IS_UNIQUE, !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
+        initEReference(getWidgetAction_InitialOperation(), theToolPackage.getInitialOperation(), null, "initialOperation", null, 1, 1, WidgetAction.class, !EPackageImpl.IS_TRANSIENT,
+                !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, EPackageImpl.IS_COMPOSITE, !EPackageImpl.IS_RESOLVE_PROXIES, !EPackageImpl.IS_UNSETTABLE, EPackageImpl.IS_UNIQUE,
+                !EPackageImpl.IS_DERIVED, EPackageImpl.IS_ORDERED);
+
         // Initialize enums and add enum literals
         initEEnum(filL_LAYOUT_ORIENTATIONEEnum, org.eclipse.sirius.properties.FILL_LAYOUT_ORIENTATION.class, "FILL_LAYOUT_ORIENTATION");
         addEEnumLiteral(filL_LAYOUT_ORIENTATIONEEnum, org.eclipse.sirius.properties.FILL_LAYOUT_ORIENTATION.VERTICAL);
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/ReferenceDescriptionImpl.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/ReferenceDescriptionImpl.java
new file mode 100644
index 0000000000..a6b3e4d6ba
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/ReferenceDescriptionImpl.java
@@ -0,0 +1,556 @@
+/**
+ * Copyright (c) 2016 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.properties.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.properties.PropertiesPackage;
+import org.eclipse.sirius.properties.ReferenceDescription;
+import org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle;
+import org.eclipse.sirius.properties.ReferenceWidgetStyle;
+import org.eclipse.sirius.properties.WidgetAction;
+import org.eclipse.sirius.viewpoint.description.tool.InitialOperation;
+
+/**
+ * <!-- begin-user-doc --> An implementation of the model object '
+ * <em><b>Reference Description</b></em>'. <!-- end-user-doc -->
+ * <p>
+ * The following features are implemented:
+ * </p>
+ * <ul>
+ * <li>
+ * {@link org.eclipse.sirius.properties.impl.ReferenceDescriptionImpl#isMultiple
+ * <em>Multiple</em>}</li>
+ * <li>
+ * {@link org.eclipse.sirius.properties.impl.ReferenceDescriptionImpl#getValueExpression
+ * <em>Value Expression</em>}</li>
+ * <li>
+ * {@link org.eclipse.sirius.properties.impl.ReferenceDescriptionImpl#getDisplayExpression
+ * <em>Display Expression</em>}</li>
+ * <li>
+ * {@link org.eclipse.sirius.properties.impl.ReferenceDescriptionImpl#getOnClickOperation
+ * <em>On Click Operation</em>}</li>
+ * <li>
+ * {@link org.eclipse.sirius.properties.impl.ReferenceDescriptionImpl#getActions
+ * <em>Actions</em>}</li>
+ * <li>
+ * {@link org.eclipse.sirius.properties.impl.ReferenceDescriptionImpl#getStyle
+ * <em>Style</em>}</li>
+ * <li>
+ * {@link org.eclipse.sirius.properties.impl.ReferenceDescriptionImpl#getConditionalStyles
+ * <em>Conditional Styles</em>}</li>
+ * </ul>
+ *
+ * @generated
+ */
+public class ReferenceDescriptionImpl extends WidgetDescriptionImpl implements ReferenceDescription {
+    /**
+     * The default value of the '{@link #isMultiple() <em>Multiple</em>}'
+     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @see #isMultiple()
+     * @generated
+     * @ordered
+     */
+    protected static final boolean MULTIPLE_EDEFAULT = false;
+
+    /**
+     * The cached value of the '{@link #isMultiple() <em>Multiple</em>}'
+     * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @see #isMultiple()
+     * @generated
+     * @ordered
+     */
+    protected boolean multiple = ReferenceDescriptionImpl.MULTIPLE_EDEFAULT;
+
+    /**
+     * The default value of the '{@link #getValueExpression()
+     * <em>Value Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @see #getValueExpression()
+     * @generated
+     * @ordered
+     */
+    protected static final String VALUE_EXPRESSION_EDEFAULT = null;
+
+    /**
+     * The cached value of the '{@link #getValueExpression()
+     * <em>Value Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @see #getValueExpression()
+     * @generated
+     * @ordered
+     */
+    protected String valueExpression = ReferenceDescriptionImpl.VALUE_EXPRESSION_EDEFAULT;
+
+    /**
+     * The default value of the '{@link #getDisplayExpression()
+     * <em>Display Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @see #getDisplayExpression()
+     * @generated
+     * @ordered
+     */
+    protected static final String DISPLAY_EXPRESSION_EDEFAULT = null;
+
+    /**
+     * The cached value of the '{@link #getDisplayExpression()
+     * <em>Display Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @see #getDisplayExpression()
+     * @generated
+     * @ordered
+     */
+    protected String displayExpression = ReferenceDescriptionImpl.DISPLAY_EXPRESSION_EDEFAULT;
+
+    /**
+     * The cached value of the '{@link #getOnClickOperation()
+     * <em>On Click Operation</em>}' containment reference. <!-- begin-user-doc
+     * --> <!-- end-user-doc -->
+     *
+     * @see #getOnClickOperation()
+     * @generated
+     * @ordered
+     */
+    protected InitialOperation onClickOperation;
+
+    /**
+     * The cached value of the '{@link #getActions() <em>Actions</em>}'
+     * containment reference list. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @see #getActions()
+     * @generated
+     * @ordered
+     */
+    protected EList<WidgetAction> actions;
+
+    /**
+     * The cached value of the '{@link #getStyle() <em>Style</em>}' containment
+     * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @see #getStyle()
+     * @generated
+     * @ordered
+     */
+    protected ReferenceWidgetStyle style;
+
+    /**
+     * The cached value of the '{@link #getConditionalStyles()
+     * <em>Conditional Styles</em>}' containment reference list. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @see #getConditionalStyles()
+     * @generated
+     * @ordered
+     */
+    protected EList<ReferenceWidgetConditionalStyle> conditionalStyles;
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    protected ReferenceDescriptionImpl() {
+        super();
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    protected EClass eStaticClass() {
+        return PropertiesPackage.Literals.REFERENCE_DESCRIPTION;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public boolean isMultiple() {
+        return multiple;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public void setMultiple(boolean newMultiple) {
+        boolean oldMultiple = multiple;
+        multiple = newMultiple;
+        if (eNotificationRequired()) {
+            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.REFERENCE_DESCRIPTION__MULTIPLE, oldMultiple, multiple));
+        }
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public String getValueExpression() {
+        return valueExpression;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public void setValueExpression(String newValueExpression) {
+        String oldValueExpression = valueExpression;
+        valueExpression = newValueExpression;
+        if (eNotificationRequired()) {
+            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.REFERENCE_DESCRIPTION__VALUE_EXPRESSION, oldValueExpression, valueExpression));
+        }
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public String getDisplayExpression() {
+        return displayExpression;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public void setDisplayExpression(String newDisplayExpression) {
+        String oldDisplayExpression = displayExpression;
+        displayExpression = newDisplayExpression;
+        if (eNotificationRequired()) {
+            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION, oldDisplayExpression, displayExpression));
+        }
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public InitialOperation getOnClickOperation() {
+        return onClickOperation;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    public NotificationChain basicSetOnClickOperation(InitialOperation newOnClickOperation, NotificationChain msgs) {
+        InitialOperation oldOnClickOperation = onClickOperation;
+        onClickOperation = newOnClickOperation;
+        if (eNotificationRequired()) {
+            ENotificationImpl notification = new ENotificationImpl(this, Notification.SET, PropertiesPackage.REFERENCE_DESCRIPTION__ON_CLICK_OPERATION, oldOnClickOperation, newOnClickOperation);
+            if (msgs == null) {
+                msgs = notification;
+            } else {
+                msgs.add(notification);
+            }
+        }
+        return msgs;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public void setOnClickOperation(InitialOperation newOnClickOperation) {
+        if (newOnClickOperation != onClickOperation) {
+            NotificationChain msgs = null;
+            if (onClickOperation != null) {
+                msgs = ((InternalEObject) onClickOperation).eInverseRemove(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.REFERENCE_DESCRIPTION__ON_CLICK_OPERATION, null, msgs);
+            }
+            if (newOnClickOperation != null) {
+                msgs = ((InternalEObject) newOnClickOperation).eInverseAdd(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.REFERENCE_DESCRIPTION__ON_CLICK_OPERATION, null, msgs);
+            }
+            msgs = basicSetOnClickOperation(newOnClickOperation, msgs);
+            if (msgs != null) {
+                msgs.dispatch();
+            }
+        } else if (eNotificationRequired()) {
+            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.REFERENCE_DESCRIPTION__ON_CLICK_OPERATION, newOnClickOperation, newOnClickOperation));
+        }
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public EList<WidgetAction> getActions() {
+        if (actions == null) {
+            actions = new EObjectContainmentEList<WidgetAction>(WidgetAction.class, this, PropertiesPackage.REFERENCE_DESCRIPTION__ACTIONS);
+        }
+        return actions;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public ReferenceWidgetStyle getStyle() {
+        return style;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    public NotificationChain basicSetStyle(ReferenceWidgetStyle newStyle, NotificationChain msgs) {
+        ReferenceWidgetStyle oldStyle = style;
+        style = newStyle;
+        if (eNotificationRequired()) {
+            ENotificationImpl notification = new ENotificationImpl(this, Notification.SET, PropertiesPackage.REFERENCE_DESCRIPTION__STYLE, oldStyle, newStyle);
+            if (msgs == null) {
+                msgs = notification;
+            } else {
+                msgs.add(notification);
+            }
+        }
+        return msgs;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public void setStyle(ReferenceWidgetStyle newStyle) {
+        if (newStyle != style) {
+            NotificationChain msgs = null;
+            if (style != null) {
+                msgs = ((InternalEObject) style).eInverseRemove(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.REFERENCE_DESCRIPTION__STYLE, null, msgs);
+            }
+            if (newStyle != null) {
+                msgs = ((InternalEObject) newStyle).eInverseAdd(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.REFERENCE_DESCRIPTION__STYLE, null, msgs);
+            }
+            msgs = basicSetStyle(newStyle, msgs);
+            if (msgs != null) {
+                msgs.dispatch();
+            }
+        } else if (eNotificationRequired()) {
+            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.REFERENCE_DESCRIPTION__STYLE, newStyle, newStyle));
+        }
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public EList<ReferenceWidgetConditionalStyle> getConditionalStyles() {
+        if (conditionalStyles == null) {
+            conditionalStyles = new EObjectContainmentEList<ReferenceWidgetConditionalStyle>(ReferenceWidgetConditionalStyle.class, this, PropertiesPackage.REFERENCE_DESCRIPTION__CONDITIONAL_STYLES);
+        }
+        return conditionalStyles;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public NotificationChain eInverseRemove(InternalEObject otherEnd, int featureID, NotificationChain msgs) {
+        switch (featureID) {
+        case PropertiesPackage.REFERENCE_DESCRIPTION__ON_CLICK_OPERATION:
+            return basicSetOnClickOperation(null, msgs);
+        case PropertiesPackage.REFERENCE_DESCRIPTION__ACTIONS:
+            return ((InternalEList<?>) getActions()).basicRemove(otherEnd, msgs);
+        case PropertiesPackage.REFERENCE_DESCRIPTION__STYLE:
+            return basicSetStyle(null, msgs);
+        case PropertiesPackage.REFERENCE_DESCRIPTION__CONDITIONAL_STYLES:
+            return ((InternalEList<?>) getConditionalStyles()).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 PropertiesPackage.REFERENCE_DESCRIPTION__MULTIPLE:
+            return isMultiple();
+        case PropertiesPackage.REFERENCE_DESCRIPTION__VALUE_EXPRESSION:
+            return getValueExpression();
+        case PropertiesPackage.REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION:
+            return getDisplayExpression();
+        case PropertiesPackage.REFERENCE_DESCRIPTION__ON_CLICK_OPERATION:
+            return getOnClickOperation();
+        case PropertiesPackage.REFERENCE_DESCRIPTION__ACTIONS:
+            return getActions();
+        case PropertiesPackage.REFERENCE_DESCRIPTION__STYLE:
+            return getStyle();
+        case PropertiesPackage.REFERENCE_DESCRIPTION__CONDITIONAL_STYLES:
+            return getConditionalStyles();
+        }
+        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 PropertiesPackage.REFERENCE_DESCRIPTION__MULTIPLE:
+            setMultiple((Boolean) newValue);
+            return;
+        case PropertiesPackage.REFERENCE_DESCRIPTION__VALUE_EXPRESSION:
+            setValueExpression((String) newValue);
+            return;
+        case PropertiesPackage.REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION:
+            setDisplayExpression((String) newValue);
+            return;
+        case PropertiesPackage.REFERENCE_DESCRIPTION__ON_CLICK_OPERATION:
+            setOnClickOperation((InitialOperation) newValue);
+            return;
+        case PropertiesPackage.REFERENCE_DESCRIPTION__ACTIONS:
+            getActions().clear();
+            getActions().addAll((Collection<? extends WidgetAction>) newValue);
+            return;
+        case PropertiesPackage.REFERENCE_DESCRIPTION__STYLE:
+            setStyle((ReferenceWidgetStyle) newValue);
+            return;
+        case PropertiesPackage.REFERENCE_DESCRIPTION__CONDITIONAL_STYLES:
+            getConditionalStyles().clear();
+            getConditionalStyles().addAll((Collection<? extends ReferenceWidgetConditionalStyle>) newValue);
+            return;
+        }
+        super.eSet(featureID, newValue);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public void eUnset(int featureID) {
+        switch (featureID) {
+        case PropertiesPackage.REFERENCE_DESCRIPTION__MULTIPLE:
+            setMultiple(ReferenceDescriptionImpl.MULTIPLE_EDEFAULT);
+            return;
+        case PropertiesPackage.REFERENCE_DESCRIPTION__VALUE_EXPRESSION:
+            setValueExpression(ReferenceDescriptionImpl.VALUE_EXPRESSION_EDEFAULT);
+            return;
+        case PropertiesPackage.REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION:
+            setDisplayExpression(ReferenceDescriptionImpl.DISPLAY_EXPRESSION_EDEFAULT);
+            return;
+        case PropertiesPackage.REFERENCE_DESCRIPTION__ON_CLICK_OPERATION:
+            setOnClickOperation((InitialOperation) null);
+            return;
+        case PropertiesPackage.REFERENCE_DESCRIPTION__ACTIONS:
+            getActions().clear();
+            return;
+        case PropertiesPackage.REFERENCE_DESCRIPTION__STYLE:
+            setStyle((ReferenceWidgetStyle) null);
+            return;
+        case PropertiesPackage.REFERENCE_DESCRIPTION__CONDITIONAL_STYLES:
+            getConditionalStyles().clear();
+            return;
+        }
+        super.eUnset(featureID);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public boolean eIsSet(int featureID) {
+        switch (featureID) {
+        case PropertiesPackage.REFERENCE_DESCRIPTION__MULTIPLE:
+            return multiple != ReferenceDescriptionImpl.MULTIPLE_EDEFAULT;
+        case PropertiesPackage.REFERENCE_DESCRIPTION__VALUE_EXPRESSION:
+            return ReferenceDescriptionImpl.VALUE_EXPRESSION_EDEFAULT == null ? valueExpression != null : !ReferenceDescriptionImpl.VALUE_EXPRESSION_EDEFAULT.equals(valueExpression);
+        case PropertiesPackage.REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION:
+            return ReferenceDescriptionImpl.DISPLAY_EXPRESSION_EDEFAULT == null ? displayExpression != null : !ReferenceDescriptionImpl.DISPLAY_EXPRESSION_EDEFAULT.equals(displayExpression);
+        case PropertiesPackage.REFERENCE_DESCRIPTION__ON_CLICK_OPERATION:
+            return onClickOperation != null;
+        case PropertiesPackage.REFERENCE_DESCRIPTION__ACTIONS:
+            return actions != null && !actions.isEmpty();
+        case PropertiesPackage.REFERENCE_DESCRIPTION__STYLE:
+            return style != null;
+        case PropertiesPackage.REFERENCE_DESCRIPTION__CONDITIONAL_STYLES:
+            return conditionalStyles != null && !conditionalStyles.isEmpty();
+        }
+        return super.eIsSet(featureID);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public String toString() {
+        if (eIsProxy()) {
+            return super.toString();
+        }
+
+        StringBuffer result = new StringBuffer(super.toString());
+        result.append(" (multiple: ");
+        result.append(multiple);
+        result.append(", valueExpression: ");
+        result.append(valueExpression);
+        result.append(", displayExpression: ");
+        result.append(displayExpression);
+        result.append(')');
+        return result.toString();
+    }
+
+} // ReferenceDescriptionImpl
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/ReferenceWidgetConditionalStyleImpl.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/ReferenceWidgetConditionalStyleImpl.java
new file mode 100644
index 0000000000..90b1185804
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/ReferenceWidgetConditionalStyleImpl.java
@@ -0,0 +1,192 @@
+/**
+ * Copyright (c) 2016 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.properties.impl;
+
+import org.eclipse.emf.common.notify.Notification;
+import org.eclipse.emf.common.notify.NotificationChain;
+import org.eclipse.emf.ecore.EClass;
+import org.eclipse.emf.ecore.InternalEObject;
+import org.eclipse.emf.ecore.impl.ENotificationImpl;
+import org.eclipse.sirius.properties.PropertiesPackage;
+import org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle;
+import org.eclipse.sirius.properties.ReferenceWidgetStyle;
+
+/**
+ * <!-- begin-user-doc --> An implementation of the model object '
+ * <em><b>Reference Widget Conditional Style</b></em>'. <!-- end-user-doc -->
+ * <p>
+ * The following features are implemented:
+ * </p>
+ * <ul>
+ * <li>
+ * {@link org.eclipse.sirius.properties.impl.ReferenceWidgetConditionalStyleImpl#getStyle
+ * <em>Style</em>}</li>
+ * </ul>
+ *
+ * @generated
+ */
+public class ReferenceWidgetConditionalStyleImpl extends WidgetConditionalStyleImpl implements ReferenceWidgetConditionalStyle {
+    /**
+     * The cached value of the '{@link #getStyle() <em>Style</em>}' containment
+     * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @see #getStyle()
+     * @generated
+     * @ordered
+     */
+    protected ReferenceWidgetStyle style;
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    protected ReferenceWidgetConditionalStyleImpl() {
+        super();
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    protected EClass eStaticClass() {
+        return PropertiesPackage.Literals.REFERENCE_WIDGET_CONDITIONAL_STYLE;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public ReferenceWidgetStyle getStyle() {
+        return style;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    public NotificationChain basicSetStyle(ReferenceWidgetStyle newStyle, NotificationChain msgs) {
+        ReferenceWidgetStyle oldStyle = style;
+        style = newStyle;
+        if (eNotificationRequired()) {
+            ENotificationImpl notification = new ENotificationImpl(this, Notification.SET, PropertiesPackage.REFERENCE_WIDGET_CONDITIONAL_STYLE__STYLE, oldStyle, newStyle);
+            if (msgs == null) {
+                msgs = notification;
+            } else {
+                msgs.add(notification);
+            }
+        }
+        return msgs;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public void setStyle(ReferenceWidgetStyle newStyle) {
+        if (newStyle != style) {
+            NotificationChain msgs = null;
+            if (style != null) {
+                msgs = ((InternalEObject) style).eInverseRemove(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.REFERENCE_WIDGET_CONDITIONAL_STYLE__STYLE, null, msgs);
+            }
+            if (newStyle != null) {
+                msgs = ((InternalEObject) newStyle).eInverseAdd(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.REFERENCE_WIDGET_CONDITIONAL_STYLE__STYLE, null, msgs);
+            }
+            msgs = basicSetStyle(newStyle, msgs);
+            if (msgs != null) {
+                msgs.dispatch();
+            }
+        } else if (eNotificationRequired()) {
+            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.REFERENCE_WIDGET_CONDITIONAL_STYLE__STYLE, newStyle, newStyle));
+        }
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public NotificationChain eInverseRemove(InternalEObject otherEnd, int featureID, NotificationChain msgs) {
+        switch (featureID) {
+        case PropertiesPackage.REFERENCE_WIDGET_CONDITIONAL_STYLE__STYLE:
+            return basicSetStyle(null, 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 PropertiesPackage.REFERENCE_WIDGET_CONDITIONAL_STYLE__STYLE:
+            return getStyle();
+        }
+        return super.eGet(featureID, resolve, coreType);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public void eSet(int featureID, Object newValue) {
+        switch (featureID) {
+        case PropertiesPackage.REFERENCE_WIDGET_CONDITIONAL_STYLE__STYLE:
+            setStyle((ReferenceWidgetStyle) newValue);
+            return;
+        }
+        super.eSet(featureID, newValue);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public void eUnset(int featureID) {
+        switch (featureID) {
+        case PropertiesPackage.REFERENCE_WIDGET_CONDITIONAL_STYLE__STYLE:
+            setStyle((ReferenceWidgetStyle) null);
+            return;
+        }
+        super.eUnset(featureID);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public boolean eIsSet(int featureID) {
+        switch (featureID) {
+        case PropertiesPackage.REFERENCE_WIDGET_CONDITIONAL_STYLE__STYLE:
+            return style != null;
+        }
+        return super.eIsSet(featureID);
+    }
+
+} // ReferenceWidgetConditionalStyleImpl
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/ReferenceWidgetStyleImpl.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/ReferenceWidgetStyleImpl.java
new file mode 100644
index 0000000000..089223639b
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/ReferenceWidgetStyleImpl.java
@@ -0,0 +1,44 @@
+/**
+ * Copyright (c) 2016 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.properties.impl;
+
+import org.eclipse.emf.ecore.EClass;
+import org.eclipse.sirius.properties.PropertiesPackage;
+import org.eclipse.sirius.properties.ReferenceWidgetStyle;
+
+/**
+ * <!-- begin-user-doc --> An implementation of the model object '
+ * <em><b>Reference Widget Style</b></em>'. <!-- end-user-doc -->
+ *
+ * @generated
+ */
+public class ReferenceWidgetStyleImpl extends WidgetStyleImpl implements ReferenceWidgetStyle {
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    protected ReferenceWidgetStyleImpl() {
+        super();
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    protected EClass eStaticClass() {
+        return PropertiesPackage.Literals.REFERENCE_WIDGET_STYLE;
+    }
+
+} // ReferenceWidgetStyleImpl
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/SingleReferenceDescriptionImpl.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/SingleReferenceDescriptionImpl.java
deleted file mode 100644
index e0290d4840..0000000000
--- a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/SingleReferenceDescriptionImpl.java
+++ /dev/null
@@ -1,572 +0,0 @@
-/**
- * Copyright (c) 2016 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.properties.impl;
-
-import org.eclipse.emf.common.notify.Notification;
-import org.eclipse.emf.common.notify.NotificationChain;
-import org.eclipse.emf.ecore.EClass;
-import org.eclipse.emf.ecore.InternalEObject;
-import org.eclipse.emf.ecore.impl.ENotificationImpl;
-import org.eclipse.sirius.properties.OperationDescription;
-import org.eclipse.sirius.properties.PropertiesPackage;
-import org.eclipse.sirius.properties.SingleReferenceDescription;
-
-/**
- * <!-- begin-user-doc --> An implementation of the model object '
- * <em><b>Single Reference Description</b></em>'. <!-- end-user-doc -->
- * <p>
- * The following features are implemented:
- * </p>
- * <ul>
- * <li>
- * {@link org.eclipse.sirius.properties.impl.SingleReferenceDescriptionImpl#getValueExpression
- * <em>Value Expression</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.impl.SingleReferenceDescriptionImpl#getDisplayExpression
- * <em>Display Expression</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.impl.SingleReferenceDescriptionImpl#getCreateOperation
- * <em>Create Operation</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.impl.SingleReferenceDescriptionImpl#getSearchOperation
- * <em>Search Operation</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.impl.SingleReferenceDescriptionImpl#getUnsetOperation
- * <em>Unset Operation</em>}</li>
- * <li>
- * {@link org.eclipse.sirius.properties.impl.SingleReferenceDescriptionImpl#getOnClickOperation
- * <em>On Click Operation</em>}</li>
- * </ul>
- *
- * @generated
- */
-public class SingleReferenceDescriptionImpl extends WidgetDescriptionImpl implements SingleReferenceDescription {
-    /**
-     * The default value of the '{@link #getValueExpression()
-     * <em>Value Expression</em>}' attribute. <!-- begin-user-doc --> <!--
-     * end-user-doc -->
-     *
-     * @see #getValueExpression()
-     * @generated
-     * @ordered
-     */
-    protected static final String VALUE_EXPRESSION_EDEFAULT = null;
-
-    /**
-     * The cached value of the '{@link #getValueExpression()
-     * <em>Value Expression</em>}' attribute. <!-- begin-user-doc --> <!--
-     * end-user-doc -->
-     *
-     * @see #getValueExpression()
-     * @generated
-     * @ordered
-     */
-    protected String valueExpression = SingleReferenceDescriptionImpl.VALUE_EXPRESSION_EDEFAULT;
-
-    /**
-     * The default value of the '{@link #getDisplayExpression()
-     * <em>Display Expression</em>}' attribute. <!-- begin-user-doc --> <!--
-     * end-user-doc -->
-     *
-     * @see #getDisplayExpression()
-     * @generated
-     * @ordered
-     */
-    protected static final String DISPLAY_EXPRESSION_EDEFAULT = null;
-
-    /**
-     * The cached value of the '{@link #getDisplayExpression()
-     * <em>Display Expression</em>}' attribute. <!-- begin-user-doc --> <!--
-     * end-user-doc -->
-     *
-     * @see #getDisplayExpression()
-     * @generated
-     * @ordered
-     */
-    protected String displayExpression = SingleReferenceDescriptionImpl.DISPLAY_EXPRESSION_EDEFAULT;
-
-    /**
-     * The cached value of the '{@link #getCreateOperation()
-     * <em>Create Operation</em>}' containment reference. <!-- begin-user-doc
-     * --> <!-- end-user-doc -->
-     *
-     * @see #getCreateOperation()
-     * @generated
-     * @ordered
-     */
-    protected OperationDescription createOperation;
-
-    /**
-     * The cached value of the '{@link #getSearchOperation()
-     * <em>Search Operation</em>}' containment reference. <!-- begin-user-doc
-     * --> <!-- end-user-doc -->
-     *
-     * @see #getSearchOperation()
-     * @generated
-     * @ordered
-     */
-    protected OperationDescription searchOperation;
-
-    /**
-     * The cached value of the '{@link #getUnsetOperation()
-     * <em>Unset Operation</em>}' containment reference. <!-- begin-user-doc -->
-     * <!-- end-user-doc -->
-     *
-     * @see #getUnsetOperation()
-     * @generated
-     * @ordered
-     */
-    protected OperationDescription unsetOperation;
-
-    /**
-     * The cached value of the '{@link #getOnClickOperation()
-     * <em>On Click Operation</em>}' containment reference. <!-- begin-user-doc
-     * --> <!-- end-user-doc -->
-     *
-     * @see #getOnClickOperation()
-     * @generated
-     * @ordered
-     */
-    protected OperationDescription onClickOperation;
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    protected SingleReferenceDescriptionImpl() {
-        super();
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    protected EClass eStaticClass() {
-        return PropertiesPackage.Literals.SINGLE_REFERENCE_DESCRIPTION;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public String getValueExpression() {
-        return valueExpression;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void setValueExpression(String newValueExpression) {
-        String oldValueExpression = valueExpression;
-        valueExpression = newValueExpression;
-        if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__VALUE_EXPRESSION, oldValueExpression, valueExpression));
-        }
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public String getDisplayExpression() {
-        return displayExpression;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void setDisplayExpression(String newDisplayExpression) {
-        String oldDisplayExpression = displayExpression;
-        displayExpression = newDisplayExpression;
-        if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION, oldDisplayExpression, displayExpression));
-        }
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public OperationDescription getCreateOperation() {
-        return createOperation;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    public NotificationChain basicSetCreateOperation(OperationDescription newCreateOperation, NotificationChain msgs) {
-        OperationDescription oldCreateOperation = createOperation;
-        createOperation = newCreateOperation;
-        if (eNotificationRequired()) {
-            ENotificationImpl notification = new ENotificationImpl(this, Notification.SET, PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__CREATE_OPERATION, oldCreateOperation, newCreateOperation);
-            if (msgs == null) {
-                msgs = notification;
-            } else {
-                msgs.add(notification);
-            }
-        }
-        return msgs;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void setCreateOperation(OperationDescription newCreateOperation) {
-        if (newCreateOperation != createOperation) {
-            NotificationChain msgs = null;
-            if (createOperation != null) {
-                msgs = ((InternalEObject) createOperation).eInverseRemove(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__CREATE_OPERATION, null, msgs);
-            }
-            if (newCreateOperation != null) {
-                msgs = ((InternalEObject) newCreateOperation).eInverseAdd(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__CREATE_OPERATION, null, msgs);
-            }
-            msgs = basicSetCreateOperation(newCreateOperation, msgs);
-            if (msgs != null) {
-                msgs.dispatch();
-            }
-        } else if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__CREATE_OPERATION, newCreateOperation, newCreateOperation));
-        }
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public OperationDescription getSearchOperation() {
-        return searchOperation;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    public NotificationChain basicSetSearchOperation(OperationDescription newSearchOperation, NotificationChain msgs) {
-        OperationDescription oldSearchOperation = searchOperation;
-        searchOperation = newSearchOperation;
-        if (eNotificationRequired()) {
-            ENotificationImpl notification = new ENotificationImpl(this, Notification.SET, PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__SEARCH_OPERATION, oldSearchOperation, newSearchOperation);
-            if (msgs == null) {
-                msgs = notification;
-            } else {
-                msgs.add(notification);
-            }
-        }
-        return msgs;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void setSearchOperation(OperationDescription newSearchOperation) {
-        if (newSearchOperation != searchOperation) {
-            NotificationChain msgs = null;
-            if (searchOperation != null) {
-                msgs = ((InternalEObject) searchOperation).eInverseRemove(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__SEARCH_OPERATION, null, msgs);
-            }
-            if (newSearchOperation != null) {
-                msgs = ((InternalEObject) newSearchOperation).eInverseAdd(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__SEARCH_OPERATION, null, msgs);
-            }
-            msgs = basicSetSearchOperation(newSearchOperation, msgs);
-            if (msgs != null) {
-                msgs.dispatch();
-            }
-        } else if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__SEARCH_OPERATION, newSearchOperation, newSearchOperation));
-        }
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public OperationDescription getUnsetOperation() {
-        return unsetOperation;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    public NotificationChain basicSetUnsetOperation(OperationDescription newUnsetOperation, NotificationChain msgs) {
-        OperationDescription oldUnsetOperation = unsetOperation;
-        unsetOperation = newUnsetOperation;
-        if (eNotificationRequired()) {
-            ENotificationImpl notification = new ENotificationImpl(this, Notification.SET, PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION, oldUnsetOperation, newUnsetOperation);
-            if (msgs == null) {
-                msgs = notification;
-            } else {
-                msgs.add(notification);
-            }
-        }
-        return msgs;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void setUnsetOperation(OperationDescription newUnsetOperation) {
-        if (newUnsetOperation != unsetOperation) {
-            NotificationChain msgs = null;
-            if (unsetOperation != null) {
-                msgs = ((InternalEObject) unsetOperation).eInverseRemove(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION, null, msgs);
-            }
-            if (newUnsetOperation != null) {
-                msgs = ((InternalEObject) newUnsetOperation).eInverseAdd(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION, null, msgs);
-            }
-            msgs = basicSetUnsetOperation(newUnsetOperation, msgs);
-            if (msgs != null) {
-                msgs.dispatch();
-            }
-        } else if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION, newUnsetOperation, newUnsetOperation));
-        }
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public OperationDescription getOnClickOperation() {
-        return onClickOperation;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    public NotificationChain basicSetOnClickOperation(OperationDescription newOnClickOperation, NotificationChain msgs) {
-        OperationDescription oldOnClickOperation = onClickOperation;
-        onClickOperation = newOnClickOperation;
-        if (eNotificationRequired()) {
-            ENotificationImpl notification = new ENotificationImpl(this, Notification.SET, PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION, oldOnClickOperation,
-                    newOnClickOperation);
-            if (msgs == null) {
-                msgs = notification;
-            } else {
-                msgs.add(notification);
-            }
-        }
-        return msgs;
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void setOnClickOperation(OperationDescription newOnClickOperation) {
-        if (newOnClickOperation != onClickOperation) {
-            NotificationChain msgs = null;
-            if (onClickOperation != null) {
-                msgs = ((InternalEObject) onClickOperation).eInverseRemove(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION, null,
-                        msgs);
-            }
-            if (newOnClickOperation != null) {
-                msgs = ((InternalEObject) newOnClickOperation).eInverseAdd(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION, null,
-                        msgs);
-            }
-            msgs = basicSetOnClickOperation(newOnClickOperation, msgs);
-            if (msgs != null) {
-                msgs.dispatch();
-            }
-        } else if (eNotificationRequired()) {
-            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION, newOnClickOperation, newOnClickOperation));
-        }
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public NotificationChain eInverseRemove(InternalEObject otherEnd, int featureID, NotificationChain msgs) {
-        switch (featureID) {
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__CREATE_OPERATION:
-            return basicSetCreateOperation(null, msgs);
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__SEARCH_OPERATION:
-            return basicSetSearchOperation(null, msgs);
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION:
-            return basicSetUnsetOperation(null, msgs);
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION:
-            return basicSetOnClickOperation(null, 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 PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__VALUE_EXPRESSION:
-            return getValueExpression();
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION:
-            return getDisplayExpression();
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__CREATE_OPERATION:
-            return getCreateOperation();
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__SEARCH_OPERATION:
-            return getSearchOperation();
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION:
-            return getUnsetOperation();
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION:
-            return getOnClickOperation();
-        }
-        return super.eGet(featureID, resolve, coreType);
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void eSet(int featureID, Object newValue) {
-        switch (featureID) {
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__VALUE_EXPRESSION:
-            setValueExpression((String) newValue);
-            return;
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION:
-            setDisplayExpression((String) newValue);
-            return;
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__CREATE_OPERATION:
-            setCreateOperation((OperationDescription) newValue);
-            return;
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__SEARCH_OPERATION:
-            setSearchOperation((OperationDescription) newValue);
-            return;
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION:
-            setUnsetOperation((OperationDescription) newValue);
-            return;
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION:
-            setOnClickOperation((OperationDescription) newValue);
-            return;
-        }
-        super.eSet(featureID, newValue);
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public void eUnset(int featureID) {
-        switch (featureID) {
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__VALUE_EXPRESSION:
-            setValueExpression(SingleReferenceDescriptionImpl.VALUE_EXPRESSION_EDEFAULT);
-            return;
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION:
-            setDisplayExpression(SingleReferenceDescriptionImpl.DISPLAY_EXPRESSION_EDEFAULT);
-            return;
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__CREATE_OPERATION:
-            setCreateOperation((OperationDescription) null);
-            return;
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__SEARCH_OPERATION:
-            setSearchOperation((OperationDescription) null);
-            return;
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION:
-            setUnsetOperation((OperationDescription) null);
-            return;
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION:
-            setOnClickOperation((OperationDescription) null);
-            return;
-        }
-        super.eUnset(featureID);
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public boolean eIsSet(int featureID) {
-        switch (featureID) {
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__VALUE_EXPRESSION:
-            return SingleReferenceDescriptionImpl.VALUE_EXPRESSION_EDEFAULT == null ? valueExpression != null : !SingleReferenceDescriptionImpl.VALUE_EXPRESSION_EDEFAULT.equals(valueExpression);
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION:
-            return SingleReferenceDescriptionImpl.DISPLAY_EXPRESSION_EDEFAULT == null ? displayExpression != null
-                    : !SingleReferenceDescriptionImpl.DISPLAY_EXPRESSION_EDEFAULT.equals(displayExpression);
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__CREATE_OPERATION:
-            return createOperation != null;
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__SEARCH_OPERATION:
-            return searchOperation != null;
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION:
-            return unsetOperation != null;
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION:
-            return onClickOperation != null;
-        }
-        return super.eIsSet(featureID);
-    }
-
-    /**
-     * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
-     * @generated
-     */
-    @Override
-    public String toString() {
-        if (eIsProxy()) {
-            return super.toString();
-        }
-
-        StringBuffer result = new StringBuffer(super.toString());
-        result.append(" (valueExpression: ");
-        result.append(valueExpression);
-        result.append(", displayExpression: ");
-        result.append(displayExpression);
-        result.append(')');
-        return result.toString();
-    }
-
-} // SingleReferenceDescriptionImpl
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/WidgetActionImpl.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/WidgetActionImpl.java
new file mode 100644
index 0000000000..8efbd14dcb
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/WidgetActionImpl.java
@@ -0,0 +1,271 @@
+/**
+ * Copyright (c) 2016 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.properties.impl;
+
+import org.eclipse.emf.common.notify.Notification;
+import org.eclipse.emf.common.notify.NotificationChain;
+import org.eclipse.emf.ecore.EClass;
+import org.eclipse.emf.ecore.InternalEObject;
+import org.eclipse.emf.ecore.impl.ENotificationImpl;
+import org.eclipse.emf.ecore.impl.MinimalEObjectImpl;
+import org.eclipse.sirius.properties.PropertiesPackage;
+import org.eclipse.sirius.properties.WidgetAction;
+import org.eclipse.sirius.viewpoint.description.tool.InitialOperation;
+
+/**
+ * <!-- begin-user-doc --> An implementation of the model object '
+ * <em><b>Widget Action</b></em>'. <!-- end-user-doc -->
+ * <p>
+ * The following features are implemented:
+ * </p>
+ * <ul>
+ * <li>
+ * {@link org.eclipse.sirius.properties.impl.WidgetActionImpl#getLabelExpression
+ * <em>Label Expression</em>}</li>
+ * <li>
+ * {@link org.eclipse.sirius.properties.impl.WidgetActionImpl#getInitialOperation
+ * <em>Initial Operation</em>}</li>
+ * </ul>
+ *
+ * @generated
+ */
+public class WidgetActionImpl extends MinimalEObjectImpl.Container implements WidgetAction {
+    /**
+     * The default value of the '{@link #getLabelExpression()
+     * <em>Label Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @see #getLabelExpression()
+     * @generated
+     * @ordered
+     */
+    protected static final String LABEL_EXPRESSION_EDEFAULT = null;
+
+    /**
+     * The cached value of the '{@link #getLabelExpression()
+     * <em>Label Expression</em>}' attribute. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     *
+     * @see #getLabelExpression()
+     * @generated
+     * @ordered
+     */
+    protected String labelExpression = WidgetActionImpl.LABEL_EXPRESSION_EDEFAULT;
+
+    /**
+     * The cached value of the '{@link #getInitialOperation()
+     * <em>Initial Operation</em>}' containment reference. <!-- begin-user-doc
+     * --> <!-- end-user-doc -->
+     *
+     * @see #getInitialOperation()
+     * @generated
+     * @ordered
+     */
+    protected InitialOperation initialOperation;
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    protected WidgetActionImpl() {
+        super();
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    protected EClass eStaticClass() {
+        return PropertiesPackage.Literals.WIDGET_ACTION;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public String getLabelExpression() {
+        return labelExpression;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public void setLabelExpression(String newLabelExpression) {
+        String oldLabelExpression = labelExpression;
+        labelExpression = newLabelExpression;
+        if (eNotificationRequired()) {
+            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.WIDGET_ACTION__LABEL_EXPRESSION, oldLabelExpression, labelExpression));
+        }
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public InitialOperation getInitialOperation() {
+        return initialOperation;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    public NotificationChain basicSetInitialOperation(InitialOperation newInitialOperation, NotificationChain msgs) {
+        InitialOperation oldInitialOperation = initialOperation;
+        initialOperation = newInitialOperation;
+        if (eNotificationRequired()) {
+            ENotificationImpl notification = new ENotificationImpl(this, Notification.SET, PropertiesPackage.WIDGET_ACTION__INITIAL_OPERATION, oldInitialOperation, newInitialOperation);
+            if (msgs == null) {
+                msgs = notification;
+            } else {
+                msgs.add(notification);
+            }
+        }
+        return msgs;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public void setInitialOperation(InitialOperation newInitialOperation) {
+        if (newInitialOperation != initialOperation) {
+            NotificationChain msgs = null;
+            if (initialOperation != null) {
+                msgs = ((InternalEObject) initialOperation).eInverseRemove(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.WIDGET_ACTION__INITIAL_OPERATION, null, msgs);
+            }
+            if (newInitialOperation != null) {
+                msgs = ((InternalEObject) newInitialOperation).eInverseAdd(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.WIDGET_ACTION__INITIAL_OPERATION, null, msgs);
+            }
+            msgs = basicSetInitialOperation(newInitialOperation, msgs);
+            if (msgs != null) {
+                msgs.dispatch();
+            }
+        } else if (eNotificationRequired()) {
+            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.WIDGET_ACTION__INITIAL_OPERATION, newInitialOperation, newInitialOperation));
+        }
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public NotificationChain eInverseRemove(InternalEObject otherEnd, int featureID, NotificationChain msgs) {
+        switch (featureID) {
+        case PropertiesPackage.WIDGET_ACTION__INITIAL_OPERATION:
+            return basicSetInitialOperation(null, 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 PropertiesPackage.WIDGET_ACTION__LABEL_EXPRESSION:
+            return getLabelExpression();
+        case PropertiesPackage.WIDGET_ACTION__INITIAL_OPERATION:
+            return getInitialOperation();
+        }
+        return super.eGet(featureID, resolve, coreType);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public void eSet(int featureID, Object newValue) {
+        switch (featureID) {
+        case PropertiesPackage.WIDGET_ACTION__LABEL_EXPRESSION:
+            setLabelExpression((String) newValue);
+            return;
+        case PropertiesPackage.WIDGET_ACTION__INITIAL_OPERATION:
+            setInitialOperation((InitialOperation) newValue);
+            return;
+        }
+        super.eSet(featureID, newValue);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public void eUnset(int featureID) {
+        switch (featureID) {
+        case PropertiesPackage.WIDGET_ACTION__LABEL_EXPRESSION:
+            setLabelExpression(WidgetActionImpl.LABEL_EXPRESSION_EDEFAULT);
+            return;
+        case PropertiesPackage.WIDGET_ACTION__INITIAL_OPERATION:
+            setInitialOperation((InitialOperation) null);
+            return;
+        }
+        super.eUnset(featureID);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public boolean eIsSet(int featureID) {
+        switch (featureID) {
+        case PropertiesPackage.WIDGET_ACTION__LABEL_EXPRESSION:
+            return WidgetActionImpl.LABEL_EXPRESSION_EDEFAULT == null ? labelExpression != null : !WidgetActionImpl.LABEL_EXPRESSION_EDEFAULT.equals(labelExpression);
+        case PropertiesPackage.WIDGET_ACTION__INITIAL_OPERATION:
+            return initialOperation != null;
+        }
+        return super.eIsSet(featureID);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public String toString() {
+        if (eIsProxy()) {
+            return super.toString();
+        }
+
+        StringBuffer result = new StringBuffer(super.toString());
+        result.append(" (labelExpression: ");
+        result.append(labelExpression);
+        result.append(')');
+        return result.toString();
+    }
+
+} // WidgetActionImpl
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/util/PropertiesAdapterFactory.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/util/PropertiesAdapterFactory.java
index 1f630dde42..0bdf5ee2e2 100644
--- a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/util/PropertiesAdapterFactory.java
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/util/PropertiesAdapterFactory.java
@@ -38,7 +38,6 @@ import org.eclipse.sirius.properties.LabelDescription;
 import org.eclipse.sirius.properties.LabelWidgetConditionalStyle;
 import org.eclipse.sirius.properties.LabelWidgetStyle;
 import org.eclipse.sirius.properties.LayoutDescription;
-import org.eclipse.sirius.properties.MultipleReferencesDescription;
 import org.eclipse.sirius.properties.OperationDescription;
 import org.eclipse.sirius.properties.PageDescription;
 import org.eclipse.sirius.properties.PageValidationSetDescription;
@@ -47,15 +46,18 @@ import org.eclipse.sirius.properties.PropertyValidationRule;
 import org.eclipse.sirius.properties.RadioDescription;
 import org.eclipse.sirius.properties.RadioWidgetConditionalStyle;
 import org.eclipse.sirius.properties.RadioWidgetStyle;
+import org.eclipse.sirius.properties.ReferenceDescription;
+import org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle;
+import org.eclipse.sirius.properties.ReferenceWidgetStyle;
 import org.eclipse.sirius.properties.SelectDescription;
 import org.eclipse.sirius.properties.SelectWidgetConditionalStyle;
 import org.eclipse.sirius.properties.SelectWidgetStyle;
-import org.eclipse.sirius.properties.SingleReferenceDescription;
 import org.eclipse.sirius.properties.TextAreaDescription;
 import org.eclipse.sirius.properties.TextDescription;
 import org.eclipse.sirius.properties.TextWidgetConditionalStyle;
 import org.eclipse.sirius.properties.TextWidgetStyle;
 import org.eclipse.sirius.properties.ViewExtensionDescription;
+import org.eclipse.sirius.properties.WidgetAction;
 import org.eclipse.sirius.properties.WidgetConditionalStyle;
 import org.eclipse.sirius.properties.WidgetDescription;
 import org.eclipse.sirius.properties.WidgetStyle;
@@ -224,8 +226,8 @@ public class PropertiesAdapterFactory extends AdapterFactoryImpl {
         }
 
         @Override
-        public Adapter caseSingleReferenceDescription(SingleReferenceDescription object) {
-            return createSingleReferenceDescriptionAdapter();
+        public Adapter caseReferenceDescription(ReferenceDescription object) {
+            return createReferenceDescriptionAdapter();
         }
 
         @Override
@@ -234,11 +236,6 @@ public class PropertiesAdapterFactory extends AdapterFactoryImpl {
         }
 
         @Override
-        public Adapter caseMultipleReferencesDescription(MultipleReferencesDescription object) {
-            return createMultipleReferencesDescriptionAdapter();
-        }
-
-        @Override
         public Adapter caseCustomDescription(CustomDescription object) {
             return createCustomDescriptionAdapter();
         }
@@ -294,6 +291,11 @@ public class PropertiesAdapterFactory extends AdapterFactoryImpl {
         }
 
         @Override
+        public Adapter caseReferenceWidgetStyle(ReferenceWidgetStyle object) {
+            return createReferenceWidgetStyleAdapter();
+        }
+
+        @Override
         public Adapter caseWidgetConditionalStyle(WidgetConditionalStyle object) {
             return createWidgetConditionalStyleAdapter();
         }
@@ -334,6 +336,16 @@ public class PropertiesAdapterFactory extends AdapterFactoryImpl {
         }
 
         @Override
+        public Adapter caseReferenceWidgetConditionalStyle(ReferenceWidgetConditionalStyle object) {
+            return createReferenceWidgetConditionalStyleAdapter();
+        }
+
+        @Override
+        public Adapter caseWidgetAction(WidgetAction object) {
+            return createWidgetActionAdapter();
+        }
+
+        @Override
         public Adapter caseExtension(Extension object) {
             return createExtensionAdapter();
         }
@@ -706,17 +718,17 @@ public class PropertiesAdapterFactory extends AdapterFactoryImpl {
 
     /**
      * Creates a new adapter for an object of class '
-     * {@link org.eclipse.sirius.properties.SingleReferenceDescription
-     * <em>Single Reference Description</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 -->
+     * {@link org.eclipse.sirius.properties.ReferenceDescription
+     * <em>Reference Description</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.properties.SingleReferenceDescription
+     * @see org.eclipse.sirius.properties.ReferenceDescription
      * @generated
      */
-    public Adapter createSingleReferenceDescriptionAdapter() {
+    public Adapter createReferenceDescriptionAdapter() {
         return null;
     }
 
@@ -738,22 +750,6 @@ public class PropertiesAdapterFactory extends AdapterFactoryImpl {
 
     /**
      * Creates a new adapter for an object of class '
-     * {@link org.eclipse.sirius.properties.MultipleReferencesDescription
-     * <em>Multiple References Description</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.properties.MultipleReferencesDescription
-     * @generated
-     */
-    public Adapter createMultipleReferencesDescriptionAdapter() {
-        return null;
-    }
-
-    /**
-     * Creates a new adapter for an object of class '
      * {@link org.eclipse.sirius.properties.CustomDescription
      * <em>Custom Description</em>}'. <!-- begin-user-doc --> This default
      * implementation returns null so that we can easily ignore cases; it's
@@ -1057,6 +1053,53 @@ public class PropertiesAdapterFactory extends AdapterFactoryImpl {
 
     /**
      * Creates a new adapter for an object of class '
+     * {@link org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle
+     * <em>Reference Widget Conditional Style</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.properties.ReferenceWidgetConditionalStyle
+     * @generated
+     */
+    public Adapter createReferenceWidgetConditionalStyleAdapter() {
+        return null;
+    }
+
+    /**
+     * Creates a new adapter for an object of class '
+     * {@link org.eclipse.sirius.properties.WidgetAction <em>Widget Action</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.properties.WidgetAction
+     * @generated
+     */
+    public Adapter createWidgetActionAdapter() {
+        return null;
+    }
+
+    /**
+     * Creates a new adapter for an object of class '
+     * {@link org.eclipse.sirius.properties.ReferenceWidgetStyle
+     * <em>Reference Widget Style</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.properties.ReferenceWidgetStyle
+     * @generated
+     */
+    public Adapter createReferenceWidgetStyleAdapter() {
+        return null;
+    }
+
+    /**
+     * Creates a new adapter for an object of class '
      * {@link org.eclipse.sirius.viewpoint.description.Extension
      * <em>Extension</em>}'. <!-- begin-user-doc --> This default implementation
      * returns null so that we can easily ignore cases; it's useful to ignore a
diff --git a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/util/PropertiesSwitch.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/util/PropertiesSwitch.java
index a16e2141a4..092589a7d0 100644
--- a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/util/PropertiesSwitch.java
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/util/PropertiesSwitch.java
@@ -38,7 +38,6 @@ import org.eclipse.sirius.properties.LabelDescription;
 import org.eclipse.sirius.properties.LabelWidgetConditionalStyle;
 import org.eclipse.sirius.properties.LabelWidgetStyle;
 import org.eclipse.sirius.properties.LayoutDescription;
-import org.eclipse.sirius.properties.MultipleReferencesDescription;
 import org.eclipse.sirius.properties.OperationDescription;
 import org.eclipse.sirius.properties.PageDescription;
 import org.eclipse.sirius.properties.PageValidationSetDescription;
@@ -47,15 +46,18 @@ import org.eclipse.sirius.properties.PropertyValidationRule;
 import org.eclipse.sirius.properties.RadioDescription;
 import org.eclipse.sirius.properties.RadioWidgetConditionalStyle;
 import org.eclipse.sirius.properties.RadioWidgetStyle;
+import org.eclipse.sirius.properties.ReferenceDescription;
+import org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle;
+import org.eclipse.sirius.properties.ReferenceWidgetStyle;
 import org.eclipse.sirius.properties.SelectDescription;
 import org.eclipse.sirius.properties.SelectWidgetConditionalStyle;
 import org.eclipse.sirius.properties.SelectWidgetStyle;
-import org.eclipse.sirius.properties.SingleReferenceDescription;
 import org.eclipse.sirius.properties.TextAreaDescription;
 import org.eclipse.sirius.properties.TextDescription;
 import org.eclipse.sirius.properties.TextWidgetConditionalStyle;
 import org.eclipse.sirius.properties.TextWidgetStyle;
 import org.eclipse.sirius.properties.ViewExtensionDescription;
+import org.eclipse.sirius.properties.WidgetAction;
 import org.eclipse.sirius.properties.WidgetConditionalStyle;
 import org.eclipse.sirius.properties.WidgetDescription;
 import org.eclipse.sirius.properties.WidgetStyle;
@@ -373,14 +375,14 @@ public class PropertiesSwitch<T> {
             }
             return result;
         }
-        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION: {
-            SingleReferenceDescription singleReferenceDescription = (SingleReferenceDescription) theEObject;
-            T result = caseSingleReferenceDescription(singleReferenceDescription);
+        case PropertiesPackage.REFERENCE_DESCRIPTION: {
+            ReferenceDescription referenceDescription = (ReferenceDescription) theEObject;
+            T result = caseReferenceDescription(referenceDescription);
             if (result == null) {
-                result = caseWidgetDescription(singleReferenceDescription);
+                result = caseWidgetDescription(referenceDescription);
             }
             if (result == null) {
-                result = caseControlDescription(singleReferenceDescription);
+                result = caseControlDescription(referenceDescription);
             }
             if (result == null) {
                 result = defaultCase(theEObject);
@@ -395,20 +397,6 @@ public class PropertiesSwitch<T> {
             }
             return result;
         }
-        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION: {
-            MultipleReferencesDescription multipleReferencesDescription = (MultipleReferencesDescription) theEObject;
-            T result = caseMultipleReferencesDescription(multipleReferencesDescription);
-            if (result == null) {
-                result = caseWidgetDescription(multipleReferencesDescription);
-            }
-            if (result == null) {
-                result = caseControlDescription(multipleReferencesDescription);
-            }
-            if (result == null) {
-                result = defaultCase(theEObject);
-            }
-            return result;
-        }
         case PropertiesPackage.CUSTOM_DESCRIPTION: {
             CustomDescription customDescription = (CustomDescription) theEObject;
             T result = caseCustomDescription(customDescription);
@@ -524,6 +512,17 @@ public class PropertiesSwitch<T> {
             }
             return result;
         }
+        case PropertiesPackage.REFERENCE_WIDGET_STYLE: {
+            ReferenceWidgetStyle referenceWidgetStyle = (ReferenceWidgetStyle) theEObject;
+            T result = caseReferenceWidgetStyle(referenceWidgetStyle);
+            if (result == null) {
+                result = caseWidgetStyle(referenceWidgetStyle);
+            }
+            if (result == null) {
+                result = defaultCase(theEObject);
+            }
+            return result;
+        }
         case PropertiesPackage.WIDGET_CONDITIONAL_STYLE: {
             WidgetConditionalStyle widgetConditionalStyle = (WidgetConditionalStyle) theEObject;
             T result = caseWidgetConditionalStyle(widgetConditionalStyle);
@@ -609,6 +608,25 @@ public class PropertiesSwitch<T> {
             }
             return result;
         }
+        case PropertiesPackage.REFERENCE_WIDGET_CONDITIONAL_STYLE: {
+            ReferenceWidgetConditionalStyle referenceWidgetConditionalStyle = (ReferenceWidgetConditionalStyle) theEObject;
+            T result = caseReferenceWidgetConditionalStyle(referenceWidgetConditionalStyle);
+            if (result == null) {
+                result = caseWidgetConditionalStyle(referenceWidgetConditionalStyle);
+            }
+            if (result == null) {
+                result = defaultCase(theEObject);
+            }
+            return result;
+        }
+        case PropertiesPackage.WIDGET_ACTION: {
+            WidgetAction widgetAction = (WidgetAction) theEObject;
+            T result = caseWidgetAction(widgetAction);
+            if (result == null) {
+                result = defaultCase(theEObject);
+            }
+            return result;
+        }
         default:
             return defaultCase(theEObject);
         }
@@ -973,18 +991,18 @@ public class PropertiesSwitch<T> {
 
     /**
      * Returns the result of interpreting the object as an instance of '
-     * <em>Single Reference Description</em>'. <!-- begin-user-doc --> This
+     * <em>Reference Description</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>Single Reference Description</em>'.
+     *         <em>Reference Description</em>'.
      * @see #doSwitch(org.eclipse.emf.ecore.EObject) doSwitch(EObject)
      * @generated
      */
-    public T caseSingleReferenceDescription(SingleReferenceDescription object) {
+    public T caseReferenceDescription(ReferenceDescription object) {
         return null;
     }
 
@@ -1007,23 +1025,6 @@ public class PropertiesSwitch<T> {
 
     /**
      * Returns the result of interpreting the object as an instance of '
-     * <em>Multiple References Description</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>Multiple References Description</em>'.
-     * @see #doSwitch(org.eclipse.emf.ecore.EObject) doSwitch(EObject)
-     * @generated
-     */
-    public T caseMultipleReferencesDescription(MultipleReferencesDescription object) {
-        return null;
-    }
-
-    /**
-     * Returns the result of interpreting the object as an instance of '
      * <em>Custom Description</em>'. <!-- begin-user-doc --> This implementation
      * returns null; returning a non-null result will terminate the switch. <!--
      * end-user-doc -->
@@ -1347,6 +1348,57 @@ public class PropertiesSwitch<T> {
 
     /**
      * Returns the result of interpreting the object as an instance of '
+     * <em>Reference Widget Conditional Style</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>Reference Widget Conditional Style</em>'.
+     * @see #doSwitch(org.eclipse.emf.ecore.EObject) doSwitch(EObject)
+     * @generated
+     */
+    public T caseReferenceWidgetConditionalStyle(ReferenceWidgetConditionalStyle object) {
+        return null;
+    }
+
+    /**
+     * Returns the result of interpreting the object as an instance of '
+     * <em>Widget Action</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>Widget Action</em>'.
+     * @see #doSwitch(org.eclipse.emf.ecore.EObject) doSwitch(EObject)
+     * @generated
+     */
+    public T caseWidgetAction(WidgetAction object) {
+        return null;
+    }
+
+    /**
+     * Returns the result of interpreting the object as an instance of '
+     * <em>Reference Widget Style</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>Reference Widget Style</em>'.
+     * @see #doSwitch(org.eclipse.emf.ecore.EObject) doSwitch(EObject)
+     * @generated
+     */
+    public T caseReferenceWidgetStyle(ReferenceWidgetStyle object) {
+        return null;
+    }
+
+    /**
+     * Returns the result of interpreting the object as an instance of '
      * <em>Extension</em>'. <!-- begin-user-doc --> This implementation returns
      * null; returning a non-null result will terminate the switch. <!--
      * end-user-doc -->
diff --git a/incubation/org.eclipse.sirius.ui.properties/src/org/eclipse/sirius/ui/properties/internal/tabprovider/ViewDescriptionConverter.java b/incubation/org.eclipse.sirius.ui.properties/src/org/eclipse/sirius/ui/properties/internal/tabprovider/ViewDescriptionConverter.java
index f9449756e5..b820380fcb 100644
--- a/incubation/org.eclipse.sirius.ui.properties/src/org/eclipse/sirius/ui/properties/internal/tabprovider/ViewDescriptionConverter.java
+++ b/incubation/org.eclipse.sirius.ui.properties/src/org/eclipse/sirius/ui/properties/internal/tabprovider/ViewDescriptionConverter.java
@@ -43,6 +43,9 @@ import org.eclipse.eef.EEFPropertyValidationRuleDescription;
 import org.eclipse.eef.EEFRadioConditionalStyle;
 import org.eclipse.eef.EEFRadioDescription;
 import org.eclipse.eef.EEFRadioStyle;
+import org.eclipse.eef.EEFReferenceConditionalStyle;
+import org.eclipse.eef.EEFReferenceDescription;
+import org.eclipse.eef.EEFReferenceStyle;
 import org.eclipse.eef.EEFRuleAuditDescription;
 import org.eclipse.eef.EEFSelectConditionalStyle;
 import org.eclipse.eef.EEFSelectDescription;
@@ -54,6 +57,7 @@ import org.eclipse.eef.EEFTextStyle;
 import org.eclipse.eef.EEFValidationFixDescription;
 import org.eclipse.eef.EEFValidationRuleDescription;
 import org.eclipse.eef.EEFViewDescription;
+import org.eclipse.eef.EEFWidgetAction;
 import org.eclipse.eef.EEFWidgetDescription;
 import org.eclipse.eef.EEFWidgetStyle;
 import org.eclipse.eef.EEF_FILL_LAYOUT_ORIENTATION;
@@ -91,6 +95,9 @@ import org.eclipse.sirius.properties.PropertyValidationRule;
 import org.eclipse.sirius.properties.RadioDescription;
 import org.eclipse.sirius.properties.RadioWidgetConditionalStyle;
 import org.eclipse.sirius.properties.RadioWidgetStyle;
+import org.eclipse.sirius.properties.ReferenceDescription;
+import org.eclipse.sirius.properties.ReferenceWidgetConditionalStyle;
+import org.eclipse.sirius.properties.ReferenceWidgetStyle;
 import org.eclipse.sirius.properties.SelectDescription;
 import org.eclipse.sirius.properties.SelectWidgetConditionalStyle;
 import org.eclipse.sirius.properties.SelectWidgetStyle;
@@ -99,6 +106,7 @@ import org.eclipse.sirius.properties.TextDescription;
 import org.eclipse.sirius.properties.TextWidgetConditionalStyle;
 import org.eclipse.sirius.properties.TextWidgetStyle;
 import org.eclipse.sirius.properties.ViewExtensionDescription;
+import org.eclipse.sirius.properties.WidgetAction;
 import org.eclipse.sirius.properties.WidgetDescription;
 import org.eclipse.sirius.properties.WidgetStyle;
 import org.eclipse.sirius.ui.properties.internal.SiriusInputDescriptor;
@@ -398,6 +406,8 @@ public class ViewDescriptionConverter {
             description = createEEFButtonDescription((ButtonDescription) widgetDescription);
         } else if (widgetDescription instanceof RadioDescription) {
             description = createEEFRadioDescription((RadioDescription) widgetDescription);
+        } else if (widgetDescription instanceof ReferenceDescription) {
+            description = createEEFReferenceDescription((ReferenceDescription) widgetDescription);
         } else if (widgetDescription instanceof CustomDescription) {
             description = createEEFCustomDescription((CustomDescription) widgetDescription);
         }
@@ -428,6 +438,8 @@ public class ViewDescriptionConverter {
             eefWidgetStyle = EefFactory.eINSTANCE.createEEFSelectStyle();
         } else if (widgetStyle instanceof CustomWidgetStyle) {
             eefWidgetStyle = EefFactory.eINSTANCE.createEEFCustomWidgetStyle();
+        } else if (widgetStyle instanceof ReferenceWidgetStyle) {
+            eefWidgetStyle = EefFactory.eINSTANCE.createEEFReferenceStyle();
         }
 
         // Set label style
@@ -739,6 +751,41 @@ public class ViewDescriptionConverter {
         return eefRadioDescription;
     }
 
+    private EEFReferenceDescription createEEFReferenceDescription(ReferenceDescription referenceDescription) {
+        EEFReferenceDescription eefReferenceDescription = EefFactory.eINSTANCE.createEEFReferenceDescription();
+        eefReferenceDescription.setIdentifier(referenceDescription.getIdentifier());
+        eefReferenceDescription.setValueExpression(referenceDescription.getValueExpression());
+        eefReferenceDescription.setMultiple(referenceDescription.isMultiple());
+        eefReferenceDescription.setDisplayExpression(referenceDescription.getDisplayExpression());
+        eefReferenceDescription.setOnClickExpression(getExpressionForOperation(referenceDescription.getOnClickOperation()));
+        for (WidgetAction action : referenceDescription.getActions()) {
+            EEFWidgetAction eefAction = EefFactory.eINSTANCE.createEEFWidgetAction();
+            eefAction.setLabelExpression(action.getLabelExpression());
+            eefAction.setActionExpression(getExpressionForOperation(action.getInitialOperation()));
+            eefReferenceDescription.getActions().add(eefAction);
+        }
+        ReferenceWidgetStyle referenceStyle = referenceDescription.getStyle();
+        if (referenceStyle != null) {
+            eefReferenceDescription.setStyle((EEFReferenceStyle) createEEFWidgetStyle(referenceStyle));
+        }
+
+        List<ReferenceWidgetConditionalStyle> conditionalStyles = referenceDescription.getConditionalStyles();
+        if (conditionalStyles != null && !conditionalStyles.isEmpty()) {
+            List<EEFReferenceConditionalStyle> eefConditionalStyles = new ArrayList<EEFReferenceConditionalStyle>();
+            for (ReferenceWidgetConditionalStyle conditionalStyle : conditionalStyles) {
+                EEFReferenceConditionalStyle eefConditionalStyle = EefFactory.eINSTANCE.createEEFReferenceConditionalStyle();
+                eefConditionalStyle.setPreconditionExpression(conditionalStyle.getPreconditionExpression());
+                eefConditionalStyle.setStyle((EEFReferenceStyle) createEEFWidgetStyle(conditionalStyle.getStyle()));
+                eefConditionalStyles.add(eefConditionalStyle);
+            }
+
+            if (eefConditionalStyles != null && !eefConditionalStyles.isEmpty()) {
+                eefReferenceDescription.getConditionalStyles().addAll(eefConditionalStyles);
+            }
+        }
+        return eefReferenceDescription;
+    }
+
     private EEFCustomWidgetDescription createEEFCustomDescription(CustomDescription customDescription) {
         EEFCustomWidgetDescription eefCustomDescription = EefFactory.eINSTANCE.createEEFCustomWidgetDescription();
         eefCustomDescription.setIdentifier(customDescription.getIdentifier());