[482528] Add support for single reference & multiple references widgets

Bug: 482528
Change-Id: Ib96396013a8f92a4c68b720397bbc76351104bdc
Signed-off-by: Mélanie Bats <melanie.bats@obeo.fr>

44 files changed, 5323 insertions, 247 deletions

diff --git a/incubation/org.eclipse.sirius.editor.properties/help/contexts.xml b/incubation/org.eclipse.sirius.editor.properties/help/contexts.xml
index 125dc28aa9..084c9cdd92 100644
--- a/incubation/org.eclipse.sirius.editor.properties/help/contexts.xml
+++ b/incubation/org.eclipse.sirius.editor.properties/help/contexts.xml
@@ -157,4 +157,39 @@
    
       </description>
    </context>
+   <context id="SingleReferenceDescription">
+     <description>
+       Represents a single reference in the user interface.
+
+       
+         
+   <!-- Start of user code SingleReferenceDescription description -->
+   
+   <!-- End of user code SingleReferenceDescription description -->
+   
+      </description>
+   </context>
+   <context id="OperationDescription">
+     <description>
+       
+       
+         
+   <!-- Start of user code OperationDescription description -->
+   
+   <!-- End of user code OperationDescription description -->
+   
+      </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>
 </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 79537758c7..757e2433b6 100644
--- a/incubation/org.eclipse.sirius.editor.properties/plugin.xml
+++ b/incubation/org.eclipse.sirius.editor.properties/plugin.xml
@@ -19,6 +19,36 @@
   <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.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"
+                tab="viewpoint.tab.general">
+        <input type="org.eclipse.sirius.properties.MultipleReferencesDescription"/>
+      </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"
+                tab="viewpoint.tab.general">
+        <input type="org.eclipse.sirius.properties.SingleReferenceDescription"/>
+      </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"
+                tab="viewpoint.tab.general">
+        <input type="org.eclipse.sirius.properties.SingleReferenceDescription"/>
+      </propertySection>
+  	  <propertySection
                class="org.eclipse.sirius.properties.editor.properties.sections.properties.radiodescription.RadioDescriptionCandidateDisplayExpressionPropertySection"
                id="properties.section.radioDescription.CandidateDisplayExpression"
                filter="org.eclipse.sirius.properties.editor.properties.filters.properties.radiodescription.RadioDescriptionCandidateDisplayExpressionFilter"
@@ -122,6 +152,14 @@
         <input type="org.eclipse.sirius.properties.TextDescription"/>
       </propertySection>
   	  <propertySection
+               class="org.eclipse.sirius.properties.editor.properties.sections.properties.widgetdescription.WidgetDescriptionHelpExpressionPropertySection"
+               id="properties.section.widgetDescription.HelpExpression"
+               filter="org.eclipse.sirius.properties.editor.properties.filters.properties.widgetdescription.WidgetDescriptionHelpExpressionFilter"
+               afterSection="properties.section.widgetDescription.LabelExpression"
+                tab="viewpoint.tab.general">
+        <input type="org.eclipse.sirius.properties.WidgetDescription"/>
+      </propertySection>
+  	  <propertySection
                class="org.eclipse.sirius.properties.editor.properties.sections.properties.widgetdescription.WidgetDescriptionLabelExpressionPropertySection"
                id="properties.section.widgetDescription.LabelExpression"
                filter="org.eclipse.sirius.properties.editor.properties.filters.properties.widgetdescription.WidgetDescriptionLabelExpressionFilter"
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/multiplereferencesdescription/MultipleReferencesDescriptionDisplayExpressionFilter.java
new file mode 100644
index 0000000000..d2a4b22be8
--- /dev/null
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/multiplereferencesdescription/MultipleReferencesDescriptionDisplayExpressionFilter.java
@@ -0,0 +1,45 @@
+/*******************************************************************************
+ * 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.filters.properties.multiplereferencesdescription;
+
+// Start of user code specific imports
+
+import org.eclipse.emf.ecore.EStructuralFeature;
+import org.eclipse.sirius.editor.properties.filters.common.ViewpointPropertyFilter;
+import org.eclipse.sirius.properties.PropertiesPackage;
+
+// End of user code specific imports
+
+/**
+ * A filter for the displayExpression property section.
+ */
+public class MultipleReferencesDescriptionDisplayExpressionFilter extends ViewpointPropertyFilter {
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    protected EStructuralFeature getFeature() {
+        return PropertiesPackage.eINSTANCE.getMultipleReferencesDescription_DisplayExpression();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    protected boolean isRightInputType(Object arg0) {
+        return arg0 instanceof org.eclipse.sirius.properties.MultipleReferencesDescription;
+    }
+
+    // Start of user code user methods
+
+    // End 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/multiplereferencesdescription/MultipleReferencesDescriptionValueExpressionFilter.java
new file mode 100644
index 0000000000..3b323c1471
--- /dev/null
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/multiplereferencesdescription/MultipleReferencesDescriptionValueExpressionFilter.java
@@ -0,0 +1,45 @@
+/*******************************************************************************
+ * 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.filters.properties.multiplereferencesdescription;
+
+// Start of user code specific imports
+
+import org.eclipse.emf.ecore.EStructuralFeature;
+import org.eclipse.sirius.editor.properties.filters.common.ViewpointPropertyFilter;
+import org.eclipse.sirius.properties.PropertiesPackage;
+
+// End of user code specific imports
+
+/**
+ * A filter for the valueExpression property section.
+ */
+public class MultipleReferencesDescriptionValueExpressionFilter extends ViewpointPropertyFilter {
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    protected EStructuralFeature getFeature() {
+        return PropertiesPackage.eINSTANCE.getMultipleReferencesDescription_ValueExpression();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    protected boolean isRightInputType(Object arg0) {
+        return arg0 instanceof org.eclipse.sirius.properties.MultipleReferencesDescription;
+    }
+
+    // Start of user code user methods
+
+    // End 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/SingleReferenceDescriptionDisplayExpressionFilter.java b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/singlereferencedescription/SingleReferenceDescriptionDisplayExpressionFilter.java
new file mode 100644
index 0000000000..3a67687bdb
--- /dev/null
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/singlereferencedescription/SingleReferenceDescriptionDisplayExpressionFilter.java
@@ -0,0 +1,45 @@
+/*******************************************************************************
+ * 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.filters.properties.singlereferencedescription;
+
+// Start of user code specific imports
+
+import org.eclipse.emf.ecore.EStructuralFeature;
+import org.eclipse.sirius.editor.properties.filters.common.ViewpointPropertyFilter;
+import org.eclipse.sirius.properties.PropertiesPackage;
+
+// End of user code specific imports
+
+/**
+ * A filter for the displayExpression property section.
+ */
+public class SingleReferenceDescriptionDisplayExpressionFilter extends ViewpointPropertyFilter {
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    protected EStructuralFeature getFeature() {
+        return PropertiesPackage.eINSTANCE.getSingleReferenceDescription_DisplayExpression();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    protected boolean isRightInputType(Object arg0) {
+        return arg0 instanceof org.eclipse.sirius.properties.SingleReferenceDescription;
+    }
+
+    // Start of user code user methods
+
+    // End 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/singlereferencedescription/SingleReferenceDescriptionValueExpressionFilter.java
new file mode 100644
index 0000000000..c37a8c9264
--- /dev/null
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/singlereferencedescription/SingleReferenceDescriptionValueExpressionFilter.java
@@ -0,0 +1,45 @@
+/*******************************************************************************
+ * 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.filters.properties.singlereferencedescription;
+
+// Start of user code specific imports
+
+import org.eclipse.emf.ecore.EStructuralFeature;
+import org.eclipse.sirius.editor.properties.filters.common.ViewpointPropertyFilter;
+import org.eclipse.sirius.properties.PropertiesPackage;
+
+// End of user code specific imports
+
+/**
+ * A filter for the valueExpression property section.
+ */
+public class SingleReferenceDescriptionValueExpressionFilter extends ViewpointPropertyFilter {
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    protected EStructuralFeature getFeature() {
+        return PropertiesPackage.eINSTANCE.getSingleReferenceDescription_ValueExpression();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    protected boolean isRightInputType(Object arg0) {
+        return arg0 instanceof org.eclipse.sirius.properties.SingleReferenceDescription;
+    }
+
+    // Start of user code user methods
+
+    // End of user code user methods
+
+}
diff --git a/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/widgetdescription/WidgetDescriptionHelpExpressionFilter.java b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/widgetdescription/WidgetDescriptionHelpExpressionFilter.java
new file mode 100644
index 0000000000..7dac7da21f
--- /dev/null
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/filters/properties/widgetdescription/WidgetDescriptionHelpExpressionFilter.java
@@ -0,0 +1,45 @@
+/*******************************************************************************
+ * 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.filters.properties.widgetdescription;
+
+// Start of user code specific imports
+
+import org.eclipse.emf.ecore.EStructuralFeature;
+import org.eclipse.sirius.editor.properties.filters.common.ViewpointPropertyFilter;
+import org.eclipse.sirius.properties.PropertiesPackage;
+
+// End of user code specific imports
+
+/**
+ * A filter for the helpExpression property section.
+ */
+public class WidgetDescriptionHelpExpressionFilter extends ViewpointPropertyFilter {
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    protected EStructuralFeature getFeature() {
+        return PropertiesPackage.eINSTANCE.getWidgetDescription_HelpExpression();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    protected boolean isRightInputType(Object arg0) {
+        return arg0 instanceof org.eclipse.sirius.properties.WidgetDescription;
+    }
+
+    // Start of user code user methods
+
+    // End 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
new file mode 100644
index 0000000000..1419a4521a
--- /dev/null
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/multiplereferencesdescription/MultipleReferencesDescriptionDisplayExpressionPropertySection.java
@@ -0,0 +1,123 @@
+/*******************************************************************************
+ * 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;
+
+// Start of user code imports
+
+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/multiplereferencesdescription/MultipleReferencesDescriptionValueExpressionPropertySection.java b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/multiplereferencesdescription/MultipleReferencesDescriptionValueExpressionPropertySection.java
new file mode 100644
index 0000000000..055a36e35b
--- /dev/null
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/multiplereferencesdescription/MultipleReferencesDescriptionValueExpressionPropertySection.java
@@ -0,0 +1,123 @@
+/*******************************************************************************
+ * 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;
+
+// Start of user code imports
+
+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 valueExpression property of a MultipleReferencesDescription
+ * object.
+ */
+public class MultipleReferencesDescriptionValueExpressionPropertySection extends AbstractTextWithButtonPropertySection implements ContentProposalClient {
+
+    /**
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getDefaultLabelText()
+     */
+    @Override
+    protected String getDefaultLabelText() {
+        return "ValueExpression"; //$NON-NLS-1$
+    }
+
+    /**
+     * @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_ValueExpression();
+    }
+
+    /**
+     * @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(), MultipleReferencesDescriptionValueExpressionPropertySection.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/singlereferencedescription/SingleReferenceDescriptionDisplayExpressionPropertySection.java
new file mode 100644
index 0000000000..8b77c7dc40
--- /dev/null
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/singlereferencedescription/SingleReferenceDescriptionDisplayExpressionPropertySection.java
@@ -0,0 +1,123 @@
+/*******************************************************************************
+ * 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.singlereferencedescription;
+
+// Start of user code imports
+
+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 SingleReferenceDescription
+ * object.
+ */
+public class SingleReferenceDescriptionDisplayExpressionPropertySection 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.getSingleReferenceDescription_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(), SingleReferenceDescriptionDisplayExpressionPropertySection.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/SingleReferenceDescriptionValueExpressionPropertySection.java b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/singlereferencedescription/SingleReferenceDescriptionValueExpressionPropertySection.java
new file mode 100644
index 0000000000..39d84d357e
--- /dev/null
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/singlereferencedescription/SingleReferenceDescriptionValueExpressionPropertySection.java
@@ -0,0 +1,123 @@
+/*******************************************************************************
+ * 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.singlereferencedescription;
+
+// Start of user code imports
+
+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 valueExpression property of a SingleReferenceDescription
+ * object.
+ */
+public class SingleReferenceDescriptionValueExpressionPropertySection extends AbstractTextWithButtonPropertySection implements ContentProposalClient {
+
+    /**
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getDefaultLabelText()
+     */
+    @Override
+    protected String getDefaultLabelText() {
+        return "ValueExpression"; //$NON-NLS-1$
+    }
+
+    /**
+     * @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.getSingleReferenceDescription_ValueExpression();
+    }
+
+    /**
+     * @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(), SingleReferenceDescriptionValueExpressionPropertySection.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/widgetdescription/WidgetDescriptionHelpExpressionPropertySection.java b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/widgetdescription/WidgetDescriptionHelpExpressionPropertySection.java
new file mode 100644
index 0000000000..835c542cec
--- /dev/null
+++ b/incubation/org.eclipse.sirius.editor.properties/src-gen/org/eclipse/sirius/properties/editor/properties/sections/properties/widgetdescription/WidgetDescriptionHelpExpressionPropertySection.java
@@ -0,0 +1,122 @@
+/*******************************************************************************
+ * 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.widgetdescription;
+
+// Start of user code imports
+
+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 helpExpression property of a WidgetDescription object.
+ */
+public class WidgetDescriptionHelpExpressionPropertySection extends AbstractTextWithButtonPropertySection implements ContentProposalClient {
+
+    /**
+     * @see org.eclipse.sirius.properties.editor.properties.sections.AbstractTextWithButtonPropertySection#getDefaultLabelText()
+     */
+    @Override
+    protected String getDefaultLabelText() {
+        return "HelpExpression"; //$NON-NLS-1$
+    }
+
+    /**
+     * @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.getWidgetDescription_HelpExpression();
+    }
+
+    /**
+     * @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(), WidgetDescriptionHelpExpressionPropertySection.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.properties.edit/icons/full/obj16/MultipleReferencesDescription.gif b/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/MultipleReferencesDescription.gif
new file mode 100644
index 0000000000..94c953e013
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/MultipleReferencesDescription.gif
diff --git a/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/OperationDescription.gif b/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/OperationDescription.gif
new file mode 100644
index 0000000000..05dc74ad5d
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/OperationDescription.gif
diff --git a/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/SingleReferenceDescription.gif b/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/SingleReferenceDescription.gif
new file mode 100644
index 0000000000..7bac4fd380
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties.edit/icons/full/obj16/SingleReferenceDescription.gif
diff --git a/incubation/org.eclipse.sirius.properties.edit/plugin.properties b/incubation/org.eclipse.sirius.properties.edit/plugin.properties
index 41fad4a13a..0a8da243bb 100644
--- a/incubation/org.eclipse.sirius.properties.edit/plugin.properties
+++ b/incubation/org.eclipse.sirius.properties.edit/plugin.properties
@@ -78,3 +78,27 @@ _UI_DynamicMappingIf_predicateExpression_feature = Predicate Expression
 _UI_DynamicMappingIf_widget_feature = Widget
 _UI_LabelDescription_bodyExpression_feature = Body Expression
 _UI_WidgetDescription_helpExpression_feature = Help Expression
+_UI_SingleReferenceDescription_type = Single Reference Description
+_UI_SingleReferenceDescription_valueExpression_feature = Value Expression
+_UI_SingleReferenceDescription_initialOperation_feature = Initial Operation
+_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_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
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 a55acf3f07..8f110b9f90 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
@@ -40,7 +40,7 @@ import org.eclipse.sirius.properties.PropertiesPackage;
  * @generated
  */
 public class ContainerDescriptionItemProvider extends ItemProviderAdapter implements IEditingDomainItemProvider, IStructuredItemContentProvider, ITreeItemContentProvider, IItemLabelProvider,
-IItemPropertySource {
+        IItemPropertySource {
     /**
      * This constructs an instance from a factory and a notifier. <!--
      * begin-user-doc --> <!-- end-user-doc -->
@@ -186,6 +186,10 @@ IItemPropertySource {
 
         newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.CONTAINER_DESCRIPTION__WIDGETS, PropertiesFactory.eINSTANCE.createRadioDescription()));
 
+        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.CONTAINER_DESCRIPTION__WIDGETS, PropertiesFactory.eINSTANCE.createSingleReferenceDescription()));
+
+        newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.CONTAINER_DESCRIPTION__WIDGETS, PropertiesFactory.eINSTANCE.createMultipleReferencesDescription()));
+
         newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.CONTAINER_DESCRIPTION__DYNAMIC_MAPPINGS, PropertiesFactory.eINSTANCE.createDynamicMappingFor()));
     }
 
diff --git a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/DynamicMappingForItemProvider.java b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/DynamicMappingForItemProvider.java
index 448043edba..bb6c474d5f 100644
--- a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/DynamicMappingForItemProvider.java
+++ b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/DynamicMappingForItemProvider.java
@@ -40,7 +40,7 @@ import org.eclipse.sirius.properties.PropertiesPackage;
  * @generated
  */
 public class DynamicMappingForItemProvider extends ItemProviderAdapter implements IEditingDomainItemProvider, IStructuredItemContentProvider, ITreeItemContentProvider, IItemLabelProvider,
-IItemPropertySource {
+        IItemPropertySource {
     /**
      * This constructs an instance from a factory and a notifier. <!--
      * begin-user-doc --> <!-- end-user-doc -->
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 c519ef922c..34b4b4ff97 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
@@ -40,7 +40,7 @@ import org.eclipse.sirius.properties.PropertiesPackage;
  * @generated
  */
 public class DynamicMappingIfItemProvider extends ItemProviderAdapter implements IEditingDomainItemProvider, IStructuredItemContentProvider, ITreeItemContentProvider, IItemLabelProvider,
-IItemPropertySource {
+        IItemPropertySource {
     /**
      * This constructs an instance from a factory and a notifier. <!--
      * begin-user-doc --> <!-- end-user-doc -->
@@ -183,6 +183,10 @@ IItemPropertySource {
         newChildDescriptors.add(createChildParameter(PropertiesPackage.Literals.DYNAMIC_MAPPING_IF__WIDGET, PropertiesFactory.eINSTANCE.createTextAreaDescription()));
 
         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()));
     }
 
     /**
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 20413d401e..412ea3ab72 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
@@ -40,7 +40,7 @@ import org.eclipse.sirius.properties.PropertiesPackage;
  * @generated
  */
 public class GroupDescriptionItemProvider extends ItemProviderAdapter implements IEditingDomainItemProvider, IStructuredItemContentProvider, ITreeItemContentProvider, IItemLabelProvider,
-IItemPropertySource {
+        IItemPropertySource {
     /**
      * This constructs an instance from a factory and a notifier. <!--
      * begin-user-doc --> <!-- end-user-doc -->
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
new file mode 100644
index 0000000000..61e56b6dda
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/MultipleReferencesDescriptionItemProvider.java
@@ -0,0 +1,228 @@
+/**
+ * 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/OperationDescriptionItemProvider.java b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/OperationDescriptionItemProvider.java
new file mode 100644
index 0000000000..e524b0c3fc
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/OperationDescriptionItemProvider.java
@@ -0,0 +1,167 @@
+/**
+ * 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.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.ItemProviderAdapter;
+import org.eclipse.emf.edit.provider.ViewerNotification;
+import org.eclipse.sirius.properties.OperationDescription;
+import org.eclipse.sirius.properties.PropertiesPackage;
+import org.eclipse.sirius.viewpoint.description.tool.ToolFactory;
+
+/**
+ * This is the item provider adapter for a
+ * {@link org.eclipse.sirius.properties.OperationDescription} object. <!--
+ * begin-user-doc --> <!-- end-user-doc -->
+ *
+ * @generated
+ */
+public class OperationDescriptionItemProvider 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 OperationDescriptionItemProvider(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.OPERATION_DESCRIPTION__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 OperationDescription.gif. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     * 
+     * @generated
+     */
+    @Override
+    public Object getImage(Object object) {
+        return overlayImage(object, getResourceLocator().getImage("full/obj16/OperationDescription"));
+    }
+
+    /**
+     * This returns the label text for the adapted class. <!-- begin-user-doc
+     * --> <!-- end-user-doc -->
+     * 
+     * @generated
+     */
+    @Override
+    public String getText(Object object) {
+        return getString("_UI_OperationDescription_type");
+    }
+
+    /**
+     * 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(OperationDescription.class)) {
+        case PropertiesPackage.OPERATION_DESCRIPTION__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.OPERATION_DESCRIPTION__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.edit/src-gen/org/eclipse/sirius/properties/provider/PageDescriptionItemProvider.java b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/PageDescriptionItemProvider.java
index 43066a54ab..2bed63c08f 100644
--- a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/PageDescriptionItemProvider.java
+++ b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/PageDescriptionItemProvider.java
@@ -38,7 +38,7 @@ import org.eclipse.sirius.properties.PropertiesPackage;
  * @generated
  */
 public class PageDescriptionItemProvider extends ItemProviderAdapter implements IEditingDomainItemProvider, IStructuredItemContentProvider, ITreeItemContentProvider, IItemLabelProvider,
-IItemPropertySource {
+        IItemPropertySource {
     /**
      * This constructs an instance from a factory and a notifier. <!--
      * begin-user-doc --> <!-- end-user-doc -->
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 ef14f5d176..c4473686c1 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
@@ -417,6 +417,81 @@ 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 -->
+     * 
+     * @generated
+     */
+    protected SingleReferenceDescriptionItemProvider singleReferenceDescriptionItemProvider;
+
+    /**
+     * This creates an adapter for a
+     * {@link org.eclipse.sirius.properties.SingleReferenceDescription}. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public Adapter createSingleReferenceDescriptionAdapter() {
+        if (singleReferenceDescriptionItemProvider == null) {
+            singleReferenceDescriptionItemProvider = new SingleReferenceDescriptionItemProvider(this);
+        }
+
+        return singleReferenceDescriptionItemProvider;
+    }
+
+    /**
+     * This keeps track of the one adapter used for all
+     * {@link org.eclipse.sirius.properties.OperationDescription} instances.
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @generated
+     */
+    protected OperationDescriptionItemProvider operationDescriptionItemProvider;
+
+    /**
+     * This creates an adapter for a
+     * {@link org.eclipse.sirius.properties.OperationDescription}. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    @Override
+    public Adapter createOperationDescriptionAdapter() {
+        if (operationDescriptionItemProvider == null) {
+            operationDescriptionItemProvider = new OperationDescriptionItemProvider(this);
+        }
+
+        return operationDescriptionItemProvider;
+    }
+
+    /**
+     * 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 returns the root adapter factory that contains this factory. <!--
      * begin-user-doc --> <!-- end-user-doc -->
      *
@@ -559,6 +634,15 @@ public class PropertiesItemProviderAdapterFactory extends PropertiesAdapterFacto
         if (radioDescriptionItemProvider != null) {
             radioDescriptionItemProvider.dispose();
         }
+        if (singleReferenceDescriptionItemProvider != null) {
+            singleReferenceDescriptionItemProvider.dispose();
+        }
+        if (operationDescriptionItemProvider != null) {
+            operationDescriptionItemProvider.dispose();
+        }
+        if (multipleReferencesDescriptionItemProvider != null) {
+            multipleReferencesDescriptionItemProvider.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/SingleReferenceDescriptionItemProvider.java
new file mode 100644
index 0000000000..c12b98e18d
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/SingleReferenceDescriptionItemProvider.java
@@ -0,0 +1,218 @@
+/**
+ * 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.PropertiesFactory;
+import org.eclipse.sirius.properties.PropertiesPackage;
+import org.eclipse.sirius.properties.SingleReferenceDescription;
+
+/**
+ * This is the item provider adapter for a
+ * {@link org.eclipse.sirius.properties.SingleReferenceDescription} object. <!--
+ * begin-user-doc --> <!-- end-user-doc -->
+ *
+ * @generated
+ */
+public class SingleReferenceDescriptionItemProvider extends WidgetDescriptionItemProvider {
+    /**
+     * This constructs an instance from a factory and a notifier. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     */
+    public SingleReferenceDescriptionItemProvider(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_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));
+    }
+
+    /**
+     * 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_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));
+    }
+
+    /**
+     * 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.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);
+        }
+        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 SingleReferenceDescription.gif. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     * 
+     * @generated
+     */
+    @Override
+    public Object getImage(Object object) {
+        return overlayImage(object, getResourceLocator().getImage("full/obj16/SingleReferenceDescription"));
+    }
+
+    /**
+     * This returns the label text for the adapted class. <!-- begin-user-doc
+     * --> <!-- end-user-doc -->
+     * 
+     * @generated
+     */
+    @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;
+    }
+
+    /**
+     * 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(SingleReferenceDescription.class)) {
+        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION__VALUE_EXPRESSION:
+        case PropertiesPackage.SINGLE_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:
+            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.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.SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION, PropertiesFactory.eINSTANCE.createOperationDescription()));
+
+        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;
+
+        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);
+    }
+
+}
diff --git a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/ViewExtensionDescriptionItemProvider.java b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/ViewExtensionDescriptionItemProvider.java
index 5ed6d98716..c403ba13ad 100644
--- a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/ViewExtensionDescriptionItemProvider.java
+++ b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/ViewExtensionDescriptionItemProvider.java
@@ -40,7 +40,7 @@ import org.eclipse.sirius.properties.ViewExtensionDescription;
  * @generated
  */
 public class ViewExtensionDescriptionItemProvider extends ItemProviderAdapter implements IEditingDomainItemProvider, IStructuredItemContentProvider, ITreeItemContentProvider, IItemLabelProvider,
-IItemPropertySource {
+        IItemPropertySource {
     /**
      * This constructs an instance from a factory and a notifier. <!--
      * begin-user-doc --> <!-- end-user-doc -->
diff --git a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/WidgetDescriptionItemProvider.java b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/WidgetDescriptionItemProvider.java
index b524e18a36..e8d845b7b1 100644
--- a/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/WidgetDescriptionItemProvider.java
+++ b/incubation/org.eclipse.sirius.properties.edit/src-gen/org/eclipse/sirius/properties/provider/WidgetDescriptionItemProvider.java
@@ -38,7 +38,7 @@ import org.eclipse.sirius.properties.WidgetDescription;
  * @generated
  */
 public class WidgetDescriptionItemProvider extends ItemProviderAdapter implements IEditingDomainItemProvider, IStructuredItemContentProvider, ITreeItemContentProvider, IItemLabelProvider,
-IItemPropertySource {
+        IItemPropertySource {
     /**
      * This constructs an instance from a factory and a notifier. <!--
      * begin-user-doc --> <!-- end-user-doc -->
diff --git a/incubation/org.eclipse.sirius.properties/model/properties.ecore b/incubation/org.eclipse.sirius.properties/model/properties.ecore
index 2f00062e36..8bd5b0e02f 100644
--- a/incubation/org.eclipse.sirius.properties/model/properties.ecore
+++ b/incubation/org.eclipse.sirius.properties/model/properties.ecore
@@ -147,4 +147,75 @@
       </eAnnotations>
     </eStructuralFeatures>
   </eClassifiers>
+  <eClassifiers xsi:type="ecore:EClass" name="SingleReferenceDescription" eSuperTypes="#//WidgetDescription">
+    <eAnnotations source="http://www.eclipse.org/emf/2002/GenModel">
+      <details key="documentation" value="Represents a single reference 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 value."/>
+      </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="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"
+        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>
+  </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>
 </ecore:EPackage>
diff --git a/incubation/org.eclipse.sirius.properties/model/properties.genmodel b/incubation/org.eclipse.sirius.properties/model/properties.genmodel
index 90e11f6246..ebbb7dcf66 100644
--- a/incubation/org.eclipse.sirius.properties/model/properties.genmodel
+++ b/incubation/org.eclipse.sirius.properties/model/properties.genmodel
@@ -43,6 +43,7 @@
     <genClasses image="false" ecoreClass="properties.ecore#//WidgetDescription">
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//WidgetDescription/identifier"/>
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//WidgetDescription/labelExpression"/>
+      <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//WidgetDescription/helpExpression"/>
     </genClasses>
     <genClasses ecoreClass="properties.ecore#//TextDescription">
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//TextDescription/valueExpression"/>
@@ -83,5 +84,26 @@
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//RadioDescription/candidatesExpression"/>
       <genFeatures createChild="false" ecoreFeature="ecore:EAttribute properties.ecore#//RadioDescription/candidateDisplayExpression"/>
     </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>
+    <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>
   </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
new file mode 100644
index 0000000000..27cb9bd7bc
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/MultipleReferencesDescription.java
@@ -0,0 +1,300 @@
+/**
+ * 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:
+ * <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>
+ * </p>
+ *
+ * @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 selected values of the radio. <!-- 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/OperationDescription.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/OperationDescription.java
new file mode 100644
index 0000000000..4d8631d787
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/OperationDescription.java
@@ -0,0 +1,67 @@
+/**
+ * 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>Operation Description</b></em>'. <!-- end-user-doc -->
+ *
+ * <p>
+ * The following features are supported:
+ * <ul>
+ * <li>
+ * {@link org.eclipse.sirius.properties.OperationDescription#getInitialOperation
+ * <em>Initial Operation</em>}</li>
+ * </ul>
+ * </p>
+ *
+ * @see org.eclipse.sirius.properties.PropertiesPackage#getOperationDescription()
+ * @model
+ * @generated
+ */
+public interface OperationDescription extends EObject {
+    /**
+     * Returns the value of the '<em><b>Initial Operation</b></em>' containment
+     * reference. <!-- begin-user-doc -->
+     * <p>
+     * If the meaning of the '<em>Initial 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>Initial Operation</em>' containment
+     *         reference.
+     * @see #setInitialOperation(InitialOperation)
+     * @see org.eclipse.sirius.properties.PropertiesPackage#getOperationDescription_InitialOperation()
+     * @model containment="true" required="true"
+     * @generated
+     */
+    InitialOperation getInitialOperation();
+
+    /**
+     * Sets the value of the '
+     * {@link org.eclipse.sirius.properties.OperationDescription#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);
+
+} // OperationDescription
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 71a7874abc..c2068c9fe5 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
@@ -147,6 +147,33 @@ public interface PropertiesFactory extends EFactory {
     RadioDescription createRadioDescription();
 
     /**
+     * Returns a new object of class '<em>Single Reference Description</em>'.
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @return a new object of class '<em>Single Reference Description</em>'.
+     * @generated
+     */
+    SingleReferenceDescription createSingleReferenceDescription();
+
+    /**
+     * Returns a new object of class '<em>Operation Description</em>'. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @return a new object of class '<em>Operation Description</em>'.
+     * @generated
+     */
+    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 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 7b89eb695b..338528b199 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
@@ -27,7 +27,7 @@ import org.eclipse.sirius.viewpoint.description.DescriptionPackage;
  * <li>and each data type</li>
  * </ul>
  * <!-- end-user-doc -->
- *
+ * 
  * @see org.eclipse.sirius.properties.PropertiesFactory
  * @model kind="package"
  * @generated
@@ -35,21 +35,21 @@ import org.eclipse.sirius.viewpoint.description.DescriptionPackage;
 public interface PropertiesPackage extends EPackage {
     /**
      * The package name. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     String eNAME = "properties";
 
     /**
      * The package namespace URI. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     String eNS_URI = "http://www.eclipse.org/sirius/properties/1.0.0";
 
     /**
      * The package namespace name. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     String eNS_PREFIX = "properties";
@@ -57,7 +57,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The singleton instance of the package. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @generated
      */
     PropertiesPackage eINSTANCE = org.eclipse.sirius.properties.impl.PropertiesPackageImpl.init();
@@ -67,7 +67,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.impl.ViewExtensionDescriptionImpl
      * <em>View Extension Description</em>}' class. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see org.eclipse.sirius.properties.impl.ViewExtensionDescriptionImpl
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getViewExtensionDescription()
      * @generated
@@ -95,7 +95,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Pages</b></em>' containment reference
      * list. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -122,7 +122,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Groups</b></em>' containment reference
      * list. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -132,7 +132,7 @@ public interface PropertiesPackage extends EPackage {
      * The number of structural features of the '
      * <em>View Extension Description</em>' class. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -143,7 +143,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.impl.PageDescriptionImpl
      * <em>Page Description</em>}' class. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see org.eclipse.sirius.properties.impl.PageDescriptionImpl
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getPageDescription()
      * @generated
@@ -180,7 +180,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Semantic Candidate Expression</b></em>'
      * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -198,7 +198,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The number of structural features of the '<em>Page Description</em>'
      * class. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -209,7 +209,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.impl.GroupDescriptionImpl
      * <em>Group Description</em>}' class. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see org.eclipse.sirius.properties.impl.GroupDescriptionImpl
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getGroupDescription()
      * @generated
@@ -246,7 +246,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Semantic Candidate Expression</b></em>'
      * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -255,7 +255,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Container</b></em>' containment reference.
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -264,7 +264,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The number of structural features of the '<em>Group Description</em>'
      * class. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -275,7 +275,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.impl.ContainerDescriptionImpl
      * <em>Container Description</em>}' class. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see org.eclipse.sirius.properties.impl.ContainerDescriptionImpl
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getContainerDescription()
      * @generated
@@ -294,7 +294,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Widgets</b></em>' containment reference
      * list. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -303,7 +303,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Dynamic Mappings</b></em>' containment
      * reference list. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -312,7 +312,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The number of structural features of the '<em>Container Description</em>'
      * class. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -323,7 +323,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.impl.WidgetDescriptionImpl
      * <em>Widget Description</em>}' class. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see org.eclipse.sirius.properties.impl.WidgetDescriptionImpl
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getWidgetDescription()
      * @generated
@@ -360,7 +360,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The number of structural features of the '<em>Widget Description</em>'
      * class. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -371,7 +371,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.impl.TextDescriptionImpl
      * <em>Text Description</em>}' class. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see org.eclipse.sirius.properties.impl.TextDescriptionImpl
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getTextDescription()
      * @generated
@@ -417,7 +417,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Initial Operation</b></em>' containment
      * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -426,7 +426,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The number of structural features of the '<em>Text Description</em>'
      * class. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -437,7 +437,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.impl.ButtonDescriptionImpl
      * <em>Button Description</em>}' class. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see org.eclipse.sirius.properties.impl.ButtonDescriptionImpl
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getButtonDescription()
      * @generated
@@ -474,7 +474,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Button Label Expression</b></em>'
      * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -483,7 +483,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Initial Operation</b></em>' containment
      * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -492,7 +492,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The number of structural features of the '<em>Button Description</em>'
      * class. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -503,7 +503,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.impl.LabelDescriptionImpl
      * <em>Label Description</em>}' class. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see org.eclipse.sirius.properties.impl.LabelDescriptionImpl
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getLabelDescription()
      * @generated
@@ -549,7 +549,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The number of structural features of the '<em>Label Description</em>'
      * class. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -560,7 +560,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.impl.CheckboxDescriptionImpl
      * <em>Checkbox Description</em>}' class. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see org.eclipse.sirius.properties.impl.CheckboxDescriptionImpl
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getCheckboxDescription()
      * @generated
@@ -606,7 +606,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Initial Operation</b></em>' containment
      * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -615,7 +615,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The number of structural features of the '<em>Checkbox Description</em>'
      * class. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -626,7 +626,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.impl.SelectDescriptionImpl
      * <em>Select Description</em>}' class. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see org.eclipse.sirius.properties.impl.SelectDescriptionImpl
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getSelectDescription()
      * @generated
@@ -672,7 +672,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Initial Operation</b></em>' containment
      * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -681,7 +681,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Candidates Expression</b></em>' attribute.
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -690,7 +690,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Candidate Display Expression</b></em>'
      * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -699,7 +699,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The number of structural features of the '<em>Select Description</em>'
      * class. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -710,7 +710,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.impl.DynamicMappingForImpl
      * <em>Dynamic Mapping For</em>}' class. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see org.eclipse.sirius.properties.impl.DynamicMappingForImpl
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getDynamicMappingFor()
      * @generated
@@ -729,7 +729,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Domain Class Expression</b></em>'
      * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -738,7 +738,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Ifs</b></em>' containment reference list.
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -747,7 +747,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The number of structural features of the '<em>Dynamic Mapping For</em>'
      * class. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -758,7 +758,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.impl.DynamicMappingIfImpl
      * <em>Dynamic Mapping If</em>}' class. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see org.eclipse.sirius.properties.impl.DynamicMappingIfImpl
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getDynamicMappingIf()
      * @generated
@@ -768,7 +768,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Predicate Expression</b></em>' attribute.
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -777,7 +777,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Widget</b></em>' containment reference.
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -786,7 +786,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The number of structural features of the '<em>Dynamic Mapping If</em>'
      * class. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -797,7 +797,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.impl.TextAreaDescriptionImpl
      * <em>Text Area Description</em>}' class. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see org.eclipse.sirius.properties.impl.TextAreaDescriptionImpl
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getTextAreaDescription()
      * @generated
@@ -843,7 +843,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Initial Operation</b></em>' containment
      * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -861,7 +861,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The number of structural features of the '<em>Text Area Description</em>'
      * class. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -872,7 +872,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.impl.RadioDescriptionImpl
      * <em>Radio Description</em>}' class. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see org.eclipse.sirius.properties.impl.RadioDescriptionImpl
      * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getRadioDescription()
      * @generated
@@ -918,7 +918,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Initial Operation</b></em>' containment
      * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -927,7 +927,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Candidates Expression</b></em>' attribute.
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -936,7 +936,7 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The feature id for the '<em><b>Candidate Display Expression</b></em>'
      * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
@@ -945,13 +945,267 @@ public interface PropertiesPackage extends EPackage {
     /**
      * The number of structural features of the '<em>Radio Description</em>'
      * class. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      * @ordered
      */
     int RADIO_DESCRIPTION_FEATURE_COUNT = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 4;
 
     /**
+     * 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 -->
+     * 
+     * @see org.eclipse.sirius.properties.impl.SingleReferenceDescriptionImpl
+     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getSingleReferenceDescription()
+     * @generated
+     */
+    int SINGLE_REFERENCE_DESCRIPTION = 14;
+
+    /**
+     * The feature id for the '<em><b>Identifier</b></em>' attribute. <!--
+     * begin-user-doc --> <!-- end-user-doc -->
+     *
+     * @generated
+     * @ordered
+     */
+    int SINGLE_REFERENCE_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 SINGLE_REFERENCE_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 SINGLE_REFERENCE_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 SINGLE_REFERENCE_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 SINGLE_REFERENCE_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 SINGLE_REFERENCE_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 SINGLE_REFERENCE_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 SINGLE_REFERENCE_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 SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 5;
+
+    /**
+     * The number of structural features of the '
+     * <em>Single Reference Description</em>' class. <!-- begin-user-doc -->
+     * <!-- end-user-doc -->
+     * 
+     * @generated
+     * @ordered
+     */
+    int SINGLE_REFERENCE_DESCRIPTION_FEATURE_COUNT = PropertiesPackage.WIDGET_DESCRIPTION_FEATURE_COUNT + 6;
+
+    /**
+     * The meta object id for the '
+     * {@link org.eclipse.sirius.properties.impl.OperationDescriptionImpl
+     * <em>Operation Description</em>}' class. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     * 
+     * @see org.eclipse.sirius.properties.impl.OperationDescriptionImpl
+     * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getOperationDescription()
+     * @generated
+     */
+    int OPERATION_DESCRIPTION = 15;
+
+    /**
+     * The feature id for the '<em><b>Initial Operation</b></em>' containment
+     * reference. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @generated
+     * @ordered
+     */
+    int OPERATION_DESCRIPTION__INITIAL_OPERATION = 0;
+
+    /**
+     * The number of structural features of the '<em>Operation Description</em>'
+     * class. <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @generated
+     * @ordered
+     */
+    int OPERATION_DESCRIPTION_FEATURE_COUNT = 1;
+
+    /**
+     * 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 = 16;
+
+    /**
+     * 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;
+
+    /**
      * @return the meta object for class '<em>View Extension Description</em>'.
      * @see org.eclipse.sirius.properties.ViewExtensionDescription
      * @generated
@@ -962,7 +1216,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the attribute '
      * {@link org.eclipse.sirius.properties.ViewExtensionDescription#getIdentifier
      * <em>Identifier</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '<em>Identifier</em>'.
      * @see org.eclipse.sirius.properties.ViewExtensionDescription#getIdentifier()
      * @see #getViewExtensionDescription()
@@ -974,7 +1228,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the reference list '
      * {@link org.eclipse.sirius.properties.ViewExtensionDescription#getMetamodels
      * <em>Metamodels</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the reference list '<em>Metamodels</em>'.
      * @see org.eclipse.sirius.properties.ViewExtensionDescription#getMetamodels()
      * @see #getViewExtensionDescription()
@@ -986,7 +1240,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the containment reference list '
      * {@link org.eclipse.sirius.properties.ViewExtensionDescription#getPages
      * <em>Pages</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the containment reference list '
      *         <em>Pages</em>'.
      * @see org.eclipse.sirius.properties.ViewExtensionDescription#getPages()
@@ -999,7 +1253,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the reference '
      * {@link org.eclipse.sirius.properties.ViewExtensionDescription#getDefaultPage
      * <em>Default Page</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the reference '<em>Default Page</em>'.
      * @see org.eclipse.sirius.properties.ViewExtensionDescription#getDefaultPage()
      * @see #getViewExtensionDescription()
@@ -1024,7 +1278,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the containment reference list '
      * {@link org.eclipse.sirius.properties.ViewExtensionDescription#getGroups
      * <em>Groups</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the containment reference list '
      *         <em>Groups</em>'.
      * @see org.eclipse.sirius.properties.ViewExtensionDescription#getGroups()
@@ -1049,7 +1303,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the attribute '
      * {@link org.eclipse.sirius.properties.PageDescription#getIdentifier
      * <em>Identifier</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '<em>Identifier</em>'.
      * @see org.eclipse.sirius.properties.PageDescription#getIdentifier()
      * @see #getPageDescription()
@@ -1074,7 +1328,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the attribute '
      * {@link org.eclipse.sirius.properties.PageDescription#getDomainClass
      * <em>Domain Class</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '<em>Domain Class</em>'.
      * @see org.eclipse.sirius.properties.PageDescription#getDomainClass()
      * @see #getPageDescription()
@@ -1087,7 +1341,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.PageDescription#getSemanticCandidateExpression
      * <em>Semantic Candidate Expression</em>}'. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '
      *         <em>Semantic Candidate Expression</em>'.
      * @see org.eclipse.sirius.properties.PageDescription#getSemanticCandidateExpression()
@@ -1100,7 +1354,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the reference list '
      * {@link org.eclipse.sirius.properties.PageDescription#getGroups
      * <em>Groups</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the reference list '<em>Groups</em>'.
      * @see org.eclipse.sirius.properties.PageDescription#getGroups()
      * @see #getPageDescription()
@@ -1124,7 +1378,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the attribute '
      * {@link org.eclipse.sirius.properties.GroupDescription#getIdentifier
      * <em>Identifier</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '<em>Identifier</em>'.
      * @see org.eclipse.sirius.properties.GroupDescription#getIdentifier()
      * @see #getGroupDescription()
@@ -1149,7 +1403,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the attribute '
      * {@link org.eclipse.sirius.properties.GroupDescription#getDomainClass
      * <em>Domain Class</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '<em>Domain Class</em>'.
      * @see org.eclipse.sirius.properties.GroupDescription#getDomainClass()
      * @see #getGroupDescription()
@@ -1162,7 +1416,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.GroupDescription#getSemanticCandidateExpression
      * <em>Semantic Candidate Expression</em>}'. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '
      *         <em>Semantic Candidate Expression</em>'.
      * @see org.eclipse.sirius.properties.GroupDescription#getSemanticCandidateExpression()
@@ -1175,7 +1429,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the containment reference '
      * {@link org.eclipse.sirius.properties.GroupDescription#getContainer
      * <em>Container</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the containment reference '<em>Container</em>
      *         '.
      * @see org.eclipse.sirius.properties.GroupDescription#getContainer()
@@ -1189,7 +1443,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.ContainerDescription
      * <em>Container Description</em>}'. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @return the meta object for class '<em>Container Description</em>'.
      * @see org.eclipse.sirius.properties.ContainerDescription
      * @generated
@@ -1200,7 +1454,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the attribute '
      * {@link org.eclipse.sirius.properties.ContainerDescription#getIdentifier
      * <em>Identifier</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '<em>Identifier</em>'.
      * @see org.eclipse.sirius.properties.ContainerDescription#getIdentifier()
      * @see #getContainerDescription()
@@ -1212,7 +1466,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the containment reference list '
      * {@link org.eclipse.sirius.properties.ContainerDescription#getWidgets
      * <em>Widgets</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the containment reference list '
      *         <em>Widgets</em>'.
      * @see org.eclipse.sirius.properties.ContainerDescription#getWidgets()
@@ -1251,7 +1505,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the attribute '
      * {@link org.eclipse.sirius.properties.WidgetDescription#getIdentifier
      * <em>Identifier</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '<em>Identifier</em>'.
      * @see org.eclipse.sirius.properties.WidgetDescription#getIdentifier()
      * @see #getWidgetDescription()
@@ -1276,7 +1530,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the attribute '
      * {@link org.eclipse.sirius.properties.WidgetDescription#getHelpExpression
      * <em>Help Expression</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '<em>Help Expression</em>'.
      * @see org.eclipse.sirius.properties.WidgetDescription#getHelpExpression()
      * @see #getWidgetDescription()
@@ -1340,7 +1594,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.ButtonDescription#getButtonLabelExpression
      * <em>Button Label Expression</em>}'. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '
      *         <em>Button Label Expression</em>'.
      * @see org.eclipse.sirius.properties.ButtonDescription#getButtonLabelExpression()
@@ -1379,7 +1633,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the attribute '
      * {@link org.eclipse.sirius.properties.LabelDescription#getBodyExpression
      * <em>Body Expression</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '<em>Body Expression</em>'.
      * @see org.eclipse.sirius.properties.LabelDescription#getBodyExpression()
      * @see #getLabelDescription()
@@ -1392,7 +1646,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.CheckboxDescription
      * <em>Checkbox Description</em>}'. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @return the meta object for class '<em>Checkbox Description</em>'.
      * @see org.eclipse.sirius.properties.CheckboxDescription
      * @generated
@@ -1470,7 +1724,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.SelectDescription#getCandidatesExpression
      * <em>Candidates Expression</em>}'. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '<em>Candidates Expression</em>
      *         '.
      * @see org.eclipse.sirius.properties.SelectDescription#getCandidatesExpression()
@@ -1484,7 +1738,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.SelectDescription#getCandidateDisplayExpression
      * <em>Candidate Display Expression</em>}'. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '
      *         <em>Candidate Display Expression</em>'.
      * @see org.eclipse.sirius.properties.SelectDescription#getCandidateDisplayExpression()
@@ -1509,7 +1763,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the attribute '
      * {@link org.eclipse.sirius.properties.DynamicMappingFor#getIterator
      * <em>Iterator</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '<em>Iterator</em>'.
      * @see org.eclipse.sirius.properties.DynamicMappingFor#getIterator()
      * @see #getDynamicMappingFor()
@@ -1522,7 +1776,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.DynamicMappingFor#getDomainClassExpression
      * <em>Domain Class Expression</em>}'. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '
      *         <em>Domain Class Expression</em>'.
      * @see org.eclipse.sirius.properties.DynamicMappingFor#getDomainClassExpression()
@@ -1535,7 +1789,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the containment reference list '
      * {@link org.eclipse.sirius.properties.DynamicMappingFor#getIfs
      * <em>Ifs</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the containment reference list '<em>Ifs</em>
      *         '.
      * @see org.eclipse.sirius.properties.DynamicMappingFor#getIfs()
@@ -1561,7 +1815,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.DynamicMappingIf#getPredicateExpression
      * <em>Predicate Expression</em>}'. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '<em>Predicate Expression</em>
      *         '.
      * @see org.eclipse.sirius.properties.DynamicMappingIf#getPredicateExpression()
@@ -1574,7 +1828,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the containment reference '
      * {@link org.eclipse.sirius.properties.DynamicMappingIf#getWidget
      * <em>Widget</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the containment reference '<em>Widget</em>'.
      * @see org.eclipse.sirius.properties.DynamicMappingIf#getWidget()
      * @see #getDynamicMappingIf()
@@ -1587,7 +1841,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.TextAreaDescription
      * <em>Text Area Description</em>}'. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @return the meta object for class '<em>Text Area Description</em>'.
      * @see org.eclipse.sirius.properties.TextAreaDescription
      * @generated
@@ -1598,7 +1852,7 @@ public interface PropertiesPackage extends EPackage {
      * Returns the meta object for the attribute '
      * {@link org.eclipse.sirius.properties.TextAreaDescription#getLineCount
      * <em>Line Count</em>}'. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '<em>Line Count</em>'.
      * @see org.eclipse.sirius.properties.TextAreaDescription#getLineCount()
      * @see #getTextAreaDescription()
@@ -1650,7 +1904,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.RadioDescription#getCandidatesExpression
      * <em>Candidates Expression</em>}'. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '<em>Candidates Expression</em>
      *         '.
      * @see org.eclipse.sirius.properties.RadioDescription#getCandidatesExpression()
@@ -1664,7 +1918,7 @@ public interface PropertiesPackage extends EPackage {
      * {@link org.eclipse.sirius.properties.RadioDescription#getCandidateDisplayExpression
      * <em>Candidate Display Expression</em>}'. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @return the meta object for the attribute '
      *         <em>Candidate Display Expression</em>'.
      * @see org.eclipse.sirius.properties.RadioDescription#getCandidateDisplayExpression()
@@ -1674,6 +1928,246 @@ public interface PropertiesPackage extends EPackage {
     EAttribute getRadioDescription_CandidateDisplayExpression();
 
     /**
+     * Returns the meta object for class '
+     * {@link org.eclipse.sirius.properties.SingleReferenceDescription
+     * <em>Single 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
+     * @generated
+     */
+    EClass getSingleReferenceDescription();
+
+    /**
+     * Returns the meta object for the attribute '
+     * {@link org.eclipse.sirius.properties.SingleReferenceDescription#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()
+     * @generated
+     */
+    EAttribute getSingleReferenceDescription_ValueExpression();
+
+    /**
+     * Returns the meta object for the attribute '
+     * {@link org.eclipse.sirius.properties.SingleReferenceDescription#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()
+     * @generated
+     */
+    EAttribute getSingleReferenceDescription_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
+     * -->
+     *
+     * @return the meta object for the containment reference '
+     *         <em>Create Operation</em>'.
+     * @see org.eclipse.sirius.properties.SingleReferenceDescription#getCreateOperation()
+     * @see #getSingleReferenceDescription()
+     * @generated
+     */
+    EReference getSingleReferenceDescription_CreateOperation();
+
+    /**
+     * 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
+     * -->
+     *
+     * @return the meta object for the containment reference '
+     *         <em>Search Operation</em>'.
+     * @see org.eclipse.sirius.properties.SingleReferenceDescription#getSearchOperation()
+     * @see #getSingleReferenceDescription()
+     * @generated
+     */
+    EReference getSingleReferenceDescription_SearchOperation();
+
+    /**
+     * 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 -->
+     * 
+     * @return the meta object for the containment reference '
+     *         <em>Unset Operation</em>'.
+     * @see org.eclipse.sirius.properties.SingleReferenceDescription#getUnsetOperation()
+     * @see #getSingleReferenceDescription()
+     * @generated
+     */
+    EReference getSingleReferenceDescription_UnsetOperation();
+
+    /**
+     * 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
+     * -->
+     *
+     * @return the meta object for the containment reference '
+     *         <em>On Click Operation</em>'.
+     * @see org.eclipse.sirius.properties.SingleReferenceDescription#getOnClickOperation()
+     * @see #getSingleReferenceDescription()
+     * @generated
+     */
+    EReference getSingleReferenceDescription_OnClickOperation();
+
+    /**
+     * Returns the meta object for class '
+     * {@link org.eclipse.sirius.properties.OperationDescription
+     * <em>Operation Description</em>}'. <!-- begin-user-doc --> <!--
+     * end-user-doc -->
+     * 
+     * @return the meta object for class '<em>Operation Description</em>'.
+     * @see org.eclipse.sirius.properties.OperationDescription
+     * @generated
+     */
+    EClass getOperationDescription();
+
+    /**
+     * Returns the meta object for the containment reference '
+     * {@link org.eclipse.sirius.properties.OperationDescription#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.OperationDescription#getInitialOperation()
+     * @see #getOperationDescription()
+     * @generated
+     */
+    EReference getOperationDescription_InitialOperation();
+
+    /**
+     * 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();
+
+    /**
      * @return the factory that creates the instances of the model.
      * @generated
      */
@@ -1689,7 +2183,7 @@ public interface PropertiesPackage extends EPackage {
      * <li>and each data type</li>
      * </ul>
      * <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     interface Literals {
@@ -1698,7 +2192,7 @@ public interface PropertiesPackage extends EPackage {
          * {@link org.eclipse.sirius.properties.impl.ViewExtensionDescriptionImpl
          * <em>View Extension Description</em>}' class. <!-- begin-user-doc -->
          * <!-- end-user-doc -->
-         *
+         * 
          * @see org.eclipse.sirius.properties.impl.ViewExtensionDescriptionImpl
          * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getViewExtensionDescription()
          * @generated
@@ -1708,7 +2202,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Identifier</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute VIEW_EXTENSION_DESCRIPTION__IDENTIFIER = PropertiesPackage.eINSTANCE.getViewExtensionDescription_Identifier();
@@ -1716,7 +2210,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Metamodels</b></em>'
          * reference list feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EReference VIEW_EXTENSION_DESCRIPTION__METAMODELS = PropertiesPackage.eINSTANCE.getViewExtensionDescription_Metamodels();
@@ -1724,7 +2218,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Pages</b></em>' containment
          * reference list feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EReference VIEW_EXTENSION_DESCRIPTION__PAGES = PropertiesPackage.eINSTANCE.getViewExtensionDescription_Pages();
@@ -1732,7 +2226,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Default Page</b></em>'
          * reference feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EReference VIEW_EXTENSION_DESCRIPTION__DEFAULT_PAGE = PropertiesPackage.eINSTANCE.getViewExtensionDescription_DefaultPage();
@@ -1740,7 +2234,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Label Expression</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute VIEW_EXTENSION_DESCRIPTION__LABEL_EXPRESSION = PropertiesPackage.eINSTANCE.getViewExtensionDescription_LabelExpression();
@@ -1748,7 +2242,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Groups</b></em>' containment
          * reference list feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EReference VIEW_EXTENSION_DESCRIPTION__GROUPS = PropertiesPackage.eINSTANCE.getViewExtensionDescription_Groups();
@@ -1758,7 +2252,7 @@ public interface PropertiesPackage extends EPackage {
          * {@link org.eclipse.sirius.properties.impl.PageDescriptionImpl
          * <em>Page Description</em>}' class. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @see org.eclipse.sirius.properties.impl.PageDescriptionImpl
          * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getPageDescription()
          * @generated
@@ -1768,7 +2262,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Identifier</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute PAGE_DESCRIPTION__IDENTIFIER = PropertiesPackage.eINSTANCE.getPageDescription_Identifier();
@@ -1776,7 +2270,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Label Expression</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute PAGE_DESCRIPTION__LABEL_EXPRESSION = PropertiesPackage.eINSTANCE.getPageDescription_LabelExpression();
@@ -1784,7 +2278,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Domain Class</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute PAGE_DESCRIPTION__DOMAIN_CLASS = PropertiesPackage.eINSTANCE.getPageDescription_DomainClass();
@@ -1793,7 +2287,7 @@ public interface PropertiesPackage extends EPackage {
          * The meta object literal for the '
          * <em><b>Semantic Candidate Expression</b></em>' attribute feature.
          * <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute PAGE_DESCRIPTION__SEMANTIC_CANDIDATE_EXPRESSION = PropertiesPackage.eINSTANCE.getPageDescription_SemanticCandidateExpression();
@@ -1801,7 +2295,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Groups</b></em>' reference
          * list feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EReference PAGE_DESCRIPTION__GROUPS = PropertiesPackage.eINSTANCE.getPageDescription_Groups();
@@ -1811,7 +2305,7 @@ public interface PropertiesPackage extends EPackage {
          * {@link org.eclipse.sirius.properties.impl.GroupDescriptionImpl
          * <em>Group Description</em>}' class. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @see org.eclipse.sirius.properties.impl.GroupDescriptionImpl
          * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getGroupDescription()
          * @generated
@@ -1821,7 +2315,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Identifier</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute GROUP_DESCRIPTION__IDENTIFIER = PropertiesPackage.eINSTANCE.getGroupDescription_Identifier();
@@ -1829,7 +2323,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Label Expression</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute GROUP_DESCRIPTION__LABEL_EXPRESSION = PropertiesPackage.eINSTANCE.getGroupDescription_LabelExpression();
@@ -1837,7 +2331,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Domain Class</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute GROUP_DESCRIPTION__DOMAIN_CLASS = PropertiesPackage.eINSTANCE.getGroupDescription_DomainClass();
@@ -1846,7 +2340,7 @@ public interface PropertiesPackage extends EPackage {
          * The meta object literal for the '
          * <em><b>Semantic Candidate Expression</b></em>' attribute feature.
          * <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute GROUP_DESCRIPTION__SEMANTIC_CANDIDATE_EXPRESSION = PropertiesPackage.eINSTANCE.getGroupDescription_SemanticCandidateExpression();
@@ -1855,7 +2349,7 @@ public interface PropertiesPackage extends EPackage {
          * The meta object literal for the '<em><b>Container</b></em>'
          * containment reference feature. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @generated
          */
         EReference GROUP_DESCRIPTION__CONTAINER = PropertiesPackage.eINSTANCE.getGroupDescription_Container();
@@ -1865,7 +2359,7 @@ public interface PropertiesPackage extends EPackage {
          * {@link org.eclipse.sirius.properties.impl.ContainerDescriptionImpl
          * <em>Container Description</em>}' class. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @see org.eclipse.sirius.properties.impl.ContainerDescriptionImpl
          * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getContainerDescription()
          * @generated
@@ -1875,7 +2369,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Identifier</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute CONTAINER_DESCRIPTION__IDENTIFIER = PropertiesPackage.eINSTANCE.getContainerDescription_Identifier();
@@ -1883,7 +2377,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Widgets</b></em>' containment
          * reference list feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EReference CONTAINER_DESCRIPTION__WIDGETS = PropertiesPackage.eINSTANCE.getContainerDescription_Widgets();
@@ -1892,7 +2386,7 @@ public interface PropertiesPackage extends EPackage {
          * The meta object literal for the '<em><b>Dynamic Mappings</b></em>'
          * containment reference list feature. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @generated
          */
         EReference CONTAINER_DESCRIPTION__DYNAMIC_MAPPINGS = PropertiesPackage.eINSTANCE.getContainerDescription_DynamicMappings();
@@ -1902,7 +2396,7 @@ public interface PropertiesPackage extends EPackage {
          * {@link org.eclipse.sirius.properties.impl.WidgetDescriptionImpl
          * <em>Widget Description</em>}' class. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @see org.eclipse.sirius.properties.impl.WidgetDescriptionImpl
          * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getWidgetDescription()
          * @generated
@@ -1912,7 +2406,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Identifier</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute WIDGET_DESCRIPTION__IDENTIFIER = PropertiesPackage.eINSTANCE.getWidgetDescription_Identifier();
@@ -1920,7 +2414,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Label Expression</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute WIDGET_DESCRIPTION__LABEL_EXPRESSION = PropertiesPackage.eINSTANCE.getWidgetDescription_LabelExpression();
@@ -1928,7 +2422,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Help Expression</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute WIDGET_DESCRIPTION__HELP_EXPRESSION = PropertiesPackage.eINSTANCE.getWidgetDescription_HelpExpression();
@@ -1938,7 +2432,7 @@ public interface PropertiesPackage extends EPackage {
          * {@link org.eclipse.sirius.properties.impl.TextDescriptionImpl
          * <em>Text Description</em>}' class. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @see org.eclipse.sirius.properties.impl.TextDescriptionImpl
          * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getTextDescription()
          * @generated
@@ -1948,7 +2442,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Value Expression</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute TEXT_DESCRIPTION__VALUE_EXPRESSION = PropertiesPackage.eINSTANCE.getTextDescription_ValueExpression();
@@ -1957,7 +2451,7 @@ public interface PropertiesPackage extends EPackage {
          * The meta object literal for the '<em><b>Initial Operation</b></em>'
          * containment reference feature. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @generated
          */
         EReference TEXT_DESCRIPTION__INITIAL_OPERATION = PropertiesPackage.eINSTANCE.getTextDescription_InitialOperation();
@@ -1967,7 +2461,7 @@ public interface PropertiesPackage extends EPackage {
          * {@link org.eclipse.sirius.properties.impl.ButtonDescriptionImpl
          * <em>Button Description</em>}' class. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @see org.eclipse.sirius.properties.impl.ButtonDescriptionImpl
          * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getButtonDescription()
          * @generated
@@ -1987,7 +2481,7 @@ public interface PropertiesPackage extends EPackage {
          * The meta object literal for the '<em><b>Initial Operation</b></em>'
          * containment reference feature. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @generated
          */
         EReference BUTTON_DESCRIPTION__INITIAL_OPERATION = PropertiesPackage.eINSTANCE.getButtonDescription_InitialOperation();
@@ -1997,7 +2491,7 @@ public interface PropertiesPackage extends EPackage {
          * {@link org.eclipse.sirius.properties.impl.LabelDescriptionImpl
          * <em>Label Description</em>}' class. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @see org.eclipse.sirius.properties.impl.LabelDescriptionImpl
          * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getLabelDescription()
          * @generated
@@ -2007,7 +2501,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Body Expression</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute LABEL_DESCRIPTION__BODY_EXPRESSION = PropertiesPackage.eINSTANCE.getLabelDescription_BodyExpression();
@@ -2017,7 +2511,7 @@ public interface PropertiesPackage extends EPackage {
          * {@link org.eclipse.sirius.properties.impl.CheckboxDescriptionImpl
          * <em>Checkbox Description</em>}' class. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @see org.eclipse.sirius.properties.impl.CheckboxDescriptionImpl
          * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getCheckboxDescription()
          * @generated
@@ -2027,7 +2521,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Value Expression</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute CHECKBOX_DESCRIPTION__VALUE_EXPRESSION = PropertiesPackage.eINSTANCE.getCheckboxDescription_ValueExpression();
@@ -2036,7 +2530,7 @@ public interface PropertiesPackage extends EPackage {
          * The meta object literal for the '<em><b>Initial Operation</b></em>'
          * containment reference feature. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @generated
          */
         EReference CHECKBOX_DESCRIPTION__INITIAL_OPERATION = PropertiesPackage.eINSTANCE.getCheckboxDescription_InitialOperation();
@@ -2046,7 +2540,7 @@ public interface PropertiesPackage extends EPackage {
          * {@link org.eclipse.sirius.properties.impl.SelectDescriptionImpl
          * <em>Select Description</em>}' class. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @see org.eclipse.sirius.properties.impl.SelectDescriptionImpl
          * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getSelectDescription()
          * @generated
@@ -2056,7 +2550,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Value Expression</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute SELECT_DESCRIPTION__VALUE_EXPRESSION = PropertiesPackage.eINSTANCE.getSelectDescription_ValueExpression();
@@ -2065,7 +2559,7 @@ public interface PropertiesPackage extends EPackage {
          * The meta object literal for the '<em><b>Initial Operation</b></em>'
          * containment reference feature. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @generated
          */
         EReference SELECT_DESCRIPTION__INITIAL_OPERATION = PropertiesPackage.eINSTANCE.getSelectDescription_InitialOperation();
@@ -2093,7 +2587,7 @@ public interface PropertiesPackage extends EPackage {
          * {@link org.eclipse.sirius.properties.impl.DynamicMappingForImpl
          * <em>Dynamic Mapping For</em>}' class. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @see org.eclipse.sirius.properties.impl.DynamicMappingForImpl
          * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getDynamicMappingFor()
          * @generated
@@ -2103,7 +2597,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Iterator</b></em>' attribute
          * feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute DYNAMIC_MAPPING_FOR__ITERATOR = PropertiesPackage.eINSTANCE.getDynamicMappingFor_Iterator();
@@ -2120,7 +2614,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Ifs</b></em>' containment
          * reference list feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EReference DYNAMIC_MAPPING_FOR__IFS = PropertiesPackage.eINSTANCE.getDynamicMappingFor_Ifs();
@@ -2130,7 +2624,7 @@ public interface PropertiesPackage extends EPackage {
          * {@link org.eclipse.sirius.properties.impl.DynamicMappingIfImpl
          * <em>Dynamic Mapping If</em>}' class. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @see org.eclipse.sirius.properties.impl.DynamicMappingIfImpl
          * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getDynamicMappingIf()
          * @generated
@@ -2140,7 +2634,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Predicate Expression</b></em>
          * ' attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute DYNAMIC_MAPPING_IF__PREDICATE_EXPRESSION = PropertiesPackage.eINSTANCE.getDynamicMappingIf_PredicateExpression();
@@ -2148,7 +2642,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Widget</b></em>' containment
          * reference feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EReference DYNAMIC_MAPPING_IF__WIDGET = PropertiesPackage.eINSTANCE.getDynamicMappingIf_Widget();
@@ -2158,7 +2652,7 @@ public interface PropertiesPackage extends EPackage {
          * {@link org.eclipse.sirius.properties.impl.RadioDescriptionImpl
          * <em>Radio Description</em>}' class. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @see org.eclipse.sirius.properties.impl.RadioDescriptionImpl
          * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getRadioDescription()
          * @generated
@@ -2168,7 +2662,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Value Expression</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute RADIO_DESCRIPTION__VALUE_EXPRESSION = PropertiesPackage.eINSTANCE.getRadioDescription_ValueExpression();
@@ -2177,7 +2671,7 @@ public interface PropertiesPackage extends EPackage {
          * The meta object literal for the '<em><b>Initial Operation</b></em>'
          * containment reference feature. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @generated
          */
         EReference RADIO_DESCRIPTION__INITIAL_OPERATION = PropertiesPackage.eINSTANCE.getRadioDescription_InitialOperation();
@@ -2202,10 +2696,177 @@ 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 -->
+         * 
+         * @see org.eclipse.sirius.properties.impl.SingleReferenceDescriptionImpl
+         * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getSingleReferenceDescription()
+         * @generated
+         */
+        EClass SINGLE_REFERENCE_DESCRIPTION = PropertiesPackage.eINSTANCE.getSingleReferenceDescription();
+
+        /**
+         * The meta object literal for the '<em><b>Value Expression</b></em>'
+         * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
+         * 
+         * @generated
+         */
+        EAttribute SINGLE_REFERENCE_DESCRIPTION__VALUE_EXPRESSION = PropertiesPackage.eINSTANCE.getSingleReferenceDescription_ValueExpression();
+
+        /**
+         * The meta object literal for the '<em><b>Display Expression</b></em>'
+         * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
+         * 
+         * @generated
+         */
+        EAttribute SINGLE_REFERENCE_DESCRIPTION__DISPLAY_EXPRESSION = PropertiesPackage.eINSTANCE.getSingleReferenceDescription_DisplayExpression();
+
+        /**
+         * The meta object literal for the '<em><b>Create Operation</b></em>'
+         * containment reference feature. <!-- begin-user-doc --> <!--
+         * end-user-doc -->
+         * 
+         * @generated
+         */
+        EReference SINGLE_REFERENCE_DESCRIPTION__CREATE_OPERATION = PropertiesPackage.eINSTANCE.getSingleReferenceDescription_CreateOperation();
+
+        /**
+         * The meta object literal for the '<em><b>Search Operation</b></em>'
+         * containment reference feature. <!-- begin-user-doc --> <!--
+         * end-user-doc -->
+         * 
+         * @generated
+         */
+        EReference SINGLE_REFERENCE_DESCRIPTION__SEARCH_OPERATION = PropertiesPackage.eINSTANCE.getSingleReferenceDescription_SearchOperation();
+
+        /**
+         * The meta object literal for the '<em><b>Unset Operation</b></em>'
+         * containment reference feature. <!-- begin-user-doc --> <!--
+         * end-user-doc -->
+         * 
+         * @generated
+         */
+        EReference SINGLE_REFERENCE_DESCRIPTION__UNSET_OPERATION = PropertiesPackage.eINSTANCE.getSingleReferenceDescription_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 SINGLE_REFERENCE_DESCRIPTION__ON_CLICK_OPERATION = PropertiesPackage.eINSTANCE.getSingleReferenceDescription_OnClickOperation();
+
+        /**
+         * The meta object literal for the '
+         * {@link org.eclipse.sirius.properties.impl.OperationDescriptionImpl
+         * <em>Operation Description</em>}' class. <!-- begin-user-doc --> <!--
+         * end-user-doc -->
+         * 
+         * @see org.eclipse.sirius.properties.impl.OperationDescriptionImpl
+         * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getOperationDescription()
+         * @generated
+         */
+        EClass OPERATION_DESCRIPTION = PropertiesPackage.eINSTANCE.getOperationDescription();
+
+        /**
+         * The meta object literal for the '<em><b>Initial Operation</b></em>'
+         * containment reference feature. <!-- begin-user-doc --> <!--
+         * end-user-doc -->
+         * 
+         * @generated
+         */
+        EReference OPERATION_DESCRIPTION__INITIAL_OPERATION = PropertiesPackage.eINSTANCE.getOperationDescription_InitialOperation();
+
+        /**
+         * 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.TextAreaDescriptionImpl
          * <em>Text Area Description</em>}' class. <!-- begin-user-doc --> <!--
          * end-user-doc -->
-         *
+         * 
          * @see org.eclipse.sirius.properties.impl.TextAreaDescriptionImpl
          * @see org.eclipse.sirius.properties.impl.PropertiesPackageImpl#getTextAreaDescription()
          * @generated
@@ -2215,7 +2876,7 @@ public interface PropertiesPackage extends EPackage {
         /**
          * The meta object literal for the '<em><b>Line Count</b></em>'
          * attribute feature. <!-- begin-user-doc --> <!-- end-user-doc -->
-         *
+         * 
          * @generated
          */
         EAttribute TEXT_AREA_DESCRIPTION__LINE_COUNT = PropertiesPackage.eINSTANCE.getTextAreaDescription_LineCount();
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
new file mode 100644
index 0000000000..6760611ef2
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/SingleReferenceDescription.java
@@ -0,0 +1,238 @@
+/**
+ * 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:
+ * <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>
+ * </p>
+ *
+ * @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 selected values of the radio. <!-- 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 -->
+     * <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 --> <!-- 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 -->
+     * <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 --> <!-- 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 -->
+     * <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 --> <!-- 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 -->
+     * <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 --> <!-- 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/WidgetDescription.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/WidgetDescription.java
index a91682a466..4bd6d61b02 100644
--- a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/WidgetDescription.java
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/WidgetDescription.java
@@ -57,7 +57,7 @@ public interface WidgetDescription extends EObject {
      * {@link org.eclipse.sirius.properties.WidgetDescription#getIdentifier
      * <em>Identifier</em>}' attribute. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @param value
      *            the new value of the '<em>Identifier</em>' attribute.
      * @see #getIdentifier()
@@ -73,7 +73,7 @@ public interface WidgetDescription extends EObject {
      * 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#getWidgetDescription_LabelExpression()
@@ -88,7 +88,7 @@ public interface WidgetDescription extends EObject {
      * {@link org.eclipse.sirius.properties.WidgetDescription#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()
@@ -104,7 +104,7 @@ public interface WidgetDescription extends EObject {
      * there really should be more of a description here...
      * </p>
      * <!-- end-user-doc -->
-     *
+     * 
      * @return the value of the '<em>Help Expression</em>' attribute.
      * @see #setHelpExpression(String)
      * @see org.eclipse.sirius.properties.PropertiesPackage#getWidgetDescription_HelpExpression()
@@ -119,7 +119,7 @@ public interface WidgetDescription extends EObject {
      * {@link org.eclipse.sirius.properties.WidgetDescription#getHelpExpression
      * <em>Help Expression</em>}' attribute. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @param value
      *            the new value of the '<em>Help Expression</em>' attribute.
      * @see #getHelpExpression()
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
new file mode 100644
index 0000000000..173a83e3cc
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/MultipleReferencesDescriptionImpl.java
@@ -0,0 +1,733 @@
+/**
+ * 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:
+ * <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>
+ * </p>
+ *
+ * @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/OperationDescriptionImpl.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/OperationDescriptionImpl.java
new file mode 100644
index 0000000000..cde575e609
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/OperationDescriptionImpl.java
@@ -0,0 +1,194 @@
+/**
+ * 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.OperationDescription;
+import org.eclipse.sirius.properties.PropertiesPackage;
+import org.eclipse.sirius.viewpoint.description.tool.InitialOperation;
+
+/**
+ * <!-- begin-user-doc --> An implementation of the model object '
+ * <em><b>Operation Description</b></em>'. <!-- end-user-doc -->
+ * <p>
+ * The following features are implemented:
+ * <ul>
+ * <li>
+ * {@link org.eclipse.sirius.properties.impl.OperationDescriptionImpl#getInitialOperation
+ * <em>Initial Operation</em>}</li>
+ * </ul>
+ * </p>
+ *
+ * @generated
+ */
+public class OperationDescriptionImpl extends MinimalEObjectImpl.Container implements OperationDescription {
+    /**
+     * 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 OperationDescriptionImpl() {
+        super();
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @generated
+     */
+    @Override
+    protected EClass eStaticClass() {
+        return PropertiesPackage.Literals.OPERATION_DESCRIPTION;
+    }
+
+    /**
+     * <!-- 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.OPERATION_DESCRIPTION__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.OPERATION_DESCRIPTION__INITIAL_OPERATION, null, msgs);
+            }
+            if (newInitialOperation != null) {
+                msgs = ((InternalEObject) newInitialOperation).eInverseAdd(this, InternalEObject.EOPPOSITE_FEATURE_BASE - PropertiesPackage.OPERATION_DESCRIPTION__INITIAL_OPERATION, null, msgs);
+            }
+            msgs = basicSetInitialOperation(newInitialOperation, msgs);
+            if (msgs != null) {
+                msgs.dispatch();
+            }
+        } else if (eNotificationRequired()) {
+            eNotify(new ENotificationImpl(this, Notification.SET, PropertiesPackage.OPERATION_DESCRIPTION__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.OPERATION_DESCRIPTION__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.OPERATION_DESCRIPTION__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.OPERATION_DESCRIPTION__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.OPERATION_DESCRIPTION__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.OPERATION_DESCRIPTION__INITIAL_OPERATION:
+            return initialOperation != null;
+        }
+        return super.eIsSet(featureID);
+    }
+
+} // OperationDescriptionImpl
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 e0cc2f4d43..08909a9906 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
@@ -23,11 +23,14 @@ import org.eclipse.sirius.properties.DynamicMappingFor;
 import org.eclipse.sirius.properties.DynamicMappingIf;
 import org.eclipse.sirius.properties.GroupDescription;
 import org.eclipse.sirius.properties.LabelDescription;
+import org.eclipse.sirius.properties.MultipleReferencesDescription;
+import org.eclipse.sirius.properties.OperationDescription;
 import org.eclipse.sirius.properties.PageDescription;
 import org.eclipse.sirius.properties.PropertiesFactory;
 import org.eclipse.sirius.properties.PropertiesPackage;
 import org.eclipse.sirius.properties.RadioDescription;
 import org.eclipse.sirius.properties.SelectDescription;
+import org.eclipse.sirius.properties.SingleReferenceDescription;
 import org.eclipse.sirius.properties.TextAreaDescription;
 import org.eclipse.sirius.properties.TextDescription;
 import org.eclipse.sirius.properties.ViewExtensionDescription;
@@ -101,6 +104,12 @@ public class PropertiesFactoryImpl extends EFactoryImpl implements PropertiesFac
             return createTextAreaDescription();
         case PropertiesPackage.RADIO_DESCRIPTION:
             return createRadioDescription();
+        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION:
+            return createSingleReferenceDescription();
+        case PropertiesPackage.OPERATION_DESCRIPTION:
+            return createOperationDescription();
+        case PropertiesPackage.MULTIPLE_REFERENCES_DESCRIPTION:
+            return createMultipleReferencesDescription();
         default:
             throw new IllegalArgumentException("The class '" + eClass.getName() + "' is not a valid classifier");
         }
@@ -244,6 +253,39 @@ public class PropertiesFactoryImpl extends EFactoryImpl implements PropertiesFac
      * @generated
      */
     @Override
+    public SingleReferenceDescription createSingleReferenceDescription() {
+        SingleReferenceDescriptionImpl singleReferenceDescription = new SingleReferenceDescriptionImpl();
+        return singleReferenceDescription;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @generated
+     */
+    @Override
+    public OperationDescription createOperationDescription() {
+        OperationDescriptionImpl operationDescription = new OperationDescriptionImpl();
+        return operationDescription;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @generated
+     */
+    @Override
+    public MultipleReferencesDescription createMultipleReferencesDescription() {
+        MultipleReferencesDescriptionImpl multipleReferencesDescription = new MultipleReferencesDescriptionImpl();
+        return multipleReferencesDescription;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @generated
+     */
+    @Override
     public TextAreaDescription createTextAreaDescription() {
         TextAreaDescriptionImpl textAreaDescription = new TextAreaDescriptionImpl();
         return textAreaDescription;
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 66f93739b6..4bf6917bf3 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
@@ -24,11 +24,14 @@ import org.eclipse.sirius.properties.DynamicMappingFor;
 import org.eclipse.sirius.properties.DynamicMappingIf;
 import org.eclipse.sirius.properties.GroupDescription;
 import org.eclipse.sirius.properties.LabelDescription;
+import org.eclipse.sirius.properties.MultipleReferencesDescription;
+import org.eclipse.sirius.properties.OperationDescription;
 import org.eclipse.sirius.properties.PageDescription;
 import org.eclipse.sirius.properties.PropertiesFactory;
 import org.eclipse.sirius.properties.PropertiesPackage;
 import org.eclipse.sirius.properties.RadioDescription;
 import org.eclipse.sirius.properties.SelectDescription;
+import org.eclipse.sirius.properties.SingleReferenceDescription;
 import org.eclipse.sirius.properties.TextAreaDescription;
 import org.eclipse.sirius.properties.TextDescription;
 import org.eclipse.sirius.properties.ViewExtensionDescription;
@@ -40,109 +43,130 @@ import org.eclipse.sirius.viewpoint.description.tool.ToolPackage;
 /**
  * <!-- begin-user-doc --> An implementation of the model <b>Package</b>. <!--
  * end-user-doc -->
- *
+ * 
  * @generated
  */
 public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPackage {
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     private EClass viewExtensionDescriptionEClass = null;
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     private EClass pageDescriptionEClass = null;
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     private EClass groupDescriptionEClass = null;
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     private EClass containerDescriptionEClass = null;
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     private EClass widgetDescriptionEClass = null;
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     private EClass textDescriptionEClass = null;
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     private EClass buttonDescriptionEClass = null;
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     private EClass labelDescriptionEClass = null;
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     private EClass checkboxDescriptionEClass = null;
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     private EClass selectDescriptionEClass = null;
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     private EClass dynamicMappingForEClass = null;
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     private EClass dynamicMappingIfEClass = null;
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     private EClass textAreaDescriptionEClass = null;
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     private EClass radioDescriptionEClass = null;
 
     /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @generated
+     */
+    private EClass singleReferenceDescriptionEClass = null;
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @generated
+     */
+    private EClass operationDescriptionEClass = null;
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @generated
+     */
+    private EClass multipleReferencesDescriptionEClass = null;
+
+    /**
      * Creates an instance of the model <b>Package</b>, registered with
      * {@link org.eclipse.emf.ecore.EPackage.Registry EPackage.Registry} by the
      * package package URI value.
@@ -163,7 +187,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     private static boolean isInited = false;
@@ -213,7 +237,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -223,7 +247,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -233,7 +257,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -243,7 +267,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -253,7 +277,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -263,7 +287,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -273,7 +297,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -283,7 +307,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -293,7 +317,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -303,7 +327,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -313,7 +337,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -323,7 +347,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -333,7 +357,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -343,7 +367,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -353,7 +377,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -363,7 +387,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -373,7 +397,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -383,7 +407,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -393,7 +417,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -403,7 +427,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -413,7 +437,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -423,7 +447,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -433,7 +457,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -443,7 +467,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -453,7 +477,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -463,7 +487,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -473,7 +497,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -483,7 +507,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -493,7 +517,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -503,7 +527,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -513,7 +537,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -523,7 +547,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -533,7 +557,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -543,7 +567,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -553,7 +577,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -563,7 +587,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -573,7 +597,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -583,7 +607,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -593,7 +617,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -603,7 +627,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -613,7 +637,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -623,7 +647,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -633,7 +657,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -643,7 +667,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -653,7 +677,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -663,7 +687,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -673,7 +697,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -683,7 +707,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -693,7 +717,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -703,7 +727,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -713,7 +737,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -723,7 +747,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -733,7 +757,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -743,7 +767,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -753,7 +777,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -763,7 +787,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -773,7 +797,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -783,7 +807,187 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
+     * @generated
+     */
+    @Override
+    public EClass getSingleReferenceDescription() {
+        return singleReferenceDescriptionEClass;
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @generated
+     */
+    @Override
+    public EAttribute getSingleReferenceDescription_ValueExpression() {
+        return (EAttribute) singleReferenceDescriptionEClass.getEStructuralFeatures().get(0);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @generated
+     */
+    @Override
+    public EAttribute getSingleReferenceDescription_DisplayExpression() {
+        return (EAttribute) singleReferenceDescriptionEClass.getEStructuralFeatures().get(1);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @generated
+     */
+    @Override
+    public EReference getSingleReferenceDescription_CreateOperation() {
+        return (EReference) singleReferenceDescriptionEClass.getEStructuralFeatures().get(2);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @generated
+     */
+    @Override
+    public EReference getSingleReferenceDescription_SearchOperation() {
+        return (EReference) singleReferenceDescriptionEClass.getEStructuralFeatures().get(3);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @generated
+     */
+    @Override
+    public EReference getSingleReferenceDescription_UnsetOperation() {
+        return (EReference) singleReferenceDescriptionEClass.getEStructuralFeatures().get(4);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @generated
+     */
+    @Override
+    public EReference getSingleReferenceDescription_OnClickOperation() {
+        return (EReference) singleReferenceDescriptionEClass.getEStructuralFeatures().get(5);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @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);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @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);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
+     * @generated
+     */
+    @Override
+    public EReference getMultipleReferencesDescription_DownOperation() {
+        return (EReference) multipleReferencesDescriptionEClass.getEStructuralFeatures().get(7);
+    }
+
+    /**
+     * <!-- begin-user-doc --> <!-- end-user-doc -->
+     * 
      * @generated
      */
     @Override
@@ -793,7 +997,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     private boolean isCreated = false;
@@ -802,7 +1006,7 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
      * Creates the meta-model objects for the package. This method is guarded to
      * have no affect on any invocation but its first. <!-- begin-user-doc -->
      * <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     public void createPackageContents() {
@@ -882,11 +1086,32 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
         createEReference(radioDescriptionEClass, PropertiesPackage.RADIO_DESCRIPTION__INITIAL_OPERATION);
         createEAttribute(radioDescriptionEClass, PropertiesPackage.RADIO_DESCRIPTION__CANDIDATES_EXPRESSION);
         createEAttribute(radioDescriptionEClass, PropertiesPackage.RADIO_DESCRIPTION__CANDIDATE_DISPLAY_EXPRESSION);
+
+        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);
+
+        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);
     }
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     private boolean isInitialized = false;
@@ -927,6 +1152,8 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
         selectDescriptionEClass.getESuperTypes().add(this.getWidgetDescription());
         textAreaDescriptionEClass.getESuperTypes().add(this.getTextDescription());
         radioDescriptionEClass.getESuperTypes().add(this.getWidgetDescription());
+        singleReferenceDescriptionEClass.getESuperTypes().add(this.getWidgetDescription());
+        multipleReferencesDescriptionEClass.getESuperTypes().add(this.getWidgetDescription());
 
         // Initialize classes and features; add operations and parameters
         initEClass(viewExtensionDescriptionEClass, ViewExtensionDescription.class, "ViewExtensionDescription", !EPackageImpl.IS_ABSTRACT, !EPackageImpl.IS_INTERFACE,
@@ -1068,6 +1295,59 @@ public class PropertiesPackageImpl extends EPackageImpl implements PropertiesPac
                 !EPackageImpl.IS_TRANSIENT, !EPackageImpl.IS_VOLATILE, EPackageImpl.IS_CHANGEABLE, !EPackageImpl.IS_UNSETTABLE, !EPackageImpl.IS_ID, 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,
+                !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,
+                !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, !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,
+                !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(operationDescriptionEClass, OperationDescription.class, "OperationDescription", !EPackageImpl.IS_ABSTRACT, !EPackageImpl.IS_INTERFACE, EPackageImpl.IS_GENERATED_INSTANCE_CLASS);
+        initEReference(getOperationDescription_InitialOperation(), theToolPackage.getInitialOperation(), null, "initialOperation", null, 1, 1, OperationDescription.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(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);
+
         // Create resource
         createResource(PropertiesPackage.eNS_URI);
     }
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
new file mode 100644
index 0000000000..9b2cf06fd7
--- /dev/null
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/SingleReferenceDescriptionImpl.java
@@ -0,0 +1,571 @@
+/**
+ * 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:
+ * <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>
+ * </p>
+ *
+ * @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/WidgetDescriptionImpl.java b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/WidgetDescriptionImpl.java
index deaaec8323..186a00db0f 100644
--- a/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/WidgetDescriptionImpl.java
+++ b/incubation/org.eclipse.sirius.properties/src-gen/org/eclipse/sirius/properties/impl/WidgetDescriptionImpl.java
@@ -42,7 +42,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
     /**
      * The default value of the '{@link #getIdentifier() <em>Identifier</em>}'
      * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @see #getIdentifier()
      * @generated
      * @ordered
@@ -52,7 +52,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
     /**
      * The cached value of the '{@link #getIdentifier() <em>Identifier</em>}'
      * attribute. <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @see #getIdentifier()
      * @generated
      * @ordered
@@ -63,7 +63,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
      * The default value of the '{@link #getLabelExpression()
      * <em>Label Expression</em>}' attribute. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see #getLabelExpression()
      * @generated
      * @ordered
@@ -74,7 +74,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
      * The cached value of the '{@link #getLabelExpression()
      * <em>Label Expression</em>}' attribute. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see #getLabelExpression()
      * @generated
      * @ordered
@@ -85,7 +85,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
      * The default value of the '{@link #getHelpExpression()
      * <em>Help Expression</em>}' attribute. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see #getHelpExpression()
      * @generated
      * @ordered
@@ -96,7 +96,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
      * The cached value of the '{@link #getHelpExpression()
      * <em>Help Expression</em>}' attribute. <!-- begin-user-doc --> <!--
      * end-user-doc -->
-     *
+     * 
      * @see #getHelpExpression()
      * @generated
      * @ordered
@@ -105,7 +105,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     protected WidgetDescriptionImpl() {
@@ -114,7 +114,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -124,7 +124,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -134,7 +134,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -148,7 +148,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -158,7 +158,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -172,7 +172,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -182,7 +182,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -196,7 +196,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -214,7 +214,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -235,7 +235,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -256,7 +256,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
@@ -274,7 +274,7 @@ public abstract class WidgetDescriptionImpl extends MinimalEObjectImpl.Container
 
     /**
      * <!-- begin-user-doc --> <!-- end-user-doc -->
-     *
+     * 
      * @generated
      */
     @Override
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 88c186fd42..52e3ce941b 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
@@ -22,10 +22,13 @@ import org.eclipse.sirius.properties.DynamicMappingFor;
 import org.eclipse.sirius.properties.DynamicMappingIf;
 import org.eclipse.sirius.properties.GroupDescription;
 import org.eclipse.sirius.properties.LabelDescription;
+import org.eclipse.sirius.properties.MultipleReferencesDescription;
+import org.eclipse.sirius.properties.OperationDescription;
 import org.eclipse.sirius.properties.PageDescription;
 import org.eclipse.sirius.properties.PropertiesPackage;
 import org.eclipse.sirius.properties.RadioDescription;
 import org.eclipse.sirius.properties.SelectDescription;
+import org.eclipse.sirius.properties.SingleReferenceDescription;
 import org.eclipse.sirius.properties.TextAreaDescription;
 import org.eclipse.sirius.properties.TextDescription;
 import org.eclipse.sirius.properties.ViewExtensionDescription;
@@ -158,6 +161,21 @@ public class PropertiesAdapterFactory extends AdapterFactoryImpl {
         }
 
         @Override
+        public Adapter caseSingleReferenceDescription(SingleReferenceDescription object) {
+            return createSingleReferenceDescriptionAdapter();
+        }
+
+        @Override
+        public Adapter caseOperationDescription(OperationDescription object) {
+            return createOperationDescriptionAdapter();
+        }
+
+        @Override
+        public Adapter caseMultipleReferencesDescription(MultipleReferencesDescription object) {
+            return createMultipleReferencesDescriptionAdapter();
+        }
+
+        @Override
         public Adapter caseExtension(Extension object) {
             return createExtensionAdapter();
         }
@@ -392,6 +410,54 @@ 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 -->
+     * 
+     * @return the new adapter.
+     * @see org.eclipse.sirius.properties.SingleReferenceDescription
+     * @generated
+     */
+    public Adapter createSingleReferenceDescriptionAdapter() {
+        return null;
+    }
+
+    /**
+     * Creates a new adapter for an object of class '
+     * {@link org.eclipse.sirius.properties.OperationDescription
+     * <em>Operation 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.OperationDescription
+     * @generated
+     */
+    public Adapter createOperationDescriptionAdapter() {
+        return null;
+    }
+
+    /**
+     * 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.TextAreaDescription
      * <em>Text Area Description</em>}'. <!-- begin-user-doc --> This default
      * implementation returns null so that we can easily ignore cases; it's
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 93c146ba5f..594e36218b 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
@@ -22,10 +22,13 @@ import org.eclipse.sirius.properties.DynamicMappingFor;
 import org.eclipse.sirius.properties.DynamicMappingIf;
 import org.eclipse.sirius.properties.GroupDescription;
 import org.eclipse.sirius.properties.LabelDescription;
+import org.eclipse.sirius.properties.MultipleReferencesDescription;
+import org.eclipse.sirius.properties.OperationDescription;
 import org.eclipse.sirius.properties.PageDescription;
 import org.eclipse.sirius.properties.PropertiesPackage;
 import org.eclipse.sirius.properties.RadioDescription;
 import org.eclipse.sirius.properties.SelectDescription;
+import org.eclipse.sirius.properties.SingleReferenceDescription;
 import org.eclipse.sirius.properties.TextAreaDescription;
 import org.eclipse.sirius.properties.TextDescription;
 import org.eclipse.sirius.properties.ViewExtensionDescription;
@@ -244,6 +247,36 @@ public class PropertiesSwitch<T> {
             }
             return result;
         }
+        case PropertiesPackage.SINGLE_REFERENCE_DESCRIPTION: {
+            SingleReferenceDescription singleReferenceDescription = (SingleReferenceDescription) theEObject;
+            T result = caseSingleReferenceDescription(singleReferenceDescription);
+            if (result == null) {
+                result = caseWidgetDescription(singleReferenceDescription);
+            }
+            if (result == null) {
+                result = defaultCase(theEObject);
+            }
+            return result;
+        }
+        case PropertiesPackage.OPERATION_DESCRIPTION: {
+            OperationDescription operationDescription = (OperationDescription) theEObject;
+            T result = caseOperationDescription(operationDescription);
+            if (result == null) {
+                result = defaultCase(theEObject);
+            }
+            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 = defaultCase(theEObject);
+            }
+            return result;
+        }
         default:
             return defaultCase(theEObject);
         }
@@ -472,6 +505,57 @@ public class PropertiesSwitch<T> {
 
     /**
      * Returns the result of interpreting the object as an instance of '
+     * <em>Single 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>'.
+     * @see #doSwitch(org.eclipse.emf.ecore.EObject) doSwitch(EObject)
+     * @generated
+     */
+    public T caseSingleReferenceDescription(SingleReferenceDescription object) {
+        return null;
+    }
+
+    /**
+     * Returns the result of interpreting the object as an instance of '
+     * <em>Operation 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>Operation Description</em>'.
+     * @see #doSwitch(org.eclipse.emf.ecore.EObject) doSwitch(EObject)
+     * @generated
+     */
+    public T caseOperationDescription(OperationDescription object) {
+        return null;
+    }
+
+    /**
+     * 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>Text Area Description</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 b9cafdce60..2671552c9d 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
@@ -19,9 +19,11 @@ import org.eclipse.eef.EEFDynamicMappingFor;
 import org.eclipse.eef.EEFDynamicMappingIf;
 import org.eclipse.eef.EEFGroupDescription;
 import org.eclipse.eef.EEFLabelDescription;
+import org.eclipse.eef.EEFMultipleReferencesDescription;
 import org.eclipse.eef.EEFPageDescription;
 import org.eclipse.eef.EEFRadioDescription;
 import org.eclipse.eef.EEFSelectDescription;
+import org.eclipse.eef.EEFSingleReferenceDescription;
 import org.eclipse.eef.EEFTextDescription;
 import org.eclipse.eef.EEFViewDescription;
 import org.eclipse.eef.EEFWidgetDescription;
@@ -33,9 +35,12 @@ import org.eclipse.sirius.properties.DynamicMappingFor;
 import org.eclipse.sirius.properties.DynamicMappingIf;
 import org.eclipse.sirius.properties.GroupDescription;
 import org.eclipse.sirius.properties.LabelDescription;
+import org.eclipse.sirius.properties.MultipleReferencesDescription;
+import org.eclipse.sirius.properties.OperationDescription;
 import org.eclipse.sirius.properties.PageDescription;
 import org.eclipse.sirius.properties.RadioDescription;
 import org.eclipse.sirius.properties.SelectDescription;
+import org.eclipse.sirius.properties.SingleReferenceDescription;
 import org.eclipse.sirius.properties.TextAreaDescription;
 import org.eclipse.sirius.properties.TextDescription;
 import org.eclipse.sirius.properties.WidgetDescription;
@@ -164,6 +169,10 @@ public class ViewDescriptionConverter {
             description = createEEFButtonDescription((ButtonDescription) widgetDescription);
         } else if (widgetDescription instanceof RadioDescription) {
             description = createEEFRadioDescription((RadioDescription) widgetDescription);
+        } else if (widgetDescription instanceof SingleReferenceDescription) {
+            description = createEEFSingleReferenceDescription((SingleReferenceDescription) widgetDescription);
+        } else if (widgetDescription instanceof MultipleReferencesDescription) {
+            description = createEEFMultipleReferencesDescription((MultipleReferencesDescription) widgetDescription);
         }
 
         if (description != null) {
@@ -250,4 +259,74 @@ public class ViewDescriptionConverter {
         return eefRadioDescription;
     }
 
+    private EEFSingleReferenceDescription createEEFSingleReferenceDescription(SingleReferenceDescription singleReferenceDescription) {
+        EEFSingleReferenceDescription eefSingleReferenceDescription = EefFactory.eINSTANCE.createEEFSingleReferenceDescription();
+
+        eefSingleReferenceDescription.setIdentifier(singleReferenceDescription.getIdentifier());
+        eefSingleReferenceDescription.setLabelExpression(singleReferenceDescription.getLabelExpression());
+        eefSingleReferenceDescription.setValueExpression(singleReferenceDescription.getValueExpression());
+        eefSingleReferenceDescription.setDisplayExpression(singleReferenceDescription.getDisplayExpression());
+        OperationDescription createOperationDescription = singleReferenceDescription.getCreateOperation();
+        if (createOperationDescription != null) {
+            InitialOperation initialOperation = createOperationDescription.getInitialOperation();
+            eefSingleReferenceDescription.setCreateExpression(getExpressionForOperation(initialOperation));
+        }
+        OperationDescription searchOperationDescription = singleReferenceDescription.getSearchOperation();
+        if (searchOperationDescription != null) {
+            InitialOperation initialOperation = searchOperationDescription.getInitialOperation();
+            eefSingleReferenceDescription.setSearchExpression(getExpressionForOperation(initialOperation));
+        }
+        OperationDescription unsetOperationDescription = singleReferenceDescription.getUnsetOperation();
+        if (unsetOperationDescription != null) {
+            InitialOperation initialOperation = unsetOperationDescription.getInitialOperation();
+            eefSingleReferenceDescription.setUnsetExpression(getExpressionForOperation(initialOperation));
+        }
+        OperationDescription onClickOperationDescription = singleReferenceDescription.getOnClickOperation();
+        if (onClickOperationDescription != null) {
+            InitialOperation initialOperation = onClickOperationDescription.getInitialOperation();
+            eefSingleReferenceDescription.setOnClickExpression(getExpressionForOperation(initialOperation));
+        }
+        return eefSingleReferenceDescription;
+    }
+
+    private EEFMultipleReferencesDescription createEEFMultipleReferencesDescription(MultipleReferencesDescription multipleReferencesDescription) {
+        EEFMultipleReferencesDescription eefMultipleReferencesDescription = EefFactory.eINSTANCE.createEEFMultipleReferencesDescription();
+
+        eefMultipleReferencesDescription.setIdentifier(multipleReferencesDescription.getIdentifier());
+        eefMultipleReferencesDescription.setLabelExpression(multipleReferencesDescription.getLabelExpression());
+        eefMultipleReferencesDescription.setValueExpression(multipleReferencesDescription.getValueExpression());
+        eefMultipleReferencesDescription.setDisplayExpression(multipleReferencesDescription.getDisplayExpression());
+        OperationDescription createOperationDescription = multipleReferencesDescription.getCreateOperation();
+        if (createOperationDescription != null) {
+            InitialOperation initialOperation = createOperationDescription.getInitialOperation();
+            eefMultipleReferencesDescription.setCreateExpression(getExpressionForOperation(initialOperation));
+        }
+        OperationDescription searchOperationDescription = multipleReferencesDescription.getSearchOperation();
+        if (searchOperationDescription != null) {
+            InitialOperation initialOperation = searchOperationDescription.getInitialOperation();
+            eefMultipleReferencesDescription.setSearchExpression(getExpressionForOperation(initialOperation));
+        }
+        OperationDescription unsetOperationDescription = multipleReferencesDescription.getUnsetOperation();
+        if (unsetOperationDescription != null) {
+            InitialOperation initialOperation = unsetOperationDescription.getInitialOperation();
+            eefMultipleReferencesDescription.setUnsetExpression(getExpressionForOperation(initialOperation));
+        }
+        OperationDescription onClickOperationDescription = multipleReferencesDescription.getOnClickOperation();
+        if (onClickOperationDescription != null) {
+            InitialOperation initialOperation = onClickOperationDescription.getInitialOperation();
+            eefMultipleReferencesDescription.setOnClickExpression(getExpressionForOperation(initialOperation));
+        }
+        OperationDescription upOperationDescription = multipleReferencesDescription.getUpOperation();
+        if (upOperationDescription != null) {
+            InitialOperation initialOperation = upOperationDescription.getInitialOperation();
+            eefMultipleReferencesDescription.setUpExpression(getExpressionForOperation(initialOperation));
+        }
+        OperationDescription downOperationDescription = multipleReferencesDescription.getDownOperation();
+        if (downOperationDescription != null) {
+            InitialOperation initialOperation = downOperationDescription.getInitialOperation();
+            eefMultipleReferencesDescription.setDownExpression(getExpressionForOperation(initialOperation));
+        }
+        return eefMultipleReferencesDescription;
+    }
+
 }