[486330] Don't create/refresh a DRepresentation without needed viewpoint

- Don't create/refresh a DRepresentation if some required viewpoints are
missing.
- For tree/table it is simply the viewpoint containing the related
RepresentationDescription, for diagram it is all viewpoints owning
RepresentationDescription providing layer to the diagram to refresh.
- Consequently DialectServices.getRequiredViewpoints(DRepresentation)
API method has been added to know the required viewpoints to refresh a
representation. And AbstractRepresentationDialectServices.

Bug: 486330
Change-Id: Ifd679f690647842a06b43d64d95c2dcb67992614
Signed-off-by: Esteban Dugueperoux <esteban.dugueperoux@obeo.fr>

9 files changed, 177 insertions, 45 deletions

diff --git a/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/business/internal/dialect/DiagramDialectUIServices.java b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/business/internal/dialect/DiagramDialectUIServices.java
index abfffd8b7d..f0efdbb7d1 100644
--- a/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/business/internal/dialect/DiagramDialectUIServices.java
+++ b/plugins/org.eclipse.sirius.diagram.ui/src-diag/org/eclipse/sirius/diagram/ui/business/internal/dialect/DiagramDialectUIServices.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2015 THALES GLOBAL SERVICES and others.
+ * Copyright (c) 2007, 2016 THALES GLOBAL SERVICES and others.
  * 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
@@ -55,6 +55,7 @@ import org.eclipse.gmf.runtime.notation.View;
 import org.eclipse.jface.dialogs.MessageDialog;
 import org.eclipse.jface.viewers.ILabelProvider;
 import org.eclipse.jface.viewers.StructuredSelection;
+import org.eclipse.sirius.business.api.dialect.DialectManager;
 import org.eclipse.sirius.business.api.helper.SiriusResourceHelper;
 import org.eclipse.sirius.business.api.query.EObjectQuery;
 import org.eclipse.sirius.business.api.query.URIQuery;
@@ -222,14 +223,7 @@ public class DiagramDialectUIServices implements DialectUIServices {
     }
 
     private Set<Viewpoint> activateNeededViewpoints(Session session, DDiagram dDiagram, IProgressMonitor monitor) {
-        List<Layer> activatedLayers = dDiagram.getActivatedLayers();
-        Set<Viewpoint> neededViewpoints = new LinkedHashSet<Viewpoint>();
-        for (Layer activatedLayer : activatedLayers) {
-            if (!activatedLayer.eIsProxy() && activatedLayer.eContainer() != null) {
-                Viewpoint viewpoint = (Viewpoint) activatedLayer.eContainer().eContainer();
-                neededViewpoints.add(viewpoint);
-            }
-        }
+        Set<Viewpoint> neededViewpoints = DialectManager.INSTANCE.getRequiredViewpoints(dDiagram);
         Set<Viewpoint> selectedViewpoints = new LinkedHashSet<Viewpoint>();
         for (Viewpoint viewpoint : session.getSelectedViewpoints(false)) {
             selectedViewpoints.add(SiriusResourceHelper.getCorrespondingViewpoint(session, viewpoint));
diff --git a/plugins/org.eclipse.sirius.diagram/src-core/org/eclipse/sirius/diagram/business/internal/dialect/DiagramDialectServices.java b/plugins/org.eclipse.sirius.diagram/src-core/org/eclipse/sirius/diagram/business/internal/dialect/DiagramDialectServices.java
index ff3d6636af..5cef32dcf8 100644
--- a/plugins/org.eclipse.sirius.diagram/src-core/org/eclipse/sirius/diagram/business/internal/dialect/DiagramDialectServices.java
+++ b/plugins/org.eclipse.sirius.diagram/src-core/org/eclipse/sirius/diagram/business/internal/dialect/DiagramDialectServices.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2015 THALES GLOBAL SERVICES.
+ * Copyright (c) 2007, 2016 THALES GLOBAL SERVICES.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -12,6 +12,7 @@ package org.eclipse.sirius.diagram.business.internal.dialect;
 
 import java.text.MessageFormat;
 import java.util.Collection;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
@@ -121,27 +122,31 @@ public class DiagramDialectServices extends AbstractRepresentationDialectService
     public boolean canCreate(final EObject semantic, final RepresentationDescription desc) {
         boolean result = false;
         if (semantic != null && isSupported(desc)) {
-            DiagramDescription diagDesc = (DiagramDescription) desc;
-            ModelAccessor accessor = SiriusPlugin.getDefault().getModelAccessorRegistry().getModelAccessor(semantic);
-            if (accessor != null) {
-                result = checkDomainClass(accessor, semantic, diagDesc.getDomainClass());
-
-                // If the representation is a diagram description
-                boolean needsToCheckSemanticElement = true;
-                // We first check if the diagram description has a non null
-                // initial operation
-                if ((diagDesc.getInit() == null) || (diagDesc.getInit().getInitialOperation() == null) || (diagDesc.getInit().getInitialOperation().getFirstModelOperations() == null)) {
-                    // If the diagram description has no initial operation
-                    // we do not need to check the semantic element
-                    // => true will be returned
-                    needsToCheckSemanticElement = false;
-                }
+            Session session = new EObjectQuery(semantic).getSession();
+            // If the semantic doesn't belong to a session we don't check
+            // viewpoint selection but only others things like domainClass
+            if (session == null || isRelatedViewpointSelected(session, desc)) {
+                DiagramDescription diagDesc = (DiagramDescription) desc;
+                ModelAccessor accessor = SiriusPlugin.getDefault().getModelAccessorRegistry().getModelAccessor(semantic);
+                if (accessor != null) {
+                    result = checkDomainClass(accessor, semantic, diagDesc.getDomainClass());
+                    // If the representation is a diagram description
+                    boolean needsToCheckSemanticElement = true;
+                    // We first check if the diagram description has a non null
+                    // initial operation
+                    if ((diagDesc.getInit() == null) || (diagDesc.getInit().getInitialOperation() == null) || (diagDesc.getInit().getInitialOperation().getFirstModelOperations() == null)) {
+                        // If the diagram description has no initial operation
+                        // we do not need to check the semantic element
+                        // => true will be returned
+                        needsToCheckSemanticElement = false;
+                    }
 
-                if (needsToCheckSemanticElement) {
-                    result = result && checkSemanticElementCanBeFilled(accessor, semantic);
+                    if (needsToCheckSemanticElement) {
+                        result = result && checkSemanticElementCanBeFilled(accessor, semantic);
+                    }
                 }
+                result = result && checkPrecondition(semantic, diagDesc.getPreconditionExpression());
             }
-            result = result && checkPrecondition(semantic, diagDesc.getPreconditionExpression());
         }
         return result;
     }
@@ -173,7 +178,7 @@ public class DiagramDialectServices extends AbstractRepresentationDialectService
             monitor.subTask(MessageFormat.format(Messages.DiagramDialectServices_createDiagramMsg, name));
             diagram = createRepresentation(name, semantic, description, new SubProgressMonitor(monitor, 2));
             if (diagram != null) {
-                refresh(diagram, new SubProgressMonitor(monitor, 26));
+                DialectManager.INSTANCE.refresh(diagram, new SubProgressMonitor(monitor, 26));
                 if (DisplayMode.NORMAL.equals(DisplayServiceManager.INSTANCE.getMode())) {
                     DisplayServiceManager.INSTANCE.getDisplayService().refreshAllElementsVisibility((DDiagram) diagram);
                     monitor.worked(1);
@@ -263,6 +268,22 @@ public class DiagramDialectServices extends AbstractRepresentationDialectService
         }
     }
 
+    @Override
+    public Set<Viewpoint> getRequiredViewpoints(DRepresentation representation) {
+        Set<Viewpoint> requiredViewpoints = super.getRequiredViewpoints(representation);
+        if (representation instanceof DDiagram) {
+            DDiagram dDiagram = (DDiagram) representation;
+            List<Layer> activatedLayers = dDiagram.getActivatedLayers();
+            for (Layer activatedLayer : activatedLayers) {
+                if (!activatedLayer.eIsProxy() && activatedLayer.eContainer() != null) {
+                    Viewpoint viewpoint = (Viewpoint) activatedLayer.eContainer().eContainer();
+                    requiredViewpoints.add(viewpoint);
+                }
+            }
+        }
+        return requiredViewpoints;
+    }
+
     /**
      * {@inheritDoc}
      */
diff --git a/plugins/org.eclipse.sirius.doc/doc/Release_Notes.html b/plugins/org.eclipse.sirius.doc/doc/Release_Notes.html
index 0df94a3b04..615f0dd68c 100644
--- a/plugins/org.eclipse.sirius.doc/doc/Release_Notes.html
+++ b/plugins/org.eclipse.sirius.doc/doc/Release_Notes.html
@@ -134,6 +134,17 @@
 			<li><span class="label label-success">Added</span> 
 				<code>org.eclipse.sirius.tools.api.command.ui.NoUICallback.askForTypedVariable(List&lt;TypedVariable&gt;, List&lt;String&gt;)</code> has been created.
 			</li>
+			<li><span class="label label-success">Added</span> 
+				<code>org.eclipse.sirius.business.api.dialect.DialectServices.getRequiredViewpoints(DRepresentation)</code> has been added to have mean to get required viewpoints to use a representation.
+			</li>
+			<li><span class="label label-success">Added</span> 
+				<code>org.eclipse.sirius.business.api.dialect.AbstractRepresentationDialectServices.getRequiredViewpoints(DRepresentation)</code> has been added to have a default implementation of 
+				<code>DialectServices.getRequiredViewpoints(DRepresentation)</code> method.
+			</li>
+			<li><span class="label label-success">Added</span> 
+				<code>org.eclipse.sirius.business.api.dialect.AbstractRepresentationDialectServices.isRelatedViewpointSelected(Session, RepresentationDescription)</code> protected method has been added to check if a 
+				<code>RepresentationDescription</code> is usable in the context of the specified session.
+			</li>
 			<li><span class="label label-info">Modified</span> 
 				<code>org.eclipse.sirius.viewpoint.description.tool.SelectModelElementVariable</code> now implements 
 				<code>org.eclipse.sirius.viewpoint.description.InteractiveVariableDescription</code>.
diff --git a/plugins/org.eclipse.sirius.doc/doc/Release_Notes.textile b/plugins/org.eclipse.sirius.doc/doc/Release_Notes.textile
index a4bb19fac4..34172051e0 100644
--- a/plugins/org.eclipse.sirius.doc/doc/Release_Notes.textile
+++ b/plugins/org.eclipse.sirius.doc/doc/Release_Notes.textile
@@ -30,6 +30,9 @@ h4. Changes in @org.eclipse.sirius@
 * <span class="label label-success">Added</span> @org.eclipse.sirius.viewpoint.description.InteractiveVariableDescription@ has been created as tag interface for variables that require user interaction to be valued.
 * <span class="label label-success">Added</span> @org.eclipse.sirius.tools.api.command.ui.UICallBack.askForTypedVariable(List<TypedVariable>, List<String>)@ has been created.
 * <span class="label label-success">Added</span> @org.eclipse.sirius.tools.api.command.ui.NoUICallback.askForTypedVariable(List<TypedVariable>, List<String>)@ has been created.
+* <span class="label label-success">Added</span> @org.eclipse.sirius.business.api.dialect.DialectServices.getRequiredViewpoints(DRepresentation)@ has been added to have mean to get required viewpoints to use a representation.
+* <span class="label label-success">Added</span> @org.eclipse.sirius.business.api.dialect.AbstractRepresentationDialectServices.getRequiredViewpoints(DRepresentation)@ has been added to have a default implementation of @DialectServices.getRequiredViewpoints(DRepresentation)@ method.
+* <span class="label label-success">Added</span> @org.eclipse.sirius.business.api.dialect.AbstractRepresentationDialectServices.isRelatedViewpointSelected(Session, RepresentationDescription)@ protected method has been added to check if a @RepresentationDescription@ is usable in the context of the specified session.
 * <span class="label label-info">Modified</span> @org.eclipse.sirius.viewpoint.description.tool.SelectModelElementVariable@ now implements @org.eclipse.sirius.viewpoint.description.InteractiveVariableDescription@.
 * <span class="label label-info">Modified</span> @org.eclipse.sirius.viewpoint.description.tool.AbstractVariable@ has been moved to @org.eclipse.sirius.viewpoint.description.AbstractVariable@.
 * <span class="label label-info">Modified</span> @org.eclipse.sirius.viewpoint.description.tool.SubVariable@ has been moved to @org.eclipse.sirius.viewpoint.description.SubVariable@.
diff --git a/plugins/org.eclipse.sirius.table/src/org/eclipse/sirius/table/business/internal/dialect/TableDialectServices.java b/plugins/org.eclipse.sirius.table/src/org/eclipse/sirius/table/business/internal/dialect/TableDialectServices.java
index 5c3c021470..3249c983e2 100644
--- a/plugins/org.eclipse.sirius.table/src/org/eclipse/sirius/table/business/internal/dialect/TableDialectServices.java
+++ b/plugins/org.eclipse.sirius.table/src/org/eclipse/sirius/table/business/internal/dialect/TableDialectServices.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2015 THALES GLOBAL SERVICES and others.
+ * Copyright (c) 2007, 2016 THALES GLOBAL SERVICES and others.
  * 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
@@ -29,6 +29,7 @@ import org.eclipse.emf.transaction.util.TransactionUtil;
 import org.eclipse.sirius.business.api.dialect.AbstractRepresentationDialectServices;
 import org.eclipse.sirius.business.api.dialect.description.IInterpretedExpressionQuery;
 import org.eclipse.sirius.business.api.query.DRepresentationElementQuery;
+import org.eclipse.sirius.business.api.query.EObjectQuery;
 import org.eclipse.sirius.business.api.query.IdentifiedElementQuery;
 import org.eclipse.sirius.business.api.session.CustomDataConstants;
 import org.eclipse.sirius.business.api.session.Session;
@@ -112,12 +113,17 @@ public class TableDialectServices extends AbstractRepresentationDialectServices
     public boolean canCreate(final EObject semantic, final RepresentationDescription desc) {
         boolean result = false;
         if (semantic != null && isSupported(desc)) {
-            TableDescription tableDesc = (TableDescription) desc;
-            ModelAccessor accessor = SiriusPlugin.getDefault().getModelAccessorRegistry().getModelAccessor(semantic);
-            if (accessor != null) {
-                result = checkDomainClass(accessor, semantic, tableDesc.getDomainClass());
+            Session session = new EObjectQuery(semantic).getSession();
+            // If the semantic doesn't belong to a session we don't check
+            // viewpoint selection but only others things like domainClass
+            if (session == null || isRelatedViewpointSelected(session, desc)) {
+                TableDescription tableDesc = (TableDescription) desc;
+                ModelAccessor accessor = SiriusPlugin.getDefault().getModelAccessorRegistry().getModelAccessor(semantic);
+                if (accessor != null) {
+                    result = checkDomainClass(accessor, semantic, tableDesc.getDomainClass());
+                }
+                result = result && checkPrecondition(semantic, tableDesc.getPreconditionExpression());
             }
-            result = result && checkPrecondition(semantic, tableDesc.getPreconditionExpression());
         }
         return result;
     }
diff --git a/plugins/org.eclipse.sirius.tree/src/org/eclipse/sirius/tree/business/internal/dialect/TreeDialectServices.java b/plugins/org.eclipse.sirius.tree/src/org/eclipse/sirius/tree/business/internal/dialect/TreeDialectServices.java
index f5d3340b15..1b721258bc 100644
--- a/plugins/org.eclipse.sirius.tree/src/org/eclipse/sirius/tree/business/internal/dialect/TreeDialectServices.java
+++ b/plugins/org.eclipse.sirius.tree/src/org/eclipse/sirius/tree/business/internal/dialect/TreeDialectServices.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2010, 2015 THALES GLOBAL SERVICES and others.
+ * Copyright (c) 2010, 2016 THALES GLOBAL SERVICES and others.
  * 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
@@ -216,12 +216,17 @@ public class TreeDialectServices extends AbstractRepresentationDialectServices {
     public boolean canCreate(EObject semantic, RepresentationDescription desc) {
         boolean result = false;
         if (semantic != null && isSupported(desc)) {
-            TreeDescription treeDesc = (TreeDescription) desc;
-            ModelAccessor accessor = SiriusPlugin.getDefault().getModelAccessorRegistry().getModelAccessor(semantic);
-            if (accessor != null) {
-                result = checkDomainClass(accessor, semantic, treeDesc.getDomainClass());
+            Session session = new EObjectQuery(semantic).getSession();
+            // If the semantic doesn't belong to a session we don't check
+            // viewpoint selection but only others things like domainClass
+            if (session == null || isRelatedViewpointSelected(session, desc)) {
+                TreeDescription treeDesc = (TreeDescription) desc;
+                ModelAccessor accessor = SiriusPlugin.getDefault().getModelAccessorRegistry().getModelAccessor(semantic);
+                if (accessor != null) {
+                    result = checkDomainClass(accessor, semantic, treeDesc.getDomainClass());
+                }
+                result = result && checkPrecondition(semantic, treeDesc.getPreconditionExpression());
             }
-            result = result && checkPrecondition(semantic, treeDesc.getPreconditionExpression());
         }
         return result;
     }
diff --git a/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/api/dialect/AbstractRepresentationDialectServices.java b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/api/dialect/AbstractRepresentationDialectServices.java
index e603fedb9b..b824a8b6af 100644
--- a/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/api/dialect/AbstractRepresentationDialectServices.java
+++ b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/api/dialect/AbstractRepresentationDialectServices.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009, 2015 THALES GLOBAL SERVICES and others.
+ * Copyright (c) 2009, 2016 THALES GLOBAL SERVICES and others.
  * 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
@@ -14,6 +14,7 @@ import java.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Iterator;
+import java.util.LinkedHashSet;
 import java.util.Map;
 import java.util.Set;
 
@@ -27,6 +28,8 @@ import org.eclipse.emf.ecore.util.EcoreUtil;
 import org.eclipse.sirius.business.api.dialect.identifier.RepresentationElementIdentifier;
 import org.eclipse.sirius.business.api.helper.SiriusUtil;
 import org.eclipse.sirius.business.api.helper.task.AbstractCommandTask;
+import org.eclipse.sirius.business.api.query.EObjectQuery;
+import org.eclipse.sirius.business.api.query.RepresentationDescriptionQuery;
 import org.eclipse.sirius.business.api.query.ViewpointQuery;
 import org.eclipse.sirius.business.api.session.CustomDataConstants;
 import org.eclipse.sirius.business.api.session.Session;
@@ -40,6 +43,7 @@ import org.eclipse.sirius.tools.api.command.CommandContext;
 import org.eclipse.sirius.tools.api.command.ui.UICallBack;
 import org.eclipse.sirius.tools.api.interpreter.InterpreterUtil;
 import org.eclipse.sirius.viewpoint.DRepresentation;
+import org.eclipse.sirius.viewpoint.DSemanticDecorator;
 import org.eclipse.sirius.viewpoint.Messages;
 import org.eclipse.sirius.viewpoint.ViewpointPackage;
 import org.eclipse.sirius.viewpoint.description.RepresentationDescription;
@@ -176,7 +180,60 @@ public abstract class AbstractRepresentationDialectServices implements DialectSe
      */
     @Override
     public boolean canRefresh(DRepresentation representation) {
-        return isSupported(representation);
+        return isSupported(representation) && areRequiredViewpointsSelected(representation);
+    }
+
+    private boolean areRequiredViewpointsSelected(DRepresentation representation) {
+        boolean areRequiredViewpointsSelected = false;
+        if (representation != null) {
+            Collection<Viewpoint> requiredViewpoints = getRequiredViewpoints(representation);
+            if (!requiredViewpoints.isEmpty()) {
+                Session session = new EObjectQuery(representation).getSession();
+                if (session == null) {
+                    // To manage case representation is in creation then not yet
+                    // added to session, for example on viewpoint first
+                    // selection
+                    EObject target = ((DSemanticDecorator) representation).getTarget();
+                    session = new EObjectQuery(target).getSession();
+                }
+                if (session != null) {
+                    areRequiredViewpointsSelected = session.getSelectedViewpoints(false).containsAll(requiredViewpoints);
+                }
+            }
+        }
+        return areRequiredViewpointsSelected;
+    }
+
+    /**
+     * Tell if the {@link Viewpoint} owner of the
+     * {@link RepresentationDescription} is enabled on {@link Session}.
+     * 
+     * @param session
+     *            the {@link Session}
+     * @param representationDescription
+     *            a {@link RepresentationDescription} in the context of the
+     *            {@link Session}
+     * @return true if the {@link Viewpoint} owner of the
+     *         {@link RepresentationDescription} is enabled on {@link Session}
+     */
+    protected boolean isRelatedViewpointSelected(Session session, RepresentationDescription representationDescription) {
+        boolean isRelatedViewpointSelected = false;
+        Viewpoint parentViewpoint = new RepresentationDescriptionQuery(representationDescription).getParentViewpoint();
+        isRelatedViewpointSelected = session != null && parentViewpoint != null && session.getSelectedViewpoints(false).contains(parentViewpoint);
+        return isRelatedViewpointSelected;
+    }
+
+    @Override
+    public Set<Viewpoint> getRequiredViewpoints(DRepresentation representation) {
+        Set<Viewpoint> requiredViewpoints = new LinkedHashSet<Viewpoint>();
+        RepresentationDescription representationDescription = getDescription(representation);
+        if (representationDescription != null) {
+            Viewpoint parentViewpoint = new RepresentationDescriptionQuery(representationDescription).getParentViewpoint();
+            if (parentViewpoint != null) {
+                requiredViewpoints.add(parentViewpoint);
+            }
+        }
+        return requiredViewpoints;
     }
 
     /**
diff --git a/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/api/dialect/DialectServices.java b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/api/dialect/DialectServices.java
index f527947fea..c1d9bfe94e 100644
--- a/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/api/dialect/DialectServices.java
+++ b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/api/dialect/DialectServices.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2014 THALES GLOBAL SERVICES.
+ * Copyright (c) 2007, 2016 THALES GLOBAL SERVICES.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -12,6 +12,7 @@ package org.eclipse.sirius.business.api.dialect;
 
 import java.util.Collection;
 import java.util.Map;
+import java.util.Set;
 
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.emf.common.notify.Notification;
@@ -176,10 +177,14 @@ public interface DialectServices {
     /**
      * Tell whether the dialect is able to refresh the given representation.
      * 
+     * NOTE: a prerequisite to have a {@link DRepresentation} refreshable is to
+     * have its required viewpoints selected in the current session.
+     * 
      * @param representation
      *            representation to refresh.
      * @return true if the dialect can refresh the representation, false
      *         otherwise.
+     * @see DialectServices#getRequiredViewpoints(DRepresentation)
      */
     boolean canRefresh(DRepresentation representation);
 
@@ -187,6 +192,9 @@ public interface DialectServices {
      * Tell whether the dialect is able to create a representation from the
      * given representation description and the semantic object.
      * 
+     * NOTE: If the semantic does not belong to a session we do not check that
+     * required viewpoint is selected but only others things like domainClass
+     * 
      * @param semantic
      *            semantic object used to create the representation.
      * @param desc
@@ -354,4 +362,18 @@ public interface DialectServices {
      * @since 1.0.0 M6
      */
     boolean allowsEStructuralFeatureCustomization(EObject element);
+
+    /**
+     * Tell which {@link Viewpoint viewpoints} are required to do a refresh of
+     * the specified <code>representation</code>.
+     * 
+     * NOTE: only available viewpoints are returned. In some cases, the
+     * Viewpoint of a selected layer might not be available: for example if it
+     * is not installed.
+     * 
+     * @param representation
+     *            the specified {@link DRepresentation}
+     * @return the collection of required {@link Viewpoint viewpoints}
+     */
+    Set<Viewpoint> getRequiredViewpoints(DRepresentation representation);
 }
diff --git a/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/internal/dialect/DialectManagerImpl.java b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/internal/dialect/DialectManagerImpl.java
index f8fbb32703..d2121dbb9d 100644
--- a/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/internal/dialect/DialectManagerImpl.java
+++ b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/internal/dialect/DialectManagerImpl.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2015 THALES GLOBAL SERVICES and others.
+ * Copyright (c) 2007, 2016 THALES GLOBAL SERVICES and others.
  * 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
@@ -17,6 +17,7 @@ import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.NullProgressMonitor;
@@ -592,4 +593,16 @@ public class DialectManagerImpl implements DialectManager {
         }
         return customizationAllowed;
     }
+
+    @Override
+    public Set<Viewpoint> getRequiredViewpoints(DRepresentation representation) {
+        Set<Viewpoint> requiredViewpoints = null;
+        for (Dialect dialect : dialects.values()) {
+            if (dialect.getServices().handles(getDescription(representation))) {
+                requiredViewpoints = dialect.getServices().getRequiredViewpoints(representation);
+                break;
+            }
+        }
+        return requiredViewpoints;
+    }
 }