1 files changed, 116 insertions, 0 deletions
diff --git a/plugins/org.eclipse.sirius.diagram/src/org/eclipse/sirius/diagram/business/internal/refresh/SiriusDiagramSessionEventBroker.java b/plugins/org.eclipse.sirius.diagram/src/org/eclipse/sirius/diagram/business/internal/refresh/SiriusDiagramSessionEventBroker.java
new file mode 100644
index 0000000000..ed93caec6b
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+++ b/plugins/org.eclipse.sirius.diagram/src/org/eclipse/sirius/diagram/business/internal/refresh/SiriusDiagramSessionEventBroker.java
@@ -0,0 +1,116 @@
+/*******************************************************************************
+ * Copyright (c) 2011, 2021 THALES GLOBAL SERVICES.
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *    Obeo - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.sirius.diagram.business.internal.refresh;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.WeakHashMap;
+
+import org.eclipse.emf.common.command.Command;
+import org.eclipse.emf.common.notify.Notification;
+import org.eclipse.emf.transaction.TransactionalEditingDomain;
+import org.eclipse.sirius.business.api.session.ModelChangeTrigger;
+import org.eclipse.sirius.business.api.session.Session;
+import org.eclipse.sirius.business.internal.session.SessionEventBrokerImpl;
+import org.eclipse.sirius.ext.base.Option;
+import org.eclipse.sirius.ext.base.Options;
+import org.eclipse.sirius.tools.api.SiriusPlugin;
+
+import com.google.common.base.Predicate;
+
+/**
+ * Specific {@link ModelChangeTrigger} per Session to synchronize the GMF notation models from the Session Resource
+ * changes (DAnalysis).
+ * 
+ * @author <a href="mailto:esteban.dugueperoux@obeo.fr">Esteban Dugueperoux</a>
+ */
+public final class SiriusDiagramSessionEventBroker implements ModelChangeTrigger {
+
+    /**
+     * Priority of this {@link ModelChangeTrigger}.
+     */
+    public static final int PRIORITY = 4;
+
+    /**
+     * Use of Weak reference to have {@link SiriusDiagramSessionEventBroker} automatically garbage collected once the
+     * {@link Session}'s SessionEventBroker has disposed all its ModelChangeTrigger
+     **/
+    private static final Map<Session, SiriusDiagramSessionEventBroker> INSTANCES_MAP = new WeakHashMap<Session, SiriusDiagramSessionEventBroker>();
+
+    private static Predicate<Notification> scope = new DSemanticDiagramScopePredicate();
+
+    private static SiriusGMFSynchronizerDispatcher viewpointGMFSynchronizerDispatcher = new SiriusGMFSynchronizerDispatcher();
+
+    private SiriusDiagramSessionEventBroker() {
+        // Can't instantiate this singleton
+    }
+
+    /**
+     * Return a SiriusDiagramSessionEventBroker for this session, create a new one if not already existing.
+     * 
+     * @param session
+     *            {@link Session} for which to get a SiriusDiagramSessionEventBroker
+     * 
+     * @return a SiriusDiagramSessionEventBroker for this session
+     */
+    public static SiriusDiagramSessionEventBroker getInstance(Session session) {
+        return initializeDiagramEventBroker(session);
+    }
+
+    private static SiriusDiagramSessionEventBroker initializeDiagramEventBroker(Session session) {
+        SiriusDiagramSessionEventBroker reference = INSTANCES_MAP.get(session);
+        if (reference == null) {
+            SiriusDiagramSessionEventBroker viewpointDiagramSessionEventBroker = new SiriusDiagramSessionEventBroker();
+            session.getEventBroker().addLocalTrigger(SessionEventBrokerImpl.asFilter(scope), viewpointDiagramSessionEventBroker);
+            reference = viewpointDiagramSessionEventBroker;
+            INSTANCES_MAP.put(session, reference);
+        }
+        return reference;
+    }
+
+    @Override
+    public Option<Command> localChangesAboutToCommit(Collection<Notification> notifications) {
+        if (!SiriusPlugin.getDefault().isRepairInProgress()) {
+            TransactionalEditingDomain domain = getSession().getTransactionalEditingDomain();
+            Option<Command> triggerCommand = Options.newSome(viewpointGMFSynchronizerDispatcher.getGMFNotationModelSynchronizationCmd(domain, notifications));
+            return triggerCommand;
+        } else {
+            return Options.newNone();
+        }
+    }
+
+    private Session getSession() {
+        Session session = null;
+        for (Entry<Session, SiriusDiagramSessionEventBroker> entry : INSTANCES_MAP.entrySet()) {
+            if (this.equals(entry.getValue())) {
+                session = entry.getKey();
+                break;
+            }
+        }
+        return session;
+    }
+
+    /**
+     * Return the low priority to get call after others synchronizers (DDiagramSynchronizer, DTreeSynchronizer,
+     * DTableSynchronizer, ...), excepts for RefreshLayoutTrigger from sequence dialect which must be called of this one
+     * to avoid StackOverflow.
+     * 
+     * {@inheritDoc}
+     */
+    @Override
+    public int priority() {
+        return PRIORITY;
+    }
+
+}