Bug 511616: [Infra] CreateRelationshipCommand should allow modifications

of source and target on ConfigureRequest from CreateRequest

https://bugs.eclipse.org/bugs/show_bug.cgi?id=511616

- Creating a new command to override GMF basic one
- Use this command in DefaultEditHelper, the basic helper used in
Papyrus for almost any element.

Signed-off-by: Remi Schnekenburger <rschnekenburger@eclipsesource.com>

2 files changed, 79 insertions, 0 deletions

diff --git a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/commands/CreateRelationshipCommandEx.java b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/commands/CreateRelationshipCommandEx.java
new file mode 100644
index 00000000000..68e889a17e1
--- /dev/null
+++ b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/commands/CreateRelationshipCommandEx.java
@@ -0,0 +1,57 @@
+/*****************************************************************************
+ * Copyright (c) 2017 CEA LIST 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
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   CEA LIST - Initial API and implementation
+ *   
+ *****************************************************************************/
+
+package org.eclipse.papyrus.infra.gmfdiag.common.commands;
+
+import org.eclipse.gmf.runtime.emf.type.core.commands.CreateRelationshipCommand;
+import org.eclipse.gmf.runtime.emf.type.core.requests.ConfigureRequest;
+import org.eclipse.gmf.runtime.emf.type.core.requests.CreateRelationshipRequest;
+
+/**
+ * Specific {@link CreateRelationshipCommand} that does not set the source and target in the configure request if it is already set.
+ * <p>
+ * This allows to override the source and/or the target in the advices. Basic GMF implementation reset the {@link CreateRelationshipRequest#SOURCE} & {@link CreateRelationshipRequest#TARGET} when the configureRequest is created, with original values.
+ * </p>
+ */
+public class CreateRelationshipCommandEx extends CreateRelationshipCommand {
+
+	/**
+	 * Constructor.
+	 *
+	 * @param request
+	 *            the element creation request
+	 */
+	public CreateRelationshipCommandEx(CreateRelationshipRequest request) {
+		super(request);
+	}
+
+	@Override
+	protected ConfigureRequest createConfigureRequest() {
+		// let the super() create the requests as usual
+		ConfigureRequest result = super.createConfigureRequest();
+		
+		// retrieve those from create request
+		Object requestSource = getRequest().getParameter(CreateRelationshipRequest.SOURCE); 
+		Object requestTarget = getRequest().getParameter(CreateRelationshipRequest.TARGET);
+		
+		// overrides parameters only if necessary, e.g. set and different
+		if (requestSource != null && !requestSource.equals(result.getParameter(CreateRelationshipRequest.SOURCE))) {
+			result.setParameter(CreateRelationshipRequest.SOURCE, requestSource);
+		}
+		if (requestTarget != null && !requestTarget.equals(result.getParameter(CreateRelationshipRequest.TARGET))) {
+			result.setParameter(CreateRelationshipRequest.TARGET, requestTarget);
+		}
+		return result;
+	}
+
+}
diff --git a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/helper/DefaultEditHelper.java b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/helper/DefaultEditHelper.java
index 8a03c87f595..5c16a7215f5 100644
--- a/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/helper/DefaultEditHelper.java
+++ b/plugins/infra/gmfdiag/org.eclipse.papyrus.infra.gmfdiag.common/src/org/eclipse/papyrus/infra/gmfdiag/common/helper/DefaultEditHelper.java
@@ -24,6 +24,7 @@ import org.eclipse.emf.ecore.EClassifier;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.EReference;
 import org.eclipse.gmf.runtime.common.core.command.ICommand;
+import org.eclipse.gmf.runtime.common.core.command.IdentityCommand;
 import org.eclipse.gmf.runtime.emf.type.core.ElementTypeRegistry;
 import org.eclipse.gmf.runtime.emf.type.core.IClientContext;
 import org.eclipse.gmf.runtime.emf.type.core.IContainerDescriptor;
@@ -40,6 +41,7 @@ import org.eclipse.papyrus.commands.DestroyElementPapyrusCommand;
 import org.eclipse.papyrus.infra.emf.commands.UnsetValueCommand;
 import org.eclipse.papyrus.infra.emf.requests.UnsetRequest;
 import org.eclipse.papyrus.infra.gmfdiag.common.commands.CreateEditBasedElementCommand;
+import org.eclipse.papyrus.infra.gmfdiag.common.commands.CreateRelationshipCommandEx;
 import org.eclipse.papyrus.infra.services.edit.utils.CacheRegistry;
 import org.eclipse.papyrus.infra.services.edit.utils.IRequestCacheEntries;
 import org.eclipse.papyrus.infra.types.core.notification.AbstractNotifierEditHelper;
@@ -159,6 +161,26 @@ public class DefaultEditHelper extends AbstractNotifierEditHelper {
 	}
 
 	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	protected ICommand getCreateRelationshipCommand(CreateRelationshipRequest req) {
+		EObject source = req.getSource();
+        EObject target = req.getTarget();
+
+        boolean noSourceOrTarget = (source == null || target == null);
+        boolean noSourceAndTarget = (source == null && target == null);
+
+        if (noSourceOrTarget && !noSourceAndTarget) {
+            // The request isn't complete yet. Return the identity command so
+            // that the create relationship gesture is enabled.
+            return IdentityCommand.INSTANCE;
+        }
+        
+		return new CreateRelationshipCommandEx(req);
+	}
+	
+	/**
 	 * Gets the command to destroy a single child of an element of my kind along
 	 * with its dependents (not related by containment). By default, returns a
 	 * composite that destroys the elements and zero or more dependents.