| /******************************************************************************* |
| * Copyright (c) 2005, 2012 IBM Corporation 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: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.bpel.ui.adapters.delegates; |
| |
| import org.eclipse.emf.ecore.EClass; |
| import org.eclipse.emf.ecore.EObject; |
| import org.eclipse.emf.ecore.EReference; |
| |
| /** |
| * An IndirectContainer which can create the EObject which is the target of the |
| * indirection when an object is first inserted, and discard it when the last object |
| * is removed from the list. This is useful (for example) in Scope. |
| */ |
| public class OptionalIndirectContainer extends IndirectContainer { |
| |
| public OptionalIndirectContainer(EReference feature, AbstractContainer innerContainer) { |
| super(feature, innerContainer); |
| } |
| |
| protected void createTarget(Object object) { |
| EClass targetClass = fIndirectionFeature.getEReferenceType(); |
| EObject newTarget = targetClass.getEPackage().getEFactoryInstance().create(targetClass); |
| ((EObject)object).eSet(fIndirectionFeature, newTarget); |
| } |
| |
| protected void discardTarget(Object object) { |
| ((EObject)object).eSet(fIndirectionFeature, null); |
| } |
| |
| /* IContainer */ |
| |
| @Override |
| public boolean addChild(EObject object, EObject child, EObject insertBefore) { |
| if (getTarget(object) == null) { |
| createTarget(object); |
| boolean result = super.addChild(object, child, insertBefore); |
| if (getChildren(object).isEmpty()) discardTarget(object); |
| return result; |
| } |
| return super.addChild(object, child, insertBefore); |
| } |
| |
| @Override |
| public boolean removeChild(EObject object, EObject child) { |
| if (getTarget(object) == null) return false; |
| boolean result = super.removeChild(object, child); |
| if (getChildren(object).isEmpty()) discardTarget(object); |
| return result; |
| } |
| |
| @Override |
| public boolean replaceChild(EObject object, EObject oldChild, EObject newChild) { |
| if (getTarget(object) == null) return false; |
| return super.replaceChild(object, oldChild, newChild); |
| } |
| } |