| /******************************************************************************* |
| * Copyright (c) 2007, 2008 Oracle. 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: |
| * Oracle - initial API and implementation |
| ******************************************************************************/ |
| package org.eclipse.jpt.utility.internal.model.value; |
| |
| import java.util.Iterator; |
| import org.eclipse.jpt.utility.internal.ClassTools; |
| import org.eclipse.jpt.utility.internal.iterators.EmptyIterator; |
| import org.eclipse.jpt.utility.internal.model.AbstractModel; |
| import org.eclipse.jpt.utility.model.value.CollectionValueModel; |
| |
| /** |
| * A read-only collection value model for when you |
| * don't need to support a collection. In particular, this |
| * is useful for the leaf nodes of a tree that never have |
| * children. |
| * |
| * We don't use a singleton because we hold on to listeners. |
| */ |
| public final class NullCollectionValueModel<E> |
| extends AbstractModel |
| implements CollectionValueModel<E> |
| { |
| private static final long serialVersionUID = 1L; |
| |
| /** |
| * Default constructor. |
| */ |
| public NullCollectionValueModel() { |
| super(); |
| } |
| |
| |
| // ********** CollectionValueModel implementation ********** |
| |
| public int size() { |
| return 0; |
| } |
| |
| public Iterator<E> iterator() { |
| return EmptyIterator.instance(); |
| } |
| |
| |
| // ********** Object overrides ********** |
| |
| @Override |
| public String toString() { |
| return ClassTools.shortClassNameForObject(this); |
| } |
| |
| } |