plugins/org.eclipse.epf.library.edit/src/org/eclipse/epf/library/edit/category/ObjectLinkItemProviderList.java

//------------------------------------------------------------------------------
// Copyright (c) 2005, 2006 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 implementation
//------------------------------------------------------------------------------
package org.eclipse.epf.library.edit.category;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

import org.eclipse.emf.common.notify.AdapterFactory;
import org.eclipse.emf.common.notify.Notifier;

/**
 * @author Phong Nguyen Le
 * @since 1.0
 */
public class ObjectLinkItemProviderList {

	public static List createList(AdapterFactory adapterFactory, List oldList,
			Object parent, Collection children) {
		List newChildren = new ArrayList();
		for (Iterator iter = children.iterator(); iter.hasNext();) {
			Notifier obj = (Notifier) iter.next();

			// look if there is an existing ObjectLinkItemProvider for this task
			// in the current children list first
			ObjectLinkItemProvider child = findExistingObjectLinkItemProvider(
					oldList, obj);
			if (child == null) {
				child = new ObjectLinkItemProvider(adapterFactory, parent, obj);
			} else {
				oldList.remove(child);
			}
			newChildren.add(child);
		}
		
		// dispose the old children
		if (oldList != null) {
			for (Iterator iter = oldList.iterator(); iter.hasNext();) {
				ObjectLinkItemProvider child = (ObjectLinkItemProvider) iter
						.next();
				child.dispose();
			}
		}
		return newChildren;
	}

	private static ObjectLinkItemProvider findExistingObjectLinkItemProvider(
			List children, Object obj) {
		if (children == null || children.isEmpty())
			return null;
		for (Iterator iter = children.iterator(); iter.hasNext();) {
			ObjectLinkItemProvider child = (ObjectLinkItemProvider) iter.next();
			if (child.getLinkedObject() == obj)
				return child;
		}
		return null;
	}

}