//------------------------------------------------------------------------------
// 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.authoring.gef.util;

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

import org.eclipse.emf.common.command.Command;
import org.eclipse.epf.authoring.ui.util.UIHelper;
import org.eclipse.epf.library.edit.ICommandListener;
import org.eclipse.epf.library.edit.process.command.VaryActivityCommand;

/**
 * Provides instructure to listens to actions like LocalContribution, Local Replace 
 * in WorkBreakdown Structure. Loads at time of plugin load.  
 * @see VaryActivityCommand
 *  
 * @author Shashidhar Kannoori
 * @author Shilpa Toraskar
 * @since  1.0
 */
public final class DiagramEditorUtil {

	
	private static DiagramEditorUtil instance = null;

	private List commandListeners;

	private DiagramEditorUtil() {
	}

	public static DiagramEditorUtil getInstance() {
		if (instance == null) {
			synchronized (DiagramEditorUtil.class) {
				if (instance == null) {
					instance = new DiagramEditorUtil();
				}
			}
		}
		return instance;
	}
	public List getVaryCommandListeners() {
		if (commandListeners == null) {
			commandListeners = new ArrayList();
		}

		commandListeners.add(new ICommandListener() {
			
			public void notifyExecuted(Command command) {
				// get contributor/replacer of the activity
				//
				Object wrapper = ((VaryActivityCommand)command).getWrapper();
				UIHelper.closeDiagramEditors(wrapper, new ArrayList());
				UIHelper.refreshOpenDiagramEditorsOfParent(wrapper, new ArrayList());
			}

			public Class getCommandType() {
				return VaryActivityCommand.class;
			}

			public void preUndo(Command command) {
				// get old contributor/replacer of the activity
				//
				Collection list = ((VaryActivityCommand)command).getResult();
				
				List listx = new ArrayList();
				for(Iterator iterator = list.iterator(); iterator.hasNext();){
					Object object = iterator.next();
					UIHelper.closeDiagramEditors(object, listx);
					UIHelper.refreshOpenDiagramEditorsOfParent(object, listx);
					listx.clear();
			}
				
		}

			public void preExecute(Command command) {
			}
		});

		return commandListeners;
	}
}