/******************************************************************************

 * Copyright (c) 2006, 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 API and implementation 

 ****************************************************************************/

package org.eclipse.gmf.runtime.diagram.ui.commands;

import java.util.Iterator;

import org.eclipse.core.commands.operations.IUndoableOperation;

import org.eclipse.gef.commands.Command;

import org.eclipse.gef.commands.CompoundCommand;

/**

 * Class containing commands utility methods.

 * 

 * @author aboyko

 *

 */

public class CommandUtilities {

	/**

	 * This utility function determines whether the command is redoable.

	 * Since GEF commands API doesn't support for canRedo method, this

	 * utility will help to travel through the contents of GEF wrapper

	 * commands and determine redoability of the GEF command based on

	 * the redoability of the commands it contains.

	 * 

	 * @param command The command to be examined

	 * @return <code>true</code> if the passed command is redoable

	 */

	public static boolean canRedo(Command command)

	{

		if (command == null)

			return false;

		if (command instanceof IUndoableOperation)

		{

			return ((IUndoableOperation) command).canRedo();

		}

		else if (command instanceof CompoundCommand)

		{

			for ( Iterator iter = ((CompoundCommand)command).getCommands().iterator(); iter.hasNext(); )

			{

				try

				{

					if (!canRedo((Command)iter.next()))

						return false;

				}

				catch (ClassCastException e)

				{

					return false;

				}

			}

			return true;

		}

		else if (command instanceof ICommandProxy)

		{

			return ((ICommandProxy)command).getICommand().canRedo();

		}

		return command.canExecute();

	}

}