/* 
 * Copyright (c) 2008 Stiftung Deutsches Elektronen-Synchrotron, 
 * Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY.
 *
 * THIS SOFTWARE IS PROVIDED UNDER THIS LICENSE ON AN "../AS IS" BASIS. 
 * WITHOUT WARRANTY OF ANY KIND, EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED 
 * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR PARTICULAR PURPOSE AND 
 * NON-INFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE 
 * FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR 
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. SHOULD THE SOFTWARE PROVE DEFECTIVE 
 * IN ANY RESPECT, THE USER ASSUMES THE COST OF ANY NECESSARY SERVICING, REPAIR OR 
 * CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS LICENSE. 
 * NO USE OF ANY SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER THIS DISCLAIMER.
 * DESY HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, 
 * OR MODIFICATIONS.
 * THE FULL LICENSE SPECIFYING FOR THE SOFTWARE THE REDISTRIBUTION, MODIFICATION, 
 * USAGE AND OTHER RIGHTS AND OBLIGATIONS IS INCLUDED WITH THE DISTRIBUTION OF THIS 
 * PROJECT IN THE FILE LICENSE.HTML. IF THE LICENSE IS NOT INCLUDED YOU MAY FIND A COPY 
 * AT HTTP://WWW.DESY.DE/LEGAL/LICENSE.HTM
 */
 package org.csstudio.sds.ui.internal.commands;

import org.csstudio.sds.model.AbstractWidgetModel;
import org.csstudio.sds.model.ContainerModel;
import org.eclipse.gef.commands.Command;

/**
 * An undoable command that can be used to change the order of a widget in the model.
 * 
 * @author Kai Meyer
 * 
 */
public final class ChangeOrderCommand extends Command {
	/**
	 * The new index for the widget model.
	 */
	private int _newIndex;
	/**
	 * The old index of the widget model.
	 */
	private int _oldIndex;
	/**
	 * The widget model, which index has to be changed.
	 */
	private AbstractWidgetModel _widgetModel;
	/**
	 * The parent display model of the widget model.
	 */
	private ContainerModel _container;
	
	/**
	 * Constructor.
	 * @param containerModel
	 * 			The parent display model
	 * @param widgetModel
	 * 			The widget model
	 * @param index
	 * 			The new index
	 */
	public ChangeOrderCommand(final ContainerModel containerModel, final AbstractWidgetModel widgetModel, final int index) {
		assert containerModel != null;
		assert widgetModel != null;
		_newIndex = index;
		_widgetModel = widgetModel;
		_container = containerModel;
		_oldIndex = _container.getIndexOf(_widgetModel);
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public void execute() {
		_container.changeOrder(_widgetModel, _newIndex);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void undo() {
		_container.changeOrder(_widgetModel, _oldIndex);
	}
	
}