/* 
 * 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 java.util.ArrayList;
import java.util.List;

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

/**
 * A command, that deletes an widget model from the display model.
 * 
 * @author Sven Wende & Stefan Hofer
 * 
 */
public final class DeleteWidgetsCommand extends Command {
	/**
	 * The display model.
	 */
	private ContainerModel _container;

	/**
	 * The element that gets deleted.
	 */
	private List<AbstractWidgetModel> _deletedWidgets;

	/**
	 * The original indices of the deleted widgets within the container.
	 */
	private List<Integer> _indices;

	/**
	 * The graphical viewer.
	 */
	private EditPartViewer _viewer;

	/**
	 * Constructor.
	 * 
	 * @param container
	 *            the display model
	 * @param widgets
	 *            the widgets, that should be deleted
	 */
	public DeleteWidgetsCommand(final EditPartViewer viewer, final ContainerModel container, final List<AbstractWidgetModel> widgets) {
		assert container != null;
		assert widgets != null;
		_viewer = viewer;
		_container = container;
		_deletedWidgets = widgets;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void execute() {
		// very important for performance (deselecting all widgets before a
		// delete operation reduces unnecessary refresh calls on the property
		// view)
		if (_viewer != null) {
			_viewer.deselectAll();
		}

		_indices = new ArrayList<Integer>(_deletedWidgets.size());
		for (AbstractWidgetModel w : _deletedWidgets) {
			_indices.add(_container.getIndexOf(w));
		}

		_container.removeWidgets(_deletedWidgets);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void undo() {
		_container.addWidgets(_indices, _deletedWidgets);
		// _container.selectWidgets(_deletedWidgets);
	}

}