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

import org.csstudio.sds.model.AbstractWidgetModel;
import org.csstudio.sds.model.DisplayModel;
import org.csstudio.sds.ui.editparts.AbstractBaseEditPart;
import org.csstudio.sds.ui.internal.editparts.DisplayEditPart;
import org.eclipse.gef.EditPart;
import org.eclipse.gef.EditPartViewer;
import org.eclipse.gef.commands.Command;

/**
 * An undoable command that can be used remove the current selection of a
 * graphical viewer.
 * 
 * @author swende
 * 
 */
public final class SetSelectionCommand extends Command {

	private List<AbstractWidgetModel> _oldSelection;
	
	private EditPartViewer _viewer;

	private DisplayModel _displayModel;
	
	private List<AbstractWidgetModel> _newSelection;

	/**
	 * Constructor.
	 * @param viewer the graphical viewer 
	 */
	public SetSelectionCommand(EditPartViewer viewer, List<AbstractWidgetModel> selectedWidgets) {
		assert viewer != null;
		assert selectedWidgets!=null;
		_viewer = viewer;
		_displayModel = (DisplayModel)((DisplayEditPart) _viewer.getRootEditPart().getChildren().get(0)).getModel();
		_newSelection = selectedWidgets;
	}

	public SetSelectionCommand(EditPartViewer viewer, AbstractWidgetModel widget) {
		this(viewer, Arrays.asList(widget));
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void execute() {
		// memorize old selection
		_oldSelection = new ArrayList<AbstractWidgetModel>();
		
		for(EditPart ep : (List<EditPart>)_viewer.getSelectedEditParts()) {
			if(ep instanceof AbstractBaseEditPart) {
				_oldSelection.add(((AbstractBaseEditPart)ep).getWidgetModel());
			}
		}

		// select new widgets
		_displayModel.selectWidgets(_newSelection);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void undo() {
		_displayModel.selectWidgets(_oldSelection);
	}

}