/* 
 * Copyright (c) 2006 Stiftung Deutsches Elektronen-Synchroton, 
 * 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.GuideModel;
import org.csstudio.sds.util.GuideUtil;
import org.eclipse.gef.commands.Command;

/**
 * A command to change a Guide.
 * @author Kai Meyer
 */
public final class ChangeGuideCommand extends Command {

	/**
	 * The AbstzractWidgetModel.
	 */
	private AbstractWidgetModel _model;
	/**
	 * The old guide.
	 */
	private GuideModel _oldGuide;
	/**
	 * The new guide.
	 */
	private GuideModel _newGuide;
	/**
	 * The old alignment.
	 */
	private int _oldAlign;
	/**
	 * The new alignment.
	 */
	private int _newAlign;
	/**
	 * The orientation of the guide.
	 */
	private boolean _horizontal;
	
	/**
	 * Constructor.
	 * @param model
	 * 			The AbstractWidgetModel
	 * @param horizontalGuide
	 * 			The horizontal guide
	 */
	public ChangeGuideCommand(final AbstractWidgetModel model, final boolean horizontalGuide) {
		super();
		_model = model;
		_horizontal = horizontalGuide;
	}
	
	/**
	 * Changes the guide.
	 * @param newGuide
	 * 			The new guide
	 * @param newAlignment
	 * 			The new alignment
	 */
	protected void changeGuide(final GuideModel newGuide, final int newAlignment) {
		// You need to re-attach the part even if the oldGuide and the newGuide are the same
		// because the alignment could have changed
		if (newGuide != null) {
			newGuide.attachPart(_model, newAlignment);
		}
	}
		
	/**
	 * {@inheritDoc}
	 */
	@Override
	public void execute() {
		// Cache the old values
		_oldGuide = GuideUtil.getInstance().getGuide(_model, _horizontal);		
		if (_oldGuide != null) {
			_oldAlign = _oldGuide.getAlignment(_model);
		}
		redo();
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public void redo() {
		changeGuide(_newGuide, _newAlign);
	}
	
	/**
	 * Sets the new guide.
	 * @param guide
	 * 			The new guide
	 * @param alignment
	 * 			The new alignment
	 */
	public void setNewGuide(final GuideModel guide, final int alignment) {
		_newGuide = guide;
		_newAlign = alignment;
	}
	
	/**
	 * {@inheritDoc}
	 */
	@Override
	public void undo() {
		changeGuide(_oldGuide, _oldAlign);
	}

}