/* 
 * 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.properties.view;

import org.eclipse.gef.commands.Command;

/**
 * A Command used to restore the default value of a property.
 * 
 * @author Sven Wende
 */
final class ResetValueCommand extends Command {

	/**
	 * The property that has to be reset.
	 */
	private Object _propertyName;

	/**
	 * The current non-default value of the property.
	 */
	private Object _undoValue;

	/**
	 * The property source whose property has to be reset.
	 */
	private IPropertySource _target;

	/**
	 * Default Constructor: Sets the label for the Command.
	 * 
	 * @since 3.1
	 */
	public ResetValueCommand() {
		super("Restore Default Value");
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public boolean canExecute() {
		boolean answer = false;
		if (_target != null && _propertyName != null) {
			answer = _target.isPropertySet(_propertyName);
			if (_target instanceof IPropertySource2) {
				answer = answer
						&& (((IPropertySource2) _target)
								.isPropertyResettable(_propertyName));
			}
		}
		return answer;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void execute() {
		_undoValue = _target.getPropertyValue(_propertyName);
		if (_undoValue instanceof IPropertySource) {
			_undoValue = ((IPropertySource) _undoValue).getEditableValue();
		}
		redo();
	}

	/**
	 * Sets the IPropertySource.
	 * 
	 * @param propSource
	 *            the IPropertySource whose property has to be reset
	 */
	public void setTarget(final IPropertySource propSource) {
		_target = propSource;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void redo() {
		_target.resetPropertyValue(_propertyName);
	}

	/**
	 * Sets the property that is to be reset.
	 * 
	 * @param pName
	 *            the property to be reset
	 */
	public void setPropertyId(final Object pName) {
		_propertyName = pName;
	}

	/**
	 * Restores the non-default value that was reset.
	 * 
	 * @see org.eclipse.gef.commands.Command#undo()
	 */
	@Override
	public void undo() {
		_target.setPropertyValue(_propertyName, _undoValue);
	}

}