/* 
 * 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;

import java.util.ArrayList;
import java.util.List;

/**
 * A tracker for error messages. Error messages are kept internally and can be
 * requested as one joined <code>String</code>.
 * 
 * @author Alexander Will
 * @version $Revision: 1.3 $
 * 
 */
public class ErrorMessagesTracker {
	/**
	 * Error messages that have been tracked.
	 */
	private List<String> _errorMessages;

	/**
	 * Standard constructor.
	 */
	public ErrorMessagesTracker() {
		resetErrorMessages();
	}

	/**
	 * Reset the internal error messages log.
	 */
	protected final void resetErrorMessages() {
		_errorMessages = new ArrayList<String>();
	}

	/**
	 * Add an error message to the internal error messages log.
	 * 
	 * @param errorMessage
	 *            An error message.
	 */
	protected final void trackErrorMessage(final String errorMessage) {
		_errorMessages.add(errorMessage);
	}

	/**
	 * Return whether an error occurred during the last operation of this
	 * service.
	 * 
	 * @return True, if an error occurred during the last operation of this
	 *         service.
	 */
	public final boolean isErrorOccurred() {
		return (_errorMessages.size() > 0);
	}

	/**
	 * Return the internal error messages protocol of the last operation of this
	 * service.
	 * 
	 * @return The internal error messages protocol of the last operation of
	 *         this service.
	 */
	public final List<String> getErrorMessages() {
		return new ArrayList<String>(_errorMessages);
	}
}