f@0: /*  
f@0:  CCmI Editor - A Collaborative Cross-Modal Diagram Editing Tool
f@0:   
f@0:  Copyright (C) 2011  Queen Mary University of London (http://ccmi.eecs.qmul.ac.uk/)
f@0: 
f@0:  This program is free software: you can redistribute it and/or modify
f@0:  it under the terms of the GNU General Public License as published by
f@0:  the Free Software Foundation, either version 3 of the License, or
f@0:  (at your option) any later version.
f@0: 
f@0:  This program is distributed in the hope that it will be useful,
f@0:  but WITHOUT ANY WARRANTY; without even the implied warranty of
f@0:  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
f@0:  GNU General Public License for more details.
f@0: 
f@0:  You should have received a copy of the GNU General Public License
f@0:  along with this program.  If not, see <http://www.gnu.org/licenses/>.
f@0: */
f@0: package uk.ac.qmul.eecs.ccmi.diagrammodel;
f@0: 
f@0: import java.util.Comparator;
f@0: 
f@0: /**
f@0:  * A Comparator for diagram elements. The elements are ordered by their id.  
f@0:  *
f@0:  * @see DiagramElement#getId()
f@0:  */
f@0: public class DiagramElementComparator implements Comparator<DiagramElement> {
f@0: 	public static DiagramElementComparator getInstance(){
f@0: 		if(comparator == null)
f@0: 			comparator = new DiagramElementComparator();
f@0: 		return comparator;
f@0: 	}
f@0: 	
f@0: 	@Override
f@0: 	public int compare(DiagramElement de1, DiagramElement de2) {
f@0: 		if(de1.getId() == de2.getId())
f@0: 			return 0;
f@0: 		else if(de1.getId() < de2.getId())
f@0: 			return -1;
f@0: 		else 
f@0: 			return 1;
f@0: 	}	
f@0: 
f@0: 	private static DiagramElementComparator comparator;
f@0: }