CommonParentRowColumnAffinity.java

/*******************************************************************************
 * Copyright 2014 University of Southern California
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 * 	http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 * This code was developed by the Information Integration Group as part 
 * of the Karma project at the Information Sciences Institute of the 
 * University of Southern California.  For more information, publications, 
 * and related projects, please see: http://www.isi.edu/integration
 ******************************************************************************/
package edu.isi.karma.kr2rml.affinity;

import edu.isi.karma.rep.HNodePath;

public class CommonParentRowColumnAffinity implements ColumnAffinity {

	public static final ColumnAffinity INSTANCE = new CommonParentRowColumnAffinity();
	private int distanceToParent;
	private CommonParentRowColumnAffinity()
	{
		
	}
	private CommonParentRowColumnAffinity(HNodePath a, HNodePath b)
	{
		distanceToParent = a.length() - HNodePath.findCommon(a, b).length();
	}
	
	@Override
	public ColumnAffinity generateAffinity(HNodePath a, HNodePath b)
	{
		return new CommonParentRowColumnAffinity(a, b);
	}
	@Override
	public int compareTo(ColumnAffinity o) {
		if(o instanceof NoColumnAffinity)
		{
			return -1;
		}
		else if(o instanceof CommonParentRowColumnAffinity)
		{
			CommonParentRowColumnAffinity c = (CommonParentRowColumnAffinity) o;
			return this.distanceToParent - c.getDistanceToParent();
		}
		return 1;
	}

	@Override
	public boolean isValidFor(HNodePath a, HNodePath b) {
		return (!HNodePath.findCommon(a, b).isEmpty());
	}

	@Override
	public boolean isCloserThan(ColumnAffinity otherAffinity) {
		
		return compareTo(otherAffinity) < 0;
	}

	public int getDistanceToParent()
	{
		return distanceToParent;
	}
	
	
}