/*!
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU Lesser General Public License for more details.
*
* Copyright (c) 2002-2013 Pentaho Corporation.. All rights reserved.
*/
package org.pentaho.reporting.libraries.css.resolver.impl;
import java.util.Comparator;
import org.pentaho.reporting.libraries.css.model.CSSStyleRule;
import org.pentaho.reporting.libraries.css.selectors.CSSSelector;
import org.pentaho.reporting.libraries.css.selectors.SelectorWeight;
/**
* Creation-Date: 08.12.2005, 21:31:51
*
* @author Thomas Morgner
*/
public class CSSStyleRuleComparator implements Comparator
{
public CSSStyleRuleComparator()
{
}
/**
* Compares its two arguments for order. Returns a negative integer, zero, or
* a positive integer as the first argument is less than, equal to, or greater
* than the second.<p>
* <p/>
* The implementor must ensure that <tt>sgn(compare(x, y)) == -sgn(compare(y,
* x))</tt> for all <tt>x</tt> and <tt>y</tt>. (This implies that
* <tt>compare(x, y)</tt> must throw an exception if and only if
* <tt>compare(y, x)</tt> throws an exception.)<p>
* <p/>
* The implementor must also ensure that the relation is transitive:
* <tt>((compare(x, y)>0) && (compare(y, z)>0))</tt> implies
* <tt>compare(x, z)>0</tt>.<p>
* <p/>
* Finally, the implementer must ensure that <tt>compare(x, y)==0</tt> implies
* that <tt>sgn(compare(x, z))==sgn(compare(y, z))</tt> for all
* <tt>z</tt>.<p>
* <p/>
* It is generally the case, but <i>not</i> strictly required that
* <tt>(compare(x, y)==0) == (x.equals(y))</tt>. Generally speaking, any
* comparator that violates this condition should clearly indicate this fact.
* The recommended language is "Note: this comparator imposes orderings that
* are inconsistent with equals."
*
* @param o1 the first object to be compared.
* @param o2 the second object to be compared.
* @return a negative integer, zero, or a positive integer as the first
* argument is less than, equal to, or greater than the second.
* @throws ClassCastException if the arguments' types prevent them from being
* compared by this Comparator.
*/
public int compare(final Object o1, final Object o2)
{
final CSSStyleRule r1 = (CSSStyleRule) o1;
final CSSStyleRule r2 = (CSSStyleRule) o2;
final CSSSelector selector1 = r1.getSelector();
final CSSSelector selector2 = r2.getSelector();
final SelectorWeight weight1 = selector1.getWeight();
final SelectorWeight weight2 = selector2.getWeight();
return weight1.compareTo(weight2);
}
}