001    /*
002     * Sonar, open source software quality management tool.
003     * Copyright (C) 2009 SonarSource SA
004     * mailto:contact AT sonarsource DOT com
005     *
006     * Sonar is free software; you can redistribute it and/or
007     * modify it under the terms of the GNU Lesser General Public
008     * License as published by the Free Software Foundation; either
009     * version 3 of the License, or (at your option) any later version.
010     *
011     * Sonar is distributed in the hope that it will be useful,
012     * but WITHOUT ANY WARRANTY; without even the implied warranty of
013     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014     * Lesser General Public License for more details.
015     *
016     * You should have received a copy of the GNU Lesser General Public
017     * License along with Sonar; if not, write to the Free Software
018     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
019     */
020    package org.sonar.squid.measures;
021    
022    public class AbstractnessFormula implements CalculatedMetricFormula {
023    
024      public double calculate(Measurable measurable) {
025        if (measurable.getDouble(Metric.CLASSES) == 0) {
026          return 0;
027        }
028        return (measurable.getDouble(Metric.ABSTRACT_CLASSES) + measurable.getDouble(Metric.INTERFACES)) / measurable.getDouble(Metric.CLASSES);
029      }
030    
031    }