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    
021    package org.sonar.api.measures;
022    
023    import java.util.List;
024    import java.util.Collections;
025    import java.util.Collection;
026    
027    /**
028     * @since 2.0
029     *
030     * Used to consolidate a distribution measure throughout the resource tree
031     */
032    public class SumChildDistributionFormula implements Formula {
033    
034      public List<Metric> dependsUponMetrics() {
035        return Collections.emptyList();
036      }
037    
038      public Measure calculate(FormulaData data, FormulaContext context) {
039        Collection<Measure> measures = data.getChildrenMeasures(context.getTargetMetric());
040        if (measures == null || measures.isEmpty()) {
041          return null;
042        }
043        else {
044          CountDistributionBuilder distribution = new CountDistributionBuilder(context.getTargetMetric());
045          for (Measure measure : measures) {
046            distribution.add(measure);
047          }
048          return distribution.build();
049        }
050      }
051    }