VEventStartComparator.java

/**
 * Licensed to Apereo under one or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information regarding copyright ownership. Apereo
 * licenses this file to you 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 the
 * following location:
 *
 * <p>http://www.apache.org/licenses/LICENSE-2.0
 *
 * <p>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.
 */
package org.jasig.portlet.calendar;

import java.util.Comparator;
import net.fortuna.ical4j.model.component.VEvent;

/**
 * VEventStartComparator compares to VEvents and orders them by starting date. For events that start
 * at the time, whichever event ends first will be considered "first".
 *
 * @author Jen Bourey
 */
public class VEventStartComparator implements Comparator<VEvent> {

  /*
   * (non-Javadoc)
   * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
   */
  public int compare(VEvent event1, VEvent event2) {

    if (event1.getStartDate().getDate().before(event2.getStartDate().getDate())) return -1;
    else if (event1.getStartDate().getDate().after(event2.getStartDate().getDate())) return 1;
    else if (event1.getStartDate().getDate().equals(event2.getStartDate().getDate())) {
      if (event1.getEndDate() == null && event2.getEndDate() == null) return 0;
      else if (event1.getEndDate() == null) return -1;
      else if (event2.getEndDate() == null) return 1;
      if (event1.getEndDate().getDate().before(event2.getEndDate().getDate())) return -1;
      else if (event1.getEndDate().getDate().before(event2.getEndDate().getDate())) return 1;
    }

    int comp = 0;

    if (event1.getSummary() != null && event2.getSummary() != null) {
      comp = event1.getSummary().getValue().compareTo(event2.getSummary().getValue());
      if (comp != 0) return comp;
    }
    if (event1.getName() != null && event2.getName() != null) {
      comp = event1.getName().compareTo(event2.getName());
      if (comp != 0) return comp;
    }
    if (event1.getDescription() != null && event2.getDescription() != null) {
      comp = event1.getDescription().getValue().compareTo(event2.getDescription().getValue());
      if (comp != 0) return comp;
    }
    return 0;
  }
}