001    // Copyright 2004, 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.bean;
016    
017    /**
018     *  Used to emit a stream of alterating string values: "even", "odd", etc.  This
019     *  is often used in the Inspector pages to make the class of a <tr> alternate
020     *  for presentation reasons.
021     *
022     *  @author Howard Lewis Ship
023     *
024     **/
025    
026    public class EvenOdd
027    {
028        private boolean even = true;
029    
030        /**
031         *  Returns "even" or "odd".  Whatever it returns on one invocation, it will
032         *  return the opposite on the next.  By default, the first value
033         *  returned is "even".
034         *
035         **/
036    
037        public String getNext()
038        {
039            String result = even ? "even" : "odd";
040    
041            even = !even;
042    
043            return result;
044        }
045        
046        public boolean isEven()
047        {
048            return even;
049        }
050    
051            /**
052             *  Overrides the even flag.
053             * 
054             **/
055            
056        public void setEven(boolean value)
057        {
058            even = value;
059        }
060    }