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>
020     * alternate for presentation reasons.
021     * 
022     * @author Howard Lewis Ship
023     */
024    
025    public class EvenOdd
026    {
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 returned is
033         * "even".
034         */
035    
036        public String getNext()
037        {
038            String result = even ? "even" : "odd";
039    
040            even = !even;
041    
042            return result;
043        }
044    
045        public boolean isEven()
046        {
047            return even;
048        }
049    
050        /**
051         * Overrides the even flag.
052         */
053    
054        public void setEven(boolean value)
055        {
056            even = value;
057        }
058    }