001    /**
002     *  Licensed to the Apache Software Foundation (ASF) under one or more
003     *  contributor license agreements.  See the NOTICE file distributed with
004     *  this work for additional information regarding copyright ownership.
005     *  The ASF licenses this file to You under the Apache License, Version 2.0
006     *  (the "License"); you may not use this file except in compliance with
007     *  the License.  You may obtain a copy of the License at
008     *
009     *     http://www.apache.org/licenses/LICENSE-2.0
010     *
011     *  Unless required by applicable law or agreed to in writing, software
012     *  distributed under the License is distributed on an "AS IS" BASIS,
013     *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     *  See the License for the specific language governing permissions and
015     *  limitations under the License.
016     */
017    package org.apache.geronimo.console.infomanager;
018    
019    import java.util.TreeMap;
020    import java.util.Map;
021    
022    /**
023     * A Map that can remove items as they are accessed, which makes it
024     * easier to show a list of the remaining items.
025     *
026     * @version $Rev: 706640 $ $Date: 2008-10-21 14:44:05 +0000 (Tue, 21 Oct 2008) $
027     */
028    public class ShrinkingMap extends TreeMap {
029        private boolean shrinking = false;
030    
031        public ShrinkingMap() {
032        }
033    
034        public ShrinkingMap(Map defaults) {
035            super(defaults);
036        }
037    
038        public boolean isShrinking() {
039            return shrinking;
040        }
041    
042        public void setShrinking(boolean shrinking) {
043            this.shrinking = shrinking;
044        }
045    
046        public synchronized Object get(Object key) {
047            if(shrinking) {
048                return super.remove(key);
049            } else {
050                return super.get(key);
051            }
052        }
053    
054        public Map getRemainingItems() {
055            shrinking = false;
056            return this;
057        }
058    }