platform/openide.util.lookup/src/org/openide/util/LookupListener.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * 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.openide.util;

import java.util.*;


/** General listener for changes in lookup.
 *
 * @author  Jaroslav Tulach
 */
public interface LookupListener extends EventListener {
    /** A change in lookup occured. Please note that this method
     * should never block since it might be called from lookup implementation
     * internal threads. If you block here you are in risk that the thread
     * you wait for might in turn to wait for the lookup internal thread to
     * finish its work.
     * @param ev event describing the change
     */
    public void resultChanged(LookupEvent ev);
}