001    // Copyright 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.annotations;
016    
017    import java.lang.reflect.Method;
018    
019    import org.apache.hivemind.Resource;
020    import org.apache.tapestry.enhance.EnhancementOperation;
021    import org.apache.tapestry.spec.IComponentSpecification;
022    
023    /**
024     * A chain-of-command interface for secondary annotation workers; workers that must execute
025     * <em>after</em> other workers.
026     * 
027     * @author Howard M. Lewis Ship
028     */
029    public interface SecondaryAnnotationWorker
030    {
031        /**
032         * Sees if the particular worker can process the method (because it handles an annotation
033         * associated with the method).
034         * 
035         * @param method
036         *            to check
037         * @return true if the worker should be invoked, false otherwise
038         */
039        boolean canEnhance(Method method);
040    
041        /**
042         * Invoked an <em>all</em> workers in the command chain, if <em>any</em> worker returns true
043         * from {@link #canEnhance(Method)}.
044         * 
045         * @param op
046         *            enhancement operation
047         * @param spec
048         *            specification for the component being enhanced
049         * @param method
050         *            the method
051         * @param classResource
052         *            a resource representing the class; combined with the method a
053         *            {@link org.apache.hivemind.Location} can be created
054         */
055        void peformEnhancement(EnhancementOperation op, IComponentSpecification spec,
056                Method method, Resource classResource);
057    }