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
015package org.apache.tapestry.annotations;
016
017import java.lang.reflect.Method;
018
019import org.apache.hivemind.Resource;
020import org.apache.tapestry.enhance.EnhancementOperation;
021import 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 */
029public 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    public 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    public void peformEnhancement(EnhancementOperation op, IComponentSpecification spec,
056            Method method, Resource classResource);
057}