    001// Copyright 2011 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.tapestry5.services.transform;
    016
    017import org.apache.tapestry5.plastic.PlasticClass;
    018import org.apache.tapestry5.services.ComponentEventHandler;
    019
    020/**
    021 * Additional utilities, beyond {@link PlasticClass}, needed when transforming.
    022 *
    023 * @since 5.3
    024 */
    025public interface TransformationSupport
    026{
    027    /**
    028     * @param typeName Java type name (which may be a primitive type or array, or fully qualified class name)
    029     * @return corresponding Java Class
    030     */
    031    Class toClass(String typeName);
    032
    033    /**
    034     * Returns true if the class being transformed is a root class: it does not inherit
    035     * from another transformed class, but instead inherits from Object.
    036     *
    037     * @return true if root
    038     */
    039    boolean isRootTransformation();
    040
    041    /**
    042     * Adds an event handler. Added event handlers execute <em>before</em> calls to super-class event handlers,
    043     * or calls to event handler methods.
    044     *
    045     * @param eventType            type of event
    046     * @param minContextValues     number of context values required to activate the handler
    047     * @param operationDescription Used with {@link org.apache.tapestry5.ioc.OperationTracker} when invoking the handler
    048     * @param handler              code to execute when the event matches
    049     */
    050    void addEventHandler(String eventType, int minContextValues, String operationDescription, ComponentEventHandler handler);
    051
    052}