001 // Copyright 2011, 2012 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.tapestry5.plastic; 016 017 /** 018 * Allows a listener to be notified about classes about to be loaded by the manager's class loader. 019 * Some classes are loaded by the same class loader but not transformed (for example, inner classes). These 020 * do not generate events. In many cases, transforming a class will cause supporting classes (representing 021 * {@link MethodInvocation}s, and other things) to be created; these do generate events, and can be distinguished 022 * by the {@linkplain PlasticClassEvent#getType() event's type property}. 023 * 024 * @see PlasticClassListenerHub 025 */ 026 public interface PlasticClassListener 027 { 028 /** 029 * Invoked just before a class is to be loaded. Separate events are fired for supporting classes before 030 * the event for the primary class (the class being transformed or created from scratch). 031 * 032 * @param event 033 * describes the class to be loaded, and gives access to its disassembled 034 * bytecode (for debugging purposes) 035 */ 036 void classWillLoad(PlasticClassEvent event); 037 }