001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements. See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership. The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the  "License");
007     * you may not use this file except in compliance with the License.
008     * You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    /*
019     * $Id: FilterGenerator.java 468649 2006-10-28 07:00:55Z minchau $
020     */
021    
022    package org.apache.xalan.xsltc.compiler.util;
023    
024    import org.apache.bcel.generic.ALOAD;
025    import org.apache.bcel.generic.Instruction;
026    import org.apache.xalan.xsltc.compiler.Stylesheet;
027    
028    /**
029     * This class implements auxliary classes needed to compile 
030     * filters (predicates). These classes defined a single method
031     * of type <tt>TestGenerator</tt>.
032     * @author Jacek Ambroziak
033     * @author Santiago Pericas-Geertsen
034     */
035    public final class FilterGenerator extends ClassGenerator {
036        private static int TRANSLET_INDEX = 5;   // translet
037        private final Instruction _aloadTranslet;
038    
039        public FilterGenerator(String className, String superClassName,
040                               String fileName,
041                               int accessFlags, String[] interfaces,
042                               Stylesheet stylesheet) {
043            super(className, superClassName, fileName,
044                  accessFlags, interfaces, stylesheet);
045            
046            _aloadTranslet = new ALOAD(TRANSLET_INDEX);
047        }
048    
049        /**
050         * The index of the translet pointer within the execution of
051         * the test method.
052         */
053        public final Instruction loadTranslet() {
054            return _aloadTranslet;
055        }
056        
057        /**
058         * Returns <tt>true</tt> since this class is external to the
059         * translet.
060         */
061        public boolean isExternal() {
062            return true;
063        }
064    }