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: PositionCall.java 468650 2006-10-28 07:03:30Z minchau $
020     */
021    
022    package org.apache.xalan.xsltc.compiler;
023    
024    import org.apache.bcel.generic.ConstantPoolGen;
025    import org.apache.bcel.generic.ILOAD;
026    import org.apache.bcel.generic.INVOKEINTERFACE;
027    import org.apache.bcel.generic.InstructionList;
028    import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
029    import org.apache.xalan.xsltc.compiler.util.CompareGenerator;
030    import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
031    import org.apache.xalan.xsltc.compiler.util.TestGenerator;
032    
033    /**
034     * @author Jacek Ambroziak
035     * @author Santiago Pericas-Geertsen
036     * @author Morten Jorgensen
037     */
038    final class PositionCall extends FunctionCall {
039    
040        public PositionCall(QName fname) {
041            super(fname);
042        }
043    
044        public boolean hasPositionCall() {
045            return true;
046        }
047    
048        public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
049            final InstructionList il = methodGen.getInstructionList();
050    
051            if (methodGen instanceof CompareGenerator) {
052                il.append(((CompareGenerator)methodGen).loadCurrentNode());
053            }
054            else if (methodGen instanceof TestGenerator) {
055                il.append(new ILOAD(POSITION_INDEX));
056            }
057            else {
058                final ConstantPoolGen cpg = classGen.getConstantPool();
059                final int index = cpg.addInterfaceMethodref(NODE_ITERATOR,
060                                                           "getPosition",
061                                                           "()I");
062    
063                il.append(methodGen.loadIterator());
064                il.append(new INVOKEINTERFACE(index,1));
065            }
066        }
067    }