1/*
2 * reserved comment block
3 * DO NOT REMOVE OR ALTER!
4 */
5/*
6 * Licensed to the Apache Software Foundation (ASF) under one or more
7 * contributor license agreements.  See the NOTICE file distributed with
8 * this work for additional information regarding copyright ownership.
9 * The ASF licenses this file to You under the Apache License, Version 2.0
10 * (the "License"); you may not use this file except in compliance with
11 * the License.  You may obtain a copy of the License at
12 *
13 *      http://www.apache.org/licenses/LICENSE-2.0
14 *
15 * Unless required by applicable law or agreed to in writing, software
16 * distributed under the License is distributed on an "AS IS" BASIS,
17 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
18 * See the License for the specific language governing permissions and
19 * limitations under the License.
20 */
21
22package com.sun.org.apache.xalan.internal.xsltc.compiler;
23
24import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
25import com.sun.org.apache.bcel.internal.generic.InstructionList;
26import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
27import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
28import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
29import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
30
31/**
32 * @author Morten Jorgensen
33 */
34final class Fallback extends Instruction {
35
36    private boolean _active = false;
37
38    /**
39     * This element never produces any data on the stack
40     */
41    public Type typeCheck(SymbolTable stable) throws TypeCheckError {
42        if (_active) {
43            return(typeCheckContents(stable));
44        }
45        else {
46            return Type.Void;
47        }
48    }
49
50    /**
51     * Activate this fallback element
52     */
53    public void activate() {
54        _active = true;
55    }
56
57    public String toString() {
58        return("fallback");
59    }
60
61    /**
62     * Parse contents only if this fallback element is put in place of
63     * some unsupported element or non-XSLTC extension element
64     */
65    public void parseContents(Parser parser) {
66        if (_active) parseChildren(parser);
67    }
68
69    /**
70     * Translate contents only if this fallback element is put in place of
71     * some unsupported element or non-XSLTC extension element
72     */
73    public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
74        final ConstantPoolGen cpg = classGen.getConstantPool();
75        final InstructionList il = methodGen.getInstructionList();
76
77        if (_active) translateContents(classGen, methodGen);
78    }
79}
80