1 /*
2  * reserved comment block
3  * DO NOT REMOVE OR ALTER!
4  */
5 /*
6  * Copyright 2001-2004 The Apache Software Foundation.
7  *
8  * Licensed under the Apache License, Version 2.0 (the "License");
9  * you may not use this file except in compliance with the License.
10  * You may obtain a copy of the License at
11  *
12  *     http://www.apache.org/licenses/LICENSE-2.0
13  *
14  * Unless required by applicable law or agreed to in writing, software
15  * distributed under the License is distributed on an "AS IS" BASIS,
16  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17  * See the License for the specific language governing permissions and
18  * limitations under the License.
19  */
20 /*
21  * $Id: Fallback.java,v 1.2.4.1 2005/09/01 14:22:25 pvedula Exp $
22  */
23 
24 package com.sun.org.apache.xalan.internal.xsltc.compiler;
25 
26 import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
27 import com.sun.org.apache.bcel.internal.generic.InstructionList;
28 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
29 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
30 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
31 import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
32 
33 /**
34  * @author Morten Jorgensen
35  */
36 final class Fallback extends Instruction {
37 
38     private boolean _active = false;
39 
40     /**
41      * This element never produces any data on the stack
42      */
typeCheck(SymbolTable stable)43     public Type typeCheck(SymbolTable stable) throws TypeCheckError {
44         if (_active) {
45             return(typeCheckContents(stable));
46         }
47         else {
48             return Type.Void;
49         }
50     }
51 
52     /**
53      * Activate this fallback element
54      */
activate()55     public void activate() {
56         _active = true;
57     }
58 
toString()59     public String toString() {
60         return("fallback");
61     }
62 
63     /**
64      * Parse contents only if this fallback element is put in place of
65      * some unsupported element or non-XSLTC extension element
66      */
parseContents(Parser parser)67     public void parseContents(Parser parser) {
68         if (_active) parseChildren(parser);
69     }
70 
71     /**
72      * Translate contents only if this fallback element is put in place of
73      * some unsupported element or non-XSLTC extension element
74      */
translate(ClassGenerator classGen, MethodGenerator methodGen)75     public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
76         final ConstantPoolGen cpg = classGen.getConstantPool();
77         final InstructionList il = methodGen.getInstructionList();
78 
79         if (_active) translateContents(classGen, methodGen);
80     }
81 }
82