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      */

    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      */

    55     public void activate() {

    56         _active = true;

    57     }

    58 

    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      */

    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      */

    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 }