code: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements. See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership. The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the  "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  /*
   * $Id$
   */
  
  package org.apache.xalan.xsltc.compiler;
  
  import java.util.StringTokenizer;
  import java.util.Vector;
  
  import org.apache.bcel.generic.ConstantPoolGen;
  import org.apache.bcel.generic.INVOKESPECIAL;
  import org.apache.bcel.generic.InstructionList;
  import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
  import org.apache.xalan.xsltc.compiler.util.ErrorMsg;
  import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
  import org.apache.xalan.xsltc.compiler.util.Type;
  import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
  
  /**
   * @author Jacek Ambroziak
   * @author Santiago Pericas-Geertsen
   * @author Morten Jorgensen
   */
  final class UseAttributeSets extends Instruction {
  
      // Only error that can occur:
      private final static String ATTR_SET_NOT_FOUND =
  	"";
  
      // Contains the names of all references attribute sets
      private final Vector _sets = new Vector(2);
  
      /**
       * Constructur - define initial attribute sets to use
       */
      public UseAttributeSets(String setNames, Parser parser) {
  	setParser(parser);
  	addAttributeSets(setNames);
      }
  
      /**
       * This method is made public to enable an AttributeSet object to merge
       * itself with another AttributeSet (including any other AttributeSets
       * the two may inherit from).
       */
      public void addAttributeSets(String setNames) {
  	if ((setNames != null) && (!setNames.equals(Constants.EMPTYSTRING))) {
  	    final StringTokenizer tokens = new StringTokenizer(setNames);
  	    while (tokens.hasMoreTokens()) {
  		final QName qname = 
  		    getParser().getQNameIgnoreDefaultNs(tokens.nextToken());
  		_sets.add(qname);
  	    }
  	}
      }
  
      /**
       * Do nada.
       */
      public Type typeCheck(SymbolTable stable) throws TypeCheckError {
  	return Type.Void;
      }
  
      /**
       * Generate a call to the method compiled for this attribute set
       */
      public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
  
  	final ConstantPoolGen cpg = classGen.getConstantPool();
  	final InstructionList il = methodGen.getInstructionList();
  	final SymbolTable symbolTable = getParser().getSymbolTable();
  
  	// Go through each attribute set and generate a method call
  	for (int i=0; i<_sets.size(); i++) {
  	    // Get the attribute set name
  	    final QName name = (QName)_sets.elementAt(i);
  	    // Get the AttributeSet reference from the symbol table
  	    final AttributeSet attrs = symbolTable.lookupAttributeSet(name);
  	    // Compile the call to the set's method if the set exists
  	    if (attrs != null) {
  		final String methodName = attrs.getMethodName();
  		il.append(classGen.loadTranslet());
  		il.append(methodGen.loadDOM());
  		il.append(methodGen.loadIterator());
  		il.append(methodGen.loadHandler());
  		final int method = cpg.addMethodref(classGen.getClassName(),
  						    methodName, ATTR_SET_SIG);
  		il.append(new INVOKESPECIAL(method));
  	    }
  	    // Generate an error if the attribute set does not exist
  	    else {
  		final Parser parser = getParser();
  		final String atrs = name.toString();
  		reportError(this, parser, ErrorMsg.ATTRIBSET_UNDEF_ERR, atrs);
  	    }
  	}
      }
  }
  