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 org.apache.bcel.generic.ConstantPoolGen;
  import org.apache.bcel.generic.GETSTATIC;
  import org.apache.bcel.generic.INVOKEINTERFACE;
  import org.apache.bcel.generic.InstructionList;
  import org.apache.bcel.generic.PUSH;
  import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
  import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
  import org.apache.xalan.xsltc.compiler.util.Util;
  
  /**
   * @author Jacek Ambroziak
   * @author Santiago Pericas-Geertsen
   * @author Morten Jorgensen
   */
  final class Text extends Instruction {
  
      private String _text;
      private boolean _escaping = true;
      private boolean _ignore = false;
      private boolean _textElement = false;
  
      /**
       * Create a blank Text syntax tree node.
       */
      public Text() {
  	_textElement = true;
      }
  
      /**
       * Create text syntax tree node.
       * @param text is the text to put in the node.
       */
      public Text(String text) {
  	_text = text;
      }
  
      /**
       * Returns the text wrapped inside this node
       * @return The text wrapped inside this node
       */
      protected String getText() {
  	return _text;
      }
  
      /**
       * Set the text for this node. Appends the given text to any already
       * existing text (using string concatenation, so use only when needed).
       * @param text is the text to wrap inside this node.
       */
      protected void setText(String text) {
  	if (_text == null)
  	    _text = text;
  	else
  	    _text = _text + text;
      }
  
      public void display(int indent) {
  	indent(indent);
  	Util.println("Text");
  	indent(indent + IndentIncrement);
  	Util.println(_text);
      }
  		
      public void parseContents(Parser parser) {
          final String str = getAttribute("disable-output-escaping");
  	if ((str != null) && (str.equals("yes"))) _escaping = false;
  
  	parseChildren(parser);
  
  	if (_text == null) {
  	    if (_textElement) {
  		_text = EMPTYSTRING;
  	    }
  	    else {
  		_ignore = true;
  	    }
  	}
  	else if (_textElement) {
  	    if (_text.length() == 0) _ignore = true;
  	}
  	else if (getParent() instanceof LiteralElement) {
  	    LiteralElement element = (LiteralElement)getParent();
  	    String space = element.getAttribute("xml:space");
  	    if ((space == null) || (!space.equals("preserve")))
          {
              int i;
              final int textLength = _text.length();
              for (i = 0; i < textLength; i++) {
                  char c = _text.charAt(i);
                  if (!isWhitespace(c))
                      break;
              }
              if (i == textLength)
                  _ignore = true;
          }
  	}
  	else {
          int i;
          final int textLength = _text.length();
          for (i = 0; i < textLength; i++) 
          {
              char c = _text.charAt(i);
              if (!isWhitespace(c))
                  break;
          }
          if (i == textLength)
              _ignore = true;
  	}
      }
  
      public void ignore() {
  	_ignore = true;
      }
  
      public boolean isIgnore() {
      	return _ignore;
      }
      
      public boolean isTextElement() {
  	return _textElement;
      }
  
      protected boolean contextDependent() {
  	return false;
      }
   
      private static boolean isWhitespace(char c)
      {
      	return (c == 0x20 || c == 0x09 || c == 0x0A || c == 0x0D);
      }
   
      public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
  	final ConstantPoolGen cpg = classGen.getConstantPool();
  	final InstructionList il = methodGen.getInstructionList();
  
  	if (!_ignore) {
  	    // Turn off character escaping if so is wanted.
  	    final int esc = cpg.addInterfaceMethodref(OUTPUT_HANDLER,
  						      "setEscaping", "(Z)Z");
  	    if (!_escaping) {
  		il.append(methodGen.loadHandler());
  		il.append(new PUSH(cpg, false));
  		il.append(new INVOKEINTERFACE(esc, 2));
  	    }
  
              il.append(methodGen.loadHandler());
  
              // Call characters(String) or characters(char[],int,int), as
              // appropriate.
              if (!canLoadAsArrayOffsetLength()) {
                  final int characters = cpg.addInterfaceMethodref(OUTPUT_HANDLER,
                                                             "characters",
                                                             "("+STRING_SIG+")V");
                  il.append(new PUSH(cpg, _text));
                  il.append(new INVOKEINTERFACE(characters, 2));
              } else {
                  final int characters = cpg.addInterfaceMethodref(OUTPUT_HANDLER,
                                                                   "characters",
                                                                   "([CII)V");
                  loadAsArrayOffsetLength(classGen, methodGen);
  	        il.append(new INVOKEINTERFACE(characters, 4));
              }
  
  	    // Restore character escaping setting to whatever it was.
  	    // Note: setEscaping(bool) returns the original (old) value
  	    if (!_escaping) {
  		il.append(methodGen.loadHandler());
  		il.append(SWAP);
  		il.append(new INVOKEINTERFACE(esc, 2));
  		il.append(POP);
  	    }
  	}
  	translateContents(classGen, methodGen);
      }
  
      /**
       * Check whether this Text node can be stored in a char[] in the translet.
       * Calling this is precondition to calling loadAsArrayOffsetLength.
       * @see #loadAsArrayOffsetLength(ClassGenerator,MethodGenerator)
       * @return true if this Text node can be
       */
      public boolean canLoadAsArrayOffsetLength() {
          // Magic number!  21845*3 == 65535.  BCEL uses a DataOutputStream to
          // serialize class files.  The Java run-time places a limit on the size
          // of String data written using a DataOutputStream - it cannot require
          // more than 64KB when represented as UTF-8.  The number of bytes
          // required to represent a Java string as UTF-8 cannot be greater
          // than three times the number of char's in the string, hence the
          // check for 21845.
  
          return (_text.length() <= 21845);
      }
  
      /**
       * Generates code that loads the array that will contain the character
       * data represented by this Text node, followed by the offset of the
       * data from the start of the array, and then the length of the data.
       *
       * The pre-condition to calling this method is that
       * canLoadAsArrayOffsetLength() returns true.
       * @see #canLoadArrayOffsetLength()
       */
      public void loadAsArrayOffsetLength(ClassGenerator classGen,
                                          MethodGenerator methodGen) {
          final ConstantPoolGen cpg = classGen.getConstantPool();
          final InstructionList il = methodGen.getInstructionList();
          final XSLTC xsltc = classGen.getParser().getXSLTC();
  
          // The XSLTC object keeps track of character data
          // that is to be stored in char arrays.
          final int offset = xsltc.addCharacterData(_text);
          final int length = _text.length();
          String charDataFieldName =
              STATIC_CHAR_DATA_FIELD + (xsltc.getCharacterDataCount()-1);
  
          il.append(new GETSTATIC(cpg.addFieldref(xsltc.getClassName(),
                                         charDataFieldName,
                                         STATIC_CHAR_DATA_FIELD_SIG)));
          il.append(new PUSH(cpg, offset));
          il.append(new PUSH(cpg, _text.length()));
      }
  }
  