stdoutwriter.java

java语法解释器生成器

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * JFlex 1.4.2                                                             *
 * Copyright (C) 1998-2008  Gerwin Klein <[e-mail]>                    *
 * All rights reserved.                                                    *
 *                                                                         *
 * This program is free software; you can redistribute it and/or modify    *
 * it under the terms of the GNU General Public License. See the file      *
 * COPYRIGHT for more information.                                         *
 *                                                                         *
 * This program is distributed in the hope that it will be useful,         *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of          *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           *
 * GNU General Public License for more details.                            *
 *                                                                         *
 * You should have received a copy of the GNU General Public License along *
 * with this program; if not, write to the Free Software Foundation, Inc., *
 * 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA                 *
 *                                                                         *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

package JFlex;


import java.io.*;
import java.awt.TextArea;


/**
 * Convenience class for JFlex stdout, redirects output to a TextArea
 * if in GUI mode.
 *
 * @author Gerwin Klein
 * @version JFlex 1.4.2, $Revision: 358 $, $Date: 2008-05-27 16:28:29 +1000 (Tue, 27 May 2008) $
 */
public final class StdOutWriter extends PrintWriter {
  
  /** text area to write to if in gui mode, gui mode = (text != null) */
  private TextArea text;

  /** 
   * approximation of the current column in the text area
   * for auto wrapping at <code>wrap</code> characters
   **/
  private int col;
 
  /** auto wrap lines in gui mode at this value */
  private final static int wrap = 78;

  /** A StdOutWriter, attached to System.out, no gui mode */
  public StdOutWriter() {
    super(System.out,true);
  }
  
  /** A StdOutWrite, attached to the specified output stream, no gui mode */
  public StdOutWriter(OutputStream out) {
    super(out,true);    
  }

  /**
   * Set the TextArea to write text to. Will continue
   * to write to System.out if text is <code>null</code>.
   *
   * @param text  the TextArea to write to
   */
  public void setGUIMode(TextArea text) {
    this.text = text;
  }

  /** Write a single character. */
  public void write(int c) {
    if (text != null) {
      text.append(String.valueOf((char) c));
      if (++col > wrap) println();
    }
    else
      super.write(c);
  }

  /** Write a portion of an array of characters. */
  public void write(char buf[], int off, int len) {
    if (text != null) {
      text.append(new String(buf,off,len));
      if ((col+=len) > wrap) println();
    }
    else
      super.write(buf, off, len);
  }
  
  /** Write a portion of a string. */
  public void write(String s, int off, int len) {
    if (text != null) {
      text.append(s.substring(off,off+len));
      if ((col+=len) > wrap) println();
    }
    else {
      super.write(s,off,len); 
      flush();
    }
  }

  /**
   * Begin a new line. Which actual character/s is/are written 
   * depends on the runtime platform.
   */
  public void println() {
    if (text != null) {
      text.append(Out.NL);
      col = 0;
    }
    else
      super.println();
  }
}