/* LogViewer.java
 *
 * created: Wed Aug 30 2000
 *
 * This file is part of Artemis
 * 
 * Copyright (C) 2000  Genome Research Limited
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * 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.
 *
 * $Header: /nfs/disk222/yeastpub/Repository/powmap/diana/components/LogViewer.java,v 1.3 2000/11/01 15:00:00 kmr Exp $
 */

package diana.components;

import diana.*;

import java.io.*;

/**
 *  A class for viewing log messages in a FileViewer component.
 *
 *  @author Kim Rutherford <kmr@sanger.ac.uk>
 *  @version $Id: LogViewer.java,v 1.3 2000/11/01 15:00:00 kmr Exp $
 **/

public class LogViewer
    implements Logger {
  /**
   *  Create a new, empty LogViewer component.
   **/
  public LogViewer () {

  }

  /**
   *  Send the given String to the log.
   **/
  public void log (final String message) {
    maybeMakeViewer ();

    file_viewer.appendString (message);
  }

  /**
   *  Read from the given Reader and send it to the log.
   **/
  public void log (final Reader reader)
      throws IOException {
    maybeMakeViewer ();

    file_viewer.appendFile (reader);
  }

  /**
   *  Call setVisible () on the FileViewer that this object contains.
   **/
  public void setVisible (final boolean flag) {
    maybeMakeViewer ();

    file_viewer.setVisible (flag);
  }

  /**
   *  If file_viewer is null make a FileViewer and assign it to file_viewer.
   **/
  private void maybeMakeViewer () {
    if (file_viewer == null) {
      file_viewer = new FileViewer ("Log Viewer", false) {
        public void dispose () {
          // if the FileViewer is deleted we want to know
          file_viewer = null;
          super.dispose ();
        }
      };

      file_viewer.pack ();
    }
  }

  /**
   *  The FileViewer that is used to show the messages.
   **/
  private FileViewer file_viewer = null;
}
