/*
 * Jalview - A Sequence Alignment Editor and Viewer ($$Version-Rel$$)
 * Copyright (C) $$Year-Rel$$ The Jalview Authors
 * 
 * This file is part of Jalview.
 * 
 * Jalview 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 3
 * of the License, or (at your option) any later version.
 *  
 * Jalview 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 Jalview.  If not, see <http://www.gnu.org/licenses/>.
 * The Jalview Authors are detailed in the 'AUTHORS' file.
 */
package jalview.javascript.log4j;

import jalview.javascript.log4j.spi.LoggingEvent;
import jalview.javascript.log4j.spi.OptionHandler;

import org.apache.log4j.PatternLayout;
//import org.apache.log4j.TTCCLayout;

public abstract class Layout implements OptionHandler
{

  // Note that the line.separator property can be looked up even by
  // applets.
  public final static String LINE_SEP = System
          .getProperty("line.separator");

  public final static int LINE_SEP_LEN = LINE_SEP.length();

  /**
   * Implement this method to create your own layout format.
   */
  abstract public String format(LoggingEvent event);

  /**
   * Returns the content type output by this layout. The base class returns
   * "text/plain".
   */
  public String getContentType()
  {
    return "text/plain";
  }

  /**
   * Returns the header for the layout format. The base class returns
   * <code>null</code>.
   */
  public String getHeader()
  {
    return null;
  }

  /**
   * Returns the footer for the layout format. The base class returns
   * <code>null</code>.
   */
  public String getFooter()
  {
    return null;
  }

  /**
   * If the layout handles the throwable object contained within
   * {@link LoggingEvent}, then the layout should return <code>false</code>.
   * Otherwise, if the layout ignores throwable object, then the layout should
   * return <code>true</code>. If ignoresThrowable is true, the appender is
   * responsible for rendering the throwable.
   * <p>
   * The {@link SimpleLayout}, {@link TTCCLayout}, {@link PatternLayout} all
   * return <code>true</code>. The {@link org.apache.log4j.xml.XMLLayout}
   * returns <code>false</code>.
   * 
   * @since 0.8.4
   */
  abstract public boolean ignoresThrowable();

}