/*
    * EL4J, the Extension Library for the J2EE, adds incremental enhancements to
    * the spring framework, http://el4j.sf.net
    * Copyright (C) 2005 by ELCA Informatique SA, Av. de la Harpe 22-24,
    * 1000 Lausanne, Switzerland, http://www.elca.ch
    *
    * EL4J is published under the GNU Lesser General Public License (LGPL)
    * Version 2.1. See http://www.gnu.org/licenses/
    *
   * 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 Lesser General Public License for more details.
   *
   * For alternative licensing, please contact info@elca.ch
   */
  package ch.elca.el4j.services.gui.swing.cookswing;
  
  import java.lang.reflect.Method;
  
  import javax.swing.JPanel;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.w3c.dom.Element;
  
  import cookxml.core.DecodeEngine;
  import cookxml.core.exception.CookXmlException;
  import cookxml.core.exception.CreatorException;
  import cookxml.core.interfaces.Creator;
  
  /**
   * The cookSwing creator for general purpose <create-component>s.
   * The create-method is invoked when the XML tag is opened and
   * the finish-method when the tag is closed.
   *
   * @svnLink $Revision: 3873 $;$Date: 2009-08-04 13:59:45 +0200 (Di, 04. Aug 2009) $;$Author: swismer $;$URL: https://el4j.svn.sourceforge.net/svnroot/el4j/branches/el4j_3_1/el4j/framework/modules/swing/src/main/java/ch/elca/el4j/services/gui/swing/cookswing/CreateComponentCreator.java $
   *
   * @author Stefan Wismer (SWI)
   */
  public class CreateComponentCreator implements Creator {
  	// <create-component> specific attributes
  	/**
  	 * The XML attribute name for the create method.
  	 */
  	protected static final String CREATE_METHOD = "create-method";
  	
  	/**
  	 * The XML attribute name for the finish method.
  	 */
  	protected static final String FINISH_METHOD = "finish-method";
  	
  	/**
  	 * The logger.
  	 */
  	private static final Logger s_logger = LoggerFactory
  		.getLogger(CreateComponentCreator.class);
  	
  	/** {@inheritDoc} */
  	public Object create(String parentNS, String parentTag, Element elm,
  		Object parentObj, DecodeEngine decodeEngine) throws CreatorException {
  		
  		Object form = decodeEngine.getVariable("this");
  		String methodName = elm.getAttribute(CREATE_METHOD);
  		
  		if (!methodName.equals("")) {
  			return invokeMethod(form, methodName);
  		} else {
  			return new JPanel();
  		}
  	}
  
  	/** {@inheritDoc} */
  	public Object editFinished(String parentNS, String parentTag, Element elm,
  		Object parentObj, Object obj, DecodeEngine decodeEngine) throws CookXmlException {
  		
  		Object form = decodeEngine.getVariable("this");
  		String methodName = elm.getAttribute(FINISH_METHOD);
  		
  		if (!methodName.equals("")) {
  			invokeMethod(form, methodName, obj);
  		}
  		return obj;
  	}
  	
  	/**
  	 * Invoke a potentially private method.
  	 *
  	 * @param form          the form object
  	 * @param methodName    the method name
  	 * @param parameters    optional parameters
  	 * @return              the return value of the invoked method
  	 */
  	protected Object invokeMethod(Object form, String methodName, Object... parameters) {
  		Class<?> formClass = form.getClass();
  		while (formClass != Object.class) {
  			// list all methods to access private methods as well
  			final Method[] publicMethods = formClass.getDeclaredMethods();
  			for (int i = 0; i < publicMethods.length; ++i) {
 				if (methodName.equals(publicMethods[i].getName())) {
 					try {
 						publicMethods[i].setAccessible(true);
 						return publicMethods[i].invoke(form, parameters);
 					} catch (Exception e) {
 						// try next method
 						continue;
 					}
 				}
 			}
 			formClass = formClass.getSuperclass();
 		}
 		s_logger.error("Error processing <create-component>. Could not find method '" + methodName + "'.");
 		return null;
 	}
 }