public LayoutDynamicMBean(Layout layout) throws IntrospectionException 
{
        
    this.layout = layout;
    buildDynamicMBeanInfo();
}

 public Object getAttribute(String attributeName) throws ReflectionException, AttributeNotFoundException, MBeanException 
{
       // Check attributeName is not null to avoid NullPointerException later on
    if (attributeName == null) {
      throw new RuntimeOperationsException(new IllegalArgumentException(
			"Attribute name cannot be null"),
       "Cannot invoke a getter of " + dClassName + " with null attribute name");
    }
    MethodUnion mu = (MethodUnion) dynamicProps.get(attributeName);
    cat.debug("----name="+attributeName+", mu="+mu);
    if(mu != null && mu.readMethod != null) {
      try {
	return mu.readMethod.invoke(layout, null);
      } catch(Exception e) {
	return null;
      }
    }
    // If attributeName has not been recognized throw an AttributeNotFoundException
    throw(new AttributeNotFoundException("Cannot find " + attributeName +
					 " attribute in " + dClassName));
}

 protected Logger getLogger() 
{
    return cat;
}

 public MBeanInfo getMBeanInfo() 
{
    cat.debug("getMBeanInfo called.");
    MBeanAttributeInfo[] attribs = new MBeanAttributeInfo[dAttributes.size()];
    dAttributes.toArray(attribs);
    return new MBeanInfo(dClassName,
			 dDescription,
			 attribs,
			 dConstructors,
			 dOperations,
			 new MBeanNotificationInfo[0]);
}

 public Object invoke(String operationName,
    Object[] params,
    String[] signature) throws ReflectionException, MBeanException 
{
    if(operationName.equals("activateOptions") &&
                     layout instanceof OptionHandler) {
      OptionHandler oh = (OptionHandler) layout;
      oh.activateOptions();
      return "Options activated.";
    }
    return null;
}

 public  void setAttribute(Attribute attribute) throws InvalidAttributeValueException, ReflectionException, AttributeNotFoundException, MBeanException 
{
    // Check attribute is not null to avoid NullPointerException later on
    if (attribute == null) {
      throw new RuntimeOperationsException(
                  new IllegalArgumentException("Attribute cannot be null"),
		  "Cannot invoke a setter of " + dClassName +
		  " with null attribute");
    }
    String name = attribute.getName();
    Object value = attribute.getValue();
    if (name == null) {
      throw new RuntimeOperationsException(
                    new IllegalArgumentException("Attribute name cannot be null"),
		    "Cannot invoke the setter of "+dClassName+
		    " with null attribute name");
    }
    MethodUnion mu = (MethodUnion) dynamicProps.get(name);
    if(mu != null && mu.writeMethod != null) {
      Object[] o = new Object[1];
      Class[] params = mu.writeMethod.getParameterTypes();
      if(params[0] == org.apache.log4j.Priority.class) {
	value = OptionConverter.toLevel((String) value,
					(Level) getAttribute(name));
      }
      o[0] = value;
      try {
	mu.writeMethod.invoke(layout,  o);
      } catch(Exception e) {
	cat.error("FIXME", e);
      }
    } else {
      throw(new AttributeNotFoundException("Attribute " + name +
					   " not found in " +
					   this.getClass().getName()));
    }
}