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 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
 * or http://forgerock.org/license/CDDLv1.0.html.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at legal-notices/CDDLv1_0.txt.
 * If applicable, add the following below this CDDL HEADER, with the
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 *      Copyright 2008-2009 Sun Microsystems, Inc.
 */

package org.forgerock.opendj.config;

/**
 * A visitor of property definitions, in the style of the visitor design
 * pattern. Classes implementing this interface can query property definitions
 * in a type-safe manner when the kind of property definition is unknown at
 * compile time. When a visitor is passed to a property definition's accept
 * method, the corresponding visit method most applicable to that property
 * definition is invoked.
 * <p>
 * Each <code>visitXXX</code> method is provided with a default implementation
 * which calls {@link #visitUnknown(PropertyDefinition, Object)}. Sub-classes
 * can override any or all of the methods to provide their own type-specific
 * behavior.
 *
 * @param <R>
 *            The return type of this visitor's methods. Use
 *            {@link java.lang.Void} for visitors that do not need to return
 *            results.
 * @param <P>
 *            The type of the additional parameter to this visitor's methods.
 *            Use {@link java.lang.Void} for visitors that do not need an
 *            additional parameter.
 */
public abstract class PropertyDefinitionVisitor<R, P> {

    /**
     * Default constructor.
     */
    protected PropertyDefinitionVisitor() {
        // No implementation required.
    }

    /**
     * Visit a dseecompat Global ACI property definition.
     *
     * @param pd
     *            The Global ACI property definition to visit.
     * @param p
     *            A visitor specified parameter.
     * @return Returns a visitor specified result.
     */
    public R visitACI(ACIPropertyDefinition pd, P p) {
        return visitUnknown(pd, p);
    }

    /**
     * Visit an aggregation property definition.
     *
     * @param <C>
     *            The type of client managed object configuration that this
     *            aggregation property definition refers to.
     * @param <S>
     *            The type of server managed object configuration that this
     *            aggregation property definition refers to.
     * @param pd
     *            The aggregation property definition to visit.
     * @param p
     *            A visitor specified parameter.
     * @return Returns a visitor specified result.
     */
    public <C extends ConfigurationClient, S extends Configuration> R visitAggregation(
        AggregationPropertyDefinition<C, S> pd, P p) {
        return visitUnknown(pd, p);
    }

    /**
     * Visit an attribute type property definition.
     *
     * @param pd
     *            The attribute type property definition to visit.
     * @param p
     *            A visitor specified parameter.
     * @return Returns a visitor specified result.
     */
    public R visitAttributeType(AttributeTypePropertyDefinition pd, P p) {
        return visitUnknown(pd, p);
    }

    /**
     * Visit a boolean property definition.
     *
     * @param pd
     *            The boolean property definition to visit.
     * @param p
     *            A visitor specified parameter.
     * @return Returns a visitor specified result.
     */
    public R visitBoolean(BooleanPropertyDefinition pd, P p) {
        return visitUnknown(pd, p);
    }

    /**
     * Visit a class property definition.
     *
     * @param pd
     *            The class property definition to visit.
     * @param p
     *            A visitor specified parameter.
     * @return Returns a visitor specified result.
     */
    public R visitClass(ClassPropertyDefinition pd, P p) {
        return visitUnknown(pd, p);
    }

    /**
     * Visit a DN property definition.
     *
     * @param pd
     *            The DN property definition to visit.
     * @param p
     *            A visitor specified parameter.
     * @return Returns a visitor specified result.
     */
    public R visitDN(DNPropertyDefinition pd, P p) {
        return visitUnknown(pd, p);
    }

    /**
     * Visit a duration property definition.
     *
     * @param pd
     *            The duration property definition to visit.
     * @param p
     *            A visitor specified parameter.
     * @return Returns a visitor specified result.
     */
    public R visitDuration(DurationPropertyDefinition pd, P p) {
        return visitUnknown(pd, p);
    }

    /**
     * Visit an enumeration property definition.
     *
     * @param <E>
     *            The enumeration that should be used for values of the property
     *            definition.
     * @param pd
     *            The enumeration property definition to visit.
     * @param p
     *            A visitor specified parameter.
     * @return Returns a visitor specified result.
     */
    public <E extends Enum<E>> R visitEnum(EnumPropertyDefinition<E> pd, P p) {
        return visitUnknown(pd, p);
    }

    /**
     * Visit an integer property definition.
     *
     * @param pd
     *            The integer property definition to visit.
     * @param p
     *            A visitor specified parameter.
     * @return Returns a visitor specified result.
     */
    public R visitInteger(IntegerPropertyDefinition pd, P p) {
        return visitUnknown(pd, p);
    }

    /**
     * Visit a IP address property definition.
     *
     * @param pd
     *            The IP address property definition to visit.
     * @param p
     *            A visitor specified parameter.
     * @return Returns a visitor specified result.
     */
    public R visitIPAddress(IPAddressPropertyDefinition pd, P p) {
        return visitUnknown(pd, p);
    }

    /**
     * Visit a IP address mask property definition.
     *
     * @param pd
     *            The IP address mask property definition to visit.
     * @param p
     *            A visitor specified parameter.
     * @return Returns a visitor specified result.
     */
    public R visitIPAddressMask(IPAddressMaskPropertyDefinition pd, P p) {
        return visitUnknown(pd, p);
    }

    /**
     * Visit a size property definition.
     *
     * @param pd
     *            The size property definition to visit.
     * @param p
     *            A visitor specified parameter.
     * @return Returns a visitor specified result.
     */
    public R visitSize(SizePropertyDefinition pd, P p) {
        return visitUnknown(pd, p);
    }

    /**
     * Visit a string property definition.
     *
     * @param pd
     *            The string property definition to visit.
     * @param p
     *            A visitor specified parameter.
     * @return Returns a visitor specified result.
     */
    public R visitString(StringPropertyDefinition pd, P p) {
        return visitUnknown(pd, p);
    }

    /**
     * Visit an unknown type of property definition. Implementations of this
     * method can provide default behavior for unknown property definition
     * types.
     * <p>
     * The default implementation of this method throws an
     * {@link PropertyException}. Sub-classes can override this
     * method with their own default behavior.
     *
     * @param <T>
     *            The type of the underlying property.
     * @param pd
     *            The property definition to visit.
     * @param p
     *            A visitor specified parameter.
     * @return Returns a visitor specified result.
     * @throws PropertyException
     *             Visitor implementations may optionally throw this exception.
     */
    public <T> R visitUnknown(PropertyDefinition<T> pd, P p) {
        throw PropertyException.unknownPropertyDefinitionException(pd, p);
    }

}
