001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.configuration2.builder;
018
019import org.apache.commons.configuration2.ImmutableConfiguration;
020import org.apache.commons.configuration2.event.EventType;
021
022/**
023 * <p>
024 * A specialized event class which is generated by a
025 * {@link ConfigurationBuilder} when a result configuration has been created.
026 * </p>
027 * <p>
028 * Events of this type are fired in the {@code getConfiguration()} method of a
029 * configuration builder each time a new result object is created. At the time
030 * the event is fired, no lock is held. The newly created {@code ImmutableConfiguration}
031 * object is available as a property of this event.
032 * </p>
033 * <p>
034 * A use case for this event is to perform special initializations on newly
035 * created configuration objects. It is also an indication that a builder is now
036 * fully initialized; i.e. the managed configuration is available.
037 * </p>
038 *
039 * @since 2.0
040 */
041public class ConfigurationBuilderResultCreatedEvent extends
042        ConfigurationBuilderEvent
043{
044    /**
045     * The specialized event type for a newly created result configuration.
046     * Events of this type are generated by a configuration builder when a
047     * result configuration has been created.
048     */
049    public static final EventType<ConfigurationBuilderResultCreatedEvent> RESULT_CREATED =
050            new EventType<>(ANY,
051                    "RESULT_CREATED");
052
053    /** The newly created configuration object. */
054    private final ImmutableConfiguration configuration;
055
056    /**
057     * Creates a new instance of {@code ConfigurationBuilderResultCreatedEvent}
058     * and initializes its properties.
059     *
060     * @param source the {@code ConfigurationBuilder} object which triggered
061     *        this event (must not be <b>null</b>)
062     * @param evType the type of this event (must not be <b>null</b>)
063     * @param createdConfiguration the newly created {@code ImmutableConfiguration}
064     *        object (must not be <b>null</b>)
065     * @throws IllegalArgumentException if a required parameter is null
066     */
067    public ConfigurationBuilderResultCreatedEvent(
068            final ConfigurationBuilder<?> source,
069            final EventType<? extends ConfigurationBuilderResultCreatedEvent> evType,
070            final ImmutableConfiguration createdConfiguration)
071    {
072        super(source, evType);
073        if (createdConfiguration == null)
074        {
075            throw new IllegalArgumentException(
076                    "Configuration must not be null!");
077        }
078        configuration = createdConfiguration;
079    }
080
081    /**
082     * Returns the newly created {@code ImmutableConfiguration} object.
083     *
084     * @return the newly created {@code ImmutableConfiguration}
085     */
086    public ImmutableConfiguration getConfiguration()
087    {
088        return configuration;
089    }
090}