001/*
002    Licensed to the Apache Software Foundation (ASF) under one
003    or more contributor license agreements.  See the NOTICE file
004    distributed with this work for additional information
005    regarding copyright ownership.  The ASF licenses this file
006    to you under the Apache License, Version 2.0 (the
007    "License"); you may not use this file except in compliance
008    with the License.  You may obtain a copy of the License at
009
010       http://www.apache.org/licenses/LICENSE-2.0
011
012    Unless required by applicable law or agreed to in writing,
013    software distributed under the License is distributed on an
014    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015    KIND, either express or implied.  See the License for the
016    specific language governing permissions and limitations
017    under the License.  
018 */
019
020package org.apache.wiki.event;
021
022import org.apache.wiki.WikiEngine;
023
024/**
025  * WikiEngineEvent indicates a change in the state of the WikiEngine.
026  * 
027  * @see     org.apache.wiki.event.WikiEvent
028  * @since   2.4.20
029  */
030public class WikiEngineEvent extends WikiEvent
031{
032    private static final long serialVersionUID = 1829433967558773970L;
033
034    /** Indicates a WikiEngine initialization event, fired as the 
035      * wiki service is being initialized (in progress). */
036    public static final int INITIALIZING   = -1;
037
038    /** Indicates a WikiEngine initialized event, fired after the 
039      * wiki service is fully available. */
040    public static final int INITIALIZED    = 0;
041
042    /** Indicates a WikiEngine closing event, fired as a signal that
043      * the wiki service is shutting down. */
044    public static final int SHUTDOWN       = 1;
045
046    /** Indicates a WikiEngine stopped event, fired after halting the wiki service.
047      * A WikiEngine in this state is not expected to provide further services. 
048      */
049    public static final int STOPPED        = 2;
050
051    private WikiEngine m_engine;
052
053    // ............
054
055
056     /**
057      *  Constructs an instance of this event.
058      * @param eventSource  the Object that is the source of the event,
059      * which <b>must</b> be the WikiEngine. If it is not, this
060      * method thows a ClassCastException
061      * @param type the event type
062      */
063    public WikiEngineEvent( Object eventSource, int type )
064    {
065        super( eventSource, type );
066        m_engine = (WikiEngine)eventSource;
067    }
068
069
070    /**
071     *  Sets the type of this event.
072     *
073     * @param type      the type of this WikiEngineEvent.
074     */
075    protected void setType( int type )
076    {
077        if ( type >= INITIALIZING && type <= STOPPED )
078        {
079            super.setType(type);
080        }
081        else
082        {
083            super.setType(ERROR);
084        }
085    }
086
087
088    /**
089     *  Returns the WikiEngine that spawned this event.
090     *
091     * @return  the WikiEngine that spawned this event.
092     */
093    public WikiEngine getEngine()
094    {
095        return m_engine;
096    }
097
098
099    /**
100     *  Returns the WikiEngine that spawned this event.
101     *
102     * @return  the WikiEngine that spawned this event.
103     * @deprecated  use {@link #getEngine()} instead.
104     */
105    public WikiEngine getWikiEngine()
106    {
107        return m_engine;
108    }
109
110
111   /**
112     * Returns <code>true</code> if the int value is a WikiPageEvent type.
113     * @param type the event type
114     * @return the result
115     */
116    public static boolean isValidType( int type )
117    {
118        return type >= INITIALIZING && type <= STOPPED;
119    }
120
121
122    /**
123     *  Returns a textual representation of the event type.
124     *
125     * @return a String representation of the type
126     */
127    public final String eventName()
128    {
129        switch ( getType() )
130        {
131            case INITIALIZING:         return "INITIALIZING";
132            case INITIALIZED:          return "INITIALIZED";
133            case SHUTDOWN:             return "SHUTDOWN";
134            case STOPPED:              return "STOPPED";
135            default:                   return super.eventName();
136        }
137    }
138
139
140    /**
141     *  Returns a human-readable description of the event type.
142     *
143     * @return a String description of the type
144     */
145    public final String getTypeDescription()
146    {
147        switch ( getType() )
148        {
149            case INITIALIZING:         return "wiki engine initializing";
150            case INITIALIZED:          return "wiki engine initialized";
151            case SHUTDOWN:             return "wiki engine shutting down";
152            case STOPPED:              return "wiki engine stopped";
153            default:                   return super.getTypeDescription();
154        }
155    }
156
157} // end class org.apache.wiki.event.WikiEngineEvent