/* ====================================================================
* Loom Software License, version 1.1
*
* Copyright (c) 2003, Loom Group. All rights reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. Neither the name of the Loom Group nor the name "Loom" nor
* the names of its contributors may be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* ====================================================================
*
* Loom includes code from the Apache Software Foundation
*
* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 1997-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software
* itself, if and wherever such third-party acknowledgments
* normally appear.
*
* 4. The names "Jakarta", "Avalon", and "Apache Software Foundation"
* must not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
package org.codehaus.loom.components.application;
import org.apache.avalon.phoenix.ApplicationEvent;
import org.apache.avalon.phoenix.ApplicationListener;
import org.apache.avalon.phoenix.BlockEvent;
import org.apache.avalon.phoenix.BlockListener;
import org.apache.avalon.phoenix.metadata.SarMetaData;
import org.apache.avalon.phoenix.metainfo.BlockInfo;
import org.codehaus.loom.components.util.ComponentInfoConverter;
/**
* Manage a set of {@link ApplicationListener} objects and propogate {@link
* ApplicationEvent} notifications to these listeners. Not all events pass an
* Applicationevent parameter.
*
* @author Peter Donald
* @author <a href="mailto:Paul_Hammant@yahoo.com">Paul Hammant</a>
*/
final class ListenerSupport
{
//Set of block listeners. Must be accessed from synchronized code
private BlockListener[] m_blockListeners = new BlockListener[ 0 ];
//Set of listeners. Must be accessed from synchronized code
private ApplicationListener[] m_listeners = new ApplicationListener[ 0 ];
/**
* fire Event indicating that the Application represented by specified
* metaData is starting.
*
* @param metaData the metaData
*/
void fireApplicationStartingEvent( final SarMetaData metaData )
throws Exception
{
final ApplicationEvent event =
new ApplicationEvent( metaData.getName(), metaData );
applicationStarting( event );
}
/**
* fire Event indicating that Block represented by specific entry has been
* added.
*
* @param entry the entry
*/
void fireBlockAddedEvent( final BlockEntry entry )
{
blockAdded( createEvent( entry ) );
}
/**
* fire Event indicating that Block represented by specific entry is being
* removed.
*
* @param entry the entry
*/
void fireBlockRemovedEvent( final BlockEntry entry )
{
blockRemoved( createEvent( entry ) );
}
/**
* Utility method to create an event for a specific entry.
*
* @param entry the entry
* @return the new event
*/
private BlockEvent createEvent( final BlockEntry entry )
{
final BlockInfo blockInfo =
ComponentInfoConverter.toBlockInfo( entry.getInfo() );
return new BlockEvent( entry.getName(),
entry.getProxy(),
blockInfo );
}
/**
* Add a ApplicationListener to those requiring notification of {@link
* ApplicationEvent}s.
*
* @param listener the ApplicationListener
*/
public synchronized void addApplicationListener(
final ApplicationListener listener )
{
final ApplicationListener[] listeners = new ApplicationListener[ 1 +
m_listeners.length ];
System.arraycopy( m_listeners, 0, listeners, 0, m_listeners.length );
listeners[ m_listeners.length ] = listener;
m_listeners = listeners;
}
/**
* Remove a ApplicationListener from those requiring notification of {@link
* ApplicationEvent}s.
*
* @param listener the ApplicationListener
*/
public synchronized void removeApplicationListener(
final ApplicationListener listener )
{
int index = 0;
while( index < m_listeners.length )
{
if( m_listeners[ index ] == listener )
{
break;
}
index++;
}
if( m_listeners.length != index )
{
final ApplicationListener[] listeners =
new ApplicationListener[ m_listeners.length - 1 ];
System.arraycopy( m_listeners, 0, listeners, 0, index );
final int length = m_listeners.length - index - 1;
System.arraycopy( m_listeners,
index + 1,
listeners,
index,
length );
}
}
/**
* Add a BlockListener to those requiring notification of {@link
* BlockEvent}s.
*
* @param listener the BlockListener
*/
public synchronized void addBlockListener( final BlockListener listener )
{
final BlockListener[] listeners = new BlockListener[ 1 +
m_blockListeners.length ];
System.arraycopy( m_blockListeners,
0,
listeners,
0,
m_blockListeners.length );
listeners[ m_listeners.length ] = listener;
m_blockListeners = listeners;
}
/**
* Remove a BlockListener from those requiring notification of {@link
* BlockEvent}s.
*
* @param listener the BlockListener
*/
public synchronized void removeBlockListener( final BlockListener listener )
{
int index = 0;
while( index < m_blockListeners.length )
{
if( m_blockListeners[ index ] == listener )
{
break;
}
index++;
}
if( m_blockListeners.length != index )
{
final BlockListener[] listeners =
new BlockListener[ m_blockListeners.length - 1 ];
System.arraycopy( m_blockListeners, 0, listeners, 0, index );
final int length = m_blockListeners.length - index - 1;
System.arraycopy( m_blockListeners,
index + 1,
listeners,
index,
length );
}
}
/**
* Notification that the application is starting
*
* @param event the ApplicationEvent
*/
private synchronized void applicationStarting(
final ApplicationEvent event )
throws Exception
{
for( int i = 0; i < m_listeners.length; i++ )
{
m_listeners[ i ].applicationStarting( event );
}
}
/**
* Notification that the application has started.
*/
public synchronized void applicationStarted()
{
for( int i = 0; i < m_listeners.length; i++ )
{
m_listeners[ i ].applicationStarted();
}
}
/**
* Notification that the application is stopping
*/
public synchronized void applicationStopping()
{
for( int i = 0; i < m_listeners.length; i++ )
{
m_listeners[ i ].applicationStopping();
}
}
/**
* Notification that the application has stopped
*/
public synchronized void applicationStopped()
{
for( int i = 0; i < m_listeners.length; i++ )
{
m_listeners[ i ].applicationStopped();
}
}
/**
* Notification that the application has failed
*/
public synchronized void applicationFailure(
final Exception causeOfFailure )
{
for( int i = 0; i < m_listeners.length; i++ )
{
m_listeners[ i ].applicationFailure( causeOfFailure );
}
}
/**
* Notification that a block has just been added to Server Application.
*
* @param event the BlockEvent
*/
private synchronized void blockAdded( final BlockEvent event )
{
for( int i = 0; i < m_listeners.length; i++ )
{
m_listeners[ i ].blockAdded( event );
}
//Now notify the plain BlockListeners
for( int i = 0; i < m_blockListeners.length; i++ )
{
m_blockListeners[ i ].blockAdded( event );
}
}
/**
* Notification that a block is just about to be removed from Server
* Application.
*
* @param event the BlockEvent
*/
private synchronized void blockRemoved( final BlockEvent event )
{
for( int i = 0; i < m_listeners.length; i++ )
{
m_listeners[ i ].blockRemoved( event );
}
//Now notify the plain BlockListeners
for( int i = 0; i < m_blockListeners.length; i++ )
{
m_blockListeners[ i ].blockRemoved( event );
}
}
}