/*
* This library is part of OpenCms -
* the Open Source Content Management System
*
* Copyright (c) Alkacon Software GmbH (http://www.alkacon.com)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* For further information about Alkacon Software, please see the
* company website: http://www.alkacon.com
*
* For further information about OpenCms, please see the
* project website: http://www.opencms.org
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package org.opencms.main;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.commons.logging.Log;
/**
* Manager that controls the OpenCms event system.
*
* There is only one instance of this event manager class used by the OpenCms runtime.
* This instance can be obtained by calling {@link OpenCms#getEventManager()}.<p>
*
* Events can be used in OpenCms to notify custom event listeners that certain system events have happened.
* Event listeners have to implement the interface {@link org.opencms.main.I_CmsEventListener}.<p>
*
* @since 7.0.0
*
* @see org.opencms.main.CmsEvent
* @see org.opencms.main.I_CmsEventListener
*/
public class CmsEventManager {
/** Required as template for event list generation. */
protected static final I_CmsEventListener[] EVENT_LIST = new I_CmsEventListener[0];
/** The static log object for this class. */
private static final Log LOG = CmsLog.getLog(CmsEventManager.class);
/** Stores the active event listeners. */
private Map<Integer, List<I_CmsEventListener>> m_eventListeners;
/**
* Create a new instance of an OpenCms event manager.<p>
*/
public CmsEventManager() {
m_eventListeners = new HashMap<Integer, List<I_CmsEventListener>>();
}
/**
* Add an OpenCms event listener that listens to all events.<p>
*
* @param listener the listener to add
*/
public void addCmsEventListener(I_CmsEventListener listener) {
addCmsEventListener(listener, null);
}
/**
* Add an OpenCms event listener.<p>
*
* @param listener the listener to add
* @param eventTypes the events to listen for
*/
public void addCmsEventListener(I_CmsEventListener listener, int[] eventTypes) {
synchronized (m_eventListeners) {
if (eventTypes == null) {
// no event types given - register the listener for all event types
eventTypes = new int[] {I_CmsEventListener.LISTENERS_FOR_ALL_EVENTS.intValue()};
}
for (int i = 0; i < eventTypes.length; i++) {
// register the listener for all configured event types
Integer eventType = new Integer(eventTypes[i]);
List<I_CmsEventListener> listeners = m_eventListeners.get(eventType);
if (listeners == null) {
listeners = new ArrayList<I_CmsEventListener>();
m_eventListeners.put(eventType, listeners);
}
if (!listeners.contains(listener)) {
// add listerner only if it is not already registered
listeners.add(listener);
}
}
}
}
/**
* Notify all event listeners that a particular event has occurred.<p>
*
* @param event the event that is forwarded to all listeners
*/
public void fireEvent(CmsEvent event) {
fireEventHandler(m_eventListeners.get(event.getTypeInteger()), event);
fireEventHandler(m_eventListeners.get(I_CmsEventListener.LISTENERS_FOR_ALL_EVENTS), event);
}
/**
* Notify all event listeners that a particular event has occurred without any additional event data.<p>
*
* @param type event type
*/
public void fireEvent(int type) {
fireEvent(type, new HashMap<String, Object>());
}
/**
* Notify all event listeners that a particular event has occurred.<p>
*
* @param type event type
* @param data event data
*/
public void fireEvent(int type, Map<String, Object> data) {
fireEvent(new CmsEvent(type, data));
}
/**
* Removes a cms event listener.<p>
*
* @param listener the listener to remove
*/
public void removeCmsEventListener(I_CmsEventListener listener) {
synchronized (m_eventListeners) {
Iterator<Integer> it = m_eventListeners.keySet().iterator();
while (it.hasNext()) {
List<I_CmsEventListener> listeners = m_eventListeners.get(it.next());
listeners.remove(listener);
}
}
}
/**
* Returns the map of all configured event listeners.<p>
*
* @return the map of all configured event listeners
*/
protected Map<Integer, List<I_CmsEventListener>> getEventListeners() {
return m_eventListeners;
}
/**
* Initialize this event manager with all events from the given base event manager.<p>
*
* @param base the base event manager to initialize this event manager with
*/
protected void initialize(CmsEventManager base) {
m_eventListeners = new HashMap<Integer, List<I_CmsEventListener>>(base.getEventListeners());
}
/**
* Fires the specified event to a list of event listeners.<p>
*
* @param listeners the listeners to fire
* @param event the event to fire
*/
protected void fireEventHandler(List<I_CmsEventListener> listeners, CmsEvent event) {
if (!LOG.isDebugEnabled()) {
// no logging required
if ((listeners != null) && (listeners.size() > 0)) {
// handle all event listeners that listen to this event type
I_CmsEventListener[] list = listeners.toArray(EVENT_LIST);
// loop through all registered event listeners
for (int i = 0; i < list.length; i++) {
// fire the event
list[i].cmsEvent(event);
}
}
} else {
// add lots of event debug output (this should usually be disabled)
// repeat event handling code to avoid multiple "is log enabled" checks in normal operation
LOG.debug(Messages.get().getBundle().key(Messages.LOG_DEBUG_EVENT_1, event.toString()));
if ((listeners != null) && (listeners.size() > 0)) {
// handle all event listeners that listen to this event type
I_CmsEventListener[] list = listeners.toArray(EVENT_LIST);
// log the event data
if (event.getData() != null) {
Iterator<String> i = event.getData().keySet().iterator();
while (i.hasNext()) {
String key = i.next();
Object value = event.getData().get(key);
LOG.debug(Messages.get().getBundle().key(
Messages.LOG_DEBUG_EVENT_VALUE_3,
key,
value,
event.toString()));
}
} else {
LOG.debug(Messages.get().getBundle().key(Messages.LOG_DEBUG_NO_EVENT_VALUE_1, event.toString()));
}
// log all the registered event listeners
for (int j = 0; j < list.length; j++) {
LOG.debug(Messages.get().getBundle().key(
Messages.LOG_DEBUG_EVENT_LISTENERS_3,
list[j],
new Integer(j),
event.toString()));
}
// loop through all registered event listeners
for (int i = 0; i < list.length; i++) {
LOG.debug(Messages.get().getBundle().key(
Messages.LOG_DEBUG_EVENT_START_LISTENER_3,
list[i],
new Integer(i),
event.toString()));
// fire the event
list[i].cmsEvent(event);
LOG.debug(Messages.get().getBundle().key(
Messages.LOG_DEBUG_EVENT_END_LISTENER_3,
list[i],
new Integer(i),
event.toString()));
}
} else {
LOG.debug(Messages.get().getBundle().key(Messages.LOG_DEBUG_EVENT_NO_LISTENER_1, event.toString()));
}
LOG.debug(Messages.get().getBundle().key(Messages.LOG_DEBUG_EVENT_COMPLETE_1, event.toString()));
}
}
}