/*
* Created on 18/apr/2010
*
* Copyright 2010 by Andrea Vacondio (andrea.vacondio@gmail.com).
*
* This file is part of the Sejda source code
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.sejda.core.notification.context;
import org.sejda.core.context.DefaultSejdaContext;
import org.sejda.core.notification.strategy.NotificationStrategy;
import org.sejda.core.notification.strategy.SyncNotificationStrategy;
import org.sejda.model.notification.EventListener;
import org.sejda.model.notification.event.AbstractNotificationEvent;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Abstract notification context implementing common context functionalities.
*
* @author Andrea Vacondio
*/
abstract class AbstractNotificationContext implements NotificationContext {
private static final Logger LOG = LoggerFactory.getLogger(AbstractNotificationContext.class);
private final EventListenerHoldingStrategy holder;
private final NotificationStrategy strategy;
protected AbstractNotificationContext(EventListenerHoldingStrategy holder) {
this.holder = holder;
this.strategy = getStrategy();
}
@Override
public void notifyListeners(AbstractNotificationEvent event) {
synchronized (holder) {
if (holder.size() > 0) {
for (EventListener<? extends AbstractNotificationEvent> listener : holder.get(event)) {
strategy.notifyListener(listener, event);
}
}
}
}
@Override
public <T extends AbstractNotificationEvent> void addListener(EventListener<T> listener) {
synchronized (holder) {
LOG.trace("Adding event listener: {}", listener);
holder.add(listener);
}
}
@Override
public <T extends AbstractNotificationEvent> void addListener(Class<T> eventClass, EventListener<T> listener) {
synchronized (holder) {
LOG.trace("Adding event listener {} on event {}", listener, eventClass);
holder.add(eventClass, listener);
}
}
@Override
public <T extends AbstractNotificationEvent> boolean removeListener(EventListener<T> listener) {
synchronized (holder) {
LOG.trace("Removing event listener: {}", listener);
return holder.remove(listener);
}
}
@Override
public void clearListeners() {
synchronized (holder) {
holder.clear();
}
}
@Override
public int size() {
return holder.size();
}
/**
* @return a new instance of the configured notification strategy
*/
private NotificationStrategy getStrategy() {
try {
return new DefaultSejdaContext().getNotificationStrategy().newInstance();
} catch (InstantiationException e) {
LOG.warn("An error occur while instantiating a new NotificationStrategy. Default strategy will be used.", e);
} catch (IllegalAccessException e) {
LOG.warn(
"Unable to access constructor for the configured NotificationStrategy. Default strategy will be used.",
e);
}
return new SyncNotificationStrategy();
}
}