/*
 *    Geotoolkit - An Open Source Java GIS Toolkit
 *    http://www.geotoolkit.org
 *
 *    (C) 2012, Geomatys
 *
 *    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;
 *    version 2.1 of the License.
 *
 *    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.
 */
package org.geotoolkit.storage;

import java.util.HashSet;
import java.util.Set;

/**
 * Abstract storage class, adds convinient event methods.
 *
 * @author Johann Sorel (Geomatys)
 */
public abstract class AbstractStorage {

    protected final Set<StorageListener> listeners = new HashSet<>();

    public void addStorageListener(final StorageListener listener) {
        synchronized (listeners) {
            listeners.add(listener);
        }
    }

    public void removeStorageListener(final StorageListener listener) {
        synchronized (listeners) {
            listeners.remove(listener);
        }
    }

    /**
     * Forward a structure event to all listeners.
     * @param event , event to send to listeners.
     */
    protected void sendStructureEvent(final StorageEvent event){
        final StorageListener[] lst;
        synchronized (listeners) {
            lst = listeners.toArray(new StorageListener[listeners.size()]);
        }
        for(final StorageListener listener : lst){
            listener.structureChanged(event);
        }
    }

    /**
     * Forward a data event to all listeners.
     * @param event , event to send to listeners.
     */
    protected void sendContentEvent(final StorageEvent event){
        final StorageListener[] lst;
        synchronized (listeners) {
            lst = listeners.toArray(new StorageListener[listeners.size()]);
        }
        for(final StorageListener listener : lst){
            listener.contentChanged(event);
        }
    }

    /**
     * Forward given event, changing the source by this object.
     * For implementation use only.
     * @param event
     */
    public void forwardStructureEvent(StorageEvent event){
        sendStructureEvent(event.copy(this));
    }

    /**
     * Forward given event, changing the source by this object.
     * For implementation use only.
     * @param event
     */
    public void forwardContentEvent(StorageEvent event){
        sendContentEvent(event.copy(this));
    }

}