/*
 * $Id$
 *
 * Copyright (C) 2003-2015 JNode.org
 *
 * 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.
 *
 * 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., 
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
package org.jnode.plugin;

/**
 * Descriptor of a well known point in the system.
 *
 * @author Ewout Prangsma (epr@users.sourceforge.net)
 */
public interface ExtensionPoint {

    /**
     * Returns the simple identifier of this extension point.
     * This identifier is a non-empty string containing no period
     * characters ('.') and is guaranteed to be unique within the
     * defining plug-in.
     *
     * @return The simple identifier
     */
    public abstract String getSimpleIdentifier();

    /**
     * Returns the unique identifier of this extension point.
     * This identifier is unique within the plug-in registry, and is
     * composed of the identifier of the plug-in that declared this
     * extension point and this extension point's simple identifier.
     *
     * @return The unique identifier
     */
    public abstract String getUniqueIdentifier();

    /**
     * Gets the human readable name of this extensionpoint
     *
     * @return The name
     */
    public abstract String getName();

    /**
     * Gets all extensions configured to this extensionpoint.
     *
     * @return All extensions configured to this extensionpoint.
     */
    public Extension[] getExtensions();

    /**
     * Add a listener
     *
     * @param listener
     */
    public void addListener(ExtensionPointListener listener);

    /**
     * Add a listener to the front of the listeners list.
     *
     * @param listener
     */
    public void addPriorityListener(ExtensionPointListener listener);

    /**
     * Remove a listener
     *
     * @param listener
     */
    public void removeListener(ExtensionPointListener listener);

    /**
     * Gets the descriptor of the plugin in which this element was declared.
     *
     * @return The descriptor
     */
    public PluginDescriptor getDeclaringPluginDescriptor();
}