ProjectContributionEventListenerFactory.java

/*******************************************************************************
 * Copyright (c) 2008, 2010 Spring IDE Developers
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Spring IDE Developers - initial API and implementation
 *******************************************************************************/
package org.springframework.ide.eclipse.core.project;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.Platform;
import org.springframework.core.OrderComparator;
import org.springframework.ide.eclipse.core.SpringCore;

/**
 * @author Christian Dupuis
 * @since 2.2.0
 */
public class ProjectContributionEventListenerFactory {

	public static final String LISTENERS_EXTENSION_POINT = SpringCore.PLUGIN_ID + ".listeners";

	public static List<IProjectContributionEventListener> listenerDefinitions;

	public synchronized static List<IProjectContributionEventListener> getProjectContributionEventListeners() {
		if (listenerDefinitions == null) {
			listenerDefinitions = new ArrayList<IProjectContributionEventListener>();
			for (IExtension extension : Platform.getExtensionRegistry().getExtensionPoint(LISTENERS_EXTENSION_POINT)
					.getExtensions()) {
				for (IConfigurationElement element : extension.getConfigurationElements()) {
					try {
						Object listener = element.createExecutableExtension("class");
						if (listener instanceof IProjectContributionEventListener) {
							listenerDefinitions.add((IProjectContributionEventListener) listener);
						}
					}
					catch (CoreException e) {
						SpringCore.log(e);
					}
				}
			}

			// Sort depending on the defined order
			OrderComparator.sort(listenerDefinitions);
		}
		return listenerDefinitions;
	}
}