taverna-workbench-api/src/main/java/org/apache/taverna/workbench/StartupSPI.java

/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/

package org.apache.taverna.workbench;

import java.util.Comparator;

import org.apache.taverna.workbench.ui.zaria.PerspectiveSPI;

/**
 * SPI for components/plugins that want to be able to perform some configuration
 * or similar initialization on Workbench startup.
 *
 * @see ShutdownSPI
 * @author Alex Nenadic
 * @author Stian Soiland-Reyes
 */
public interface StartupSPI {

	/**
	 * Called when the Workbench is starting up for implementations of this
	 * interface to perform any configuration on start up.
	 * <p>
	 * When the configuration process has finished this method should return
	 * <code>true</code>.
	 * <p>
	 * Return <code>false</code> if and only if failure in this method will
	 * cause Workbench not to function at all.
	 *
	 */
	public boolean startup();

	/**
	 * Provides a hint for the order in which the startup hooks (that implement
	 * this interface) will be called. The lower the number, the earlier will
	 * the startup hook be invoked.
	 * <p>
	 * Custom plugins are recommended to start with a value > 100.
	 */
	public int positionHint();

	public class StartupComparator implements Comparator<StartupSPI> {
		public int compare(StartupSPI o1, StartupSPI o2) {
			return o1.positionHint() - o2.positionHint();
		}
	}

}