Activator.java

/*******************************************************************************
 * Copyright (c) 2012 Pivotal Software, Inc.
 * 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:
 *     Pivotal Software, Inc. - initial API and implementation
 *******************************************************************************/
package org.springsource.ide.eclipse.commons.internal.configurator;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IExtensionPoint;
import org.eclipse.core.runtime.IExtensionRegistry;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.preferences.DefaultScope;
import org.eclipse.ui.internal.WorkbenchPlugin;
import org.eclipse.ui.plugin.AbstractUIPlugin;
import org.osgi.framework.BundleContext;
import org.springsource.ide.eclipse.commons.core.StatusHandler;

/**
 * The activator class controls the plug-in life cycle
 * @author Steffen Pingel
 * @author Christian Dupuis
 * @author Leo Dos Santos
 */
public class Activator extends AbstractUIPlugin {

	public static final String PLUGIN_ID = "org.springsource.ide.eclipse.commons.configurator";

	public static final String PROPERTY_CONFIGURATOR_PROCESSED = PLUGIN_ID + ".processed";

	public static final String PROPERTY_CONFIGURE_TARGETS = PLUGIN_ID + ".configuretargets";

	public static final String PROPERTY_USER_INSTALL_PATH = PLUGIN_ID + ".installPath";

	private static Activator plugin;

	public static Activator getDefault() {
		return plugin;
	}

	private boolean configurationActionRegistered;

	public boolean isConfigurationActionRegistered() {
		return configurationActionRegistered;
	}

	@Override
	public void start(BundleContext context) throws Exception {
		super.start(context);
		plugin = this;
		new DefaultScope().getNode(PLUGIN_ID).putBoolean(PROPERTY_CONFIGURATOR_PROCESSED, false);

		try {
			IExtension extension = Platform.getExtensionRegistry().getExtension(
					"org.eclipse.equinox.p2.engine.actions", "org.springsource.ide.eclipse.commons.configure");
			configurationActionRegistered = extension != null;
			if (!configurationActionRegistered) {
				getLog().log(
						new Status(IStatus.ERROR, PLUGIN_ID,
								"Registeration of configure action failed. This may cause extension install to fail."));
			}
		}
		catch (Throwable t) {
			getLog().log(
					new Status(IStatus.ERROR, PLUGIN_ID,
							"Registeration of configure action failed. This may cause extension install to fail.", t));
		}
	}

	@Override
	public void stop(BundleContext context) throws Exception {
		plugin = null;
		super.stop(context);
	}

	static class ConfiguratorExtensionPointReader {

		private static final String EXTENSION_ID_CONFIGURATOR = "com.springsource.sts.ide.ui.configurator";

		private static final String ELEMENT_CONFIGURATOR = "configurator";

		private static final String ELEMENT_CLASS = "class";

		public static IConfigurator getConfigurator() {
			IExtensionRegistry registry = Platform.getExtensionRegistry();
			IExtensionPoint extensionPoint = registry.getExtensionPoint(EXTENSION_ID_CONFIGURATOR);
			IExtension[] extensions = extensionPoint.getExtensions();
			for (IExtension extension : extensions) {
				IConfigurationElement[] elements = extension.getConfigurationElements();
				for (IConfigurationElement element : elements) {
					if (element.getName().compareTo(ELEMENT_CONFIGURATOR) == 0) {
						IConfigurator configurator = readConfiguratorExtension(element);
						if (configurator != null) {
							return configurator;
						}
					}
				}
			}
			return null;
		}

		private static IConfigurator readConfiguratorExtension(IConfigurationElement configurationElement) {
			try {
				Object object = WorkbenchPlugin.createExtension(configurationElement, ELEMENT_CLASS);
				if (!(object instanceof IConfigurator)) {
					StatusHandler.log(new Status(IStatus.ERROR, Activator.PLUGIN_ID, "Could not load "
							+ object.getClass().getCanonicalName() + " must implement "
							+ IConfigurator.class.getCanonicalName()));
				}
				return (IConfigurator) object;
			}
			catch (CoreException e) {
				StatusHandler.log(new Status(IStatus.ERROR, Activator.PLUGIN_ID,
						"Could not load configurator extension", e));
			}
			return null;
		}

	}

	public static IConfigurator getConfigurator() {
		return ConfiguratorExtensionPointReader.getConfigurator();
	}

}