MetamodelContributorRegistry.java

/*******************************************************************************
 * Copyright (c) 2007 committers of openArchitectureWare and others.
 * 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:
 *     committers of openArchitectureWare - initial API and implementation
 *******************************************************************************/
package org.eclipse.xtend.shared.ui.core.metamodel;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.eclipse.core.resources.ProjectScope;
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.Platform;
import org.eclipse.core.runtime.preferences.IScopeContext;
import org.eclipse.core.runtime.preferences.InstanceScope;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.ui.preferences.ScopedPreferenceStore;
import org.eclipse.xtend.shared.ui.Activator;
import org.eclipse.xtend.shared.ui.MetamodelContributor;
import org.eclipse.xtend.shared.ui.core.preferences.PreferenceConstants;
import org.eclipse.xtend.shared.ui.internal.XtendLog;

/**
 * Provides access to metamodel contributors.
 * 
 * @author Peter
 */
public class MetamodelContributorRegistry {

	private static final String CONTRIBUTOR_ID = "org.eclipse.xtend.shared.ui.metamodelContributor";

	/**
	 * Retrieves the registered metamodel contributors.
	 * 
	 * @return A map containing all registered metamodel contributors.
	 */
	private static Map<String, Contributor> contributors = null;

	public static Map<String, Contributor> getRegisteredMetamodelContributors() {
		if (contributors == null) {
			contributors = new HashMap<String, Contributor>();
			final IExtensionRegistry registry = Platform.getExtensionRegistry();
			final IExtensionPoint point = registry.getExtensionPoint(MetamodelContributorRegistry.CONTRIBUTOR_ID);
			if (point != null) {
				final IExtension[] extensions = point.getExtensions();
				for (final IExtension extension : extensions) {
					final IConfigurationElement[] configs = extension.getConfigurationElements();
					for (final IConfigurationElement element : configs) {
						final String label = element.getAttribute("name");
						final String className = element.getAttribute("class");
						final Contributor contributor = new Contributor(label, className, element, false);
						contributors.put(className, contributor);
					}
				}
			}
		}
		return contributors;
	}

	public static List<? extends MetamodelContributor> getActiveMetamodelContributors(final IJavaProject project) {
		if (Activator.getDefault() == null)
			return Collections.emptyList();
		final ScopedPreferenceStore scopedPreferenceStore = new ScopedPreferenceStore(new InstanceScope(), Activator.getId());
		final IScopeContext[] scopes = { new ProjectScope(project.getProject()), new InstanceScope() };
		scopedPreferenceStore.setSearchContexts(scopes);
		fixMetamodelContributorPreferences(scopedPreferenceStore);

		final String metamodelContr = scopedPreferenceStore.getString(PreferenceConstants.METAMODELCONTRIBUTORS);
		final String[] mm = metamodelContr.split(",");

		final List<MetamodelContributor> result = new ArrayList<MetamodelContributor>();
		for (final String metamodelContributorName : mm) {
			if (metamodelContributorName != null && !metamodelContributorName.equals("")) {
				final MetamodelContributor metamodelContributor = MetamodelContributorRegistry
						.getMetamodelContributorByClassName(metamodelContributorName);
				if (metamodelContributor != null) {
					result.add(metamodelContributor);
				}
				else {
					XtendLog.logInfo("Metamodel contributor '" + metamodelContributorName + "' is not available\n");
				}
			}
		}
		return result;
	}

	/**
	 * fix: package name from UML2MetamodelContributor was wrong. For
	 * compatibility reasons we fix this name here on the fly. Later we could
	 * offer a migration path.
	 */
	private static void fixMetamodelContributorPreferences(final IPreferenceStore prefStore) {
		String metamodelContr = prefStore.getString(PreferenceConstants.METAMODELCONTRIBUTORS);
		if (metamodelContr.indexOf("openarchitecturware") > 0) {
			metamodelContr = metamodelContr.replace("openarchitecturware", "openarchitectureware");
			prefStore.setValue(PreferenceConstants.METAMODELCONTRIBUTORS, metamodelContr);
		}
	}

	private static MetamodelContributor getMetamodelContributorByClassName(final String metamodelContr) {
		final Contributor contributor = getRegisteredMetamodelContributors().get(metamodelContr);
		if (contributor == null)
			return null;
		return contributor.getMetaModelContributor();
	}
}