org.eclipse.core.filebuffers/src/org/eclipse/core/internal/filebuffers/ExtensionsRegistry.java - platform/eclipse.platform.text - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2015 IBM Corporation 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:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.core.internal.filebuffers;

 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.StringTokenizer;

 import org.eclipse.core.runtime.Assert;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtensionPoint;
 import org.eclipse.core.runtime.ILog;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.core.runtime.content.IContentType;
 import org.eclipse.core.runtime.content.IContentTypeManager;

 import org.eclipse.core.filebuffers.IAnnotationModelFactory;
 import org.eclipse.core.filebuffers.IDocumentSetupParticipant;
 import org.eclipse.core.filebuffers.LocationKind;


 /**
  * This registry manages sharable document factories and setup
  * participants that are specified in <code>plugin.xml</code>.
  */
 public class ExtensionsRegistry {

 	/**
 	 * Adapts {@link IContentType} with the ability to check equality. This allows to use them in a
 	 * collection.
 	 */
 	private static class ContentTypeAdapter {

 		/** The adapted content type. */
 		private IContentType fContentType;

 		/**
 		 * Creates a new content type adapter for the
 		 * given content type.
 		 *
 		 * @param contentType the content type to be adapted
 		 */
 		public ContentTypeAdapter(IContentType  contentType) {
 			Assert.isNotNull(contentType);
 			fContentType= contentType;
 		}

 		/**
 		 * Return the id of the adapted content type.
 		 *
 		 * @return the id
 		 */
 		public String getId() {
 			return fContentType.getId();
 		}

 		@Override
 		public boolean equals(Object obj) {
 			return obj instanceof ContentTypeAdapter && fContentType.getId().equals(((ContentTypeAdapter)obj).getId());
 		}

 		@Override
 		public int hashCode() {
 			return fContentType.getId().hashCode();
 		}
 	}

 	protected static final String WILDCARD= "*"; //$NON-NLS-1$

 	/** The mapping between file attributes and configuration elements describing document factories. */
 	private Map<Object, Set<IConfigurationElement>> fFactoryDescriptors= new HashMap<>();
 	/** The mapping between configuration elements for document factories and instantiated document factories. */
 	private Map<IConfigurationElement, Object> fFactories= new HashMap<>();
 	/** The mapping between file attributes and configuration elements describing document setup participants. */
 	private Map<Object, Set<IConfigurationElement>> fSetupParticipantDescriptors= new HashMap<>();
 	/** The mapping between configuration elements for setup participants and instantiated setup participants. */
 	private Map<IConfigurationElement, Object> fSetupParticipants= new HashMap<>();
 	/** The mapping between file attributes and configuration elements describing annotation model factories. */
 	private Map<Object, Set<IConfigurationElement>> fAnnotationModelFactoryDescriptors= new HashMap<>();
 	/** The mapping between configuration elements for annotation model factories */
 	private Map<IConfigurationElement, Object> fAnnotationModelFactories= new HashMap<>();
 	/** The content type manager. */
 	protected IContentTypeManager fContentTypeManager= Platform.getContentTypeManager();


 	/**
 	 * Creates a new document factory registry and initializes it with the information
 	 * found in the plug-in registry.
 	 */
 	public ExtensionsRegistry() {
 		initialize("documentCreation", "contentTypeId", true,  fFactoryDescriptors); //$NON-NLS-1$ //$NON-NLS-2$
 		initialize("documentCreation", "fileNames", false, fFactoryDescriptors); //$NON-NLS-1$ //$NON-NLS-2$
 		initialize("documentCreation", "extensions",  false, fFactoryDescriptors); //$NON-NLS-1$ //$NON-NLS-2$
 		initialize("documentSetup", "contentTypeId", true, fSetupParticipantDescriptors); //$NON-NLS-1$ //$NON-NLS-2$
 		initialize("documentSetup", "fileNames", false, fSetupParticipantDescriptors); //$NON-NLS-1$ //$NON-NLS-2$
 		initialize("documentSetup", "extensions", false, fSetupParticipantDescriptors); //$NON-NLS-1$ //$NON-NLS-2$
 		initialize("annotationModelCreation", "contentTypeId", true, fAnnotationModelFactoryDescriptors); //$NON-NLS-1$ //$NON-NLS-2$
 		initialize("annotationModelCreation", "fileNames", false, fAnnotationModelFactoryDescriptors); //$NON-NLS-1$ //$NON-NLS-2$
 		initialize("annotationModelCreation", "extensions", false, fAnnotationModelFactoryDescriptors); //$NON-NLS-1$ //$NON-NLS-2$

 	}

 	/**
 	 * Reads the comma-separated value from the given configuration element for the given attribute name and remembers
 	 * the configuration element in the given map under the individual tokens of the attribute value.
 	 *
 	 * @param attributeName the name of the attribute
 	 * @param element the configuration element
 	 * @param map the map which remembers the configuration element
 	 */
 	private void read(String attributeName, IConfigurationElement element, Map<Object, Set<IConfigurationElement>> map) {
 		String value= element.getAttribute(attributeName);
 		if (value != null) {
 			StringTokenizer tokenizer= new StringTokenizer(value, ","); //$NON-NLS-1$
 			while (tokenizer.hasMoreTokens()) {
 				String token= tokenizer.nextToken().trim();

 				Set<IConfigurationElement> s= map.get(token);
 				if (s == null) {
 					s= new HashSet<>();
 					map.put(token, s);
 				}
 				s.add(element);
 			}
 		}
 	}

 	/**
 	 * Reads the value from the given configuration element for the given attribute name and remembers
 	 * the configuration element in the given map under the individual content type of the attribute value.
 	 *
 	 * @param attributeName the name of the attribute
 	 * @param element the configuration element
 	 * @param map the map which remembers the configuration element
 	 */
 	private void readContentType(String attributeName, IConfigurationElement element, Map<Object, Set<IConfigurationElement>> map) {
 		String value= element.getAttribute(attributeName);
 		if (value != null) {
 			IContentType contentType= fContentTypeManager.getContentType(value);
 			if (contentType == null) {
 				log(new Status(IStatus.ERROR, FileBuffersPlugin.PLUGIN_ID, IStatus.OK, NLSUtility.format(FileBuffersMessages.ExtensionsRegistry_error_contentTypeDoesNotExist, value), null));
 				return;
 			}
 			ContentTypeAdapter adapter= new ContentTypeAdapter(contentType);
 			Set<IConfigurationElement> s= map.get(adapter);
 			if (s == null) {
 				s= new HashSet<>();
 				map.put(adapter, s);
 			}
 			s.add(element);
 		}
 	}

 	/**
 	 * Adds an entry to the log of this plug-in for the given status
 	 * @param status the status to log
 	 */
 	private void log(IStatus status) {
 		ILog log= FileBuffersPlugin.getDefault().getLog();
 		log.log(status);
 	}

 	/**
 	 * Initializes this registry. It retrieves all implementers of the given
 	 * extension point and remembers those implementers based on the
 	 * file name extensions in the given map.
 	 *
 	 * @param extensionPointName the name of the extension point
 	 * @param childElementName the name of the child elements
 	 * @param isContentTypeId the child element is a content type id
 	 * @param descriptors the map to be filled
 	 */
 	private void initialize(String extensionPointName, String childElementName, boolean isContentTypeId, Map<Object, Set<IConfigurationElement>> descriptors) {

 		IExtensionPoint extensionPoint= Platform.getExtensionRegistry().getExtensionPoint(FileBuffersPlugin.PLUGIN_ID, extensionPointName);
 		if (extensionPoint == null) {
 			log(new Status(IStatus.ERROR, FileBuffersPlugin.PLUGIN_ID, 0, NLSUtility.format(FileBuffersMessages.ExtensionsRegistry_error_extensionPointNotFound, extensionPointName), null));
 			return;
 		}

 		IConfigurationElement[] elements= extensionPoint.getConfigurationElements();
 		for (int i= 0; i < elements.length; i++) {
 			if (isContentTypeId)
 				readContentType(childElementName, elements[i], descriptors);
 			else
 				read(childElementName, elements[i], descriptors);
 		}
 	}

 	/**
 	 * Returns the executable extension for the given configuration element.
 	 * If there is no instantiated extension remembered for this
 	 * element, a new extension is created and put into the cache if it is of the requested type.
 	 *
 	 * @param entry the configuration element
 	 * @param extensions the map of instantiated extensions
 	 * @param extensionType the requested result type
 	 * @return the executable extension for the given configuration element.
 	 */
 	@SuppressWarnings("unchecked")
 	private <T> T getExtension(IConfigurationElement entry, Map<IConfigurationElement, Object> extensions, Class<T> extensionType) {
 		T extension= (T) extensions.get(entry);
 		if (extension != null)
 			return extension;

 		try {
 			extension= (T) entry.createExecutableExtension("class"); //$NON-NLS-1$
 		} catch (CoreException x) {
 			log(x.getStatus());
 		}

 		if (extensionType.isInstance(extension)) {
 			extensions.put(entry, extension);
 			return extension;
 		}

 		return null;
 	}

 	/**
 	 * Returns the first enumerated element of the given set.
 	 *
 	 * @param set the set from which to choose
 	 * @return the selected configuration element
 	 */
 	private IConfigurationElement selectConfigurationElement(Set<IConfigurationElement> set) {
 		if (set != null && !set.isEmpty()) {
 			Iterator<IConfigurationElement> e= set.iterator();
 			return e.next();
 		}
 		return null;
 	}

 	/**
 	 * Returns a sharable document factory for the given file name or file extension.
 	 *
 	 * @param nameOrExtension the name or extension to be used for lookup
 	 * @return the sharable document factory or <code>null</code>
 	 * @deprecated As of 3.5
 	 */
 	@Deprecated
 	protected org.eclipse.core.filebuffers.IDocumentFactory getDocumentFactory(String nameOrExtension) {
 		Set<IConfigurationElement> set= fFactoryDescriptors.get(nameOrExtension);
 		if (set != null) {
 			IConfigurationElement entry= selectConfigurationElement(set);
 			return getExtension(entry, fFactories, org.eclipse.core.filebuffers.IDocumentFactory.class);
 		}
 		return null;
 	}

 	/**
 	 * Returns a sharable document factory for the given content types.
 	 *
 	 * @param contentTypes the content types used to find the factory
 	 * @return the sharable document factory or <code>null</code>
 	 * @deprecated As of 3.5
 	 */
 	@Deprecated
 	protected org.eclipse.core.filebuffers.IDocumentFactory doGetDocumentFactory(IContentType[] contentTypes) {
 		Set<IConfigurationElement> set= null;
 		int i= 0;
 		while (i < contentTypes.length && set == null) {
 			set= fFactoryDescriptors.get(new ContentTypeAdapter(contentTypes[i++]));
 		}

 		if (set != null) {
 			IConfigurationElement entry= selectConfigurationElement(set);
 			return getExtension(entry, fFactories, org.eclipse.core.filebuffers.IDocumentFactory.class);
 		}
 		return null;
 	}

 	/**
 	 * Returns a sharable document factory for the given content types. This method considers the
 	 * base content types of the given set of content types.
 	 *
 	 * @param contentTypes the content types used to find the factory
 	 * @return the sharable document factory or <code>null</code>
 	 * @deprecated As of 3.5
 	 */
 	@Deprecated
 	protected org.eclipse.core.filebuffers.IDocumentFactory getDocumentFactory(IContentType[] contentTypes) {
 		org.eclipse.core.filebuffers.IDocumentFactory factory= doGetDocumentFactory(contentTypes);
 		while (factory == null) {
 			contentTypes= computeBaseContentTypes(contentTypes);
 			if (contentTypes == null)
 				break;
 			factory= doGetDocumentFactory(contentTypes);
 		}
 		return factory;
 	}

 	/**
 	 * Returns the set of setup participants for the given file name or extension.
 	 *
 	 * @param nameOrExtension the name or extension to be used for lookup
 	 * @return the sharable set of document setup participants
 	 */
 	protected List<IDocumentSetupParticipant> getDocumentSetupParticipants(String nameOrExtension) {
 		Set<IConfigurationElement> set= fSetupParticipantDescriptors.get(nameOrExtension);
 		if (set == null)
 			return null;

 		List<IDocumentSetupParticipant> participants= new ArrayList<>();
 		Iterator<IConfigurationElement> e= set.iterator();
 		while (e.hasNext()) {
 			IConfigurationElement entry= e.next();
 			IDocumentSetupParticipant participant= getExtension(entry, fSetupParticipants, IDocumentSetupParticipant.class);
 			if (participant != null)
 				participants.add(participant);
 		}

 		return participants;
 	}

 	/**
 	 * Returns the set of setup participants for the given content types.
 	 *
 	 * @param contentTypes the contentTypes to be used for lookup
 	 * @return the sharable set of document setup participants
 	 */
 	private List<IDocumentSetupParticipant> doGetDocumentSetupParticipants(IContentType[] contentTypes) {
 		Set<IConfigurationElement> resultSet= new HashSet<>();
 		int i= 0;
 		while (i < contentTypes.length) {
 			Set<IConfigurationElement> set= fSetupParticipantDescriptors.get(new ContentTypeAdapter(contentTypes[i++]));
 			if (set != null)
 				resultSet.addAll(set);
 		}

 		List<IDocumentSetupParticipant> participants= new ArrayList<>();
 		Iterator<IConfigurationElement> e= resultSet.iterator();
 		while (e.hasNext()) {
 			IConfigurationElement entry= e.next();
 			IDocumentSetupParticipant participant= getExtension(entry, fSetupParticipants, IDocumentSetupParticipant.class);
 			if (participant != null)
 				participants.add(participant);
 		}

 		return participants.isEmpty() ? null : participants;
 	}

 	/**
 	 * Returns the set of setup participants for the given content types. This
 	 * method considers the base content types of the given set of content
 	 * types.
 	 *
 	 * @param contentTypes the contentTypes to be used for lookup
 	 * @return the sharable set of document setup participants
 	 */
 	protected List<IDocumentSetupParticipant> getDocumentSetupParticipants(IContentType[] contentTypes) {
 		List<IDocumentSetupParticipant> participants= doGetDocumentSetupParticipants(contentTypes);
 		while (participants == null) {
 			contentTypes= computeBaseContentTypes(contentTypes);
 			if (contentTypes == null)
 				break;
 			participants= doGetDocumentSetupParticipants(contentTypes);
 		}
 		return participants;
 	}

 	/**
 	 * Returns a sharable annotation model factory for the given content types.
 	 *
 	 * @param contentTypes the content types used to find the factory
 	 * @return the sharable annotation model factory or <code>null</code>
 	 */
 	private IAnnotationModelFactory doGetAnnotationModelFactory(IContentType[] contentTypes) {
 		Set<IConfigurationElement> set= null;
 		int i= 0;
 		while (i < contentTypes.length && set == null) {
 			set= fAnnotationModelFactoryDescriptors.get(new ContentTypeAdapter(contentTypes[i++]));
 		}

 		if (set != null) {
 			IConfigurationElement entry= selectConfigurationElement(set);
 			return getExtension(entry, fAnnotationModelFactories, IAnnotationModelFactory.class);
 		}
 		return null;
 	}

 	/**
 	 * Returns a sharable annotation model factory for the given content types.
 	 * This method considers the base content types of the given set of content
 	 * types.
 	 *
 	 * @param contentTypes the content types used to find the factory
 	 * @return the sharable annotation model factory or <code>null</code>
 	 */
 	protected IAnnotationModelFactory getAnnotationModelFactory(IContentType[] contentTypes) {
 		IAnnotationModelFactory factory= doGetAnnotationModelFactory(contentTypes);
 		while (factory == null) {
 			contentTypes= computeBaseContentTypes(contentTypes);
 			if (contentTypes == null)
 				break;
 			factory= doGetAnnotationModelFactory(contentTypes);
 		}
 		return factory;
 	}

 	/**
 	 * Returns a sharable annotation model factory for the given file name or file extension.
 	 *
 	 * @param extension the name or extension to be used for lookup
 	 * @return the sharable document factory or <code>null</code>
 	 */
 	protected IAnnotationModelFactory getAnnotationModelFactory(String extension) {
 		Set<IConfigurationElement> set= fAnnotationModelFactoryDescriptors.get(extension);
 		if (set != null) {
 			IConfigurationElement entry= selectConfigurationElement(set);
 			return getExtension(entry, fAnnotationModelFactories, IAnnotationModelFactory.class);
 		}
 		return null;
 	}

 	/**
 	 * Returns the set of content types for the given location.
 	 *
 	 * @param location the location for which to look up the content types
 	 * @param locationKind the kind of the given location
 	 * @return the set of content types for the location
 	 * @since 3.3
 	 */
 	protected IContentType[] findContentTypes(IPath location, LocationKind locationKind) {
 		Assert.isLegal(locationKind != LocationKind.IFILE);
 		return fContentTypeManager.findContentTypesFor(location.lastSegment());
 	}

 	/**
 	 * Returns the set of direct base content types for the given set of content
 	 * types. Returns <code>null</code> if non of the given content types has
 	 * a direct base content type.
 	 *
 	 * @param contentTypes the content types
 	 * @return the set of direct base content types
 	 */
 	private IContentType[] computeBaseContentTypes(IContentType[] contentTypes) {
 		List<IContentType> baseTypes= new ArrayList<>();
 		for (int i= 0; i < contentTypes.length; i++) {
 			IContentType baseType= contentTypes[i].getBaseType();
 			if (baseType != null)
 				baseTypes.add(baseType);
 		}

 		IContentType[] result= null;
 		int size= baseTypes.size();
 		if (size > 0) {
 			result= new IContentType[size];
 			baseTypes.toArray(result);
 		}
 		return result;
 	}

 	/**
 	 * Returns the sharable document factory for the given location.
 	 *
 	 * @param location the location for which to looked up the factory
 	 * @param locationKind the kind of the given location
 	 * @return the sharable document factory
 	 * @since 3.3
 	 * @deprecated As of 3.5
 	 */
 	@Deprecated
 	public org.eclipse.core.filebuffers.IDocumentFactory getDocumentFactory(IPath location, LocationKind locationKind) {
 		org.eclipse.core.filebuffers.IDocumentFactory factory= getDocumentFactory(findContentTypes(location, locationKind));
 		if (factory == null)
 			factory= getDocumentFactory(location.lastSegment());
 		if (factory == null)
 			factory= getDocumentFactory(location.getFileExtension());
 		if (factory == null)
 			factory= getDocumentFactory(WILDCARD);
 		return factory;
 	}

 	/**
 	 * Returns the sharable set of document setup participants for the given location.
 	 *
 	 * @param location the location for which to look up the setup participants
 	 * @param locationKind the kind of the given location
 	 * @return the sharable set of document setup participants
 	 * @since 3.3
 	 */
 	public IDocumentSetupParticipant[] getDocumentSetupParticipants(IPath location, LocationKind locationKind) {
 		Set<IDocumentSetupParticipant> participants= new HashSet<>();

 		List<IDocumentSetupParticipant> p= getDocumentSetupParticipants(findContentTypes(location, locationKind));
 		if (p != null)
 			participants.addAll(p);

 		p= getDocumentSetupParticipants(location.lastSegment());
 		if (p != null)
 			participants.addAll(p);

 		p= getDocumentSetupParticipants(location.getFileExtension());
 		if (p != null)
 			participants.addAll(p);

 		p= getDocumentSetupParticipants(WILDCARD);
 		if (p != null)
 			participants.addAll(p);

 		IDocumentSetupParticipant[] result= new IDocumentSetupParticipant[participants.size()];
 		participants.toArray(result);
 		return result;
 	}

 	/**
 	 * Returns the sharable annotation model factory for the given location.
 	 *
 	 * @param location the location for which to look up the factory
 	 * @param locationKind the kind of the given location
 	 * @return the sharable annotation model factory
 	 * @since 3.3
 	 */
 	public IAnnotationModelFactory getAnnotationModelFactory(IPath location, LocationKind locationKind) {
 		IAnnotationModelFactory factory= getAnnotationModelFactory(findContentTypes(location, locationKind));
 		if (factory == null)
 			factory= getAnnotationModelFactory(location.lastSegment());
 		if (factory == null)
 			factory= getAnnotationModelFactory(location.getFileExtension());
 		if (factory == null)
 			factory= getAnnotationModelFactory(WILDCARD);
 		return factory;
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2000, 2015 IBM Corporation 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:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.core.internal.filebuffers;

	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.Iterator;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;
	import java.util.StringTokenizer;

	import org.eclipse.core.runtime.Assert;
	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.IExtensionPoint;
	import org.eclipse.core.runtime.ILog;
	import org.eclipse.core.runtime.IPath;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Platform;
	import org.eclipse.core.runtime.Status;
	import org.eclipse.core.runtime.content.IContentType;
	import org.eclipse.core.runtime.content.IContentTypeManager;

	import org.eclipse.core.filebuffers.IAnnotationModelFactory;
	import org.eclipse.core.filebuffers.IDocumentSetupParticipant;
	import org.eclipse.core.filebuffers.LocationKind;


	/**
	* This registry manages sharable document factories and setup
	* participants that are specified in <code>plugin.xml</code>.
	*/
	public class ExtensionsRegistry {

	/**
	* Adapts {@link IContentType} with the ability to check equality. This allows to use them in a
	* collection.
	*/
	private static class ContentTypeAdapter {

	/** The adapted content type. */
	private IContentType fContentType;

	/**
	* Creates a new content type adapter for the
	* given content type.
	*
	* @param contentType the content type to be adapted
	*/
	public ContentTypeAdapter(IContentType contentType) {
	Assert.isNotNull(contentType);
	fContentType= contentType;
	}

	/**
	* Return the id of the adapted content type.
	*
	* @return the id
	*/
	public String getId() {
	return fContentType.getId();
	}

	@Override
	public boolean equals(Object obj) {
	return obj instanceof ContentTypeAdapter && fContentType.getId().equals(((ContentTypeAdapter)obj).getId());
	}

	@Override
	public int hashCode() {
	return fContentType.getId().hashCode();
	}
	}

	protected static final String WILDCARD= "*"; //$NON-NLS-1$

	/** The mapping between file attributes and configuration elements describing document factories. */
	private Map<Object, Set<IConfigurationElement>> fFactoryDescriptors= new HashMap<>();
	/** The mapping between configuration elements for document factories and instantiated document factories. */
	private Map<IConfigurationElement, Object> fFactories= new HashMap<>();
	/** The mapping between file attributes and configuration elements describing document setup participants. */
	private Map<Object, Set<IConfigurationElement>> fSetupParticipantDescriptors= new HashMap<>();
	/** The mapping between configuration elements for setup participants and instantiated setup participants. */
	private Map<IConfigurationElement, Object> fSetupParticipants= new HashMap<>();
	/** The mapping between file attributes and configuration elements describing annotation model factories. */
	private Map<Object, Set<IConfigurationElement>> fAnnotationModelFactoryDescriptors= new HashMap<>();
	/** The mapping between configuration elements for annotation model factories */
	private Map<IConfigurationElement, Object> fAnnotationModelFactories= new HashMap<>();
	/** The content type manager. */
	protected IContentTypeManager fContentTypeManager= Platform.getContentTypeManager();


	/**
	* Creates a new document factory registry and initializes it with the information
	* found in the plug-in registry.
	*/
	public ExtensionsRegistry() {
	initialize("documentCreation", "contentTypeId", true, fFactoryDescriptors); //$NON-NLS-1$ //$NON-NLS-2$
	initialize("documentCreation", "fileNames", false, fFactoryDescriptors); //$NON-NLS-1$ //$NON-NLS-2$
	initialize("documentCreation", "extensions", false, fFactoryDescriptors); //$NON-NLS-1$ //$NON-NLS-2$
	initialize("documentSetup", "contentTypeId", true, fSetupParticipantDescriptors); //$NON-NLS-1$ //$NON-NLS-2$
	initialize("documentSetup", "fileNames", false, fSetupParticipantDescriptors); //$NON-NLS-1$ //$NON-NLS-2$
	initialize("documentSetup", "extensions", false, fSetupParticipantDescriptors); //$NON-NLS-1$ //$NON-NLS-2$
	initialize("annotationModelCreation", "contentTypeId", true, fAnnotationModelFactoryDescriptors); //$NON-NLS-1$ //$NON-NLS-2$
	initialize("annotationModelCreation", "fileNames", false, fAnnotationModelFactoryDescriptors); //$NON-NLS-1$ //$NON-NLS-2$
	initialize("annotationModelCreation", "extensions", false, fAnnotationModelFactoryDescriptors); //$NON-NLS-1$ //$NON-NLS-2$

	}

	/**
	* Reads the comma-separated value from the given configuration element for the given attribute name and remembers
	* the configuration element in the given map under the individual tokens of the attribute value.
	*
	* @param attributeName the name of the attribute
	* @param element the configuration element
	* @param map the map which remembers the configuration element
	*/
	private void read(String attributeName, IConfigurationElement element, Map<Object, Set<IConfigurationElement>> map) {
	String value= element.getAttribute(attributeName);
	if (value != null) {
	StringTokenizer tokenizer= new StringTokenizer(value, ","); //$NON-NLS-1$
	while (tokenizer.hasMoreTokens()) {
	String token= tokenizer.nextToken().trim();

	Set<IConfigurationElement> s= map.get(token);
	if (s == null) {
	s= new HashSet<>();
	map.put(token, s);
	}
	s.add(element);
	}
	}
	}

	/**
	* Reads the value from the given configuration element for the given attribute name and remembers
	* the configuration element in the given map under the individual content type of the attribute value.
	*
	* @param attributeName the name of the attribute
	* @param element the configuration element
	* @param map the map which remembers the configuration element
	*/
	private void readContentType(String attributeName, IConfigurationElement element, Map<Object, Set<IConfigurationElement>> map) {
	String value= element.getAttribute(attributeName);
	if (value != null) {
	IContentType contentType= fContentTypeManager.getContentType(value);
	if (contentType == null) {
	log(new Status(IStatus.ERROR, FileBuffersPlugin.PLUGIN_ID, IStatus.OK, NLSUtility.format(FileBuffersMessages.ExtensionsRegistry_error_contentTypeDoesNotExist, value), null));
	return;
	}
	ContentTypeAdapter adapter= new ContentTypeAdapter(contentType);
	Set<IConfigurationElement> s= map.get(adapter);
	if (s == null) {
	s= new HashSet<>();
	map.put(adapter, s);
	}
	s.add(element);
	}
	}

	/**
	* Adds an entry to the log of this plug-in for the given status
	* @param status the status to log
	*/
	private void log(IStatus status) {
	ILog log= FileBuffersPlugin.getDefault().getLog();
	log.log(status);
	}

	/**
	* Initializes this registry. It retrieves all implementers of the given
	* extension point and remembers those implementers based on the
	* file name extensions in the given map.
	*
	* @param extensionPointName the name of the extension point
	* @param childElementName the name of the child elements
	* @param isContentTypeId the child element is a content type id
	* @param descriptors the map to be filled
	*/
	private void initialize(String extensionPointName, String childElementName, boolean isContentTypeId, Map<Object, Set<IConfigurationElement>> descriptors) {

	IExtensionPoint extensionPoint= Platform.getExtensionRegistry().getExtensionPoint(FileBuffersPlugin.PLUGIN_ID, extensionPointName);
	if (extensionPoint == null) {
	log(new Status(IStatus.ERROR, FileBuffersPlugin.PLUGIN_ID, 0, NLSUtility.format(FileBuffersMessages.ExtensionsRegistry_error_extensionPointNotFound, extensionPointName), null));
	return;
	}

	IConfigurationElement[] elements= extensionPoint.getConfigurationElements();
	for (int i= 0; i < elements.length; i++) {
	if (isContentTypeId)
	readContentType(childElementName, elements[i], descriptors);
	else
	read(childElementName, elements[i], descriptors);
	}
	}

	/**
	* Returns the executable extension for the given configuration element.
	* If there is no instantiated extension remembered for this
	* element, a new extension is created and put into the cache if it is of the requested type.
	*
	* @param entry the configuration element
	* @param extensions the map of instantiated extensions
	* @param extensionType the requested result type
	* @return the executable extension for the given configuration element.
	*/
	@SuppressWarnings("unchecked")
	private <T> T getExtension(IConfigurationElement entry, Map<IConfigurationElement, Object> extensions, Class<T> extensionType) {
	T extension= (T) extensions.get(entry);
	if (extension != null)
	return extension;

	try {
	extension= (T) entry.createExecutableExtension("class"); //$NON-NLS-1$
	} catch (CoreException x) {
	log(x.getStatus());
	}

	if (extensionType.isInstance(extension)) {
	extensions.put(entry, extension);
	return extension;
	}

	return null;
	}

	/**
	* Returns the first enumerated element of the given set.
	*
	* @param set the set from which to choose
	* @return the selected configuration element
	*/
	private IConfigurationElement selectConfigurationElement(Set<IConfigurationElement> set) {
	if (set != null && !set.isEmpty()) {
	Iterator<IConfigurationElement> e= set.iterator();
	return e.next();
	}
	return null;
	}

	/**
	* Returns a sharable document factory for the given file name or file extension.
	*
	* @param nameOrExtension the name or extension to be used for lookup
	* @return the sharable document factory or <code>null</code>
	* @deprecated As of 3.5
	*/
	@Deprecated
	protected org.eclipse.core.filebuffers.IDocumentFactory getDocumentFactory(String nameOrExtension) {
	Set<IConfigurationElement> set= fFactoryDescriptors.get(nameOrExtension);
	if (set != null) {
	IConfigurationElement entry= selectConfigurationElement(set);
	return getExtension(entry, fFactories, org.eclipse.core.filebuffers.IDocumentFactory.class);
	}
	return null;
	}

	/**
	* Returns a sharable document factory for the given content types.
	*
	* @param contentTypes the content types used to find the factory
	* @return the sharable document factory or <code>null</code>
	* @deprecated As of 3.5
	*/
	@Deprecated
	protected org.eclipse.core.filebuffers.IDocumentFactory doGetDocumentFactory(IContentType[] contentTypes) {
	Set<IConfigurationElement> set= null;
	int i= 0;
	while (i < contentTypes.length && set == null) {
	set= fFactoryDescriptors.get(new ContentTypeAdapter(contentTypes[i++]));
	}

	if (set != null) {
	IConfigurationElement entry= selectConfigurationElement(set);
	return getExtension(entry, fFactories, org.eclipse.core.filebuffers.IDocumentFactory.class);
	}
	return null;
	}

	/**
	* Returns a sharable document factory for the given content types. This method considers the
	* base content types of the given set of content types.
	*
	* @param contentTypes the content types used to find the factory
	* @return the sharable document factory or <code>null</code>
	* @deprecated As of 3.5
	*/
	@Deprecated
	protected org.eclipse.core.filebuffers.IDocumentFactory getDocumentFactory(IContentType[] contentTypes) {
	org.eclipse.core.filebuffers.IDocumentFactory factory= doGetDocumentFactory(contentTypes);
	while (factory == null) {
	contentTypes= computeBaseContentTypes(contentTypes);
	if (contentTypes == null)
	break;
	factory= doGetDocumentFactory(contentTypes);
	}
	return factory;
	}

	/**
	* Returns the set of setup participants for the given file name or extension.
	*
	* @param nameOrExtension the name or extension to be used for lookup
	* @return the sharable set of document setup participants
	*/
	protected List<IDocumentSetupParticipant> getDocumentSetupParticipants(String nameOrExtension) {
	Set<IConfigurationElement> set= fSetupParticipantDescriptors.get(nameOrExtension);
	if (set == null)
	return null;

	List<IDocumentSetupParticipant> participants= new ArrayList<>();
	Iterator<IConfigurationElement> e= set.iterator();
	while (e.hasNext()) {
	IConfigurationElement entry= e.next();
	IDocumentSetupParticipant participant= getExtension(entry, fSetupParticipants, IDocumentSetupParticipant.class);
	if (participant != null)
	participants.add(participant);
	}

	return participants;
	}

	/**
	* Returns the set of setup participants for the given content types.
	*
	* @param contentTypes the contentTypes to be used for lookup
	* @return the sharable set of document setup participants
	*/
	private List<IDocumentSetupParticipant> doGetDocumentSetupParticipants(IContentType[] contentTypes) {
	Set<IConfigurationElement> resultSet= new HashSet<>();
	int i= 0;
	while (i < contentTypes.length) {
	Set<IConfigurationElement> set= fSetupParticipantDescriptors.get(new ContentTypeAdapter(contentTypes[i++]));
	if (set != null)
	resultSet.addAll(set);
	}

	List<IDocumentSetupParticipant> participants= new ArrayList<>();
	Iterator<IConfigurationElement> e= resultSet.iterator();
	while (e.hasNext()) {
	IConfigurationElement entry= e.next();
	IDocumentSetupParticipant participant= getExtension(entry, fSetupParticipants, IDocumentSetupParticipant.class);
	if (participant != null)
	participants.add(participant);
	}

	return participants.isEmpty() ? null : participants;
	}

	/**
	* Returns the set of setup participants for the given content types. This
	* method considers the base content types of the given set of content
	* types.
	*
	* @param contentTypes the contentTypes to be used for lookup
	* @return the sharable set of document setup participants
	*/
	protected List<IDocumentSetupParticipant> getDocumentSetupParticipants(IContentType[] contentTypes) {
	List<IDocumentSetupParticipant> participants= doGetDocumentSetupParticipants(contentTypes);
	while (participants == null) {
	contentTypes= computeBaseContentTypes(contentTypes);
	if (contentTypes == null)
	break;
	participants= doGetDocumentSetupParticipants(contentTypes);
	}
	return participants;
	}

	/**
	* Returns a sharable annotation model factory for the given content types.
	*
	* @param contentTypes the content types used to find the factory
	* @return the sharable annotation model factory or <code>null</code>
	*/
	private IAnnotationModelFactory doGetAnnotationModelFactory(IContentType[] contentTypes) {
	Set<IConfigurationElement> set= null;
	int i= 0;
	while (i < contentTypes.length && set == null) {
	set= fAnnotationModelFactoryDescriptors.get(new ContentTypeAdapter(contentTypes[i++]));
	}

	if (set != null) {
	IConfigurationElement entry= selectConfigurationElement(set);
	return getExtension(entry, fAnnotationModelFactories, IAnnotationModelFactory.class);
	}
	return null;
	}

	/**
	* Returns a sharable annotation model factory for the given content types.
	* This method considers the base content types of the given set of content
	* types.
	*
	* @param contentTypes the content types used to find the factory
	* @return the sharable annotation model factory or <code>null</code>
	*/
	protected IAnnotationModelFactory getAnnotationModelFactory(IContentType[] contentTypes) {
	IAnnotationModelFactory factory= doGetAnnotationModelFactory(contentTypes);
	while (factory == null) {
	contentTypes= computeBaseContentTypes(contentTypes);
	if (contentTypes == null)
	break;
	factory= doGetAnnotationModelFactory(contentTypes);
	}
	return factory;
	}

	/**
	* Returns a sharable annotation model factory for the given file name or file extension.
	*
	* @param extension the name or extension to be used for lookup
	* @return the sharable document factory or <code>null</code>
	*/
	protected IAnnotationModelFactory getAnnotationModelFactory(String extension) {
	Set<IConfigurationElement> set= fAnnotationModelFactoryDescriptors.get(extension);
	if (set != null) {
	IConfigurationElement entry= selectConfigurationElement(set);
	return getExtension(entry, fAnnotationModelFactories, IAnnotationModelFactory.class);
	}
	return null;
	}

	/**
	* Returns the set of content types for the given location.
	*
	* @param location the location for which to look up the content types
	* @param locationKind the kind of the given location
	* @return the set of content types for the location
	* @since 3.3
	*/
	protected IContentType[] findContentTypes(IPath location, LocationKind locationKind) {
	Assert.isLegal(locationKind != LocationKind.IFILE);
	return fContentTypeManager.findContentTypesFor(location.lastSegment());
	}

	/**
	* Returns the set of direct base content types for the given set of content
	* types. Returns <code>null</code> if non of the given content types has
	* a direct base content type.
	*
	* @param contentTypes the content types
	* @return the set of direct base content types
	*/
	private IContentType[] computeBaseContentTypes(IContentType[] contentTypes) {
	List<IContentType> baseTypes= new ArrayList<>();
	for (int i= 0; i < contentTypes.length; i++) {
	IContentType baseType= contentTypes[i].getBaseType();
	if (baseType != null)
	baseTypes.add(baseType);
	}

	IContentType[] result= null;
	int size= baseTypes.size();
	if (size > 0) {
	result= new IContentType[size];
	baseTypes.toArray(result);
	}
	return result;
	}

	/**
	* Returns the sharable document factory for the given location.
	*
	* @param location the location for which to looked up the factory
	* @param locationKind the kind of the given location
	* @return the sharable document factory
	* @since 3.3
	* @deprecated As of 3.5
	*/
	@Deprecated
	public org.eclipse.core.filebuffers.IDocumentFactory getDocumentFactory(IPath location, LocationKind locationKind) {
	org.eclipse.core.filebuffers.IDocumentFactory factory= getDocumentFactory(findContentTypes(location, locationKind));
	if (factory == null)
	factory= getDocumentFactory(location.lastSegment());
	if (factory == null)
	factory= getDocumentFactory(location.getFileExtension());
	if (factory == null)
	factory= getDocumentFactory(WILDCARD);
	return factory;
	}

	/**
	* Returns the sharable set of document setup participants for the given location.
	*
	* @param location the location for which to look up the setup participants
	* @param locationKind the kind of the given location
	* @return the sharable set of document setup participants
	* @since 3.3
	*/
	public IDocumentSetupParticipant[] getDocumentSetupParticipants(IPath location, LocationKind locationKind) {
	Set<IDocumentSetupParticipant> participants= new HashSet<>();

	List<IDocumentSetupParticipant> p= getDocumentSetupParticipants(findContentTypes(location, locationKind));
	if (p != null)
	participants.addAll(p);

	p= getDocumentSetupParticipants(location.lastSegment());
	if (p != null)
	participants.addAll(p);

	p= getDocumentSetupParticipants(location.getFileExtension());
	if (p != null)
	participants.addAll(p);

	p= getDocumentSetupParticipants(WILDCARD);
	if (p != null)
	participants.addAll(p);

	IDocumentSetupParticipant[] result= new IDocumentSetupParticipant[participants.size()];
	participants.toArray(result);
	return result;
	}

	/**
	* Returns the sharable annotation model factory for the given location.
	*
	* @param location the location for which to look up the factory
	* @param locationKind the kind of the given location
	* @return the sharable annotation model factory
	* @since 3.3
	*/
	public IAnnotationModelFactory getAnnotationModelFactory(IPath location, LocationKind locationKind) {
	IAnnotationModelFactory factory= getAnnotationModelFactory(findContentTypes(location, locationKind));
	if (factory == null)
	factory= getAnnotationModelFactory(location.lastSegment());
	if (factory == null)
	factory= getAnnotationModelFactory(location.getFileExtension());
	if (factory == null)
	factory= getAnnotationModelFactory(WILDCARD);
	return factory;
	}

	}