org.eclipse.gmf.runtime.emf.clipboard.core/src/org/eclipse/gmf/runtime/emf/clipboard/core/internal/ClipboardSupportManager.java - gmf-runtime/org.eclipse.gmf-runtime - Git at Google

 /******************************************************************************
  * Copyright (c) 2005, 2010 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.gmf.runtime.emf.clipboard.core.internal;

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

 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IAdaptable;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.emf.ecore.EClass;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.EPackage;
 import org.eclipse.gmf.runtime.common.core.util.Proxy;
 import org.eclipse.gmf.runtime.emf.clipboard.core.IClipboardSupportFactory;
 import org.eclipse.gmf.runtime.emf.clipboard.core.IClipboardSupportPolicy;
 import org.eclipse.gmf.runtime.emf.clipboard.core.internal.l10n.EMFClipboardCoreMessages;
 import org.eclipse.osgi.util.NLS;


 /**
  * Manager for the <tt>clipboardSupport</tt> extension point.
  *
  * @author Christian W. Damus (cdamus), crevells
  */
 public class ClipboardSupportManager {
 	public static final String EP_CLIPBOARD_SUPPORT = "org.eclipse.gmf.runtime.emf.clipboard.core.clipboardSupport"; //$NON-NLS-1$
 	static final String E_NSURI = "nsURI"; //$NON-NLS-1$
 	static final String E_CLASS = "class"; //$NON-NLS-1$
 	static final String E_POLICY = "policy"; //$NON-NLS-1$

 	/** @deprecated need a context-based solution */
 	static final String E_PRIORITY = "priority"; //$NON-NLS-1$

 	/** @deprecated need a context-based solution */
 	private static final List PRIORITIES = Arrays.asList(new String[] {
 		"lowest", "low", "medium", "high", "highest"});  //$NON-NLS-1$//$NON-NLS-2$//$NON-NLS-3$//$NON-NLS-4$//$NON-NLS-5$

 	/** An array of lists of descriptors for each priority, index by priority. */
 	private static ArrayList[] descriptors;

 	/**
 	 * Wraps an {@link EObject} to adapt it to the {@link IAdaptable} Eclipse
 	 * platform API. This is useful for passing <code>EObject</code>s into APIs
 	 * that consume adaptables.
 	 */
 	private static class EObjectAdapter extends Proxy implements IAdaptable {

 		public EObjectAdapter(EObject element) {
 			super(element);
 		}

 		/**
 		 * Returns the wrapped {@link EObject} as the adapter when possible. The
 		 * following adaptations are supported:
 		 * <ul>
 		 * <li>if the wrapped <code>EObject</code> conforms to the
 		 * <code>adapter</code> type, then it is returned</li>
 		 * <li>if this adapter, itself, conforms to the <code>adapter</code>
 		 * type, then it is returned</li>
 		 * <li>otherwise, there is no adapter (<code>null</code> returned)</li>
 		 * </ul>
 		 */
 		public Object getAdapter(Class adapter) {
 			if (adapter.isInstance(getRealObject())) {
 				return getRealObject();
 			}
 			if (adapter.isInstance(this)) {
 				return this;
 			}
 			return null;
 		}
 	}

 	/** Not instantiable by clients. */
 	private ClipboardSupportManager() {
 		super();
 	}

 	/**
 	 * Configures the extensions on the <tt>clipboardSupport</tt> extension
 	 * point.
 	 * <p>
 	 * <b>Note</b> that this method must only be called by the plug-in class
 	 * on initialization.
 	 * </p>
 	 *
 	 * @param configs the configuration elements representing extensions
 	 */
 	public static void configureExtensions(IConfigurationElement[] configs) {

 		// initialize the arrays
 		descriptors = new ArrayList[PRIORITIES.size()];
 		for (int i = 0; i < PRIORITIES.size(); i++) {
 			descriptors[i] = new ArrayList(0);
 		}

 		// create each descriptor and add to appropriate list
 		for (int i = 0; i < configs.length; i++) {
 			try {
 				Descriptor desc = new Descriptor(configs[i]);
 				descriptors[desc.getPriority()].add(desc);
 			} catch (CoreException e) {
 				ClipboardPlugin.getPlugin().log(e.getStatus());
 			}
 		}
 	}

 	/**
 	 * Retrieves the clipboard support factory (if any) that handles the
 	 * specified <code>EPackage</code>.
 	 * <p>
 	 * <b>WARNING: DO NOT USE.</b> Calling this method does not support the full
 	 * extensibility capabilities of the ClipboardSupport extension point. Use
 	 * the method {@link #lookup(EObject)} instead.
 	 *
 	 * @param ePackage an <code>EPackage</code>
 	 * @return the registered clipboard support factory, or <code>null</code>
 	 *     if none was registered or it could not be initialized
 	 */
 	public static IClipboardSupportFactory lookup(EPackage ePackage) {
 		for (int i = PRIORITIES.size() - 1; i >= 0; i--) {

 			List descriptorsAtPriorityN = descriptors[i];
 			int size = descriptorsAtPriorityN.size();

 			for (int j = 0; j < size; j++) {
 				Descriptor descriptor = (Descriptor) descriptorsAtPriorityN
 						.get(j);
 				if (descriptor.provides(ePackage)) {
 					return descriptor.getFactory();
 				}
 			}
 		}

 		return null;
 	}

 	/**
 	 * Retrieves the clipboard support factory (if any) that handles the
 	 * specified <code>EClass</code>.
 	 * <p>
 	 * <b>WARNING: DO NOT USE.</b> Calling this method does not support the full
 	 * extensibility capabilities of the ClipboardSupport extension point. Use
 	 * the method {@link #lookup(EObject)} instead.
 	 *
 	 * @param eClass an <code>EClass</code>
 	 * @return the registered clipboard support factory, or <code>null</code>
 	 *     if none was registered or it could not be initialized
 	 */
 	public static IClipboardSupportFactory lookup(EClass eClass) {
 		return lookup(eClass.getEPackage());
 	}

 	/**
 	 * Retrieves the clipboard support factory (if any) that handles the
 	 * specified <code>EObject</code>.
 	 *
 	 * @param eObject an <code>EObject</code>
 	 * @return the registered clipboard support factory, or <code>null</code>
 	 *     if none was registered or it could not be initialized
 	 */
 	public static IClipboardSupportFactory lookup(EObject eObject) {
 		for (int i = PRIORITIES.size() - 1; i >= 0; i--) {

 			List descriptorsAtPriorityN = descriptors[i];
 			int size = descriptorsAtPriorityN.size();

 			for (int j = 0; j < size; j++) {
 				Descriptor descriptor = (Descriptor) descriptorsAtPriorityN
 						.get(j);
 				if (descriptor.provides(eObject)) {
 					return descriptor.getFactory();
 				}
 			}
 		}

 		return null;
 	}

 	/**
 	 * Creates an error status with the specified <code>message</code>.
 	 *
 	 * @param code the error code
 	 * @param message the error message
 	 * @return the status object
 	 */
 	static IStatus createErrorStatus(int code, String message) {
 		return createErrorStatus(
 			code,
 			message,
 			null);
 	}

 	/**
 	 * Creates an error status with the specified <code>message</code>.
 	 *
 	 * @param code the error code
 	 * @param message the error message
 	 * @param exception an exception to log
 	 * @return the status object
 	 */
 	static IStatus createErrorStatus(int code, String message, Throwable exception) {
 		return new Status(
 			IStatus.ERROR,
 			ClipboardPlugin.getPlugin().getSymbolicName(),
 			code,
 			message,
 			exception);
 	}

 	/**
 	 * Descriptor for an extension on the <tt>clipboardSupport</tt> point.
 	 * The descriptor is responsible for lazily initializing the
 	 * {@link IClipboardSupportFactory} on its first access.
 	 *
 	 * @author Christian W. Damus (cdamus)
 	 */
 	private static final class Descriptor {
 		private EPackage ePackage = null;
 		private IClipboardSupportFactory factory;
 		private IClipboardSupportPolicy policy;
 		private IConfigurationElement config;
 		private int priority = 2;

 		private boolean factoryClassInitialized = false;
 		private boolean policyClassInitialized = false;

 		Descriptor(IConfigurationElement config) throws CoreException {
 			this.config = config;

 			String nsUri = config.getAttribute(E_NSURI);
 			if (nsUri != null && nsUri.length() > 0) {
 				ePackage = EPackage.Registry.INSTANCE.getEPackage(nsUri);
 				if (ePackage == null) {
 					throw new CoreException(createErrorStatus(
 						ClipboardStatusCodes.CLIPBOARDSUPPORT_UNRESOLVED_NSURI,
 						NLS.bind(EMFClipboardCoreMessages.unresolved_nsUri_ERROR_,
 							new Object[] {
 								ClipboardPlugin.EXTPT_CLIPBOARDSUPPORT,
 								nsUri,
 								config.getDeclaringExtension().getNamespaceIdentifier()})));
 				}
 			} else {
 				// there needs to be either an nsURI specified or a policy class
 				String policy = config.getAttribute(E_POLICY);
 				if ((policy == null) || (policy.length() == 0)) {
 					throw new CoreException(createErrorStatus(
 							ClipboardStatusCodes.CLIPBOARDSUPPORT_MISSING_CLASS,
 							NLS.bind(EMFClipboardCoreMessages.missing_nsUri_ERROR_,
 								new Object[] {
 									ClipboardPlugin.EXTPT_CLIPBOARDSUPPORT,
 									config.getDeclaringExtension().getNamespaceIdentifier()})));
 				}
 			}

 			String className = config.getAttribute(E_CLASS);
 			if ((className == null) || (className.length() == 0)) {
 				throw new CoreException(createErrorStatus(
 					ClipboardStatusCodes.CLIPBOARDSUPPORT_MISSING_CLASS,
 					NLS.bind(EMFClipboardCoreMessages.missing_class_ERROR_,
 						new Object[] {
 							ClipboardPlugin.EXTPT_CLIPBOARDSUPPORT,
 							config.getDeclaringExtension().getNamespaceIdentifier()})));
 			}

 			String priorityStr = config.getAttribute(E_PRIORITY);
 			if (priorityStr != null) {
 				priorityStr = priorityStr.toLowerCase();

 				if (PRIORITIES.contains(priorityStr)) {
 					priority = PRIORITIES.indexOf(priorityStr);
 				}
 			}
 		}

 		/**
 		 * Determines if this descriptor provides for the given EPackage by
 		 * comparing its nsURI with the nsURI attribute field. In this case, the
 		 * policy class is not consulted at all.
 		 *
 		 * @param ePackage the ePackage in question
 		 * @return true if this descriptor provides for the given ePackage
 		 */
 		private boolean provides(EPackage ePackage) {
 			return (ePackage != null && ePackage.equals(getEPackage()));
 		}

 		/**
 		 * Determines if this descriptor provides for the given EObject by
 		 * consulting the policy class if there is one provided. If there is no
 		 * policy class provided, then the {@link #provides(EPackage)} method is
 		 * called with the EPackage of the given EObject.
 		 *
 		 * @param eObject
 		 *            the eObject in question
 		 * @return true if this descriptor provides for the given eObject
 		 */
 		private boolean provides(EObject eObject) {
 			policy = getPolicy();

 			if (policy != null) {
 				try {
 					return policy.provides(new EObjectAdapter(eObject));
 				} catch (Throwable e) {
 					ClipboardPlugin.getPlugin().log(createErrorStatus(
 							ClipboardStatusCodes.CLIPBOARDSUPPORT_MISSING_CLASS,
 							NLS.bind(EMFClipboardCoreMessages.missing_class_ERROR_,
 								new Object[] {
 									IClipboardSupportFactory.class.getName(),
 									config.getAttribute(E_POLICY)}),
 							e));

 					// re-throw fatal errors
 					if (e instanceof ThreadDeath) {
 						throw (ThreadDeath) e;
 					}

 					if (e instanceof VirtualMachineError) {
 						throw (VirtualMachineError) e;
 					}

 					return false;
 				}
 			}
 			return provides(eObject.eClass().getEPackage());
 		}

 		EPackage getEPackage() {
 			return ePackage;
 		}

 		/** @deprecated need a context-based solution */
 		int getPriority() {
 			return priority;
 		}

 		IClipboardSupportFactory getFactory() {
 			if (factory == null && !factoryClassInitialized) {
 				factoryClassInitialized = true;
 				factory = createFactory();
 			}

 			return factory;
 		}

 		IClipboardSupportPolicy getPolicy() {
 			if (policy == null && !policyClassInitialized) {
 				policyClassInitialized = true;
 				policy = createPolicy();
 			}
 			return policy;
 		}

 		private IClipboardSupportFactory createFactory() {
 			IClipboardSupportFactory result = null;

 			try {
 				result = (IClipboardSupportFactory) config.createExecutableExtension(E_CLASS);
 			} catch (CoreException e) {
 				ClipboardPlugin.getPlugin().log(e.getStatus());
 			} catch (Exception e) {
 				// log any other exception, too (such as ClassCastException)
 				ClipboardPlugin.getPlugin().log(createErrorStatus(
 					ClipboardStatusCodes.CLIPBOARDSUPPORT_FACTORY_FAILED,
 					NLS.bind(EMFClipboardCoreMessages.factory_failed_ERROR_,
 						new Object[] {
 							IClipboardSupportFactory.class.getName(),
 							config.getAttribute(E_CLASS)}),
 					e));
 			}

 			return result;
 		}

 		private IClipboardSupportPolicy createPolicy() {
 			IClipboardSupportPolicy result = null;

 			String policyClassName = config.getAttribute(E_POLICY);
 			if (policyClassName != null && policyClassName.length() > 0) {
 				try {
 					result = (IClipboardSupportPolicy) config.createExecutableExtension(E_POLICY);
 				} catch (CoreException e) {
 					ClipboardPlugin.getPlugin().log(e.getStatus());
 				} catch (Exception e) {
 					// log any other exception, too (such as ClassCastException)
 					ClipboardPlugin.getPlugin().log(createErrorStatus(
 						ClipboardStatusCodes.CLIPBOARDSUPPORT_MISSING_CLASS,
 						NLS.bind(EMFClipboardCoreMessages.missing_class_ERROR_,
 							new Object[] {
 								IClipboardSupportFactory.class.getName(),
 								config.getAttribute(E_POLICY)}),
 						e));
 				}
 			}

 			return result;
 		}
 	}
 }
	/******************************************************************************
	* Copyright (c) 2005, 2010 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.gmf.runtime.emf.clipboard.core.internal;

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

	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IAdaptable;
	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Status;
	import org.eclipse.emf.ecore.EClass;
	import org.eclipse.emf.ecore.EObject;
	import org.eclipse.emf.ecore.EPackage;
	import org.eclipse.gmf.runtime.common.core.util.Proxy;
	import org.eclipse.gmf.runtime.emf.clipboard.core.IClipboardSupportFactory;
	import org.eclipse.gmf.runtime.emf.clipboard.core.IClipboardSupportPolicy;
	import org.eclipse.gmf.runtime.emf.clipboard.core.internal.l10n.EMFClipboardCoreMessages;
	import org.eclipse.osgi.util.NLS;


	/**
	* Manager for the <tt>clipboardSupport</tt> extension point.
	*
	* @author Christian W. Damus (cdamus), crevells
	*/
	public class ClipboardSupportManager {
	public static final String EP_CLIPBOARD_SUPPORT = "org.eclipse.gmf.runtime.emf.clipboard.core.clipboardSupport"; //$NON-NLS-1$
	static final String E_NSURI = "nsURI"; //$NON-NLS-1$
	static final String E_CLASS = "class"; //$NON-NLS-1$
	static final String E_POLICY = "policy"; //$NON-NLS-1$

	/** @deprecated need a context-based solution */
	static final String E_PRIORITY = "priority"; //$NON-NLS-1$

	/** @deprecated need a context-based solution */
	private static final List PRIORITIES = Arrays.asList(new String[] {
	"lowest", "low", "medium", "high", "highest"}); //$NON-NLS-1$//$NON-NLS-2$//$NON-NLS-3$//$NON-NLS-4$//$NON-NLS-5$

	/** An array of lists of descriptors for each priority, index by priority. */
	private static ArrayList[] descriptors;

	/**
	* Wraps an {@link EObject} to adapt it to the {@link IAdaptable} Eclipse
	* platform API. This is useful for passing <code>EObject</code>s into APIs
	* that consume adaptables.
	*/
	private static class EObjectAdapter extends Proxy implements IAdaptable {

	public EObjectAdapter(EObject element) {
	super(element);
	}

	/**
	* Returns the wrapped {@link EObject} as the adapter when possible. The
	* following adaptations are supported:
	* <ul>
	* <li>if the wrapped <code>EObject</code> conforms to the
	* <code>adapter</code> type, then it is returned</li>
	* <li>if this adapter, itself, conforms to the <code>adapter</code>
	* type, then it is returned</li>
	* <li>otherwise, there is no adapter (<code>null</code> returned)</li>
	* </ul>
	*/
	public Object getAdapter(Class adapter) {
	if (adapter.isInstance(getRealObject())) {
	return getRealObject();
	}
	if (adapter.isInstance(this)) {
	return this;
	}
	return null;
	}
	}

	/** Not instantiable by clients. */
	private ClipboardSupportManager() {
	super();
	}

	/**
	* Configures the extensions on the <tt>clipboardSupport</tt> extension
	* point.
	* <p>
	* <b>Note</b> that this method must only be called by the plug-in class
	* on initialization.
	* </p>
	*
	* @param configs the configuration elements representing extensions
	*/
	public static void configureExtensions(IConfigurationElement[] configs) {

	// initialize the arrays
	descriptors = new ArrayList[PRIORITIES.size()];
	for (int i = 0; i < PRIORITIES.size(); i++) {
	descriptors[i] = new ArrayList(0);
	}

	// create each descriptor and add to appropriate list
	for (int i = 0; i < configs.length; i++) {
	try {
	Descriptor desc = new Descriptor(configs[i]);
	descriptors[desc.getPriority()].add(desc);
	} catch (CoreException e) {
	ClipboardPlugin.getPlugin().log(e.getStatus());
	}
	}
	}

	/**
	* Retrieves the clipboard support factory (if any) that handles the
	* specified <code>EPackage</code>.
	* <p>
	* <b>WARNING: DO NOT USE.</b> Calling this method does not support the full
	* extensibility capabilities of the ClipboardSupport extension point. Use
	* the method {@link #lookup(EObject)} instead.
	*
	* @param ePackage an <code>EPackage</code>
	* @return the registered clipboard support factory, or <code>null</code>
	* if none was registered or it could not be initialized
	*/
	public static IClipboardSupportFactory lookup(EPackage ePackage) {
	for (int i = PRIORITIES.size() - 1; i >= 0; i--) {

	List descriptorsAtPriorityN = descriptors[i];
	int size = descriptorsAtPriorityN.size();

	for (int j = 0; j < size; j++) {
	Descriptor descriptor = (Descriptor) descriptorsAtPriorityN
	.get(j);
	if (descriptor.provides(ePackage)) {
	return descriptor.getFactory();
	}
	}
	}

	return null;
	}

	/**
	* Retrieves the clipboard support factory (if any) that handles the
	* specified <code>EClass</code>.
	* <p>
	* <b>WARNING: DO NOT USE.</b> Calling this method does not support the full
	* extensibility capabilities of the ClipboardSupport extension point. Use
	* the method {@link #lookup(EObject)} instead.
	*
	* @param eClass an <code>EClass</code>
	* @return the registered clipboard support factory, or <code>null</code>
	* if none was registered or it could not be initialized
	*/
	public static IClipboardSupportFactory lookup(EClass eClass) {
	return lookup(eClass.getEPackage());
	}

	/**
	* Retrieves the clipboard support factory (if any) that handles the
	* specified <code>EObject</code>.
	*
	* @param eObject an <code>EObject</code>
	* @return the registered clipboard support factory, or <code>null</code>
	* if none was registered or it could not be initialized
	*/
	public static IClipboardSupportFactory lookup(EObject eObject) {
	for (int i = PRIORITIES.size() - 1; i >= 0; i--) {

	List descriptorsAtPriorityN = descriptors[i];
	int size = descriptorsAtPriorityN.size();

	for (int j = 0; j < size; j++) {
	Descriptor descriptor = (Descriptor) descriptorsAtPriorityN
	.get(j);
	if (descriptor.provides(eObject)) {
	return descriptor.getFactory();
	}
	}
	}

	return null;
	}

	/**
	* Creates an error status with the specified <code>message</code>.
	*
	* @param code the error code
	* @param message the error message
	* @return the status object
	*/
	static IStatus createErrorStatus(int code, String message) {
	return createErrorStatus(
	code,
	message,
	null);
	}

	/**
	* Creates an error status with the specified <code>message</code>.
	*
	* @param code the error code
	* @param message the error message
	* @param exception an exception to log
	* @return the status object
	*/
	static IStatus createErrorStatus(int code, String message, Throwable exception) {
	return new Status(
	IStatus.ERROR,
	ClipboardPlugin.getPlugin().getSymbolicName(),
	code,
	message,
	exception);
	}

	/**
	* Descriptor for an extension on the <tt>clipboardSupport</tt> point.
	* The descriptor is responsible for lazily initializing the
	* {@link IClipboardSupportFactory} on its first access.
	*
	* @author Christian W. Damus (cdamus)
	*/
	private static final class Descriptor {
	private EPackage ePackage = null;
	private IClipboardSupportFactory factory;
	private IClipboardSupportPolicy policy;
	private IConfigurationElement config;
	private int priority = 2;

	private boolean factoryClassInitialized = false;
	private boolean policyClassInitialized = false;

	Descriptor(IConfigurationElement config) throws CoreException {
	this.config = config;

	String nsUri = config.getAttribute(E_NSURI);
	if (nsUri != null && nsUri.length() > 0) {
	ePackage = EPackage.Registry.INSTANCE.getEPackage(nsUri);
	if (ePackage == null) {
	throw new CoreException(createErrorStatus(
	ClipboardStatusCodes.CLIPBOARDSUPPORT_UNRESOLVED_NSURI,
	NLS.bind(EMFClipboardCoreMessages.unresolved_nsUri_ERROR_,
	new Object[] {
	ClipboardPlugin.EXTPT_CLIPBOARDSUPPORT,
	nsUri,
	config.getDeclaringExtension().getNamespaceIdentifier()})));
	}
	} else {
	// there needs to be either an nsURI specified or a policy class
	String policy = config.getAttribute(E_POLICY);
	if ((policy == null) \|\| (policy.length() == 0)) {
	throw new CoreException(createErrorStatus(
	ClipboardStatusCodes.CLIPBOARDSUPPORT_MISSING_CLASS,
	NLS.bind(EMFClipboardCoreMessages.missing_nsUri_ERROR_,
	new Object[] {
	ClipboardPlugin.EXTPT_CLIPBOARDSUPPORT,
	config.getDeclaringExtension().getNamespaceIdentifier()})));
	}
	}

	String className = config.getAttribute(E_CLASS);
	if ((className == null) \|\| (className.length() == 0)) {
	throw new CoreException(createErrorStatus(
	ClipboardStatusCodes.CLIPBOARDSUPPORT_MISSING_CLASS,
	NLS.bind(EMFClipboardCoreMessages.missing_class_ERROR_,
	new Object[] {
	ClipboardPlugin.EXTPT_CLIPBOARDSUPPORT,
	config.getDeclaringExtension().getNamespaceIdentifier()})));
	}

	String priorityStr = config.getAttribute(E_PRIORITY);
	if (priorityStr != null) {
	priorityStr = priorityStr.toLowerCase();

	if (PRIORITIES.contains(priorityStr)) {
	priority = PRIORITIES.indexOf(priorityStr);
	}
	}
	}

	/**
	* Determines if this descriptor provides for the given EPackage by
	* comparing its nsURI with the nsURI attribute field. In this case, the
	* policy class is not consulted at all.
	*
	* @param ePackage the ePackage in question
	* @return true if this descriptor provides for the given ePackage
	*/
	private boolean provides(EPackage ePackage) {
	return (ePackage != null && ePackage.equals(getEPackage()));
	}

	/**
	* Determines if this descriptor provides for the given EObject by
	* consulting the policy class if there is one provided. If there is no
	* policy class provided, then the {@link #provides(EPackage)} method is
	* called with the EPackage of the given EObject.
	*
	* @param eObject
	* the eObject in question
	* @return true if this descriptor provides for the given eObject
	*/
	private boolean provides(EObject eObject) {
	policy = getPolicy();

	if (policy != null) {
	try {
	return policy.provides(new EObjectAdapter(eObject));
	} catch (Throwable e) {
	ClipboardPlugin.getPlugin().log(createErrorStatus(
	ClipboardStatusCodes.CLIPBOARDSUPPORT_MISSING_CLASS,
	NLS.bind(EMFClipboardCoreMessages.missing_class_ERROR_,
	new Object[] {
	IClipboardSupportFactory.class.getName(),
	config.getAttribute(E_POLICY)}),
	e));

	// re-throw fatal errors
	if (e instanceof ThreadDeath) {
	throw (ThreadDeath) e;
	}

	if (e instanceof VirtualMachineError) {
	throw (VirtualMachineError) e;
	}

	return false;
	}
	}
	return provides(eObject.eClass().getEPackage());
	}

	EPackage getEPackage() {
	return ePackage;
	}

	/** @deprecated need a context-based solution */
	int getPriority() {
	return priority;
	}

	IClipboardSupportFactory getFactory() {
	if (factory == null && !factoryClassInitialized) {
	factoryClassInitialized = true;
	factory = createFactory();
	}

	return factory;
	}

	IClipboardSupportPolicy getPolicy() {
	if (policy == null && !policyClassInitialized) {
	policyClassInitialized = true;
	policy = createPolicy();
	}
	return policy;
	}

	private IClipboardSupportFactory createFactory() {
	IClipboardSupportFactory result = null;

	try {
	result = (IClipboardSupportFactory) config.createExecutableExtension(E_CLASS);
	} catch (CoreException e) {
	ClipboardPlugin.getPlugin().log(e.getStatus());
	} catch (Exception e) {
	// log any other exception, too (such as ClassCastException)
	ClipboardPlugin.getPlugin().log(createErrorStatus(
	ClipboardStatusCodes.CLIPBOARDSUPPORT_FACTORY_FAILED,
	NLS.bind(EMFClipboardCoreMessages.factory_failed_ERROR_,
	new Object[] {
	IClipboardSupportFactory.class.getName(),
	config.getAttribute(E_CLASS)}),
	e));
	}

	return result;
	}

	private IClipboardSupportPolicy createPolicy() {
	IClipboardSupportPolicy result = null;

	String policyClassName = config.getAttribute(E_POLICY);
	if (policyClassName != null && policyClassName.length() > 0) {
	try {
	result = (IClipboardSupportPolicy) config.createExecutableExtension(E_POLICY);
	} catch (CoreException e) {
	ClipboardPlugin.getPlugin().log(e.getStatus());
	} catch (Exception e) {
	// log any other exception, too (such as ClassCastException)
	ClipboardPlugin.getPlugin().log(createErrorStatus(
	ClipboardStatusCodes.CLIPBOARDSUPPORT_MISSING_CLASS,
	NLS.bind(EMFClipboardCoreMessages.missing_class_ERROR_,
	new Object[] {
	IClipboardSupportFactory.class.getName(),
	config.getAttribute(E_POLICY)}),
	e));
	}
	}

	return result;
	}
	}
	}