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 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.Arrays;
 import java.util.List;
 import java.util.Map;

 import org.eclipse.core.runtime.CoreException;
 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.emf.clipboard.core.IClipboardSupportFactory;
 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)
  */
 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"; //$NON-NLS-1$

 	/** @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"});  //$NON-NLS-1$//$NON-NLS-2$//$NON-NLS-3$//$NON-NLS-4$//$NON-NLS-5$

 	private static final Map clipboardSupportMap = new java.util.HashMap();

 	/** 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) {
 		for (int i = 0; i < configs.length; i++) {
 			try {
 				Descriptor desc = new Descriptor(configs[i]);
 				Descriptor previous = (Descriptor) clipboardSupportMap.get(
 					desc.getEPackage());

 				if ((previous == null)
 						|| (previous.getPriority() < desc.getPriority())) {

 					clipboardSupportMap.put(desc.getEPackage(), desc);
 				}
 			} catch (CoreException e) {
 				ClipboardPlugin.getPlugin().log(e.getStatus());
 			}
 		}
 	}

 	/**
 	 * Retrieves the clipboard support factory (if any) that handles the
 	 * specified <code>EPackage</code>.
 	 *
 	 * @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) {
 		IClipboardSupportFactory result = null;

 		Descriptor desc = (Descriptor) clipboardSupportMap.get(ePackage);
 		if (desc != null) {
 			result = desc.getFactory();
 		}

 		return result;
 	}

 	/**
 	 * Retrieves the clipboard support factory (if any) that handles the
 	 * specified <code>EClass</code>.
 	 *
 	 * @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) {
 		return lookup(eObject.eClass().getEPackage());
 	}

 	/**
 	 * 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 final EPackage ePackage;
 		private IClipboardSupportFactory factory;
 		private IConfigurationElement config;
 		private int priority = 2;

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

 			String nsUri = config.getAttribute(E_NSURI);
 			if ((nsUri == null) || (nsUri.length() == 0)) {
 				throw new CoreException(createErrorStatus(
 					ClipboardStatusCodes.CLIPBOARDSUPPORT_MISSING_NSURI,
 					NLS.bind(EMFClipboardCoreMessages.missing_nsUri_ERROR_,
 						new Object[] {
 							ClipboardPlugin.EXTPT_CLIPBOARDSUPPORT,
 							config.getDeclaringExtension().getNamespaceIdentifier()})));
 			}

 			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()})));
 			}

 			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);
 				}
 			}
 		}

 		EPackage getEPackage() {
 			return ePackage;
 		}

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

 		IClipboardSupportFactory getFactory() {
 			if ((factory == null) && (config != null)) {
 				// we only keep the config element as long as we need it in
 				//    order to attempt to instantiate the class
 				factory = createFactory();
 			}

 			return factory;
 		}

 		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));
 			} finally {
 				// we won't try again to instantiate this class
 				config = null;
 			}

 			return result;
 		}
 	}
 }
	/******************************************************************************
	* Copyright (c) 2005 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.Arrays;
	import java.util.List;
	import java.util.Map;

	import org.eclipse.core.runtime.CoreException;
	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.emf.clipboard.core.IClipboardSupportFactory;
	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)
	*/
	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"; //$NON-NLS-1$

	/** @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"}); //$NON-NLS-1$//$NON-NLS-2$//$NON-NLS-3$//$NON-NLS-4$//$NON-NLS-5$

	private static final Map clipboardSupportMap = new java.util.HashMap();

	/** 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) {
	for (int i = 0; i < configs.length; i++) {
	try {
	Descriptor desc = new Descriptor(configs[i]);
	Descriptor previous = (Descriptor) clipboardSupportMap.get(
	desc.getEPackage());

	if ((previous == null)
	\|\| (previous.getPriority() < desc.getPriority())) {

	clipboardSupportMap.put(desc.getEPackage(), desc);
	}
	} catch (CoreException e) {
	ClipboardPlugin.getPlugin().log(e.getStatus());
	}
	}
	}

	/**
	* Retrieves the clipboard support factory (if any) that handles the
	* specified <code>EPackage</code>.
	*
	* @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) {
	IClipboardSupportFactory result = null;

	Descriptor desc = (Descriptor) clipboardSupportMap.get(ePackage);
	if (desc != null) {
	result = desc.getFactory();
	}

	return result;
	}

	/**
	* Retrieves the clipboard support factory (if any) that handles the
	* specified <code>EClass</code>.
	*
	* @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) {
	return lookup(eObject.eClass().getEPackage());
	}

	/**
	* 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 final EPackage ePackage;
	private IClipboardSupportFactory factory;
	private IConfigurationElement config;
	private int priority = 2;

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

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

	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()})));
	}

	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);
	}
	}
	}

	EPackage getEPackage() {
	return ePackage;
	}

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

	IClipboardSupportFactory getFactory() {
	if ((factory == null) && (config != null)) {
	// we only keep the config element as long as we need it in
	// order to attempt to instantiate the class
	factory = createFactory();
	}

	return factory;
	}

	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));
	} finally {
	// we won't try again to instantiate this class
	config = null;
	}

	return result;
	}
	}
	}