plugins/cdo/bundles/org.eclipse.papyrus.cdo.core/src/org/eclipse/papyrus/cdo/internal/core/CDOUtils.java - papyrus/org.eclipse.papyrus-collaborativemodeling - Git at Google

 /*****************************************************************************
  * Copyright (c) 2013, 2017 CEA LIST and others.
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *   CEA LIST - Initial API and implementation
  *   Christian W. Damus (CEA) - bug 422257
  *   Eike Stepper (CEA) - bug 466520
  *
  *****************************************************************************/
 package org.eclipse.papyrus.cdo.internal.core;

 import static com.google.common.collect.Iterables.filter;
 import static com.google.common.collect.Iterables.getFirst;

 import java.util.ListIterator;
 import java.util.NoSuchElementException;
 import java.util.Set;
 import java.util.concurrent.Executor;

 import org.eclipse.core.runtime.IAdaptable;
 import org.eclipse.emf.cdo.CDOLock;
 import org.eclipse.emf.cdo.CDOObject;
 import org.eclipse.emf.cdo.common.id.CDOID;
 import org.eclipse.emf.cdo.common.id.CDOIDUtil;
 import org.eclipse.emf.cdo.dawn.spi.DawnState;
 import org.eclipse.emf.cdo.eresource.CDOResource;
 import org.eclipse.emf.cdo.eresource.CDOResourceNode;
 import org.eclipse.emf.cdo.internal.explorer.checkouts.CDOCheckoutViewProvider;
 import org.eclipse.emf.cdo.util.CDOUtil;
 import org.eclipse.emf.cdo.view.CDOView;
 import org.eclipse.emf.cdo.view.CDOViewInvalidationEvent;
 import org.eclipse.emf.cdo.view.CDOViewSet;
 import org.eclipse.emf.common.notify.Adapter;
 import org.eclipse.emf.common.notify.Notifier;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.emf.common.util.URI;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.EReference;
 import org.eclipse.emf.ecore.EStructuralFeature;
 import org.eclipse.emf.ecore.resource.Resource;
 import org.eclipse.emf.ecore.resource.ResourceSet;
 import org.eclipse.emf.ecore.util.EContentsEList.FeatureListIterator;
 import org.eclipse.emf.ecore.util.ECrossReferenceAdapter;
 import org.eclipse.emf.ecore.util.EcoreUtil;
 import org.eclipse.emf.ecore.util.InternalEList;
 import org.eclipse.emf.edit.domain.EditingDomain;
 import org.eclipse.emf.spi.cdo.InternalCDOView;
 import org.eclipse.emf.transaction.ResourceSetChangeEvent;
 import org.eclipse.emf.transaction.TransactionalEditingDomain;
 import org.eclipse.net4j.util.event.IEvent;
 import org.eclipse.net4j.util.event.IListener;
 import org.eclipse.net4j.util.lifecycle.LifecycleEvent;
 import org.eclipse.papyrus.cdo.core.resource.CDOAwareTransactionalEditingDomain;
 import org.eclipse.papyrus.cdo.core.util.CDOFunctions;

 import com.google.common.base.Predicate;
 import com.google.common.base.Predicates;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.UnmodifiableListIterator;

 /**
  * This is the CDOUtils type. Enjoy.
  */
 public class CDOUtils {

 	private static final Set<String> CDO_URI_SCHEMES = ImmutableSet.of("cdo", "dawn", CDOCheckoutViewProvider.SCHEME); //$NON-NLS-1$ //$NON-NLS-2$

 	private static Executor broadcastExecutor = new DirectExecutor();

 	@SuppressWarnings("restriction")
 	private static final Predicate<Object> IS_LEGACY_WRAPPER = Predicates.instanceOf(org.eclipse.emf.internal.cdo.object.CDOObjectWrapperBase.class);

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

 	public static <T> T adapt(Object object, Class<? extends T> type) {
 		T result = tryCast(object, type);

 		if (result == null) {
 			if (object instanceof IAdaptable) {
 				result = type.cast(((IAdaptable) object).getAdapter(type));
 			}

 			if ((result == null) && (type == CDOObject.class)) {
 				EObject eObject = adapt(object, EObject.class);
 				if (eObject != null) {
 					result = type.cast(getCDOObject(eObject));
 				}
 			}

 			if ((result == null) && (object instanceof Notifier)) {
 				result = getFirst(filter(((Notifier) object).eAdapters(), type), null);
 			}
 		}

 		return result;
 	}

 	public static <T> T tryCast(Object object, Class<? extends T> type) {
 		T result = null;

 		if (type.isInstance(object)) {
 			result = type.cast(object);
 		}

 		return result;
 	}

 	public static boolean isCDOURI(URI uri) {
 		return CDO_URI_SCHEMES.contains(uri.scheme());
 	}

 	public static boolean isCDOEditingDomain(EditingDomain domain) {
 		return domain instanceof CDOAwareTransactionalEditingDomain;
 	}

 	public static ResourceSet getResourceSet(Notifier notifier) {
 		ResourceSet result = null;

 		if (notifier instanceof CDOViewSet) {
 			result = ((CDOViewSet) notifier).getResourceSet();
 		} else if (notifier instanceof ResourceSet) {
 			result = (ResourceSet) notifier;
 		} else if (notifier instanceof Resource) {
 			result = ((Resource) notifier).getResourceSet();
 		} else if (notifier instanceof CDOResourceNode) {
 			// folders (resource nodes that aren't resources) are not in a
 			// resource set, so get the associated view's resource set
 			CDOView view = ((CDOResourceNode) notifier).cdoView();
 			if (view != null) {
 				result = view.getResourceSet();
 			}
 		} else if (notifier instanceof EObject) {
 			result = getResourceSet(((EObject) notifier).eResource());
 		}

 		return result;
 	}

 	public static boolean isCDOObject(EObject object) {
 		ResourceSet resourceSet = getResourceSet(object);

 		return (resourceSet != null) && (CDOUtil.getViewSet(resourceSet) != null);
 	}

 	public static CDOObject getCDOObject(EObject object) {
 		CDOObject result = null;

 		if (isCDOObject(object)) {
 			result = CDOUtil.getCDOObject(object);
 		}

 		return result;
 	}

 	public static CDOID getCDOID(EObject object) {
 		CDOObject cdo = getCDOObject(object);
 		return (cdo == null) ? CDOIDUtil.createExternal(EcoreUtil.getURI(object).toString()) : cdo.cdoID();
 	}

 	public static CDOView getView(ResourceSet resourceSet) {
 		CDOView result = null;

 		CDOViewSet viewSet = CDOUtil.getViewSet(resourceSet);
 		if (viewSet != null) {
 			CDOView[] views = viewSet.getViews();
 			if (views.length > 0) {
 				result = views[0];
 			}
 		}

 		return result;
 	}

 	public static CDOView getView(EObject object) {
 		CDOObject cdo = getCDOObject(object);
 		return (cdo == null) ? null : cdo.cdoView();
 	}

 	public static boolean isLockable(CDOObject object) {
 		// transient objects do not have lock states, nor do those that are not
 		// in a view or are in a closed view
 		CDOView view = object.cdoView();
 		return (view != null) && !view.isClosed() && (object.cdoLockState() != null);
 	}

 	public static boolean isLocked(CDOObject object, boolean remotely) {
 		CDOLock lock = isLockable(object) ? object.cdoWriteLock() : null;

 		return (lock != null) && (remotely ? lock.isLockedByOthers() : lock.isLocked());
 	}

 	public static void lock(CDOObject object) {
 		object.cdoWriteLock().lock();
 	}

 	public static void unlock(CDOObject object) {
 		object.cdoWriteLock().unlock();
 	}

 	public static DawnState computeState(EObject object) {
 		DawnState result = DawnState.CLEAN;

 		CDOObject cdo = getCDOObject(object);
 		if (cdo != null) {
 			if (cdo.cdoConflict()) {
 				result = DawnState.CONFLICT;
 			} else if (isLocked(cdo, true)) {
 				result = DawnState.LOCKED_REMOTELY;
 			} else if (isLocked(cdo, false)) {
 				result = DawnState.LOCKED_LOCALLY;
 			}
 		}

 		return result;
 	}

 	public static boolean isReadOnly(CDOObject object) {
 		// an object is read-only if somebody else has it locked
 		boolean result = CDOUtils.isLocked(object, true);

 		// or if the current user doesn't have permission to write it
 		if (!result) {
 			result = !object.cdoPermission().isWritable();
 		}

 		return result;
 	}

 	public static Iterable<EObject> getEObjects(Iterable<? extends CDOObject> cdoObjects) {
 		return Iterables.transform(cdoObjects, CDOFunctions.getEObject());
 	}

 	public static Iterable<EStructuralFeature.Setting> crossReference(EObject object) {
 		Iterable<EStructuralFeature.Setting> result;

 		ECrossReferenceAdapter adapter = adapt(object, ECrossReferenceAdapter.class);
 		if (adapter != null) {
 			result = adapter.getInverseReferences(object);
 		} else {
 			EObject tree = EcoreUtil.getRootContainer(object);
 			Resource resource = tree.eResource();
 			ResourceSet rset = (resource == null) ? null : resource.getResourceSet();

 			if (rset != null) {
 				result = EcoreUtil.UsageCrossReferencer.find(object, rset);
 			} else if (resource != null) {
 				result = EcoreUtil.UsageCrossReferencer.find(object, resource);
 			} else {
 				result = EcoreUtil.UsageCrossReferencer.find(object, tree);
 			}
 		}

 		return result;
 	}

 	/**
 	 * Obtains an unmodifiable iterator over the values in the specified {@code feature} of an {@code object}. The resulting iterator supplies zero
 	 * or one element for scalar features, according to whether the feature's value is {@code null} or not. In the case of a scalar feature,
 	 * the index of the element as reported by {@link ListIterator#nextIndex()} and {@link ListIterator#previousIndex()} is {@code -1}.
 	 *
 	 * @param object
 	 *            an object
 	 * @param feature
 	 *            a feature of the {@code object}
 	 * @param resolve
 	 *            whether to resolve proxies (in the case of an {@link EReference}
 	 *
 	 * @return the unmodifiable feature list iterator
 	 */
 	public static <E> FeatureListIterator<E> iterator(EObject object, final EStructuralFeature feature, boolean resolve) {
 		FeatureListIterator<E> result;

 		Object value = object.eGet(feature, resolve);
 		if (value instanceof InternalEList<?>) {
 			@SuppressWarnings("unchecked")
 			InternalEList<E> list = (InternalEList<E>) value;
 			final ListIterator<E> delegate = (resolve) ? list.listIterator() : list.basicListIterator();

 			class NonEmpty extends UnmodifiableListIterator<E>implements FeatureListIterator<E> {

 				@Override
 				public EStructuralFeature feature() {
 					return feature;
 				}

 				@Override
 				public boolean hasNext() {
 					return delegate.hasNext();
 				}

 				@Override
 				public E next() {
 					return delegate.next();
 				}

 				@Override
 				public int nextIndex() {
 					return delegate.nextIndex();
 				}

 				@Override
 				public boolean hasPrevious() {
 					return delegate.hasPrevious();
 				}

 				@Override
 				public E previous() {
 					return delegate.previous();
 				}

 				@Override
 				public int previousIndex() {
 					return delegate.previousIndex();
 				}
 			}
 			;

 			result = new NonEmpty();
 		} else if (value == null) {
 			class Empty extends UnmodifiableListIterator<E>implements FeatureListIterator<E> {

 				@Override
 				public EStructuralFeature feature() {
 					return feature;
 				}

 				@Override
 				public boolean hasNext() {
 					return false;
 				}

 				@Override
 				public E next() {
 					throw new NoSuchElementException();
 				}

 				@Override
 				public int nextIndex() {
 					return -1;
 				}

 				@Override
 				public boolean hasPrevious() {
 					return false;
 				}

 				@Override
 				public E previous() {
 					throw new NoSuchElementException();
 				}

 				@Override
 				public int previousIndex() {
 					return -2;
 				}
 			}
 			;

 			result = new Empty();
 		} else {
 			@SuppressWarnings("unchecked")
 			final E onlyValue = (E) value;

 			class Singleton extends UnmodifiableListIterator<E>implements FeatureListIterator<E> {

 				private int index = -1;

 				@Override
 				public EStructuralFeature feature() {
 					return feature;
 				}

 				@Override
 				public boolean hasNext() {
 					return index < 0;
 				}

 				@Override
 				public E next() {
 					if (!hasNext()) {
 						throw new NoSuchElementException();
 					}
 					index++;
 					return onlyValue;
 				}

 				@Override
 				public int nextIndex() {
 					return index;
 				}

 				@Override
 				public boolean hasPrevious() {
 					return index == 0;
 				}

 				@Override
 				public E previous() {
 					if (!hasPrevious()) {
 						throw new NoSuchElementException();
 					}
 					index--;
 					return onlyValue;
 				}

 				@Override
 				public int previousIndex() {
 					return index - 1;
 				}
 			}
 			;

 			result = new Singleton();
 		}

 		return result;
 	}

 	/**
 	 * <p>
 	 * Runs a code block that broadcasts notification of {@link ResourceSetChangeEvent}s, {@link CDOViewInvalidationEvent}s, etc. to listeners using the most appropriate {@linkplain #setBroadcastExecutor() executor} available. This allows a UI-safe execution
 	 * to be injected if necessary.
 	 * </p>
 	 * <p>
 	 * <strong>Note</strong> that there is no assurance that this block will be executed either synchronously or asynchronously.
 	 * </p>
 	 *
 	 * @param broadcastCommand
 	 *            the notification command to execute
 	 */
 	public static void notify(Runnable broadcastCommand) {
 		broadcastExecutor.execute(broadcastCommand);
 	}

 	public static void notify(final TransactionalEditingDomain domain, final Runnable broadcastCommand) {

 		broadcastExecutor.execute(new Runnable() {

 			@Override
 			public void run() {
 				try {
 					domain.runExclusive(broadcastCommand);
 				} catch (Exception e) {
 					Activator.log.error("Exception in execution of notification broadcast.", e); //$NON-NLS-1$
 				}
 			}
 		});
 	}

 	public static void setBroadcastExecutor(Executor executor) {
 		broadcastExecutor = (executor == null) ? new DirectExecutor() : executor;
 	}

 	/**
 	 * Remove the given {@code listener} if the event it received is a lifecycle deactivation event.
 	 *
 	 * @param listener
 	 *            a listener that received a possible deactivation event
 	 * @param possibleDeactivation
 	 *            the event that may be a lifecycle deactivation
 	 *
 	 * @return whether the listener was removed because the event was a deactivation
 	 */
 	public static boolean removeListenerFromDeactivatedLifecycle(IListener listener, IEvent possibleDeactivation) {
 		boolean result = false;

 		if (possibleDeactivation instanceof LifecycleEvent) {
 			switch (((LifecycleEvent) possibleDeactivation).getKind()) {
 			case DEACTIVATED:
 				possibleDeactivation.getSource().removeListener(listener);
 				result = true;
 				break;
 			default:
 				// Pass
 				break;
 			}
 		}

 		return result;
 	}

 	/**
 	 * Unloads a {@code cdoObject} (because {@link CDOResource}s don't implement unloading) by clearing its adapters.
 	 *
 	 * @param cdoObject
 	 *            a CDO object to unload
 	 *
 	 * @see #unload(CDOView)
 	 */
 	public static void unload(CDOObject cdoObject) {
 		EObject eObject = CDOUtil.getEObject(cdoObject);
 		if (eObject != null) {
 			// Remove all adapters *except* the all-important legacy wrapper!
 			EList<Adapter> adapters = eObject.eAdapters();
 			if (!adapters.isEmpty()) {
 				Adapter legacyWrapper = Iterables.find(eObject.eAdapters(), IS_LEGACY_WRAPPER, null);

 				// Don't do anything if the only adapter is the legacy wrapper
 				if ((legacyWrapper == null) || (adapters.size() > 1)) {
 					adapters.clear();
 					if (legacyWrapper != null) {
 						// Restore it, otherwise references to this CDOObject will break
 						adapters.add(0, legacyWrapper);
 					}
 				}
 			}
 		}
 	}

 	/**
 	 * Unloads all of the objects in a {@code cdoView} (because {@link CDOResource}s don't implement unloading) by clearing their adapters.
 	 *
 	 * @param cdoView
 	 *            a view to unload
 	 *
 	 * @see #unload(CDOObject)
 	 */
 	public static void unload(CDOView cdoView) {
 		if (cdoView instanceof InternalCDOView) {
 			for (CDOObject next : ((InternalCDOView) cdoView).getObjectsList()) {
 				// Don't clear adapters of the resource because ECrossReferenceAdapters would try to crawl the contents
 				if (!(next instanceof CDOResourceNode)) {
 					CDOUtils.unload(next);
 				}
 			}
 		}
 	}

 	//
 	// Nested types
 	//

 	private static final class DirectExecutor implements Executor {

 		@Override
 		public void execute(Runnable command) {
 			command.run();
 		}
 	}
 }
	/*****************************************************************************
	* Copyright (c) 2013, 2017 CEA LIST and others.
	*
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License 2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* CEA LIST - Initial API and implementation
	* Christian W. Damus (CEA) - bug 422257
	* Eike Stepper (CEA) - bug 466520
	*
	*****************************************************************************/
	package org.eclipse.papyrus.cdo.internal.core;

	import static com.google.common.collect.Iterables.filter;
	import static com.google.common.collect.Iterables.getFirst;

	import java.util.ListIterator;
	import java.util.NoSuchElementException;
	import java.util.Set;
	import java.util.concurrent.Executor;

	import org.eclipse.core.runtime.IAdaptable;
	import org.eclipse.emf.cdo.CDOLock;
	import org.eclipse.emf.cdo.CDOObject;
	import org.eclipse.emf.cdo.common.id.CDOID;
	import org.eclipse.emf.cdo.common.id.CDOIDUtil;
	import org.eclipse.emf.cdo.dawn.spi.DawnState;
	import org.eclipse.emf.cdo.eresource.CDOResource;
	import org.eclipse.emf.cdo.eresource.CDOResourceNode;
	import org.eclipse.emf.cdo.internal.explorer.checkouts.CDOCheckoutViewProvider;
	import org.eclipse.emf.cdo.util.CDOUtil;
	import org.eclipse.emf.cdo.view.CDOView;
	import org.eclipse.emf.cdo.view.CDOViewInvalidationEvent;
	import org.eclipse.emf.cdo.view.CDOViewSet;
	import org.eclipse.emf.common.notify.Adapter;
	import org.eclipse.emf.common.notify.Notifier;
	import org.eclipse.emf.common.util.EList;
	import org.eclipse.emf.common.util.URI;
	import org.eclipse.emf.ecore.EObject;
	import org.eclipse.emf.ecore.EReference;
	import org.eclipse.emf.ecore.EStructuralFeature;
	import org.eclipse.emf.ecore.resource.Resource;
	import org.eclipse.emf.ecore.resource.ResourceSet;
	import org.eclipse.emf.ecore.util.EContentsEList.FeatureListIterator;
	import org.eclipse.emf.ecore.util.ECrossReferenceAdapter;
	import org.eclipse.emf.ecore.util.EcoreUtil;
	import org.eclipse.emf.ecore.util.InternalEList;
	import org.eclipse.emf.edit.domain.EditingDomain;
	import org.eclipse.emf.spi.cdo.InternalCDOView;
	import org.eclipse.emf.transaction.ResourceSetChangeEvent;
	import org.eclipse.emf.transaction.TransactionalEditingDomain;
	import org.eclipse.net4j.util.event.IEvent;
	import org.eclipse.net4j.util.event.IListener;
	import org.eclipse.net4j.util.lifecycle.LifecycleEvent;
	import org.eclipse.papyrus.cdo.core.resource.CDOAwareTransactionalEditingDomain;
	import org.eclipse.papyrus.cdo.core.util.CDOFunctions;

	import com.google.common.base.Predicate;
	import com.google.common.base.Predicates;
	import com.google.common.collect.ImmutableSet;
	import com.google.common.collect.Iterables;
	import com.google.common.collect.UnmodifiableListIterator;

	/**
	* This is the CDOUtils type. Enjoy.
	*/
	public class CDOUtils {

	private static final Set<String> CDO_URI_SCHEMES = ImmutableSet.of("cdo", "dawn", CDOCheckoutViewProvider.SCHEME); //$NON-NLS-1$ //$NON-NLS-2$

	private static Executor broadcastExecutor = new DirectExecutor();

	@SuppressWarnings("restriction")
	private static final Predicate<Object> IS_LEGACY_WRAPPER = Predicates.instanceOf(org.eclipse.emf.internal.cdo.object.CDOObjectWrapperBase.class);

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

	public static <T> T adapt(Object object, Class<? extends T> type) {
	T result = tryCast(object, type);

	if (result == null) {
	if (object instanceof IAdaptable) {
	result = type.cast(((IAdaptable) object).getAdapter(type));
	}

	if ((result == null) && (type == CDOObject.class)) {
	EObject eObject = adapt(object, EObject.class);
	if (eObject != null) {
	result = type.cast(getCDOObject(eObject));
	}
	}

	if ((result == null) && (object instanceof Notifier)) {
	result = getFirst(filter(((Notifier) object).eAdapters(), type), null);
	}
	}

	return result;
	}

	public static <T> T tryCast(Object object, Class<? extends T> type) {
	T result = null;

	if (type.isInstance(object)) {
	result = type.cast(object);
	}

	return result;
	}

	public static boolean isCDOURI(URI uri) {
	return CDO_URI_SCHEMES.contains(uri.scheme());
	}

	public static boolean isCDOEditingDomain(EditingDomain domain) {
	return domain instanceof CDOAwareTransactionalEditingDomain;
	}

	public static ResourceSet getResourceSet(Notifier notifier) {
	ResourceSet result = null;

	if (notifier instanceof CDOViewSet) {
	result = ((CDOViewSet) notifier).getResourceSet();
	} else if (notifier instanceof ResourceSet) {
	result = (ResourceSet) notifier;
	} else if (notifier instanceof Resource) {
	result = ((Resource) notifier).getResourceSet();
	} else if (notifier instanceof CDOResourceNode) {
	// folders (resource nodes that aren't resources) are not in a
	// resource set, so get the associated view's resource set
	CDOView view = ((CDOResourceNode) notifier).cdoView();
	if (view != null) {
	result = view.getResourceSet();
	}
	} else if (notifier instanceof EObject) {
	result = getResourceSet(((EObject) notifier).eResource());
	}

	return result;
	}

	public static boolean isCDOObject(EObject object) {
	ResourceSet resourceSet = getResourceSet(object);

	return (resourceSet != null) && (CDOUtil.getViewSet(resourceSet) != null);
	}

	public static CDOObject getCDOObject(EObject object) {
	CDOObject result = null;

	if (isCDOObject(object)) {
	result = CDOUtil.getCDOObject(object);
	}

	return result;
	}

	public static CDOID getCDOID(EObject object) {
	CDOObject cdo = getCDOObject(object);
	return (cdo == null) ? CDOIDUtil.createExternal(EcoreUtil.getURI(object).toString()) : cdo.cdoID();
	}

	public static CDOView getView(ResourceSet resourceSet) {
	CDOView result = null;

	CDOViewSet viewSet = CDOUtil.getViewSet(resourceSet);
	if (viewSet != null) {
	CDOView[] views = viewSet.getViews();
	if (views.length > 0) {
	result = views[0];
	}
	}

	return result;
	}

	public static CDOView getView(EObject object) {
	CDOObject cdo = getCDOObject(object);
	return (cdo == null) ? null : cdo.cdoView();
	}

	public static boolean isLockable(CDOObject object) {
	// transient objects do not have lock states, nor do those that are not
	// in a view or are in a closed view
	CDOView view = object.cdoView();
	return (view != null) && !view.isClosed() && (object.cdoLockState() != null);
	}

	public static boolean isLocked(CDOObject object, boolean remotely) {
	CDOLock lock = isLockable(object) ? object.cdoWriteLock() : null;

	return (lock != null) && (remotely ? lock.isLockedByOthers() : lock.isLocked());
	}

	public static void lock(CDOObject object) {
	object.cdoWriteLock().lock();
	}

	public static void unlock(CDOObject object) {
	object.cdoWriteLock().unlock();
	}

	public static DawnState computeState(EObject object) {
	DawnState result = DawnState.CLEAN;

	CDOObject cdo = getCDOObject(object);
	if (cdo != null) {
	if (cdo.cdoConflict()) {
	result = DawnState.CONFLICT;
	} else if (isLocked(cdo, true)) {
	result = DawnState.LOCKED_REMOTELY;
	} else if (isLocked(cdo, false)) {
	result = DawnState.LOCKED_LOCALLY;
	}
	}

	return result;
	}

	public static boolean isReadOnly(CDOObject object) {
	// an object is read-only if somebody else has it locked
	boolean result = CDOUtils.isLocked(object, true);

	// or if the current user doesn't have permission to write it
	if (!result) {
	result = !object.cdoPermission().isWritable();
	}

	return result;
	}

	public static Iterable<EObject> getEObjects(Iterable<? extends CDOObject> cdoObjects) {
	return Iterables.transform(cdoObjects, CDOFunctions.getEObject());
	}

	public static Iterable<EStructuralFeature.Setting> crossReference(EObject object) {
	Iterable<EStructuralFeature.Setting> result;

	ECrossReferenceAdapter adapter = adapt(object, ECrossReferenceAdapter.class);
	if (adapter != null) {
	result = adapter.getInverseReferences(object);
	} else {
	EObject tree = EcoreUtil.getRootContainer(object);
	Resource resource = tree.eResource();
	ResourceSet rset = (resource == null) ? null : resource.getResourceSet();

	if (rset != null) {
	result = EcoreUtil.UsageCrossReferencer.find(object, rset);
	} else if (resource != null) {
	result = EcoreUtil.UsageCrossReferencer.find(object, resource);
	} else {
	result = EcoreUtil.UsageCrossReferencer.find(object, tree);
	}
	}

	return result;
	}

	/**
	* Obtains an unmodifiable iterator over the values in the specified {@code feature} of an {@code object}. The resulting iterator supplies zero
	* or one element for scalar features, according to whether the feature's value is {@code null} or not. In the case of a scalar feature,
	* the index of the element as reported by {@link ListIterator#nextIndex()} and {@link ListIterator#previousIndex()} is {@code -1}.
	*
	* @param object
	* an object
	* @param feature
	* a feature of the {@code object}
	* @param resolve
	* whether to resolve proxies (in the case of an {@link EReference}
	*
	* @return the unmodifiable feature list iterator
	*/
	public static <E> FeatureListIterator<E> iterator(EObject object, final EStructuralFeature feature, boolean resolve) {
	FeatureListIterator<E> result;

	Object value = object.eGet(feature, resolve);
	if (value instanceof InternalEList<?>) {
	@SuppressWarnings("unchecked")
	InternalEList<E> list = (InternalEList<E>) value;
	final ListIterator<E> delegate = (resolve) ? list.listIterator() : list.basicListIterator();

	class NonEmpty extends UnmodifiableListIterator<E>implements FeatureListIterator<E> {

	@Override
	public EStructuralFeature feature() {
	return feature;
	}

	@Override
	public boolean hasNext() {
	return delegate.hasNext();
	}

	@Override
	public E next() {
	return delegate.next();
	}

	@Override
	public int nextIndex() {
	return delegate.nextIndex();
	}

	@Override
	public boolean hasPrevious() {
	return delegate.hasPrevious();
	}

	@Override
	public E previous() {
	return delegate.previous();
	}

	@Override
	public int previousIndex() {
	return delegate.previousIndex();
	}
	}
	;

	result = new NonEmpty();
	} else if (value == null) {
	class Empty extends UnmodifiableListIterator<E>implements FeatureListIterator<E> {

	@Override
	public EStructuralFeature feature() {
	return feature;
	}

	@Override
	public boolean hasNext() {
	return false;
	}

	@Override
	public E next() {
	throw new NoSuchElementException();
	}

	@Override
	public int nextIndex() {
	return -1;
	}

	@Override
	public boolean hasPrevious() {
	return false;
	}

	@Override
	public E previous() {
	throw new NoSuchElementException();
	}

	@Override
	public int previousIndex() {
	return -2;
	}
	}
	;

	result = new Empty();
	} else {
	@SuppressWarnings("unchecked")
	final E onlyValue = (E) value;

	class Singleton extends UnmodifiableListIterator<E>implements FeatureListIterator<E> {

	private int index = -1;

	@Override
	public EStructuralFeature feature() {
	return feature;
	}

	@Override
	public boolean hasNext() {
	return index < 0;
	}

	@Override
	public E next() {
	if (!hasNext()) {
	throw new NoSuchElementException();
	}
	index++;
	return onlyValue;
	}

	@Override
	public int nextIndex() {
	return index;
	}

	@Override
	public boolean hasPrevious() {
	return index == 0;
	}

	@Override
	public E previous() {
	if (!hasPrevious()) {
	throw new NoSuchElementException();
	}
	index--;
	return onlyValue;
	}

	@Override
	public int previousIndex() {
	return index - 1;
	}
	}
	;

	result = new Singleton();
	}

	return result;
	}

	/**
	* <p>
	* Runs a code block that broadcasts notification of {@link ResourceSetChangeEvent}s, {@link CDOViewInvalidationEvent}s, etc. to listeners using the most appropriate {@linkplain #setBroadcastExecutor() executor} available. This allows a UI-safe execution
	* to be injected if necessary.
	* </p>
	* <p>
	* <strong>Note</strong> that there is no assurance that this block will be executed either synchronously or asynchronously.
	* </p>
	*
	* @param broadcastCommand
	* the notification command to execute
	*/
	public static void notify(Runnable broadcastCommand) {
	broadcastExecutor.execute(broadcastCommand);
	}

	public static void notify(final TransactionalEditingDomain domain, final Runnable broadcastCommand) {

	broadcastExecutor.execute(new Runnable() {

	@Override
	public void run() {
	try {
	domain.runExclusive(broadcastCommand);
	} catch (Exception e) {
	Activator.log.error("Exception in execution of notification broadcast.", e); //$NON-NLS-1$
	}
	}
	});
	}

	public static void setBroadcastExecutor(Executor executor) {
	broadcastExecutor = (executor == null) ? new DirectExecutor() : executor;
	}

	/**
	* Remove the given {@code listener} if the event it received is a lifecycle deactivation event.
	*
	* @param listener
	* a listener that received a possible deactivation event
	* @param possibleDeactivation
	* the event that may be a lifecycle deactivation
	*
	* @return whether the listener was removed because the event was a deactivation
	*/
	public static boolean removeListenerFromDeactivatedLifecycle(IListener listener, IEvent possibleDeactivation) {
	boolean result = false;

	if (possibleDeactivation instanceof LifecycleEvent) {
	switch (((LifecycleEvent) possibleDeactivation).getKind()) {
	case DEACTIVATED:
	possibleDeactivation.getSource().removeListener(listener);
	result = true;
	break;
	default:
	// Pass
	break;
	}
	}

	return result;
	}

	/**
	* Unloads a {@code cdoObject} (because {@link CDOResource}s don't implement unloading) by clearing its adapters.
	*
	* @param cdoObject
	* a CDO object to unload
	*
	* @see #unload(CDOView)
	*/
	public static void unload(CDOObject cdoObject) {
	EObject eObject = CDOUtil.getEObject(cdoObject);
	if (eObject != null) {
	// Remove all adapters except the all-important legacy wrapper!
	EList<Adapter> adapters = eObject.eAdapters();
	if (!adapters.isEmpty()) {
	Adapter legacyWrapper = Iterables.find(eObject.eAdapters(), IS_LEGACY_WRAPPER, null);

	// Don't do anything if the only adapter is the legacy wrapper
	if ((legacyWrapper == null) \|\| (adapters.size() > 1)) {
	adapters.clear();
	if (legacyWrapper != null) {
	// Restore it, otherwise references to this CDOObject will break
	adapters.add(0, legacyWrapper);
	}
	}
	}
	}
	}

	/**
	* Unloads all of the objects in a {@code cdoView} (because {@link CDOResource}s don't implement unloading) by clearing their adapters.
	*
	* @param cdoView
	* a view to unload
	*
	* @see #unload(CDOObject)
	*/
	public static void unload(CDOView cdoView) {
	if (cdoView instanceof InternalCDOView) {
	for (CDOObject next : ((InternalCDOView) cdoView).getObjectsList()) {
	// Don't clear adapters of the resource because ECrossReferenceAdapters would try to crawl the contents
	if (!(next instanceof CDOResourceNode)) {
	CDOUtils.unload(next);
	}
	}
	}
	}

	//
	// Nested types
	//

	private static final class DirectExecutor implements Executor {

	@Override
	public void execute(Runnable command) {
	command.run();
	}
	}
	}