bundles/org.eclipse.team.ui/src/org/eclipse/team/internal/ui/history/EditionHistoryPage.java - gerrit/platform/eclipse.platform.team - Git at Google

 /*******************************************************************************
  * Copyright (c) 2006, 2017 IBM Corporation and others.
  *
  * 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:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.team.internal.ui.history;

 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;

 import org.eclipse.compare.CompareUI;
 import org.eclipse.compare.ITypedElement;
 import org.eclipse.compare.structuremergeviewer.DiffNode;
 import org.eclipse.compare.structuremergeviewer.ICompareInput;
 import org.eclipse.compare.structuremergeviewer.IStructureComparator;
 import org.eclipse.compare.structuremergeviewer.IStructureCreator;
 import org.eclipse.compare.structuremergeviewer.IStructureCreator2;
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.runtime.Assert;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.osgi.util.NLS;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.team.core.TeamException;
 import org.eclipse.team.core.history.IFileRevision;
 import org.eclipse.team.internal.core.history.LocalFileHistory;
 import org.eclipse.team.internal.ui.Policy;
 import org.eclipse.team.internal.ui.TeamUIMessages;
 import org.eclipse.team.internal.ui.TeamUIPlugin;
 import org.eclipse.team.internal.ui.actions.CompareRevisionAction;
 import org.eclipse.team.internal.ui.synchronize.LocalResourceTypedElement;
 import org.eclipse.team.ui.history.HistoryPage;
 import org.eclipse.team.ui.history.IHistoryPage;
 import org.eclipse.team.ui.history.IHistoryPageSite;
 import org.eclipse.ui.IWorkbenchPage;

 /**
  * A history page for a sub-element of a file.
  * <p>
  * If the site is modal, the local edition is created up-front and destroyed when the page is destroyed.
  * Otherwise, the local edition is only created when needed. The {@link #getCompareInput(Object)} and
  * {@link #prepareInput(ICompareInput, org.eclipse.compare.CompareConfiguration, IProgressMonitor)}
  * methods are only used when the site is modal so they can use the localEdition.
  */
 public class EditionHistoryPage extends LocalHistoryPage {
 	private IFile file;

 	private Object element;

 	private LocalResourceTypedElement localFileElement;
 	private IStructureCreator structureCreator;
 	private Map<IFileRevision, ITypedElement> editions = new HashMap<IFileRevision, ITypedElement>();
 	private ITypedElement localEdition;
 	private String name;

 	class CompareEditionAction extends CompareRevisionAction {

 		public CompareEditionAction(HistoryPage page) {
 			super(page);
 		}

 		@Override
 		protected ITypedElement getElementFor(IResource resource) {
 			if (resource.equals(file))
 				return localFileElement;
 			return super.getElementFor(resource);
 		}

 		@Override
 		protected CompareFileRevisionEditorInput createCompareEditorInput(ITypedElement left, ITypedElement right, IWorkbenchPage page) {
 			ITypedElement leftEdition = getEdition(left);
 			boolean leftIsLocal = false;
 			if (leftEdition == null && left instanceof LocalResourceTypedElement) {
 				leftEdition = createLocalEdition(structureCreator, localFileElement, element);
 				leftIsLocal = true;
 			}
 			ITypedElement rightEdition = getEdition(right);
 			return new CompareEditionsEditorInput(structureCreator, left, right, leftEdition, rightEdition, leftIsLocal, page);
 		}

 		private ITypedElement getEdition(ITypedElement input) {
 			if (input instanceof FileRevisionTypedElement) {
 				FileRevisionTypedElement te = (FileRevisionTypedElement) input;
 				return getEditionFor(te.getRevision());
 			}
 			return null;
 		}
 	}

 	static class CompareEditionsEditorInput extends CompareFileRevisionEditorInput {

 		private final ITypedElement leftRevision;
 		private final ITypedElement rightRevision;
 		private final boolean leftIsLocal;
 		private IStructureCreator structureCreator;

 		public CompareEditionsEditorInput(IStructureCreator structureCreator, ITypedElement left,
 				ITypedElement right, ITypedElement leftEdition,
 				ITypedElement rightEdition, boolean leftIsLocal, IWorkbenchPage page) {
 			super(leftEdition, rightEdition, page);
 			this.structureCreator = structureCreator;
 			leftRevision = left;
 			rightRevision = right;
 			this.leftIsLocal = leftIsLocal;
 		}

 		@Override
 		public LocalResourceTypedElement getLocalElement() {
 			if (leftRevision instanceof LocalResourceTypedElement) {
 				return (LocalResourceTypedElement) leftRevision;
 			}
 			return super.getLocalElement();
 		}

 		@Override
 		protected FileRevisionTypedElement getRightRevision() {
 			if (rightRevision instanceof FileRevisionTypedElement) {
 				return (FileRevisionTypedElement) rightRevision;
 			}
 			return null;
 		}

 		@Override
 		protected FileRevisionTypedElement getLeftRevision() {
 			if (leftRevision instanceof FileRevisionTypedElement) {
 				return (FileRevisionTypedElement) leftRevision;
 			}
 			return null;
 		}
 		@Override
 		public <T> T getAdapter(Class<T> adapter) {
 			if (adapter == IFile.class)
 				return null;
 			return super.getAdapter(adapter);
 		}

 		@Override
 		protected void handleDispose() {
 			if (leftIsLocal && structureCreator != null)
 				internalDestroy(structureCreator, getLeft());
 			structureCreator = null;
 			super.handleDispose();
 		}
 	}

 	public static ITypedElement getPreviousState(IFile file, Object element) throws TeamException {
 		LocalResourceTypedElement localFileElement= new LocalResourceTypedElement(file);
 		IStructureCreator structureCreator = CompareUI.createStructureCreator(localFileElement);
 		if (structureCreator == null)
 			return null;
 		LocalFileHistory history = new LocalFileHistory(file, false);
 		history.refresh(new NullProgressMonitor());
 		IFileRevision[] revisions = history.getFileRevisions();
 		if (revisions.length == 0)
 			return null;
 		sortDescending(revisions);
 		ITypedElement localEdition = null;
 		try {
 			localEdition = createLocalEdition(structureCreator, localFileElement, element);
 			for (int i = 0; i < revisions.length; i++) {
 				IFileRevision revision = revisions[i];
 				ITypedElement edition = createEdition(structureCreator, element, new FileRevisionTypedElement(revision));
 				if (edition != null && !contentsEqual(structureCreator, localEdition, edition)) {
 					return edition;
 				}
 			}
 		} finally {
 			if (localEdition != null)
 				destroyLocalEdition(structureCreator, localFileElement, localEdition);
 		}
 		return null;
 	}

 	public EditionHistoryPage(IFile file, Object element) {
 		super(ON | ALWAYS);
 		setInput(file, element);
 	}

 	void setInput(IFile file, Object element) {
 		Assert.isNotNull(file);
 		Assert.isNotNull(element);
 		this.file = file;
 		this.element = element;
 		this.localFileElement= new LocalResourceTypedElement(getFile());
 		structureCreator = CompareUI.createStructureCreator(localFileElement);
 	}

 	@Override
 	public void setSite(IHistoryPageSite site) {
 		super.setSite(site);
 		// If the site is modal, create the local edition
 		if (site.isModal()) {
 			localEdition = createLocalEdition(structureCreator, localFileElement, element);
 		}
 	}

 	@Override
 	protected IFile getFile() {
 		return file;
 	}

 	@Override
 	protected void update(IFileRevision[] revisions, IProgressMonitor monitor) {
 		monitor.beginTask(null, 100);
 		ITypedElement te = null;
 		try {
 			if (localEdition == null) {
 				te = createLocalEdition(structureCreator, localFileElement, element);
 			} else {
 				te = localEdition;
 			}
 			if (te != null) {
 				String oldValue = getName();
 				String oldDesc = getDescription();
 				name = te.getName();
 				IFileRevision[] filtered = filterRevisions(te, revisions, Policy.subMonitorFor(monitor, 75));
 				super.update(filtered, Policy.subMonitorFor(monitor, 25));
 				firePropertyChange(this, IHistoryPage.P_NAME, oldValue, getName());
 				firePropertyChange(this, IHistoryPage.P_DESCRIPTION, oldDesc, getDescription());
 			}
 		} finally {
 			if (localEdition == null && te != null)
 				internalDestroy(structureCreator, te);
 			monitor.done();
 		}
 	}

 	private IFileRevision[] filterRevisions(ITypedElement localEdition, IFileRevision[] revisions,
 			IProgressMonitor monitor) {
 		ITypedElement previousEdition = localEdition;
 		List<IFileRevision> result = new ArrayList<IFileRevision>();
 		sortDescending(revisions);
 		editions.clear();
 		for (int i = 0; i < revisions.length; i++) {
 			IFileRevision revision = revisions[i];
 			ITypedElement edition = createEdition(new FileRevisionTypedElement(revision));
 			if (edition != null && !contentsEqual(structureCreator, previousEdition, edition)) {
 				editions.put(revision, edition);
 				previousEdition = edition;
 				result.add(revision);
 			}
 		}
 		return result.toArray(new IFileRevision[result.size()]);
 	}

 	private static void sortDescending(IFileRevision[] revisions) {
 		Arrays.sort(revisions, (d1, d2) -> -Long.compare(d1.getTimestamp(), d2.getTimestamp()));
 	}

 	private static boolean contentsEqual(IStructureCreator creator, ITypedElement previousEdition,
 			ITypedElement edition) {
 		if (previousEdition == null || creator == null || edition == null)
 			return false;
 		String contents1 = creator.getContents(previousEdition, false /* TODO: Ignore whitespace */);
 		String contents2 = creator.getContents(edition, false /* TODO: Ignore whitespace */);
 		return (contents1 != null && contents2 != null && contents1.equals(contents2));
 	}

 	@Override
 	public ICompareInput getCompareInput(Object object) {
 		ITypedElement edition = getEditionFor(object);
 		if (edition != null && localEdition != null)
 			return new DiffNode(localEdition, edition);
 		return null;
 	}

 	public ITypedElement getEditionFor(Object object) {
 		return editions.get(object);
 	}

 	private static ITypedElement createLocalEdition(IStructureCreator creator, ITypedElement input, Object element) {
 		if (creator == null)
 			return null;
 		ITypedElement result = null;
 		if (creator instanceof IStructureCreator2) {
 			IStructureCreator2 sc2 = (IStructureCreator2) creator;
 			try {
 				result = sc2.createElement(element, input, null);
 			} catch (CoreException e) {
 				TeamUIPlugin.log(e);
 			}
 		}
 		if (result == null) {
 			result = createEdition(creator, element, input);
 		}
 		return result;
 	}

 	private ITypedElement createEdition(ITypedElement input) {
 		return createEdition(structureCreator, element, input);
 	}

 	private static ITypedElement createEdition(IStructureCreator creator, Object element, ITypedElement input) {
 		if (creator == null)
 			return null;
 		IStructureComparator edition = creator.locate(element, input);
 		if (edition instanceof ITypedElement)
 			return (ITypedElement) edition;
 		return null;
 	}

 	@Override
 	public boolean isValidInput(Object object) {
 		// This page doesn't support input changes
 		return object.equals(element);
 	}

 	@Override
 	public void dispose() {
 		try {
 			disconnect();
 		} finally {
 			super.dispose();
 		}
 	}

 	private void disconnect() {
 		if (localFileElement != null)
 			localFileElement.discardBuffer();
 		internalDestroy(structureCreator, localEdition);
 		localEdition = null;
 		structureCreator = null;
 	}

 	private static void internalDestroy(IStructureCreator creator, ITypedElement te) {
 		if (te != null && creator instanceof IStructureCreator2) {
 			IStructureCreator2 sc2 = (IStructureCreator2) creator;
 			sc2.destroy(te);
 		}
 	}

 	private static void destroyLocalEdition(
 			IStructureCreator structureCreator, LocalResourceTypedElement localFileElement, ITypedElement localEdition) {
 		if (localFileElement != null)
 			localFileElement.discardBuffer();
 		if (localEdition != null && structureCreator instanceof IStructureCreator2) {
 			IStructureCreator2 sc2 = (IStructureCreator2) structureCreator;
 			sc2.destroy(localEdition);
 		}
 	}

 	@Override
 	protected String getNoChangesMessage() {
 		if (name != null)
 			return NLS.bind(TeamUIMessages.EditionHistoryPage_0, name);
 		return TeamUIMessages.EditionHistoryPage_1;
 	}

 	@Override
 	protected Image getImage(Object object) {
 		if (object == localEdition)
 			return localEdition.getImage();
 		Object revision = getRevisionFor(object);
 		if (revision != null)
 			return super.getImage(revision);
 		return super.getImage(object);
 	}

 	@Override
 	protected String getLabel(Object object) {
 		Object revision = getRevisionFor(object);
 		if (revision != null)
 			return super.getLabel(revision);
 		return super.getLabel(object);
 	}

 	private Object getRevisionFor(Object object) {
 		if (object == localEdition)
 			return localFileElement;
 		for (Iterator<IFileRevision> iterator = editions.keySet().iterator(); iterator.hasNext();) {
 			IFileRevision revision = iterator.next();
 			if (editions.get(revision) == object) {
 				return revision;
 			}
 		}
 		return null;
 	}

 	@Override
 	public String getName() {
 		if (name != null)
 			return name;
 		return super.getName();
 	}

 	@Override
 	public String getDescription() {
 		if (name != null)
 			return NLS.bind(TeamUIMessages.EditionHistoryPage_2, name);
 		return super.getDescription();
 	}

 	@Override
 	protected CompareRevisionAction createCompareAction() {
 		return new CompareEditionAction(this);
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2006, 2017 IBM Corporation and others.
	*
	* 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:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.team.internal.ui.history;

	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.HashMap;
	import java.util.Iterator;
	import java.util.List;
	import java.util.Map;

	import org.eclipse.compare.CompareUI;
	import org.eclipse.compare.ITypedElement;
	import org.eclipse.compare.structuremergeviewer.DiffNode;
	import org.eclipse.compare.structuremergeviewer.ICompareInput;
	import org.eclipse.compare.structuremergeviewer.IStructureComparator;
	import org.eclipse.compare.structuremergeviewer.IStructureCreator;
	import org.eclipse.compare.structuremergeviewer.IStructureCreator2;
	import org.eclipse.core.resources.IFile;
	import org.eclipse.core.resources.IResource;
	import org.eclipse.core.runtime.Assert;
	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IProgressMonitor;
	import org.eclipse.core.runtime.NullProgressMonitor;
	import org.eclipse.osgi.util.NLS;
	import org.eclipse.swt.graphics.Image;
	import org.eclipse.team.core.TeamException;
	import org.eclipse.team.core.history.IFileRevision;
	import org.eclipse.team.internal.core.history.LocalFileHistory;
	import org.eclipse.team.internal.ui.Policy;
	import org.eclipse.team.internal.ui.TeamUIMessages;
	import org.eclipse.team.internal.ui.TeamUIPlugin;
	import org.eclipse.team.internal.ui.actions.CompareRevisionAction;
	import org.eclipse.team.internal.ui.synchronize.LocalResourceTypedElement;
	import org.eclipse.team.ui.history.HistoryPage;
	import org.eclipse.team.ui.history.IHistoryPage;
	import org.eclipse.team.ui.history.IHistoryPageSite;
	import org.eclipse.ui.IWorkbenchPage;

	/**
	* A history page for a sub-element of a file.
	* <p>
	* If the site is modal, the local edition is created up-front and destroyed when the page is destroyed.
	* Otherwise, the local edition is only created when needed. The {@link #getCompareInput(Object)} and
	* {@link #prepareInput(ICompareInput, org.eclipse.compare.CompareConfiguration, IProgressMonitor)}
	* methods are only used when the site is modal so they can use the localEdition.
	*/
	public class EditionHistoryPage extends LocalHistoryPage {
	private IFile file;

	private Object element;

	private LocalResourceTypedElement localFileElement;
	private IStructureCreator structureCreator;
	private Map<IFileRevision, ITypedElement> editions = new HashMap<IFileRevision, ITypedElement>();
	private ITypedElement localEdition;
	private String name;

	class CompareEditionAction extends CompareRevisionAction {

	public CompareEditionAction(HistoryPage page) {
	super(page);
	}

	@Override
	protected ITypedElement getElementFor(IResource resource) {
	if (resource.equals(file))
	return localFileElement;
	return super.getElementFor(resource);
	}

	@Override
	protected CompareFileRevisionEditorInput createCompareEditorInput(ITypedElement left, ITypedElement right, IWorkbenchPage page) {
	ITypedElement leftEdition = getEdition(left);
	boolean leftIsLocal = false;
	if (leftEdition == null && left instanceof LocalResourceTypedElement) {
	leftEdition = createLocalEdition(structureCreator, localFileElement, element);
	leftIsLocal = true;
	}
	ITypedElement rightEdition = getEdition(right);
	return new CompareEditionsEditorInput(structureCreator, left, right, leftEdition, rightEdition, leftIsLocal, page);
	}

	private ITypedElement getEdition(ITypedElement input) {
	if (input instanceof FileRevisionTypedElement) {
	FileRevisionTypedElement te = (FileRevisionTypedElement) input;
	return getEditionFor(te.getRevision());
	}
	return null;
	}
	}

	static class CompareEditionsEditorInput extends CompareFileRevisionEditorInput {

	private final ITypedElement leftRevision;
	private final ITypedElement rightRevision;
	private final boolean leftIsLocal;
	private IStructureCreator structureCreator;

	public CompareEditionsEditorInput(IStructureCreator structureCreator, ITypedElement left,
	ITypedElement right, ITypedElement leftEdition,
	ITypedElement rightEdition, boolean leftIsLocal, IWorkbenchPage page) {
	super(leftEdition, rightEdition, page);
	this.structureCreator = structureCreator;
	leftRevision = left;
	rightRevision = right;
	this.leftIsLocal = leftIsLocal;
	}

	@Override
	public LocalResourceTypedElement getLocalElement() {
	if (leftRevision instanceof LocalResourceTypedElement) {
	return (LocalResourceTypedElement) leftRevision;
	}
	return super.getLocalElement();
	}

	@Override
	protected FileRevisionTypedElement getRightRevision() {
	if (rightRevision instanceof FileRevisionTypedElement) {
	return (FileRevisionTypedElement) rightRevision;
	}
	return null;
	}

	@Override
	protected FileRevisionTypedElement getLeftRevision() {
	if (leftRevision instanceof FileRevisionTypedElement) {
	return (FileRevisionTypedElement) leftRevision;
	}
	return null;
	}
	@Override
	public <T> T getAdapter(Class<T> adapter) {
	if (adapter == IFile.class)
	return null;
	return super.getAdapter(adapter);
	}

	@Override
	protected void handleDispose() {
	if (leftIsLocal && structureCreator != null)
	internalDestroy(structureCreator, getLeft());
	structureCreator = null;
	super.handleDispose();
	}
	}

	public static ITypedElement getPreviousState(IFile file, Object element) throws TeamException {
	LocalResourceTypedElement localFileElement= new LocalResourceTypedElement(file);
	IStructureCreator structureCreator = CompareUI.createStructureCreator(localFileElement);
	if (structureCreator == null)
	return null;
	LocalFileHistory history = new LocalFileHistory(file, false);
	history.refresh(new NullProgressMonitor());
	IFileRevision[] revisions = history.getFileRevisions();
	if (revisions.length == 0)
	return null;
	sortDescending(revisions);
	ITypedElement localEdition = null;
	try {
	localEdition = createLocalEdition(structureCreator, localFileElement, element);
	for (int i = 0; i < revisions.length; i++) {
	IFileRevision revision = revisions[i];
	ITypedElement edition = createEdition(structureCreator, element, new FileRevisionTypedElement(revision));
	if (edition != null && !contentsEqual(structureCreator, localEdition, edition)) {
	return edition;
	}
	}
	} finally {
	if (localEdition != null)
	destroyLocalEdition(structureCreator, localFileElement, localEdition);
	}
	return null;
	}

	public EditionHistoryPage(IFile file, Object element) {
	super(ON \| ALWAYS);
	setInput(file, element);
	}

	void setInput(IFile file, Object element) {
	Assert.isNotNull(file);
	Assert.isNotNull(element);
	this.file = file;
	this.element = element;
	this.localFileElement= new LocalResourceTypedElement(getFile());
	structureCreator = CompareUI.createStructureCreator(localFileElement);
	}

	@Override
	public void setSite(IHistoryPageSite site) {
	super.setSite(site);
	// If the site is modal, create the local edition
	if (site.isModal()) {
	localEdition = createLocalEdition(structureCreator, localFileElement, element);
	}
	}

	@Override
	protected IFile getFile() {
	return file;
	}

	@Override
	protected void update(IFileRevision[] revisions, IProgressMonitor monitor) {
	monitor.beginTask(null, 100);
	ITypedElement te = null;
	try {
	if (localEdition == null) {
	te = createLocalEdition(structureCreator, localFileElement, element);
	} else {
	te = localEdition;
	}
	if (te != null) {
	String oldValue = getName();
	String oldDesc = getDescription();
	name = te.getName();
	IFileRevision[] filtered = filterRevisions(te, revisions, Policy.subMonitorFor(monitor, 75));
	super.update(filtered, Policy.subMonitorFor(monitor, 25));
	firePropertyChange(this, IHistoryPage.P_NAME, oldValue, getName());
	firePropertyChange(this, IHistoryPage.P_DESCRIPTION, oldDesc, getDescription());
	}
	} finally {
	if (localEdition == null && te != null)
	internalDestroy(structureCreator, te);
	monitor.done();
	}
	}

	private IFileRevision[] filterRevisions(ITypedElement localEdition, IFileRevision[] revisions,
	IProgressMonitor monitor) {
	ITypedElement previousEdition = localEdition;
	List<IFileRevision> result = new ArrayList<IFileRevision>();
	sortDescending(revisions);
	editions.clear();
	for (int i = 0; i < revisions.length; i++) {
	IFileRevision revision = revisions[i];
	ITypedElement edition = createEdition(new FileRevisionTypedElement(revision));
	if (edition != null && !contentsEqual(structureCreator, previousEdition, edition)) {
	editions.put(revision, edition);
	previousEdition = edition;
	result.add(revision);
	}
	}
	return result.toArray(new IFileRevision[result.size()]);
	}

	private static void sortDescending(IFileRevision[] revisions) {
	Arrays.sort(revisions, (d1, d2) -> -Long.compare(d1.getTimestamp(), d2.getTimestamp()));
	}

	private static boolean contentsEqual(IStructureCreator creator, ITypedElement previousEdition,
	ITypedElement edition) {
	if (previousEdition == null \|\| creator == null \|\| edition == null)
	return false;
	String contents1 = creator.getContents(previousEdition, false /* TODO: Ignore whitespace */);
	String contents2 = creator.getContents(edition, false /* TODO: Ignore whitespace */);
	return (contents1 != null && contents2 != null && contents1.equals(contents2));
	}

	@Override
	public ICompareInput getCompareInput(Object object) {
	ITypedElement edition = getEditionFor(object);
	if (edition != null && localEdition != null)
	return new DiffNode(localEdition, edition);
	return null;
	}

	public ITypedElement getEditionFor(Object object) {
	return editions.get(object);
	}

	private static ITypedElement createLocalEdition(IStructureCreator creator, ITypedElement input, Object element) {
	if (creator == null)
	return null;
	ITypedElement result = null;
	if (creator instanceof IStructureCreator2) {
	IStructureCreator2 sc2 = (IStructureCreator2) creator;
	try {
	result = sc2.createElement(element, input, null);
	} catch (CoreException e) {
	TeamUIPlugin.log(e);
	}
	}
	if (result == null) {
	result = createEdition(creator, element, input);
	}
	return result;
	}

	private ITypedElement createEdition(ITypedElement input) {
	return createEdition(structureCreator, element, input);
	}

	private static ITypedElement createEdition(IStructureCreator creator, Object element, ITypedElement input) {
	if (creator == null)
	return null;
	IStructureComparator edition = creator.locate(element, input);
	if (edition instanceof ITypedElement)
	return (ITypedElement) edition;
	return null;
	}

	@Override
	public boolean isValidInput(Object object) {
	// This page doesn't support input changes
	return object.equals(element);
	}

	@Override
	public void dispose() {
	try {
	disconnect();
	} finally {
	super.dispose();
	}
	}

	private void disconnect() {
	if (localFileElement != null)
	localFileElement.discardBuffer();
	internalDestroy(structureCreator, localEdition);
	localEdition = null;
	structureCreator = null;
	}

	private static void internalDestroy(IStructureCreator creator, ITypedElement te) {
	if (te != null && creator instanceof IStructureCreator2) {
	IStructureCreator2 sc2 = (IStructureCreator2) creator;
	sc2.destroy(te);
	}
	}

	private static void destroyLocalEdition(
	IStructureCreator structureCreator, LocalResourceTypedElement localFileElement, ITypedElement localEdition) {
	if (localFileElement != null)
	localFileElement.discardBuffer();
	if (localEdition != null && structureCreator instanceof IStructureCreator2) {
	IStructureCreator2 sc2 = (IStructureCreator2) structureCreator;
	sc2.destroy(localEdition);
	}
	}

	@Override
	protected String getNoChangesMessage() {
	if (name != null)
	return NLS.bind(TeamUIMessages.EditionHistoryPage_0, name);
	return TeamUIMessages.EditionHistoryPage_1;
	}

	@Override
	protected Image getImage(Object object) {
	if (object == localEdition)
	return localEdition.getImage();
	Object revision = getRevisionFor(object);
	if (revision != null)
	return super.getImage(revision);
	return super.getImage(object);
	}

	@Override
	protected String getLabel(Object object) {
	Object revision = getRevisionFor(object);
	if (revision != null)
	return super.getLabel(revision);
	return super.getLabel(object);
	}

	private Object getRevisionFor(Object object) {
	if (object == localEdition)
	return localFileElement;
	for (Iterator<IFileRevision> iterator = editions.keySet().iterator(); iterator.hasNext();) {
	IFileRevision revision = iterator.next();
	if (editions.get(revision) == object) {
	return revision;
	}
	}
	return null;
	}

	@Override
	public String getName() {
	if (name != null)
	return name;
	return super.getName();
	}

	@Override
	public String getDescription() {
	if (name != null)
	return NLS.bind(TeamUIMessages.EditionHistoryPage_2, name);
	return super.getDescription();
	}

	@Override
	protected CompareRevisionAction createCompareAction() {
	return new CompareEditionAction(this);
	}

	}