Feature: propagate model changes to editor - https://bugs.eclipse.org/bugs/show_bug.cgi?id=265097

9 files changed, 515 insertions, 4 deletions

diff --git a/plugins/org.eclipse.xtext.ui.core/META-INF/MANIFEST.MF b/plugins/org.eclipse.xtext.ui.core/META-INF/MANIFEST.MF
index fe42442..70ad1e3 100644
--- a/plugins/org.eclipse.xtext.ui.core/META-INF/MANIFEST.MF
+++ b/plugins/org.eclipse.xtext.ui.core/META-INF/MANIFEST.MF
@@ -26,6 +26,7 @@ Export-Package: org.eclipse.xtext.ui.core,
  org.eclipse.xtext.ui.core.editor.formatting,
  org.eclipse.xtext.ui.core.editor.handler,
  org.eclipse.xtext.ui.core.editor.model,
+ org.eclipse.xtext.ui.core.editor.model.edit,
  org.eclipse.xtext.ui.core.editor.preferences,
  org.eclipse.xtext.ui.core.editor.preferences.fields,
  org.eclipse.xtext.ui.core.editor.reconciler,
diff --git a/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/model/XtextDocument.java b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/model/XtextDocument.java
index f1e36ef..c7bb986 100644
--- a/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/model/XtextDocument.java
+++ b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/model/XtextDocument.java
@@ -8,6 +8,7 @@
  *******************************************************************************/
 package org.eclipse.xtext.ui.core.editor.model;
 
+import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -206,7 +207,7 @@ public class XtextDocument extends Document implements IXtextDocument {
 		}
 
 		@Override
-		protected void beforeReadOnly(XtextResource res, org.eclipse.xtext.concurrent.IUnitOfWork<?, XtextResource> work) {
+		protected void beforeReadOnly(XtextResource res, IUnitOfWork<?, XtextResource> work) {
 			if (log.isDebugEnabled())
 				log.debug("read - " + Thread.currentThread().getName());
 			updateContentBeforeRead();
@@ -219,16 +220,30 @@ public class XtextDocument extends Document implements IXtextDocument {
 		}
 
 		@Override
-		protected void afterReadOnly(XtextResource res, Object result, org.eclipse.xtext.concurrent.IUnitOfWork<?, XtextResource> work) {
+		protected void afterReadOnly(XtextResource res, Object result, IUnitOfWork<?, XtextResource> work) {
 			ensureThatStateIsNotReturned(result, work);
 		}
 
 		@Override
-		protected void afterModify(XtextResource res, Object result, org.eclipse.xtext.concurrent.IUnitOfWork<?, XtextResource> work) {
+		protected void afterModify(XtextResource res, Object result, IUnitOfWork<?, XtextResource> work) {
 			ensureThatStateIsNotReturned(result, work);
 			notifyModelListeners(resource);
 		}
 
+		@Override
+		public <T> T modify(IUnitOfWork<T, XtextResource> work) {
+			try {
+				return super.modify(work);
+			} catch (RuntimeException e) {
+				try {
+					getState().reparse(get());
+				}
+				catch (IOException ioe) {
+				}
+				throw e;
+			}
+		}
+
 		public <T> T process(IUnitOfWork<T, XtextResource> transaction) {
 			if (transaction != null) {
 				readLock.unlock();
diff --git a/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/model/edit/DefaultDocumentEditor.java b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/model/edit/DefaultDocumentEditor.java
new file mode 100644
index 0000000..2b12bf5
--- a/dev/null
+++ b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/model/edit/DefaultDocumentEditor.java
@@ -0,0 +1,58 @@
+/*******************************************************************************
+ * Copyright (c) 2009 itemis AG (http://www.itemis.eu) 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
+ *******************************************************************************/
+package org.eclipse.xtext.ui.core.editor.model.edit;
+
+import org.eclipse.text.edits.TextEdit;
+import org.eclipse.xtext.concurrent.IUnitOfWork;
+import org.eclipse.xtext.resource.XtextResource;
+import org.eclipse.xtext.ui.core.editor.model.IXtextDocument;
+
+import com.google.inject.Inject;
+
+/**
+ * @author Knut Wannheden - Initial contribution and API
+ */
+public class DefaultDocumentEditor implements IDocumentEditor {
+
+	@Inject
+	private ITextEditComposer composer;
+
+	private final class ReconcilingUnitOfWork<T> implements IUnitOfWork<T, XtextResource> {
+
+		private final IUnitOfWork<T, XtextResource> work;
+		private final IXtextDocument document;
+
+		private ReconcilingUnitOfWork(IUnitOfWork<T, XtextResource> work, IXtextDocument document) {
+			this.work = work;
+			this.document = document;
+		}
+
+		public T exec(XtextResource state) throws Exception {
+			composer.beginRecording(state);
+			T result = work.exec(state);
+			final TextEdit edit = composer.endRecording();
+			if (edit != null) {
+				String original = document.get();
+				try {
+					edit.apply(document);
+				}
+				catch (Exception e) {
+					document.set(original);
+					throw new RuntimeException(e);
+				}
+			}
+			return result;
+		}
+	}
+
+	public <T> T process(final IUnitOfWork<T, XtextResource> work, final IXtextDocument document) {
+		IUnitOfWork<T, XtextResource> reconcilingUnitOfWork = new ReconcilingUnitOfWork<T>(work, document);
+		return document.modify(reconcilingUnitOfWork);
+	}
+
+}
diff --git a/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/model/edit/DefaultTextEditComposer.java b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/model/edit/DefaultTextEditComposer.java
new file mode 100644
index 0000000..c436074
--- a/dev/null
+++ b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/model/edit/DefaultTextEditComposer.java
@@ -0,0 +1,163 @@
+/*******************************************************************************
+ * Copyright (c) 2009 itemis AG (http://www.itemis.eu) 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
+ *******************************************************************************/
+package org.eclipse.xtext.ui.core.editor.model.edit;
+
+import java.util.Collection;
+import java.util.LinkedHashSet;
+import java.util.List;
+
+import org.eclipse.emf.common.notify.Notification;
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.emf.ecore.resource.Resource;
+import org.eclipse.emf.ecore.util.EContentAdapter;
+import org.eclipse.emf.ecore.util.EcoreUtil;
+import org.eclipse.text.edits.MultiTextEdit;
+import org.eclipse.text.edits.ReplaceEdit;
+import org.eclipse.text.edits.TextEdit;
+import org.eclipse.xtext.parsetree.CompositeNode;
+import org.eclipse.xtext.parsetree.NodeAdapter;
+import org.eclipse.xtext.parsetree.NodeUtil;
+import org.eclipse.xtext.parsetree.reconstr.SerializerUtil;
+
+import com.google.common.collect.Lists;
+import com.google.inject.Inject;
+
+/**
+ * @author Knut Wannheden - Initial contribution and API
+ */
+public class DefaultTextEditComposer extends EContentAdapter implements ITextEditComposer {
+
+	@Inject
+	private SerializerUtil serializerUtil;
+
+	private Resource resource;
+	private int resourceSize;
+	private boolean resourceChanged;
+
+	private Collection<EObject> modifiedObjects = new LinkedHashSet<EObject>();
+
+	private boolean recording = false;
+
+	@Override
+	public void notifyChanged(Notification notification) {
+		super.notifyChanged(notification);
+
+		if (!doRecord(notification))
+			return;
+
+		if (notification.getNotifier() instanceof EObject) {
+			recordObjectModification((EObject) notification.getNotifier());
+		}
+		else if (notification.getNotifier() instanceof Resource) {
+			recordResourceModification((Resource) notification.getNotifier());
+		}
+	}
+
+	protected void recordObjectModification(EObject obj) {
+		if (obj.eResource() == null || obj.eResource() != resource)
+			getModifiedObjects().remove(obj);
+		else
+			getModifiedObjects().add(obj);
+	}
+
+	protected void recordResourceModification(Resource notifier) {
+		resourceChanged = true;
+	}
+
+	protected Collection<EObject> getModifiedObjects() {
+		return modifiedObjects;
+	}
+
+	protected boolean doRecord(Notification notification) {
+		if (!recording || notification.isTouch())
+			return false;
+
+		switch (notification.getEventType()) {
+			case Notification.ADD:
+			case Notification.ADD_MANY:
+			case Notification.MOVE:
+			case Notification.REMOVE:
+			case Notification.REMOVE_MANY:
+			case Notification.SET:
+			case Notification.UNSET:
+				return true;
+			default:
+				return false;
+		}
+	}
+
+	public void beginRecording(Resource newResource) {
+		if (newResource != resource) {
+			if (resource != null)
+				resource.eAdapters().remove(this);
+			newResource.eAdapters().add(this);
+			resource = newResource;
+		}
+		if (resource.getContents().isEmpty()) {
+			resourceSize = 0;
+		}
+		else {
+			final EObject root = resource.getContents().get(0);
+			resourceSize = NodeUtil.getNodeAdapter(root).getParserNode().getTotalLength();
+		}
+		recording = true;
+	}
+
+	public TextEdit endRecording() {
+		recording = false;
+		TextEdit textEdit = getTextEdit();
+
+		getModifiedObjects().clear();
+		resourceChanged = false;
+
+		return textEdit;
+	}
+
+	public TextEdit getTextEdit() {
+		TextEdit result = null;
+
+		if (resourceChanged) {
+			String text = resource.getContents().isEmpty() ? "" : serializerUtil.serialize(
+					resource.getContents().get(0)).trim();
+			result = new ReplaceEdit(0, resourceSize, text);
+		}
+		else {
+			final Collection<EObject> modifiedObjects = getModifiedObjects();
+			if (!modifiedObjects.isEmpty()) {
+				List<TextEdit> edits = getObjectEdits();
+				if (edits.size() == 1)
+					result = edits.get(0);
+				else {
+					result = new MultiTextEdit();
+					for (TextEdit edit : edits) {
+						result.addChild(edit);
+					}
+				}
+			}
+		}
+
+		return result;
+	}
+
+	private List<TextEdit> getObjectEdits() {
+		final Collection<EObject> modifiedObjects = getModifiedObjects();
+		Collection<EObject> topLevelObjects = EcoreUtil.filterDescendants(modifiedObjects);
+		List<TextEdit> edits = Lists.newArrayList();
+
+		for (EObject eObject : topLevelObjects) {
+			NodeAdapter nodeAdapter = NodeUtil.getNodeAdapter(eObject);
+			CompositeNode node = nodeAdapter.getParserNode();
+
+			String text = serializerUtil.serialize(eObject, false);
+			TextEdit edit = new ReplaceEdit(node.getOffset(), node.getLength(), text);
+			edits.add(edit);
+		}
+		return edits;
+	}
+
+}
\ No newline at end of file
diff --git a/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/model/edit/IDocumentEditor.java b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/model/edit/IDocumentEditor.java
new file mode 100644
index 0000000..cf8b240
--- a/dev/null
+++ b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/model/edit/IDocumentEditor.java
@@ -0,0 +1,24 @@
+/*******************************************************************************
+ * Copyright (c) 2009 itemis AG (http://www.itemis.eu) 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
+ *******************************************************************************/
+package org.eclipse.xtext.ui.core.editor.model.edit;
+
+import org.eclipse.xtext.concurrent.IUnitOfWork;
+import org.eclipse.xtext.resource.XtextResource;
+import org.eclipse.xtext.ui.core.editor.model.IXtextDocument;
+
+import com.google.inject.ImplementedBy;
+
+/**
+ * @author Knut Wannheden - Initial contribution and API
+ */
+@ImplementedBy(DefaultDocumentEditor.class)
+public interface IDocumentEditor {
+
+	<T> T process(final IUnitOfWork<T, XtextResource> work, final IXtextDocument document);
+
+}
diff --git a/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/model/edit/ITextEditComposer.java b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/model/edit/ITextEditComposer.java
new file mode 100644
index 0000000..aba3130
--- a/dev/null
+++ b/plugins/org.eclipse.xtext.ui.core/src/org/eclipse/xtext/ui/core/editor/model/edit/ITextEditComposer.java
@@ -0,0 +1,27 @@
+/*******************************************************************************
+ * Copyright (c) 2009 itemis AG (http://www.itemis.eu) 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
+ *******************************************************************************/
+package org.eclipse.xtext.ui.core.editor.model.edit;
+
+import org.eclipse.emf.ecore.resource.Resource;
+import org.eclipse.text.edits.TextEdit;
+
+import com.google.inject.ImplementedBy;
+
+/**
+ * @author Knut Wannheden - Initial contribution and API
+ */
+@ImplementedBy(DefaultTextEditComposer.class)
+public interface ITextEditComposer {
+
+	void beginRecording(Resource resource);
+
+	TextEdit endRecording();
+
+	TextEdit getTextEdit();
+
+}
diff --git a/tests/org.eclipse.xtext.ui.core.tests/META-INF/MANIFEST.MF b/tests/org.eclipse.xtext.ui.core.tests/META-INF/MANIFEST.MF
index 41705d1..f048db4 100644
--- a/tests/org.eclipse.xtext.ui.core.tests/META-INF/MANIFEST.MF
+++ b/tests/org.eclipse.xtext.ui.core.tests/META-INF/MANIFEST.MF
@@ -12,7 +12,8 @@ Require-Bundle: org.eclipse.xtext.ui.core;bundle-version="0.8.0",
  org.eclipse.xtext.generator;bundle-version="0.8.0",
  org.eclipse.jdt.core;bundle-version="3.4.0",
  org.eclipse.jdt.launching;bundle-version="3.4.0",
- org.eclipse.xtext
+ org.eclipse.xtext,
+ org.eclipse.xtext.junit;bundle-version="0.8.0"
 Bundle-Activator: org.eclipse.xtext.ui.core.internal.XtextUICoreTestsPlugin
 Bundle-ActivationPolicy: lazy
 Bundle-Vendor: Eclipse.org
diff --git a/tests/org.eclipse.xtext.ui.core.tests/src/org/eclipse/xtext/ui/core/editor/model/edit/DefaultDocumentEditorTest.java b/tests/org.eclipse.xtext.ui.core.tests/src/org/eclipse/xtext/ui/core/editor/model/edit/DefaultDocumentEditorTest.java
new file mode 100644
index 0000000..d252e45
--- a/dev/null
+++ b/tests/org.eclipse.xtext.ui.core.tests/src/org/eclipse/xtext/ui/core/editor/model/edit/DefaultDocumentEditorTest.java
@@ -0,0 +1,65 @@
+/*******************************************************************************
+ * Copyright (c) 2009 itemis AG (http://www.itemis.eu) 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
+ *******************************************************************************/
+package org.eclipse.xtext.ui.core.editor.model.edit;
+
+import org.eclipse.emf.ecore.resource.Resource;
+import org.eclipse.xtext.Grammar;
+import org.eclipse.xtext.XtextStandaloneSetup;
+import org.eclipse.xtext.concurrent.IUnitOfWork;
+import org.eclipse.xtext.junit.AbstractXtextTests;
+import org.eclipse.xtext.resource.XtextResource;
+import org.eclipse.xtext.ui.core.editor.model.IXtextDocument;
+import org.eclipse.xtext.ui.core.editor.model.XtextDocument;
+import org.eclipse.xtext.util.StringInputStream;
+
+/**
+ * @author Knut Wannheden - Initial contribution and API
+ */
+public class DefaultDocumentEditorTest extends AbstractXtextTests {
+
+	private IDocumentEditor editor;
+
+	@Override
+	protected void setUp() throws Exception {
+		super.setUp();
+		with(XtextStandaloneSetup.class);
+		editor = get(IDocumentEditor.class);
+	}
+
+	public void testProcess() throws Exception {
+		String grammar = "grammar foo.Foo " + "generate foo \"foo://foo/42\" " + "Foo: \"foo\" | \"bar\" | \"baz\"; "
+				+ "Bar: foo=Foo; ";
+		final Resource res = getResource(new StringInputStream(grammar));
+		final Object expected = res.getContents().get(0);
+		final IXtextDocument document = new XtextDocument() {
+			@Override
+			public <T> T modify(IUnitOfWork<T, XtextResource> work) {
+				try {
+					return work.exec((XtextResource) res);
+				}
+				catch (Exception e) {
+					throw new RuntimeException(e);
+				}
+			}
+		};
+		document.set(grammar);
+
+		Object result = editor.process(new IUnitOfWork<Object, XtextResource>() {
+			public Object exec(XtextResource state) throws Exception {
+				assertEquals(res, state);
+				Grammar grammar = (Grammar) state.getContents().get(0);
+				grammar.setName("foo.Bar");
+				return grammar;
+			}
+		}, document);
+
+		assertEquals(expected, result);
+		assertEquals(grammar.replaceFirst("foo\\.Foo", "foo.Bar"), document.get());
+	}
+
+}
diff --git a/tests/org.eclipse.xtext.ui.core.tests/src/org/eclipse/xtext/ui/core/editor/model/edit/DefaultTextEditComposerTest.java b/tests/org.eclipse.xtext.ui.core.tests/src/org/eclipse/xtext/ui/core/editor/model/edit/DefaultTextEditComposerTest.java
new file mode 100644
index 0000000..7bb4659
--- a/dev/null
+++ b/tests/org.eclipse.xtext.ui.core.tests/src/org/eclipse/xtext/ui/core/editor/model/edit/DefaultTextEditComposerTest.java
@@ -0,0 +1,157 @@
+/*******************************************************************************
+ * Copyright (c) 2009 itemis AG (http://www.itemis.eu) 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
+ *******************************************************************************/
+package org.eclipse.xtext.ui.core.editor.model.edit;
+
+import java.io.InputStream;
+
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.emf.ecore.resource.Resource;
+import org.eclipse.text.edits.MultiTextEdit;
+import org.eclipse.text.edits.ReplaceEdit;
+import org.eclipse.text.edits.TextEdit;
+import org.eclipse.xtext.AbstractRule;
+import org.eclipse.xtext.Alternatives;
+import org.eclipse.xtext.Grammar;
+import org.eclipse.xtext.Keyword;
+import org.eclipse.xtext.ParserRule;
+import org.eclipse.xtext.XtextFactory;
+import org.eclipse.xtext.XtextStandaloneSetup;
+import org.eclipse.xtext.junit.AbstractXtextTests;
+import org.eclipse.xtext.parsetree.AbstractNode;
+import org.eclipse.xtext.parsetree.NodeUtil;
+import org.eclipse.xtext.parsetree.impl.ParsetreeUtil;
+import org.eclipse.xtext.util.StringInputStream;
+
+/**
+ * @author Knut Wannheden - Initial contribution and API
+ */
+public class DefaultTextEditComposerTest extends AbstractXtextTests {
+
+	private ITextEditComposer composer;
+
+	@Override
+	protected void setUp() throws Exception {
+		super.setUp();
+		with(new XtextStandaloneSetup());
+		composer = get(ITextEditComposer.class);
+	}
+
+	private InputStream newTestGrammar() {
+		return new StringInputStream("grammar foo.Foo " + "generate foo 'foo://foo/42' "
+				+ "Foo: 'foo' | 'bar' | 'baz'; " + "Bar: foo=Foo; ");
+	}
+
+	public void testProtocol() throws Exception {
+		Resource res = getResource(newTestGrammar());
+		assertNull(composer.endRecording());
+		composer.beginRecording(res);
+		assertNull(composer.endRecording());
+		assertNull(composer.endRecording());
+		composer.beginRecording(res);
+		Grammar grammar = (Grammar) res.getContents().get(0);
+		ParserRule rule = (ParserRule) grammar.getRules().get(0);
+		rule.setName("Bar");
+		assertNotNull(composer.endRecording());
+		assertNull(composer.endRecording());
+	}
+
+	public void testRemoveRootObject() throws Exception {
+		Resource res = getResource(newTestGrammar());
+
+		composer.beginRecording(res);
+		res.getContents().clear();
+		TextEdit edit = composer.endRecording();
+
+		assertEquals("", ((ReplaceEdit) edit).getText());
+	}
+
+	public void testReplaceRootObject() throws Exception {
+		Resource res = getResource(newTestGrammar());
+
+		composer.beginRecording(res);
+		Grammar grammar = (Grammar) getResource(
+				new StringInputStream("grammar bar.Bar " + "generate bar 'bar://bar/43' " + "Bar: 'bar'; "))
+				.getContents().get(0);
+		res.getContents().set(0, grammar);
+		TextEdit edit = composer.endRecording();
+
+		assertMatches(grammar, edit);
+	}
+
+	public void testObjectAddition() throws Exception {
+		Resource res = getResource(newTestGrammar());
+
+		composer.beginRecording(res);
+		Grammar grammar = (Grammar) res.getContents().get(0);
+		ParserRule rule = (ParserRule) grammar.getRules().get(0);
+		Alternatives alternatives = (Alternatives) rule.getAlternatives();
+		Keyword keyword = XtextFactory.eINSTANCE.createKeyword();
+		keyword.setValue("qux");
+		alternatives.getGroups().add(keyword);
+		TextEdit edit = composer.endRecording();
+
+		assertMatches(alternatives, edit);
+	}
+
+	public void testObjectRemoval() throws Exception {
+		Resource res = getResource(newTestGrammar());
+
+		composer.beginRecording(res);
+		Grammar grammar = (Grammar) res.getContents().get(0);
+		AbstractRule rule = grammar.getRules().get(0);
+		Alternatives alternatives = (Alternatives) rule.getAlternatives();
+		alternatives.getGroups().remove(2);
+		TextEdit edit = composer.endRecording();
+
+		assertMatches(alternatives, edit);
+	}
+
+	public void testObjectReplacement() throws Exception {
+		Resource res = getResource(newTestGrammar());
+
+		composer.beginRecording(res);
+		Grammar grammar = (Grammar) res.getContents().get(0);
+		ParserRule rule = (ParserRule) grammar.getRules().get(0);
+		Keyword keyword = XtextFactory.eINSTANCE.createKeyword();
+		keyword.setValue("baz");
+		rule.setAlternatives(keyword);
+		TextEdit edit = composer.endRecording();
+
+		assertMatches(rule, edit);
+	}
+
+	public void testMultiEdit() throws Exception {
+		Resource res = getResource(newTestGrammar());
+
+		composer.beginRecording(res);
+		Grammar grammar = (Grammar) res.getContents().get(0);
+		ParserRule fooRule = (ParserRule) grammar.getRules().get(0);
+		ParserRule barRule = (ParserRule) grammar.getRules().get(1);
+		Alternatives fooAlternatives = (Alternatives) fooRule.getAlternatives();
+		barRule.setAlternatives(fooAlternatives.getGroups().remove(0));
+		TextEdit edit = composer.endRecording();
+
+		assertTrue(edit instanceof MultiTextEdit);
+		TextEdit[] children = ((MultiTextEdit) edit).getChildren();
+		assertEquals(2, children.length);
+		assertMatches(fooAlternatives, children[0]);
+		assertMatches(barRule, children[1]);
+	}
+
+	private void assertMatches(EObject obj, TextEdit edit) {
+		assertTrue(edit instanceof ReplaceEdit);
+		AbstractNode node = NodeUtil.getNodeAdapter(obj).getParserNode();
+		assertEquals(ParsetreeUtil.getOffset(node), ((ReplaceEdit) edit).getOffset());
+		assertEqualsIgnoringWhitespace(getSerializer().serialize(obj, false), ((ReplaceEdit) edit).getText());
+	}
+
+	private void assertEqualsIgnoringWhitespace(String expected, String actual) {
+		assertEquals(expected.replaceAll("\\s+", " "), actual.replaceAll("\\s+", " "));
+	}
+
+}