updated edits

7 files changed, 248 insertions, 203 deletions

diff --git a/org.eclipse.text/src/org/eclipse/text/edits/Messages.properties b/org.eclipse.text/src/org/eclipse/text/edits/Messages.properties
index 5438395c346..486880f2fbc 100644
--- a/org.eclipse.text/src/org/eclipse/text/edits/Messages.properties
+++ b/org.eclipse.text/src/org/eclipse/text/edits/Messages.properties
@@ -28,4 +28,6 @@ MoveTargetEdit.different_target= Source edit has different target edit.
 MoveTargetEdit.wrong_parent=Source edit must not be the parent of the target.
 
 TextEditProcessor.invalid_length=End position lies outside of document range
-UndoMemento.invalid_length=End position lies outside of document range
+
+UndoEdit.no_children=Can\'t add children to an undo edit
+UndoEdit.can_not_be_added=Can\'t add an undo edit to another edit
diff --git a/org.eclipse.text/src/org/eclipse/text/edits/MultiTextEdit.java b/org.eclipse.text/src/org/eclipse/text/edits/MultiTextEdit.java
index bf720bb15b3..f09faf456b7 100644
--- a/org.eclipse.text/src/org/eclipse/text/edits/MultiTextEdit.java
+++ b/org.eclipse.text/src/org/eclipse/text/edits/MultiTextEdit.java
@@ -58,21 +58,14 @@ public class MultiTextEdit extends TextEdit {
 		fDefined= true;
 	}
 	
-	/**
+	/*
 	 * Copy constructor.
 	 */
-	private MultiTextEdit(MultiTextEdit other) {
+	protected MultiTextEdit(MultiTextEdit other) {
 		super(other);
 	}
 
 	/* non Java-doc
-	 * @see TextEdit#perform
-	 */	
-	/* package */ final void perform(IDocument document) {
-		// do nothing.
-	}
-
-	/* non Java-doc
 	 * @see TextEdit#copy
 	 */	
 	protected TextEdit doCopy() {
@@ -80,16 +73,28 @@ public class MultiTextEdit extends TextEdit {
 		return new MultiTextEdit(this);
 	}
 	
+	/* non Java-doc
+	 * @see TextEdit#perform
+	 */	
+	/* package */ final void perform(IDocument document) {
+		// do nothing.
+	}
+
 	/* package */ void aboutToBeAdded(TextEdit parent) {
-		if (!fDefined) {
-			if (hasChildren()) {
-				IRegion region= getCoverage(getChildren());
-				internalSetOffset(region.getOffset());
-				internalSetLength(region.getLength());
-			} else {
-				internalSetOffset(parent.getOffset());
-				internalSetLength(0);
-			}
+		defineRegion(parent.getOffset());
+	}
+
+	/* package */ void defineRegion(int parentOffset) {
+		if (fDefined)
+			return;
+		if (hasChildren()) {
+			IRegion region= getCoverage(getChildren());
+			internalSetOffset(region.getOffset());
+			internalSetLength(region.getLength());
+		} else {
+			internalSetOffset(parentOffset);
+			internalSetLength(0);
 		}
-	}	
+		fDefined= true;
+	}
 }
diff --git a/org.eclipse.text/src/org/eclipse/text/edits/TextEdit.java b/org.eclipse.text/src/org/eclipse/text/edits/TextEdit.java
index 5cc91929b17..87f899d1e5a 100644
--- a/org.eclipse.text/src/org/eclipse/text/edits/TextEdit.java
+++ b/org.eclipse.text/src/org/eclipse/text/edits/TextEdit.java
@@ -102,6 +102,9 @@ public abstract class TextEdit {
 	 * the point in time when this call is made. Any subsequent changes
 	 * to the edit's offset and length aren't reflected in the returned
 	 * region object.
+	 * <p>
+	 * Creating a region for a deleted edit will result in an assertion
+	 * failure.
 	 * 
 	 * @return the manipulated region
 	 */
@@ -111,7 +114,8 @@ public abstract class TextEdit {
 	
 	/**
 	 * Returns the offset of the edit. An offset is a 0-based 
-	 * character index.
+	 * character index. Returns <code>-1</code> if the edit
+	 * is marked as deleted
 	 * 
 	 * @return the offset of the edit
 	 */
@@ -120,7 +124,8 @@ public abstract class TextEdit {
 	}
 	
 	/**
-	 * Returns the length of the edit.
+	 * Returns the length of the edit. Returns <code>-1</code>
+	 * if the edit is marked as deleted.
 	 * 
 	 * @return the length of the edit
 	 */
@@ -313,6 +318,17 @@ public abstract class TextEdit {
 	}
 	
 	/**
+	 * Returns the size of the managed children.
+	 * 
+	 * @return the size of the children
+	 */
+	public final int getChildrenSize() {
+		if (fChildren == null)
+			return 0;
+		return fChildren.size();
+	}
+	
+	/**
 	 * Returns the text range spawned by the given array of text edits.
 	 * The method requires that the given array contains at least one
 	 * edit. If all edits passed are deleted the method returns <code>
@@ -457,26 +473,10 @@ public abstract class TextEdit {
 	//---- Execution -------------------------------------------------------
 	
 	/**
-	 * Returns whether the edit tree can be applied to the
-	 * given document or not.
-	 * 
-	 * @return <code>true</code> if the edit tree can be
-	 *  applied to the given document. Otherwise <code>false
-	 *  </code> is returned.
-	 */
-	public boolean canBeApplied(IDocument document) {
-		try {
-			TextEditProcessor processor= new TextEditProcessor(document);
-			processor.add(this);
-			return processor.canPerformEdits();
-		} finally {
-			// unconnect from text edit processor
-			fParent= null;
-		}
-	}
-	 
-	/**
-	 * Applies the edit tree rooted by this edit to the given document.
+	 * Applies the edit tree rooted by this edit to the given document. To check
+	 * if the edit tree can be applied to the document either catch <code>
+	 * MalformedTreeException</code> or use <code>TextEditProcessor</code> to
+	 * execute an edit tree.
 	 * 
 	 * @param document the document to be manipulated
 	 * @exception MalformedTreeException is thrown if the tree isn't
@@ -485,14 +485,14 @@ public abstract class TextEdit {
 	 * @exception BadLocationException is thrown if one of the edits
 	 *  in the tree can't be executed. The state of the document is
 	 *  undefined if this exception is thrown.
+	 * 
 	 * @see #checkIntegrity()
 	 * @see #perform(IDocument)
+	 * @see TextEditProcessor#performEdits()
 	 */
-	public final UndoMemento apply(IDocument document) throws MalformedTreeException, BadLocationException {
+	public final UndoEdit apply(IDocument document) throws MalformedTreeException, BadLocationException {
 		try {
-			TextEditProcessor processor= new TextEditProcessor(document);
-			processor.add(this);
-			processor.checkIntegrity();
+			TextEditProcessor processor= new TextEditProcessor(document, this);
 			return processor.performEdits();
 		} finally {
 			// unconnect from text edit processor
@@ -529,6 +529,14 @@ public abstract class TextEdit {
 	/* package */ abstract void perform(IDocument document) throws BadLocationException;
 	
 	
+	/* package */ UndoEdit dispatchPerformEdits(TextEditProcessor processor) throws BadLocationException {
+		return processor.executeDo();
+	}
+	
+	/* package */ void dispatchCheckIntegrity(TextEditProcessor processor) throws MalformedTreeException {
+		processor.checkIntegrityDo();
+	}
+	
 	//---- internal state accessors ----------------------------------------------------------
 	
 	/* package */ void internalSetParent(TextEdit parent) {
@@ -697,7 +705,7 @@ public abstract class TextEdit {
 		}	
 	}
 	
-	private static int getDelta(DocumentEvent event) {
+	/* package */ static int getDelta(DocumentEvent event) {
 		String text= event.getText();
 		return (text == null ? -event.getLength() : text.length()) - event.getLength();
 	}
diff --git a/org.eclipse.text/src/org/eclipse/text/edits/TextEditProcessor.java b/org.eclipse.text/src/org/eclipse/text/edits/TextEditProcessor.java
index c50cb2f9bc6..b6218a7c43d 100644
--- a/org.eclipse.text/src/org/eclipse/text/edits/TextEditProcessor.java
+++ b/org.eclipse.text/src/org/eclipse/text/edits/TextEditProcessor.java
@@ -30,18 +30,29 @@ import org.eclipse.jface.text.IDocument;
 public class TextEditProcessor {
 	
 	private IDocument fDocument;
-	private MultiTextEdit fRoot;
+	private TextEdit fRoot;
+	
+	private boolean fChecked;
+	private MalformedTreeException fException;
 	
 	/**
 	 * Constructs a new edit processor for the given
 	 * document.
 	 * 
 	 * @param document the document to manipulate
+	 * @param root the root of the text edit tree describing
+	 *  the modifications. By passing a text edit a a text edit
+	 *  processor the ownership of the edit is transfered to the
+	 *  text edit processors. Clients must not modify the edit
+	 *  (e.g adding new children) any longer. 
 	 */
-	public TextEditProcessor(IDocument document) {
+	public TextEditProcessor(IDocument document, TextEdit root) {
 		Assert.isNotNull(document);
+		Assert.isNotNull(root);
 		fDocument= document;
-		fRoot= new MultiTextEdit(0, fDocument.getLength()); 
+		fRoot= root;
+		if (fRoot instanceof MultiTextEdit)
+			((MultiTextEdit)fRoot).defineRegion(0);
 	}
 	
 	/**
@@ -63,23 +74,6 @@ public class TextEditProcessor {
 	}
 	
 	/**
-	 * Adds an <code>Edit</code> to this edit processor. Adding an edit
-	 * to an edit processor transfers ownership of the edit to the 
-	 * processor. So after an edit has been added to a processor the 
-	 * creator of the edit <b>must</b> not continue modifying the edit.
-	 * 
-	 * @param edit the edit to add
-	 * @exception MalformedTreeException if the text edit can not be 
-	 *  added to this edit processor.
-	 * 
-	 * @see TextEdit#addChild(TextEdit)
-	 */
-	public void add(TextEdit edit) throws MalformedTreeException {
-		checkIntegrity(edit, fDocument);
-		fRoot.addChild(edit);
-	}
-		
-	/**
 	 * Checks if the processor can execute all its edits.
 	 * 
 	 * @return <code>true</code> if the edits can be executed. Return  <code>false
@@ -88,7 +82,14 @@ public class TextEditProcessor {
 	 *  likely end in a <code>BadLocationException</code>.
 	 */
 	public boolean canPerformEdits() {
-		return checkBufferLength(fRoot, fDocument.getLength()) == null;
+		try {
+			fRoot.dispatchCheckIntegrity(this);
+			fChecked= true;
+		} catch (MalformedTreeException e) {
+			fException= e;
+			return false;
+		}
+		return true;
 	}
 	
 	/**
@@ -102,8 +103,14 @@ public class TextEditProcessor {
 	 *  tree can't be executed. The state of the document is undefined if this 
 	 *  exception is thrown.
 	 */
-	public UndoMemento performEdits() throws MalformedTreeException, BadLocationException {
-		return execute();
+	public UndoEdit performEdits() throws MalformedTreeException, BadLocationException {
+		if (!fChecked) {
+			fRoot.dispatchCheckIntegrity(this);
+		} else {
+			if (fException != null)
+				throw fException;
+		}
+		return fRoot.dispatchPerformEdits(this);
 	}
 
 	/* non Java-doc
@@ -113,49 +120,41 @@ public class TextEditProcessor {
 		return true;
 	}
 		
-	/* protected */ void checkIntegrity() throws MalformedTreeException {
-		TextEdit failure= checkBufferLength(fRoot, fDocument.getLength());
-		if (failure != null) {
-			throw new MalformedTreeException(failure.getParent(), failure, TextEditMessages.getString("TextEditProcessor.invalid_length")); //$NON-NLS-1$
-		}
-	}
+	//---- checking --------------------------------------------------------------------
 	
-	//---- Helper methods ------------------------------------------------------------------------
-		
-	private static TextEdit checkBufferLength(TextEdit root, int bufferLength) {
-		if (root.getExclusiveEnd() > bufferLength)
-			return root;
-		List children= root.internalGetChildren();
-		if (children != null) {
-			for (Iterator iter= children.iterator(); iter.hasNext();) {
-				TextEdit edit= (TextEdit)iter.next();
-				TextEdit failure= null;
-				if ((failure= checkBufferLength(edit, bufferLength)) != null)
-					return failure;
-			}
-		}
-		return null;
+	/* package */ void checkIntegrityDo() throws MalformedTreeException {
+		checkIntegrity(fRoot);
+		if (fRoot.getExclusiveEnd() > fDocument.getLength())
+			throw new MalformedTreeException(null, fRoot, TextEditMessages.getString("TextEditProcessor.invalid_length")); //$NON-NLS-1$
 	}
 	
-	private static void checkIntegrity(TextEdit root, IDocument document) {
+	private static void checkIntegrity(TextEdit root) throws MalformedTreeException {
 		root.checkIntegrity();
 		List children= root.internalGetChildren();
 		if (children != null) {
 			for (Iterator iter= children.iterator(); iter.hasNext();) {
 				TextEdit edit= (TextEdit)iter.next();
-				checkIntegrity(edit, document);
+				checkIntegrity(edit);
 			}
 		}
 	}
 	
-	private UndoMemento execute() throws BadLocationException {
+	/* package */ void checkIntegrityUndo() {
+		if (fRoot.getExclusiveEnd() > fDocument.getLength())
+			throw new MalformedTreeException(null, fRoot, TextEditMessages.getString("TextEditProcessor.invalid_length")); //$NON-NLS-1$
+	}
+	
+	//---- execution --------------------------------------------------------------------
+	
+	/* package */ UndoEdit executeDo() throws BadLocationException {
 		Updater.DoUpdater updater= null;
 		try {
-			updater= Updater.createDoUpdater();
+			updater= Updater.createDoUpdater(fRoot);
 			fDocument.addDocumentListener(updater);
 			updater.push(new TextEdit[] { fRoot });
 			updater.setIndex(0);
 			execute(fRoot, updater);
+			updater.storeRegion();
 			return updater.undo;
 		} finally {
 			if (updater != null)
@@ -178,4 +177,21 @@ public class TextEditProcessor {
 			edit.perform(fDocument);
 		}
 	}
+	
+	/* package */ UndoEdit executeUndo() throws BadLocationException {
+		Updater updater= null;
+		try {
+			updater= Updater.createUndoUpdater(fRoot);
+			fDocument.addDocumentListener(updater);
+			TextEdit[] edits= fRoot.getChildren();
+			for (int i= edits.length - 1; i >= 0; i--) {
+				edits[i].perform(fDocument);
+			}
+			updater.storeRegion();
+			return updater.undo;
+		} finally {
+			if (updater != null)
+				fDocument.removeDocumentListener(updater);
+		}
+	}		
 }
diff --git a/org.eclipse.text/src/org/eclipse/text/edits/UndoEdit.java b/org.eclipse.text/src/org/eclipse/text/edits/UndoEdit.java
new file mode 100644
index 00000000000..ee5f0575648
--- /dev/null
+++ b/org.eclipse.text/src/org/eclipse/text/edits/UndoEdit.java
@@ -0,0 +1,91 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2003 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials 
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.text.edits;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.eclipse.jface.text.BadLocationException;
+import org.eclipse.jface.text.IDocument;
+
+/**
+ * This class encapsulates the reverse changes of an executed text 
+ * edit tree. To apply an undo memento to a document use method
+ * <code>apply(IDocument)</code>.
+ * <p>
+ * Clients can add additional children to an undo edit nor can they
+ * add an undo edit as a child to another edit. Doing so results in 
+ * both cases in a <code>MalformedTreeException<code>.
+ * 
+ * @since 3.0
+ */
+public final class UndoEdit extends TextEdit {
+	
+	/* package */ UndoEdit() {
+		super(0, Integer.MAX_VALUE);
+	}
+	
+	private UndoEdit(UndoEdit other) {
+		super(other);
+	}
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.text.edits.TextEdit#internalAdd(org.eclipse.text.edits.TextEdit)
+	 */
+	/* package */ void internalAdd(TextEdit child) throws MalformedTreeException {
+		throw new MalformedTreeException(null, this, TextEditMessages.getString("UndoEdit.no_children")); //$NON-NLS-1$
+	}
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.text.edits.MultiTextEdit#aboutToBeAdded(org.eclipse.text.edits.TextEdit)
+	 */
+	/* package */ void aboutToBeAdded(TextEdit parent) {
+		throw new MalformedTreeException(parent, this, TextEditMessages.getString("UndoEdit.can_not_be_added")); //$NON-NLS-1$
+	}
+
+	/* package */ UndoEdit dispatchPerformEdits(TextEditProcessor processor) throws BadLocationException {
+		return processor.executeUndo();
+	}
+	
+	/* package */ void dispatchCheckIntegrity(TextEditProcessor processor) throws MalformedTreeException {
+		processor.checkIntegrityUndo();
+	}
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.text.edits.TextEdit#doCopy()
+	 */
+	protected TextEdit doCopy() {
+		return new UndoEdit(this);
+	}
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.text.edits.TextEdit#perform(org.eclipse.jface.text.IDocument)
+	 */
+	void perform(IDocument document) throws BadLocationException {
+		// do nothing. Only the children modify the
+		// document
+	}
+	
+	/* package */ void add(ReplaceEdit edit) {
+		List children= internalGetChildren();
+		if (children == null) {
+			children= new ArrayList(2);
+			internalSetChildren(children);
+		}
+		children.add(edit);
+	}
+	
+	/* package */ void defineRegion(int offset, int length) {
+		internalSetOffset(offset);
+		internalSetLength(length);
+	}
+}
+
diff --git a/org.eclipse.text/src/org/eclipse/text/edits/UndoMemento.java b/org.eclipse.text/src/org/eclipse/text/edits/UndoMemento.java
deleted file mode 100644
index d9de7b6db5e..00000000000
--- a/org.eclipse.text/src/org/eclipse/text/edits/UndoMemento.java
+++ /dev/null
@@ -1,101 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2000, 2003 IBM Corporation and others.
- * All rights reserved. This program and the accompanying materials 
- * are made available under the terms of the Common Public License v1.0
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/cpl-v10.html
- * 
- * Contributors:
- *     IBM Corporation - initial API and implementation
- *******************************************************************************/
-package org.eclipse.text.edits;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import org.eclipse.jface.text.Assert;
-import org.eclipse.jface.text.BadLocationException;
-import org.eclipse.jface.text.IDocument;
-
-/**
- * This class encapsulates the reverse changes of an executed text 
- * edit tree. To apply an undo memento to a document use method
- * <code>apply(IDocument)</code>.
- */
-public final class UndoMemento {
-
-	private List fEdits;
-	
-	/**
-	 * Returns whether this undo memento can be applied to the
-	 * given document or not.
-	 * 
-	 * @return <code>true</code> if the undo memento can be
-	 *  applied to the given document. Otherwise <code>false
-	 *  </code> is returned.
-	 */
-	public boolean canBeApplied(IDocument document) {
-		Assert.isNotNull(document);
-		return checkBufferLength(document.getLength()) != null;
-	}
-	 
-	/**
-	 * Applies this undo memento to the given document.
-	 * 
-	 * @param document the document to be manipulated
-	 * 
-	 * @exception MalformedTreeException is thrown if the undo isn't
-	 *  in a valid state. This exception is thrown before any edit
-	 *  is executed. So the document is still in its original state.
-	 * @exception BadLocationException is thrown if one of the edits
-	 *  of the undo can't be executed. The state of the document is
-	 *  undefined if this exception is thrown.
-	 * 
-	 * @see TextEdit#apply(IDocument)
-	 */ 
-	public UndoMemento apply(IDocument document) throws MalformedTreeException, BadLocationException {
-		Assert.isNotNull(document);
-		TextEdit failure= checkBufferLength(document.getLength());
-		if (failure != null)
-			throw new MalformedTreeException(failure.getParent(), failure, TextEditMessages.getString("UndoMemento.invalid_length")); //$NON-NLS-1$
-		return perform(document);		
-	}
-
-	/* package */ UndoMemento() {
-		fEdits= new ArrayList(5);
-	}
-	
-	/* package */ void add(ReplaceEdit edit) {
-		fEdits.add(edit);
-	}
-
-	private TextEdit checkBufferLength(int bufferLength) {
-		for (int i= fEdits.size() - 1; i >= 0; i--) {
-			ReplaceEdit edit= (ReplaceEdit)fEdits.get(i);
-			if (edit.getExclusiveEnd() > bufferLength)
-				return edit;
-			bufferLength+= getDelta(edit);
-		}
-		return null;
-	}
-		
-	private UndoMemento perform(IDocument document) throws BadLocationException {
-		Updater updater= null;
-		try {
-			updater= Updater.createUndoUpdater();
-			document.addDocumentListener(updater);
-			for (int i= fEdits.size() - 1; i >= 0; i--) {
-				((TextEdit)fEdits.get(i)).perform(document);
-			}
-			return updater.undo;
-		} finally {
-			if (updater != null)
-				document.removeDocumentListener(updater);
-		}
-	}
-	
-	private int getDelta(ReplaceEdit edit) {
-		return edit.getText().length() - edit.getLength();
-	}
-}
-
diff --git a/org.eclipse.text/src/org/eclipse/text/edits/Updater.java b/org.eclipse.text/src/org/eclipse/text/edits/Updater.java
index 2ad0ed80a3b..45887593d86 100644
--- a/org.eclipse.text/src/org/eclipse/text/edits/Updater.java
+++ b/org.eclipse.text/src/org/eclipse/text/edits/Updater.java
@@ -16,22 +16,26 @@ import org.eclipse.jface.text.DocumentEvent;
 import org.eclipse.jface.text.IDocumentListener;
 
 
-/* package */ class Updater implements IDocumentListener {
+/* package */ abstract class Updater implements IDocumentListener {
 
-	protected UndoMemento undo= new UndoMemento();
+	protected UndoEdit undo= new UndoEdit();
 	
-	public static Updater createUndoUpdater() {
-		return new Updater();
+	public static Updater createUndoUpdater(TextEdit root) {
+		return new UndoUpdater(root);
 	}
 
-	public static DoUpdater createDoUpdater() {
-		return new DoUpdater();
+	public static DoUpdater createDoUpdater(TextEdit root) {
+		return new DoUpdater(root);
 	}
 		
 	public static class DoUpdater extends Updater {
+		private TextEdit fRoot;
 		private TextEdit fActiveEdit;
 		private TreeIterationInfo fIterationInfo= new TreeIterationInfo();
 		
+		public DoUpdater(TextEdit root) {
+			fRoot= root;
+		}
 		public void push(TextEdit[] edits) {
 			fIterationInfo.push(edits);
 		}
@@ -47,6 +51,24 @@ import org.eclipse.jface.text.IDocumentListener;
 		public void documentChanged(DocumentEvent event) {
 			fActiveEdit.update(event, fIterationInfo);
 		}
+		public void storeRegion() {
+			undo.defineRegion(fRoot.getOffset(), fRoot.getLength());
+		}
+	}
+	
+	public static class UndoUpdater extends Updater {
+		private int fOffset;
+		private int fLength;
+		private UndoUpdater(TextEdit root) {
+			fOffset= root.getOffset();
+			fLength= root.getLength();
+		}
+		public void documentChanged(DocumentEvent event) {
+			fLength+= TextEdit.getDelta(event);
+		}
+		public void storeRegion() {
+			undo.defineRegion(fOffset, fLength);
+		}
 	}
 
 	protected Updater() {
@@ -66,5 +88,7 @@ import org.eclipse.jface.text.IDocumentListener;
 	}
 	
 	public void documentChanged(DocumentEvent event) {
-	}	
+	}
+	
+	public abstract void storeRegion();	
 }