ltk/org.eclipse.statet.ltk.ui/src/org/eclipse/statet/ecommons/text/ui/assist/LinkedModeBracketLevel.java - statet/org.eclipse.statet-ltk - Git at Google

 /*=============================================================================#
  # Copyright (c) 2007, 2021 Stephan Wahlbrink and others.
  #
  # This program and the accompanying materials are made available under the
  # terms of the Eclipse Public License 2.0 which is available at
  # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
  # which is available at https://www.apache.org/licenses/LICENSE-2.0.
  #
  # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
  #
  # Contributors:
  #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
  #=============================================================================*/

 package org.eclipse.statet.ecommons.text.ui.assist;

 import static org.eclipse.statet.ltk.ui.LtkUI.BUNDLE_ID;

 import java.util.List;

 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.BadPositionCategoryException;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.IDocumentExtension;
 import org.eclipse.jface.text.IDocumentListener;
 import org.eclipse.jface.text.IPositionUpdater;
 import org.eclipse.jface.text.Position;
 import org.eclipse.jface.text.TextUtilities;
 import org.eclipse.jface.text.link.ILinkedModeListener;
 import org.eclipse.jface.text.link.LinkedModeModel;
 import org.eclipse.jface.text.link.LinkedModeUI.ExitFlags;
 import org.eclipse.jface.text.link.LinkedModeUI.IExitPolicy;
 import org.eclipse.jface.text.link.LinkedPosition;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.StyledText;
 import org.eclipse.swt.events.VerifyEvent;
 import org.eclipse.ui.statushandlers.StatusManager;

 import org.eclipse.statet.jcommons.lang.NonNullByDefault;
 import org.eclipse.statet.jcommons.lang.Nullable;

 import org.eclipse.statet.ecommons.text.core.DocumentEnhancement;
 import org.eclipse.statet.ecommons.text.core.sections.DocContentSections;
 import org.eclipse.statet.ecommons.text.core.util.ExclusivePositionUpdater;
 import org.eclipse.statet.ecommons.ui.swt.WidgetUtils;


 /**
  * Linked mode exit policy for auto inserted pairs like brackets or quotes.
  */
 @NonNullByDefault
 public abstract class LinkedModeBracketLevel implements IExitPolicy, ILinkedModeListener {


 	public static final int CONSOLE_MODE=                   0x00000001;
 	public static final int AUTODELETE=                     1 << 24;


 	private static final String POSITION_CATEGORY= "org.eclipse.statet.ecommons.text.ui.BracketLevel"; //$NON-NLS-1$
 	private static final IPositionUpdater POSITION_UPDATER= new ExclusivePositionUpdater(POSITION_CATEGORY);

 	private static class DocumentData {

 		private int counter;

 	}


 	public static abstract class InBracketPosition extends LinkedPosition {


 		private Position openPos;
 		private Position closePos;


 		@SuppressWarnings("null")
 		public InBracketPosition(
 				final IDocument document, final int offset, final int length, final int sequence) {
 			super(document, offset, length, sequence);
 		}


 		public abstract char getOpenChar();

 		public abstract char getCloseChar();

 		protected int getCloseLength() {
 			return 1;
 		}


 		void createOpenClosePositions(final IDocument document)
 				throws BadPositionCategoryException, BadLocationException {
 			{	final Position pos= new Position(getOffset() - 1, 1);
 				assert (document.getChar(pos.getOffset()) == getOpenChar());
 				document.addPosition(POSITION_CATEGORY, pos);
 				this.openPos= pos;
 			}
 			{	final Position pos= new Position(getOffset() + getLength(), 1);
 				assert (document.getChar(pos.getOffset()) == getCloseChar());
 				document.addPosition(POSITION_CATEGORY, pos);
 				this.closePos= pos;
 			}
 		}

 		boolean hasOpenClosePositions() {
 			return (this.openPos != null && this.closePos != null);
 		}

 		Position getOpenPosition() {
 			return this.openPos;
 		}

 		Position getClosePosition() {
 			return this.closePos;
 		}


 		/**
 		 * Whether CR key event should insert new line
 		 *
 		 * Default returns always <code>true</code>.
 		 *
 		 * @param charOffset event offset
 		 * @return
 		 * @throws BadLocationException
 		 */
 		protected boolean insertCR(final int charOffset) throws BadLocationException {
 			return true;
 		}

 		protected boolean isEscaped(final int offset) throws BadLocationException {
 			return false;
 		}

 		/**
 		 * If the char is part of the existing end of the language element
 		 * (closing bracket).
 		 * If <code>true</code>, the input is ignored but the caret is updated.
 		 *
 		 * @param level the bracket level
 		 * @param charOffset event offset
 		 * @return <code>true</code> if valid close offset otherwise <code>false</code>
 		 * @throws BadLocationException
 		 */
 		public boolean matchesOpen(final LinkedModeBracketLevel level, final int offset, final char character)
 				throws BadLocationException {
 			return (getOffset() == offset + 1 && getOpenChar() == character
 					&& !isEscaped(offset) );
 		}

 		/**
 		 * If the char is part of the existing end of the language element
 		 * (closing bracket).
 		 * If <code>true</code>, the input is ignored but the caret is updated.
 		 *
 		 * @param level the bracket level
 		 * @param charOffset event offset
 		 * @return <code>true</code> if valid close offset otherwise <code>false</code>
 		 * @throws BadLocationException
 		 */
 		public boolean matchesClose(final LinkedModeBracketLevel level, final int offset, final char character)
 				throws BadLocationException {
 			return (getOffset() + getLength() == offset
 					&& getCloseLength() == 1 && getCloseChar() == character
 					&& level.getPartitionType(getOffset()) == level.getPartitionType(offset)
 					&& !isEscaped(offset) );
 		}

 	}


 	private final IDocument document;
 	private final DocContentSections documentContentInfo;

 	private final List<? extends LinkedPosition> positions;
 	private final int mode;

 	private boolean hasOwnPositions;
 	private @Nullable DocumentData documentData;


 	public LinkedModeBracketLevel(final LinkedModeModel model,
 			final IDocument document, final DocContentSections documentContentInfo,
 			final List<? extends LinkedPosition> positions, final int mode) {
 		this.document= document;
 		this.documentContentInfo= documentContentInfo;

 		this.positions= positions;
 		this.mode= mode;

 		init(model);
 	}

 	protected void init(final LinkedModeModel model) {
 		if ((this.mode & AUTODELETE) != 0 && this.document instanceof IDocumentExtension) {
 			final DocumentData documentData= fetchDocumentData();
 			if (documentData != null) {
 				this.documentData= documentData;
 				try {
 					model.addLinkingListener(this);

 					setupPositionCategory(documentData);

 					for (final LinkedPosition position : this.positions) {
 						if (position instanceof InBracketPosition) {
 							final InBracketPosition inPos= (InBracketPosition) position;
 							inPos.createOpenClosePositions(this.document);
 						}
 					}
 				}
 				catch (final Exception e) {
 					StatusManager.getManager().handle(new Status(IStatus.ERROR, BUNDLE_ID,
 							"An error occurred when preparing auto-undo of autoedit insertions.",
 							e ));
 				}
 			}
 		}
 	}


 	private void setupPositionCategory(final DocumentData documentData) {
 		this.hasOwnPositions= true;
 		documentData.counter++;

 		if (!this.document.containsPositionCategory(POSITION_CATEGORY)) {
 			this.document.addPositionCategory(POSITION_CATEGORY);
 			this.document.addPositionUpdater(POSITION_UPDATER);
 		}
 	}

 	private void disposePositionCategory() {
 		if (this.document.containsPositionCategory(POSITION_CATEGORY)) {
 			try {
 				this.document.removePositionCategory(POSITION_CATEGORY);
 				this.document.removePositionUpdater(POSITION_UPDATER);
 			}
 			catch (final BadPositionCategoryException e) {}
 		}
 	}

 	protected final DocumentData fetchDocumentData() {
 		final DocumentEnhancement documentEnhancement= DocumentEnhancement.get(this.document);
 		DocumentData data= (DocumentData) documentEnhancement.getData(POSITION_CATEGORY);
 		if (data == null) {
 			data= new DocumentData();
 			documentEnhancement.setData(POSITION_CATEGORY, data);
 		}
 		return data;
 	}


 	protected final int getPositionIdx(final int offset) {
 		for (int i= 0; i < this.positions.size(); i++) {
 			if (this.positions.get(i).includes(offset)) {
 				return i;
 			}
 		}
 		return -1;
 	}


 	@Override
 	public @Nullable ExitFlags doExit(final LinkedModeModel model, final VerifyEvent event,
 			final int offset, final int length) {
 		try {
 			final int posIdx= getPositionIdx(offset);
 			final InBracketPosition inPos= (posIdx >= 0 && this.positions.get(posIdx) instanceof InBracketPosition) ?
 					(InBracketPosition) this.positions.get(posIdx) : null;
 			switch (event.character) {
 			case 0x0A: // cr
 			case 0x0D:
 				if ((this.mode & CONSOLE_MODE) != 0) {
 					return new ExitFlags(ILinkedModeListener.EXIT_ALL, true);
 				}
 				if (length > 0 || (inPos != null && inPos.insertCR(offset))) {
 					return new ExitFlags(ILinkedModeListener.NONE, true);
 				}
 				return null;
 			case SWT.BS: // backspace
 				if ((this.mode & AUTODELETE) != 0
 						&& !this.hasOwnPositions
 						&& length == 0
 						&& inPos != null && inPos.getOffset() == offset && inPos.getLength() == 0) {
 					int count= 2;
 					for (int i= posIdx + 1; i < this.positions.size(); i++) {
 						final LinkedPosition position= this.positions.get(i);
 						if (position instanceof InBracketPosition) {
 							if (position.getOffset() == offset + count
 									&& position.getLength() == 0) {
 								count+= 2;
 							}
 							else {
 								break;
 							}
 						}
 					}
 					this.document.replace(offset - 1, count, ""); //$NON-NLS-1$
 					return new ExitFlags(ILinkedModeListener.NONE, false);
 				}
 				return null;
 			}
 			// don't enter the character if if its the closing peer
 			if (length == 0 && inPos != null && inPos.matchesClose(this, offset, event.character) ) {
 				skipChars(event, 1);
 				if (posIdx == this.positions.size() - 1) {
 					return new ExitFlags(ILinkedModeListener.NONE, false);
 				}
 				else {
 					return null;
 				}
 			}
 			// don't enter the character if if its the opening peer
 			if (length == 0
 					&& (posIdx < 0 || !this.positions.get(posIdx).includes(offset + 1)) ) {
 				final int nextIdx= getPositionIdx(offset + 1);
 				if (nextIdx > 0 && this.positions.get(nextIdx) instanceof InBracketPosition
 						&& ((InBracketPosition) this.positions.get(nextIdx)).matchesOpen(this, offset, event.character) ) {
 					skipChars(event, 1);
 					return null;
 				}
 			}
 		}
 		catch (final BadLocationException e) {
 		}
 		return null;
 	}

 	@Override
 	public void resume(final LinkedModeModel model, final int flags) {
 	}

 	@Override
 	public void suspend(final LinkedModeModel model) {
 	}

 	@Override
 	public void left(final LinkedModeModel model, final int flags) {
 		if ((this.mode & AUTODELETE) != 0
 				&& this.hasOwnPositions
 				&& flags == ILinkedModeListener.EXTERNAL_MODIFICATION) {
 			((IDocumentExtension) this.document).registerPostNotificationReplace(null, new IDocumentExtension.IReplace() {
 				@Override
 				public void perform(final IDocument document, final @Nullable IDocumentListener owner) {
 					checkOwnPositionCleanup();

 					try {
 						int startOffset= -1;
 						int endOffset= -1;
 						for (final LinkedPosition position : LinkedModeBracketLevel.this.positions) {
 							if (position instanceof InBracketPosition) {
 								final InBracketPosition inPos= (InBracketPosition) position;
 								if (!inPos.hasOpenClosePositions()) {
 									break;
 								}
 								if (startOffset < 0) {
 									if ((inPos.getOpenPosition().isDeleted() || inPos.getOpenPosition().getLength() == 0)
 											&& (inPos.isDeleted() || inPos.getLength() == 0)
 											&& !inPos.getClosePosition().isDeleted() ) {
 										startOffset= inPos.getClosePosition().getOffset();
 										endOffset= inPos.getClosePosition().getOffset() + inPos.getCloseLength();
 									}
 								}
 								else {
 									if (inPos.getOpenPosition().getOffset() == endOffset
 											&& !inPos.getOpenPosition().isDeleted()
 											&& (inPos.isDeleted() || inPos.getLength() == 0)
 											&& !inPos.getClosePosition().isDeleted() ) {
 										endOffset= inPos.getClosePosition().getOffset() + inPos.getCloseLength();
 									}
 									else {
 										break;
 									}
 								}
 							}
 						}
 						if (startOffset >= 0 && endOffset > startOffset) {
 								document.replace(startOffset, endOffset - startOffset, ""); //$NON-NLS-1$
 						}
 					}
 					catch (final Exception e) {
 						StatusManager.getManager().handle(new Status(IStatus.ERROR, BUNDLE_ID,
 								"An error occurred when performing auto-undo of autoedit insertions.",
 								e ));
 					}
 				}
 			});
 			return;
 		}

 		checkOwnPositionCleanup();
 	}

 	private void checkOwnPositionCleanup() {
 		final DocumentData documentData= this.documentData;
 		if (documentData == null) {
 			return;
 		}
 		if (this.hasOwnPositions) {
 			documentData.counter--;

 			if (documentData.counter == 0) {
 				disposePositionCategory();
 			}
 		}
 	}

 	private void skipChars(final VerifyEvent event, final int n) {
 		event.doit= false;
 		final StyledText styledText= (StyledText)event.widget;
 		WidgetUtils.setSelection(styledText, styledText.getCaretOffset() + n, event.time);
 	}


 	/**
 	 * Utility method returning the partition type at the given offset
 	 *
 	 * @param offset
 	 * @return the partition type
 	 * @throws BadLocationException
 	 */
 	public String getPartitionType(final int offset) throws BadLocationException {
 		return TextUtilities.getPartition(this.document, this.documentContentInfo.getPartitioning(),
 				offset, true).getType();
 	}

 }
	/*=============================================================================#
	# Copyright (c) 2007, 2021 Stephan Wahlbrink and others.
	#
	# This program and the accompanying materials are made available under the
	# terms of the Eclipse Public License 2.0 which is available at
	# https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
	# which is available at https://www.apache.org/licenses/LICENSE-2.0.
	#
	# SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
	#
	# Contributors:
	# Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
	#=============================================================================*/

	package org.eclipse.statet.ecommons.text.ui.assist;

	import static org.eclipse.statet.ltk.ui.LtkUI.BUNDLE_ID;

	import java.util.List;

	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Status;
	import org.eclipse.jface.text.BadLocationException;
	import org.eclipse.jface.text.BadPositionCategoryException;
	import org.eclipse.jface.text.IDocument;
	import org.eclipse.jface.text.IDocumentExtension;
	import org.eclipse.jface.text.IDocumentListener;
	import org.eclipse.jface.text.IPositionUpdater;
	import org.eclipse.jface.text.Position;
	import org.eclipse.jface.text.TextUtilities;
	import org.eclipse.jface.text.link.ILinkedModeListener;
	import org.eclipse.jface.text.link.LinkedModeModel;
	import org.eclipse.jface.text.link.LinkedModeUI.ExitFlags;
	import org.eclipse.jface.text.link.LinkedModeUI.IExitPolicy;
	import org.eclipse.jface.text.link.LinkedPosition;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.custom.StyledText;
	import org.eclipse.swt.events.VerifyEvent;
	import org.eclipse.ui.statushandlers.StatusManager;

	import org.eclipse.statet.jcommons.lang.NonNullByDefault;
	import org.eclipse.statet.jcommons.lang.Nullable;

	import org.eclipse.statet.ecommons.text.core.DocumentEnhancement;
	import org.eclipse.statet.ecommons.text.core.sections.DocContentSections;
	import org.eclipse.statet.ecommons.text.core.util.ExclusivePositionUpdater;
	import org.eclipse.statet.ecommons.ui.swt.WidgetUtils;


	/**
	* Linked mode exit policy for auto inserted pairs like brackets or quotes.
	*/
	@NonNullByDefault
	public abstract class LinkedModeBracketLevel implements IExitPolicy, ILinkedModeListener {


	public static final int CONSOLE_MODE= 0x00000001;
	public static final int AUTODELETE= 1 << 24;


	private static final String POSITION_CATEGORY= "org.eclipse.statet.ecommons.text.ui.BracketLevel"; //$NON-NLS-1$
	private static final IPositionUpdater POSITION_UPDATER= new ExclusivePositionUpdater(POSITION_CATEGORY);

	private static class DocumentData {

	private int counter;

	}


	public static abstract class InBracketPosition extends LinkedPosition {


	private Position openPos;
	private Position closePos;


	@SuppressWarnings("null")
	public InBracketPosition(
	final IDocument document, final int offset, final int length, final int sequence) {
	super(document, offset, length, sequence);
	}


	public abstract char getOpenChar();

	public abstract char getCloseChar();

	protected int getCloseLength() {
	return 1;
	}


	void createOpenClosePositions(final IDocument document)
	throws BadPositionCategoryException, BadLocationException {
	{ final Position pos= new Position(getOffset() - 1, 1);
	assert (document.getChar(pos.getOffset()) == getOpenChar());
	document.addPosition(POSITION_CATEGORY, pos);
	this.openPos= pos;
	}
	{ final Position pos= new Position(getOffset() + getLength(), 1);
	assert (document.getChar(pos.getOffset()) == getCloseChar());
	document.addPosition(POSITION_CATEGORY, pos);
	this.closePos= pos;
	}
	}

	boolean hasOpenClosePositions() {
	return (this.openPos != null && this.closePos != null);
	}

	Position getOpenPosition() {
	return this.openPos;
	}

	Position getClosePosition() {
	return this.closePos;
	}


	/**
	* Whether CR key event should insert new line
	*
	* Default returns always <code>true</code>.
	*
	* @param charOffset event offset
	* @return
	* @throws BadLocationException
	*/
	protected boolean insertCR(final int charOffset) throws BadLocationException {
	return true;
	}

	protected boolean isEscaped(final int offset) throws BadLocationException {
	return false;
	}

	/**
	* If the char is part of the existing end of the language element
	* (closing bracket).
	* If <code>true</code>, the input is ignored but the caret is updated.
	*
	* @param level the bracket level
	* @param charOffset event offset
	* @return <code>true</code> if valid close offset otherwise <code>false</code>
	* @throws BadLocationException
	*/
	public boolean matchesOpen(final LinkedModeBracketLevel level, final int offset, final char character)
	throws BadLocationException {
	return (getOffset() == offset + 1 && getOpenChar() == character
	&& !isEscaped(offset) );
	}

	/**
	* If the char is part of the existing end of the language element
	* (closing bracket).
	* If <code>true</code>, the input is ignored but the caret is updated.
	*
	* @param level the bracket level
	* @param charOffset event offset
	* @return <code>true</code> if valid close offset otherwise <code>false</code>
	* @throws BadLocationException
	*/
	public boolean matchesClose(final LinkedModeBracketLevel level, final int offset, final char character)
	throws BadLocationException {
	return (getOffset() + getLength() == offset
	&& getCloseLength() == 1 && getCloseChar() == character
	&& level.getPartitionType(getOffset()) == level.getPartitionType(offset)
	&& !isEscaped(offset) );
	}

	}


	private final IDocument document;
	private final DocContentSections documentContentInfo;

	private final List<? extends LinkedPosition> positions;
	private final int mode;

	private boolean hasOwnPositions;
	private @Nullable DocumentData documentData;


	public LinkedModeBracketLevel(final LinkedModeModel model,
	final IDocument document, final DocContentSections documentContentInfo,
	final List<? extends LinkedPosition> positions, final int mode) {
	this.document= document;
	this.documentContentInfo= documentContentInfo;

	this.positions= positions;
	this.mode= mode;

	init(model);
	}

	protected void init(final LinkedModeModel model) {
	if ((this.mode & AUTODELETE) != 0 && this.document instanceof IDocumentExtension) {
	final DocumentData documentData= fetchDocumentData();
	if (documentData != null) {
	this.documentData= documentData;
	try {
	model.addLinkingListener(this);

	setupPositionCategory(documentData);

	for (final LinkedPosition position : this.positions) {
	if (position instanceof InBracketPosition) {
	final InBracketPosition inPos= (InBracketPosition) position;
	inPos.createOpenClosePositions(this.document);
	}
	}
	}
	catch (final Exception e) {
	StatusManager.getManager().handle(new Status(IStatus.ERROR, BUNDLE_ID,
	"An error occurred when preparing auto-undo of autoedit insertions.",
	e ));
	}
	}
	}
	}


	private void setupPositionCategory(final DocumentData documentData) {
	this.hasOwnPositions= true;
	documentData.counter++;

	if (!this.document.containsPositionCategory(POSITION_CATEGORY)) {
	this.document.addPositionCategory(POSITION_CATEGORY);
	this.document.addPositionUpdater(POSITION_UPDATER);
	}
	}

	private void disposePositionCategory() {
	if (this.document.containsPositionCategory(POSITION_CATEGORY)) {
	try {
	this.document.removePositionCategory(POSITION_CATEGORY);
	this.document.removePositionUpdater(POSITION_UPDATER);
	}
	catch (final BadPositionCategoryException e) {}
	}
	}

	protected final DocumentData fetchDocumentData() {
	final DocumentEnhancement documentEnhancement= DocumentEnhancement.get(this.document);
	DocumentData data= (DocumentData) documentEnhancement.getData(POSITION_CATEGORY);
	if (data == null) {
	data= new DocumentData();
	documentEnhancement.setData(POSITION_CATEGORY, data);
	}
	return data;
	}


	protected final int getPositionIdx(final int offset) {
	for (int i= 0; i < this.positions.size(); i++) {
	if (this.positions.get(i).includes(offset)) {
	return i;
	}
	}
	return -1;
	}


	@Override
	public @Nullable ExitFlags doExit(final LinkedModeModel model, final VerifyEvent event,
	final int offset, final int length) {
	try {
	final int posIdx= getPositionIdx(offset);
	final InBracketPosition inPos= (posIdx >= 0 && this.positions.get(posIdx) instanceof InBracketPosition) ?
	(InBracketPosition) this.positions.get(posIdx) : null;
	switch (event.character) {
	case 0x0A: // cr
	case 0x0D:
	if ((this.mode & CONSOLE_MODE) != 0) {
	return new ExitFlags(ILinkedModeListener.EXIT_ALL, true);
	}
	if (length > 0 \|\| (inPos != null && inPos.insertCR(offset))) {
	return new ExitFlags(ILinkedModeListener.NONE, true);
	}
	return null;
	case SWT.BS: // backspace
	if ((this.mode & AUTODELETE) != 0
	&& !this.hasOwnPositions
	&& length == 0
	&& inPos != null && inPos.getOffset() == offset && inPos.getLength() == 0) {
	int count= 2;
	for (int i= posIdx + 1; i < this.positions.size(); i++) {
	final LinkedPosition position= this.positions.get(i);
	if (position instanceof InBracketPosition) {
	if (position.getOffset() == offset + count
	&& position.getLength() == 0) {
	count+= 2;
	}
	else {
	break;
	}
	}
	}
	this.document.replace(offset - 1, count, ""); //$NON-NLS-1$
	return new ExitFlags(ILinkedModeListener.NONE, false);
	}
	return null;
	}
	// don't enter the character if if its the closing peer
	if (length == 0 && inPos != null && inPos.matchesClose(this, offset, event.character) ) {
	skipChars(event, 1);
	if (posIdx == this.positions.size() - 1) {
	return new ExitFlags(ILinkedModeListener.NONE, false);
	}
	else {
	return null;
	}
	}
	// don't enter the character if if its the opening peer
	if (length == 0
	&& (posIdx < 0 \|\| !this.positions.get(posIdx).includes(offset + 1)) ) {
	final int nextIdx= getPositionIdx(offset + 1);
	if (nextIdx > 0 && this.positions.get(nextIdx) instanceof InBracketPosition
	&& ((InBracketPosition) this.positions.get(nextIdx)).matchesOpen(this, offset, event.character) ) {
	skipChars(event, 1);
	return null;
	}
	}
	}
	catch (final BadLocationException e) {
	}
	return null;
	}

	@Override
	public void resume(final LinkedModeModel model, final int flags) {
	}

	@Override
	public void suspend(final LinkedModeModel model) {
	}

	@Override
	public void left(final LinkedModeModel model, final int flags) {
	if ((this.mode & AUTODELETE) != 0
	&& this.hasOwnPositions
	&& flags == ILinkedModeListener.EXTERNAL_MODIFICATION) {
	((IDocumentExtension) this.document).registerPostNotificationReplace(null, new IDocumentExtension.IReplace() {
	@Override
	public void perform(final IDocument document, final @Nullable IDocumentListener owner) {
	checkOwnPositionCleanup();

	try {
	int startOffset= -1;
	int endOffset= -1;
	for (final LinkedPosition position : LinkedModeBracketLevel.this.positions) {
	if (position instanceof InBracketPosition) {
	final InBracketPosition inPos= (InBracketPosition) position;
	if (!inPos.hasOpenClosePositions()) {
	break;
	}
	if (startOffset < 0) {
	if ((inPos.getOpenPosition().isDeleted() \|\| inPos.getOpenPosition().getLength() == 0)
	&& (inPos.isDeleted() \|\| inPos.getLength() == 0)
	&& !inPos.getClosePosition().isDeleted() ) {
	startOffset= inPos.getClosePosition().getOffset();
	endOffset= inPos.getClosePosition().getOffset() + inPos.getCloseLength();
	}
	}
	else {
	if (inPos.getOpenPosition().getOffset() == endOffset
	&& !inPos.getOpenPosition().isDeleted()
	&& (inPos.isDeleted() \|\| inPos.getLength() == 0)
	&& !inPos.getClosePosition().isDeleted() ) {
	endOffset= inPos.getClosePosition().getOffset() + inPos.getCloseLength();
	}
	else {
	break;
	}
	}
	}
	}
	if (startOffset >= 0 && endOffset > startOffset) {
	document.replace(startOffset, endOffset - startOffset, ""); //$NON-NLS-1$
	}
	}
	catch (final Exception e) {
	StatusManager.getManager().handle(new Status(IStatus.ERROR, BUNDLE_ID,
	"An error occurred when performing auto-undo of autoedit insertions.",
	e ));
	}
	}
	});
	return;
	}

	checkOwnPositionCleanup();
	}

	private void checkOwnPositionCleanup() {
	final DocumentData documentData= this.documentData;
	if (documentData == null) {
	return;
	}
	if (this.hasOwnPositions) {
	documentData.counter--;

	if (documentData.counter == 0) {
	disposePositionCategory();
	}
	}
	}

	private void skipChars(final VerifyEvent event, final int n) {
	event.doit= false;
	final StyledText styledText= (StyledText)event.widget;
	WidgetUtils.setSelection(styledText, styledText.getCaretOffset() + n, event.time);
	}


	/**
	* Utility method returning the partition type at the given offset
	*
	* @param offset
	* @return the partition type
	* @throws BadLocationException
	*/
	public String getPartitionType(final int offset) throws BadLocationException {
	return TextUtilities.getPartition(this.document, this.documentContentInfo.getPartitioning(),
	offset, true).getType();
	}

	}