docmlet/org.eclipse.statet.docmlet.tex.ui/src/org/eclipse/statet/internal/docmlet/tex/ui/editors/LtxCommandCompletionProposal.java - statet/org.eclipse.statet-docmlet - Git at Google

 /*=============================================================================#
  # Copyright (c) 2009, 2019 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.internal.docmlet.tex.ui.editors;

 import static org.eclipse.statet.jcommons.lang.ObjectUtils.nonNullAssert;

 import java.util.ArrayList;
 import java.util.List;

 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.DocumentEvent;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.IDocumentListener;
 import org.eclipse.jface.text.TextSelection;
 import org.eclipse.jface.text.contentassist.BoldStylerProvider;
 import org.eclipse.jface.text.link.LinkedModeModel;
 import org.eclipse.jface.text.link.LinkedModeUI;
 import org.eclipse.jface.text.link.LinkedPosition;
 import org.eclipse.jface.text.link.LinkedPositionGroup;
 import org.eclipse.jface.text.source.SourceViewer;
 import org.eclipse.jface.viewers.StyledString;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.VerifyKeyListener;
 import org.eclipse.swt.events.VerifyEvent;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.widgets.Display;

 import org.eclipse.statet.jcommons.collections.IntArrayList;
 import org.eclipse.statet.jcommons.collections.IntIntervalArrays;
 import org.eclipse.statet.jcommons.collections.IntList;
 import org.eclipse.statet.jcommons.lang.NonNullByDefault;
 import org.eclipse.statet.jcommons.text.core.SearchPattern;

 import org.eclipse.statet.ecommons.text.ITokenScanner;
 import org.eclipse.statet.ecommons.text.ui.BracketLevel;
 import org.eclipse.statet.ecommons.ui.util.UIAccess;
 import org.eclipse.statet.ecommons.ui.viewers.ViewerLabelUtils;

 import org.eclipse.statet.docmlet.tex.core.commands.Argument;
 import org.eclipse.statet.docmlet.tex.core.commands.EnvDefinitions;
 import org.eclipse.statet.docmlet.tex.core.commands.TexCommand;
 import org.eclipse.statet.docmlet.tex.core.source.LtxHeuristicTokenScanner;
 import org.eclipse.statet.docmlet.tex.ui.TexUIResources;
 import org.eclipse.statet.internal.docmlet.tex.ui.sourceediting.LtxArgumentListContextInformation;
 import org.eclipse.statet.internal.docmlet.tex.ui.sourceediting.LtxAssistInvocationContext;
 import org.eclipse.statet.internal.docmlet.tex.ui.sourceediting.TexBracketLevel;
 import org.eclipse.statet.ltk.ui.sourceediting.assist.SourceProposal;


 @NonNullByDefault
 public class LtxCommandCompletionProposal extends SourceProposal<LtxAssistInvocationContext> {


 	public static class LtxCommandProposalParameters extends ProposalParameters<LtxAssistInvocationContext> {


 		public TexCommand command;


 		public LtxCommandProposalParameters(
 				final LtxAssistInvocationContext context, final int replacementOffset,
 				final SearchPattern namePattern, final int baseRelevance) {
 			super(context, replacementOffset, namePattern, baseRelevance);
 		}

 		public LtxCommandProposalParameters(
 				final LtxAssistInvocationContext context, final int replacementOffset,
 				final SearchPattern namePattern) {
 			super(context, replacementOffset, namePattern);
 		}

 		public LtxCommandProposalParameters(
 				final LtxAssistInvocationContext context,
 				final TexCommand command) {
 			super(context, context.getInvocationOffset(), 0);

 			this.command= command;
 		}

 		/** Only for context information */
 		public LtxCommandProposalParameters(
 				final LtxAssistInvocationContext context, final int replacementOffset) {
 			super(context, replacementOffset, 0);
 		}

 	}


 	public static class Env extends LtxCommandCompletionProposal {


 		protected Env(final LtxCommandProposalParameters parameters) {
 			super(parameters);
 		}


 		@Override
 		protected StyledString computeStyledText() {
 			final StyledString styledText= new StyledString(this.command.getControlWord());
 			styledText.append(QUALIFIER_SEPARATOR, StyledString.QUALIFIER_STYLER);
 			styledText.append(this.command.getDescription(), StyledString.QUALIFIER_STYLER);
 			return styledText;
 		}

 	}


 	public static class ContextInformationProposal extends LtxCommandCompletionProposal {


 		public ContextInformationProposal(final LtxCommandProposalParameters parameters) {
 			super(parameters);
 		}


 		@Override
 		public boolean isAutoInsertable() {
 			return true;
 		}

 		@Override
 		protected void doApply(final char trigger, final int stateMask,
 				final int caretOffset, final int replacementOffset, final int replacementLength)
 				throws BadLocationException {
 			final ApplyData applyData= getApplyData();

 			applyData.clearSelection();
 			applyData.setContextInformation(new LtxArgumentListContextInformation(
 					getReplacementOffset(), // allow negative offsets
 					this.command ));
 		}

 	}


 	private static class LinkedSepMode implements IDocumentListener, VerifyKeyListener {

 		private final SourceViewer viewer;
 		private final IDocument document;
 		private final int offset;

 		private boolean inserted;
 		private boolean intern;

 		public LinkedSepMode(final SourceViewer viewer, final IDocument document, final int offset) {
 			this.viewer= viewer;
 			this.document= document;
 			this.offset= offset;
 		}

 		public void install() {
 			if (UIAccess.isOkToUse(this.viewer)) {
 				this.viewer.getTextWidget().addVerifyKeyListener(this);
 				this.document.addDocumentListener(this);
 			}
 		}

 		@Override
 		public void verifyKey(final VerifyEvent event) {
 			if (this.viewer.getDocument() == this.document) {
 				final Point selection= this.viewer.getSelectedRange();
 				if (!this.inserted
 						&& selection.x == this.offset && selection.y == 0
 						&& (event.character != 0) ) {
 					try {
 						final int currentChar= (this.offset < this.document.getLength()) ? this.document.getChar(this.offset) : '\n';
 						final char c= event.character;
 						if (currentChar <= 0x20 && currentChar != c
 								&& c >= 0x20 && !Character.isLetterOrDigit(c) ) {
 							this.intern= true;
 							this.document.replace(this.offset, 0, "" + c + c);
 							// install linked mode?
 							this.inserted= true;
 							event.doit= false;
 							this.viewer.setSelection(new TextSelection(this.offset+1, 0), true);
 							return;
 						}
 					}
 					catch (final BadLocationException e) {
 					}
 					finally {
 						this.intern= false;
 					}
 				}
 				if (this.inserted && event.character == SWT.BS
 						&& selection.x == this.offset + 1 && selection.y == 0) {
 					try {
 						this.intern= true;
 						this.document.replace(this.offset, 2, "");
 						this.inserted= false;
 						event.doit= false;
 						return;
 					}
 					catch (final BadLocationException e) {
 					}
 					finally {
 						this.intern= false;
 					}
 				}
 			}
 		}

 		@Override
 		public void documentAboutToBeChanged(final DocumentEvent event) {
 		}

 		@Override
 		public void documentChanged(final DocumentEvent event) {
 			if (!this.intern) {
 				dispose();
 			}
 		}

 		private void dispose() {
 			this.viewer.getTextWidget().removeVerifyKeyListener(this);
 			this.document.removeDocumentListener(this);
 		}

 	}


 	private static final boolean isFollowedByOpeningBracket(final int forwardOffset, final boolean allowSquare,
 			final LtxAssistInvocationContext context) {
 		final LtxHeuristicTokenScanner scanner= context.getLtxHeuristicTokenScanner();
 		scanner.configure(context.getDocument());
 		final int idx= scanner.findAnyNonBlankForward(forwardOffset, ITokenScanner.UNBOUND, false);
 		return (idx >= 0
 				&& (scanner.getChar() == '{' || (allowSquare && scanner.getChar() == '[')) );
 	}

 	private static final boolean isClosedBracket(final int backwardOffset, final int forwardOffset,
 			final LtxAssistInvocationContext context) {
 		final int searchType= LtxHeuristicTokenScanner.CURLY_BRACKET_TYPE;
 		int[] balance= new int[3];
 		balance[searchType]++;
 		final LtxHeuristicTokenScanner scanner= context.getLtxHeuristicTokenScanner();
 		scanner.configureDefaultPartitions(context.getDocument());
 		balance= scanner.computeBracketBalance(backwardOffset, forwardOffset, balance, searchType);
 		return (balance[searchType] <= 0);
 	}


 	protected final TexCommand command;


 	protected LtxCommandCompletionProposal(final LtxCommandProposalParameters parameters) {
 		super(parameters);

 		this.command= nonNullAssert(parameters.command);
 	}


 	@Override
 	protected String getName() {
 		return this.command.getControlWord();
 	}

 	@Override
 	protected int computeReplacementLength(final int replacementOffset, final Point selection,
 			final int caretOffset, final boolean overwrite) throws BadLocationException {
 		int end= Math.max(caretOffset, selection.x + selection.y);
 		if (overwrite) {
 			final LtxAssistInvocationContext context= getInvocationContext();
 			final IDocument document= context.getDocument();
 			end--;
 			SEARCH_END: while (++end < document.getLength()) {
 				switch (document.getChar(end)) {
 				case 'a':
 				case 'b':
 				case 'c':
 				case 'd':
 				case 'e':
 				case 'f':
 				case 'g':
 				case 'h':
 				case 'i':
 				case 'j':
 				case 'k':
 				case 'l':
 				case 'm':
 				case 'n':
 				case 'o':
 				case 'p':
 				case 'q':
 				case 'r':
 				case 's':
 				case 't':
 				case 'u':
 				case 'v':
 				case 'w':
 				case 'x':
 				case 'y':
 				case 'z':
 				case 'A':
 				case 'B':
 				case 'C':
 				case 'D':
 				case 'E':
 				case 'F':
 				case 'G':
 				case 'H':
 				case 'I':
 				case 'J':
 				case 'K':
 				case 'L':
 				case 'M':
 				case 'N':
 				case 'O':
 				case 'P':
 				case 'Q':
 				case 'R':
 				case 'S':
 				case 'T':
 				case 'U':
 				case 'V':
 				case 'W':
 				case 'X':
 				case 'Y':
 				case 'Z':
 					continue SEARCH_END;
 				default:
 					break SEARCH_END;
 				}
 			}
 		}
 		return (end - replacementOffset);
 	}


 	@Override
 	public String getSortingString() {
 		return this.command.getControlWord();
 	}


 	@Override
 	public String getDisplayString() {
 		return getStyledDisplayString().getString();
 	}

 	@Override
 	protected StyledString computeStyledText() {
 		final StyledString styledText= new StyledString(((this.command.getType() & TexCommand.MASK_MAIN) == TexCommand.ENV) ?
 						this.command.getControlWord() : "\\" + this.command.getControlWord() );
 		for (final Argument arg : this.command.getArguments()) {
 			if ((arg.getType() & Argument.OPTIONAL) != 0) {
 				styledText.append("[]");
 			}
 			else {
 				styledText.append("{}");
 			}
 		}
 		styledText.append(" – " + this.command.getDescription(), StyledString.QUALIFIER_STYLER);
 		return styledText;
 	}

 	@Override
 	protected void styleMatchingRegions(final StyledString styledText,
 			final int matchRule, int[] matchingRegions,
 			final BoldStylerProvider boldStylerProvider) {
 		matchingRegions= IntIntervalArrays.insertRegion(matchingRegions, 0, 1);
 		ViewerLabelUtils.setStyle(styledText, matchingRegions, boldStylerProvider.getBoldStyler());
 	}

 	@Override
 	public Image getImage() {
 		return TexUIResources.INSTANCE.getCommandImage(this.command);
 	}


 	@Override
 	public boolean isAutoInsertable() {
 		return true;
 	}


 	@Override
 	protected void doApply(final char trigger, final int stateMask, final int caretOffset,
 			final int replacementOffset, final int replacementLength) throws BadLocationException {
 		final LtxAssistInvocationContext context= getInvocationContext();
 		final IDocument document= context.getDocument();
 		final ApplyData applyData= getApplyData();

 		final StringBuilder replacement= new StringBuilder(this.command.getControlWord());
 		if ((stateMask & 0x1) == 0x1) {
 			replacement.insert(0, '\\');
 		}
 		int cursor= replacement.length();
 		int mode= 0;
 		IntList positions= null;
 		if (this.command == EnvDefinitions.VERBATIM_verb_COMMAND) {
 			mode= 201;
 		}
 		else if ((this.command.getType() & TexCommand.MASK_MAIN) != TexCommand.ENV) {
 			final List<Argument> args= this.command.getArguments();
 			if (args != null && !args.isEmpty()) {
 				final boolean isFirstOptional= args.get(0).isOptional();
 				int idxFirstRequired= -1;
 				for (int i= (isFirstOptional) ? 1 : 0; i < args.size(); i++) {
 					final Argument arg= args.get(i);
 					if (arg.isRequired()) {
 						idxFirstRequired= i;
 						break;
 					}
 				}
 				if (idxFirstRequired >= 0) {
 					if (replacementOffset+replacementLength < document.getLength()-1
 							&& (document.getChar(replacementOffset+replacementLength) == '{'
 									|| (isFirstOptional && document.getChar(replacementOffset+replacementLength) == '[') )) {
 						cursor ++;
 						mode= 10;
 					}
 					else if (!isFollowedByOpeningBracket(
 							replacementOffset + replacementLength, isFirstOptional, context )) {
 						replacement.append('{');
 						cursor ++;
 						mode= 11;
 					}
 					if (mode >= 10) {
 						if (mode == 11 && !isClosedBracket(
 								replacementOffset, replacementOffset + replacementLength, context )) {
 							replacement.append('}');

 							positions= new IntArrayList();
 							mode= 0;
 							if (isFirstOptional) {
 								positions.add(mode);
 							}
 							mode++;
 							positions.add(mode++);
 							for (int i= idxFirstRequired+1; i < args.size(); i++) {
 								if (args.get(i).isRequired()) {
 									replacement.append("{}");
 									mode++;
 									positions.add(mode++);
 								}
 								else if (positions.getAt(positions.size() - 1) != mode) {
 									positions.add(mode);
 								}
 							}
 							if (positions.getAt(positions.size() - 1) != mode) {
 								positions.add(mode);
 							}
 							mode= 110 + 1;
 							// add multiple arguments
 						}
 					}
 				}
 			}
 		}
 		document.replace(replacementOffset, replacementLength, replacement.toString());

 		applyData.setSelection(replacementOffset + cursor);
 		if (mode > 100 && mode < 200) {
 			createLinkedMode(replacementOffset + cursor - (mode - 110), positions).enter();
 		}
 		else if (mode > 200 && mode < 300) {
 			createLinkedVerbMode(replacementOffset + cursor);
 		}
 		if ((this.command.getType() & TexCommand.MASK_MAIN) == TexCommand.GENERICENV) {
 			reinvokeAssist();
 		}
 	}

 	private LinkedModeUI createLinkedMode(final int offset, final IntList positions)
 			throws BadLocationException {
 		final LtxAssistInvocationContext context= getInvocationContext();
 		final IDocument document= context.getDocument();

 		final LinkedModeModel model= new LinkedModeModel();
 		int pos= 0;

 		final List<LinkedPosition> linked= new ArrayList<>(positions.size());
 		for (int i= 0; i < positions.size() - 1; i++) {
 			final LinkedPositionGroup group= new LinkedPositionGroup();
 			final LinkedPosition position= (positions.getAt(i) % 2 == 1) ?
 					TexBracketLevel.createPosition('{', document,
 							offset + positions.getAt(i), 0, pos++ ) :
 					new LinkedPosition(document,
 							offset + positions.getAt(i), 0, pos++ );
 			group.addPosition(position);
 			linked.add(position);
 			model.addGroup(group);
 		}

 		model.forceInstall();

 		final TexBracketLevel level= new TexBracketLevel(model,
 				document, context.getEditor().getDocumentContentInfo(),
 				linked, BracketLevel.AUTODELETE );

 		/* create UI */
 		final LinkedModeUI ui= new LinkedModeUI(model, context.getSourceViewer());
 		ui.setCyclingMode(LinkedModeUI.CYCLE_WHEN_NO_PARENT);
 		ui.setExitPosition(context.getSourceViewer(), offset + positions.getAt(positions.size() - 1), 0, pos);
 		ui.setSimpleMode(true);
 		ui.setExitPolicy(level);
 		return ui;
 	}

 	private void createLinkedVerbMode(final int offset) throws BadLocationException {
 		final LtxAssistInvocationContext context= getInvocationContext();
 		final IDocument document= context.getDocument();

 		final LinkedSepMode mode= new LinkedSepMode(context.getSourceViewer(), document, offset);
 		Display.getCurrent().asyncExec(new Runnable() {
 			@Override
 			public void run() {
 				mode.install();
 			}
 		});
 	}

 }
	/*=============================================================================#
	# Copyright (c) 2009, 2019 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.internal.docmlet.tex.ui.editors;

	import static org.eclipse.statet.jcommons.lang.ObjectUtils.nonNullAssert;

	import java.util.ArrayList;
	import java.util.List;

	import org.eclipse.jface.text.BadLocationException;
	import org.eclipse.jface.text.DocumentEvent;
	import org.eclipse.jface.text.IDocument;
	import org.eclipse.jface.text.IDocumentListener;
	import org.eclipse.jface.text.TextSelection;
	import org.eclipse.jface.text.contentassist.BoldStylerProvider;
	import org.eclipse.jface.text.link.LinkedModeModel;
	import org.eclipse.jface.text.link.LinkedModeUI;
	import org.eclipse.jface.text.link.LinkedPosition;
	import org.eclipse.jface.text.link.LinkedPositionGroup;
	import org.eclipse.jface.text.source.SourceViewer;
	import org.eclipse.jface.viewers.StyledString;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.custom.VerifyKeyListener;
	import org.eclipse.swt.events.VerifyEvent;
	import org.eclipse.swt.graphics.Image;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.widgets.Display;

	import org.eclipse.statet.jcommons.collections.IntArrayList;
	import org.eclipse.statet.jcommons.collections.IntIntervalArrays;
	import org.eclipse.statet.jcommons.collections.IntList;
	import org.eclipse.statet.jcommons.lang.NonNullByDefault;
	import org.eclipse.statet.jcommons.text.core.SearchPattern;

	import org.eclipse.statet.ecommons.text.ITokenScanner;
	import org.eclipse.statet.ecommons.text.ui.BracketLevel;
	import org.eclipse.statet.ecommons.ui.util.UIAccess;
	import org.eclipse.statet.ecommons.ui.viewers.ViewerLabelUtils;

	import org.eclipse.statet.docmlet.tex.core.commands.Argument;
	import org.eclipse.statet.docmlet.tex.core.commands.EnvDefinitions;
	import org.eclipse.statet.docmlet.tex.core.commands.TexCommand;
	import org.eclipse.statet.docmlet.tex.core.source.LtxHeuristicTokenScanner;
	import org.eclipse.statet.docmlet.tex.ui.TexUIResources;
	import org.eclipse.statet.internal.docmlet.tex.ui.sourceediting.LtxArgumentListContextInformation;
	import org.eclipse.statet.internal.docmlet.tex.ui.sourceediting.LtxAssistInvocationContext;
	import org.eclipse.statet.internal.docmlet.tex.ui.sourceediting.TexBracketLevel;
	import org.eclipse.statet.ltk.ui.sourceediting.assist.SourceProposal;


	@NonNullByDefault
	public class LtxCommandCompletionProposal extends SourceProposal<LtxAssistInvocationContext> {


	public static class LtxCommandProposalParameters extends ProposalParameters<LtxAssistInvocationContext> {


	public TexCommand command;


	public LtxCommandProposalParameters(
	final LtxAssistInvocationContext context, final int replacementOffset,
	final SearchPattern namePattern, final int baseRelevance) {
	super(context, replacementOffset, namePattern, baseRelevance);
	}

	public LtxCommandProposalParameters(
	final LtxAssistInvocationContext context, final int replacementOffset,
	final SearchPattern namePattern) {
	super(context, replacementOffset, namePattern);
	}

	public LtxCommandProposalParameters(
	final LtxAssistInvocationContext context,
	final TexCommand command) {
	super(context, context.getInvocationOffset(), 0);

	this.command= command;
	}

	/** Only for context information */
	public LtxCommandProposalParameters(
	final LtxAssistInvocationContext context, final int replacementOffset) {
	super(context, replacementOffset, 0);
	}

	}


	public static class Env extends LtxCommandCompletionProposal {


	protected Env(final LtxCommandProposalParameters parameters) {
	super(parameters);
	}


	@Override
	protected StyledString computeStyledText() {
	final StyledString styledText= new StyledString(this.command.getControlWord());
	styledText.append(QUALIFIER_SEPARATOR, StyledString.QUALIFIER_STYLER);
	styledText.append(this.command.getDescription(), StyledString.QUALIFIER_STYLER);
	return styledText;
	}

	}


	public static class ContextInformationProposal extends LtxCommandCompletionProposal {


	public ContextInformationProposal(final LtxCommandProposalParameters parameters) {
	super(parameters);
	}


	@Override
	public boolean isAutoInsertable() {
	return true;
	}

	@Override
	protected void doApply(final char trigger, final int stateMask,
	final int caretOffset, final int replacementOffset, final int replacementLength)
	throws BadLocationException {
	final ApplyData applyData= getApplyData();

	applyData.clearSelection();
	applyData.setContextInformation(new LtxArgumentListContextInformation(
	getReplacementOffset(), // allow negative offsets
	this.command ));
	}

	}


	private static class LinkedSepMode implements IDocumentListener, VerifyKeyListener {

	private final SourceViewer viewer;
	private final IDocument document;
	private final int offset;

	private boolean inserted;
	private boolean intern;

	public LinkedSepMode(final SourceViewer viewer, final IDocument document, final int offset) {
	this.viewer= viewer;
	this.document= document;
	this.offset= offset;
	}

	public void install() {
	if (UIAccess.isOkToUse(this.viewer)) {
	this.viewer.getTextWidget().addVerifyKeyListener(this);
	this.document.addDocumentListener(this);
	}
	}

	@Override
	public void verifyKey(final VerifyEvent event) {
	if (this.viewer.getDocument() == this.document) {
	final Point selection= this.viewer.getSelectedRange();
	if (!this.inserted
	&& selection.x == this.offset && selection.y == 0
	&& (event.character != 0) ) {
	try {
	final int currentChar= (this.offset < this.document.getLength()) ? this.document.getChar(this.offset) : '\n';
	final char c= event.character;
	if (currentChar <= 0x20 && currentChar != c
	&& c >= 0x20 && !Character.isLetterOrDigit(c) ) {
	this.intern= true;
	this.document.replace(this.offset, 0, "" + c + c);
	// install linked mode?
	this.inserted= true;
	event.doit= false;
	this.viewer.setSelection(new TextSelection(this.offset+1, 0), true);
	return;
	}
	}
	catch (final BadLocationException e) {
	}
	finally {
	this.intern= false;
	}
	}
	if (this.inserted && event.character == SWT.BS
	&& selection.x == this.offset + 1 && selection.y == 0) {
	try {
	this.intern= true;
	this.document.replace(this.offset, 2, "");
	this.inserted= false;
	event.doit= false;
	return;
	}
	catch (final BadLocationException e) {
	}
	finally {
	this.intern= false;
	}
	}
	}
	}

	@Override
	public void documentAboutToBeChanged(final DocumentEvent event) {
	}

	@Override
	public void documentChanged(final DocumentEvent event) {
	if (!this.intern) {
	dispose();
	}
	}

	private void dispose() {
	this.viewer.getTextWidget().removeVerifyKeyListener(this);
	this.document.removeDocumentListener(this);
	}

	}


	private static final boolean isFollowedByOpeningBracket(final int forwardOffset, final boolean allowSquare,
	final LtxAssistInvocationContext context) {
	final LtxHeuristicTokenScanner scanner= context.getLtxHeuristicTokenScanner();
	scanner.configure(context.getDocument());
	final int idx= scanner.findAnyNonBlankForward(forwardOffset, ITokenScanner.UNBOUND, false);
	return (idx >= 0
	&& (scanner.getChar() == '{' \|\| (allowSquare && scanner.getChar() == '[')) );
	}

	private static final boolean isClosedBracket(final int backwardOffset, final int forwardOffset,
	final LtxAssistInvocationContext context) {
	final int searchType= LtxHeuristicTokenScanner.CURLY_BRACKET_TYPE;
	int[] balance= new int[3];
	balance[searchType]++;
	final LtxHeuristicTokenScanner scanner= context.getLtxHeuristicTokenScanner();
	scanner.configureDefaultPartitions(context.getDocument());
	balance= scanner.computeBracketBalance(backwardOffset, forwardOffset, balance, searchType);
	return (balance[searchType] <= 0);
	}


	protected final TexCommand command;


	protected LtxCommandCompletionProposal(final LtxCommandProposalParameters parameters) {
	super(parameters);

	this.command= nonNullAssert(parameters.command);
	}


	@Override
	protected String getName() {
	return this.command.getControlWord();
	}

	@Override
	protected int computeReplacementLength(final int replacementOffset, final Point selection,
	final int caretOffset, final boolean overwrite) throws BadLocationException {
	int end= Math.max(caretOffset, selection.x + selection.y);
	if (overwrite) {
	final LtxAssistInvocationContext context= getInvocationContext();
	final IDocument document= context.getDocument();
	end--;
	SEARCH_END: while (++end < document.getLength()) {
	switch (document.getChar(end)) {
	case 'a':
	case 'b':
	case 'c':
	case 'd':
	case 'e':
	case 'f':
	case 'g':
	case 'h':
	case 'i':
	case 'j':
	case 'k':
	case 'l':
	case 'm':
	case 'n':
	case 'o':
	case 'p':
	case 'q':
	case 'r':
	case 's':
	case 't':
	case 'u':
	case 'v':
	case 'w':
	case 'x':
	case 'y':
	case 'z':
	case 'A':
	case 'B':
	case 'C':
	case 'D':
	case 'E':
	case 'F':
	case 'G':
	case 'H':
	case 'I':
	case 'J':
	case 'K':
	case 'L':
	case 'M':
	case 'N':
	case 'O':
	case 'P':
	case 'Q':
	case 'R':
	case 'S':
	case 'T':
	case 'U':
	case 'V':
	case 'W':
	case 'X':
	case 'Y':
	case 'Z':
	continue SEARCH_END;
	default:
	break SEARCH_END;
	}
	}
	}
	return (end - replacementOffset);
	}


	@Override
	public String getSortingString() {
	return this.command.getControlWord();
	}


	@Override
	public String getDisplayString() {
	return getStyledDisplayString().getString();
	}

	@Override
	protected StyledString computeStyledText() {
	final StyledString styledText= new StyledString(((this.command.getType() & TexCommand.MASK_MAIN) == TexCommand.ENV) ?
	this.command.getControlWord() : "\\" + this.command.getControlWord() );
	for (final Argument arg : this.command.getArguments()) {
	if ((arg.getType() & Argument.OPTIONAL) != 0) {
	styledText.append("[]");
	}
	else {
	styledText.append("{}");
	}
	}
	styledText.append(" – " + this.command.getDescription(), StyledString.QUALIFIER_STYLER);
	return styledText;
	}

	@Override
	protected void styleMatchingRegions(final StyledString styledText,
	final int matchRule, int[] matchingRegions,
	final BoldStylerProvider boldStylerProvider) {
	matchingRegions= IntIntervalArrays.insertRegion(matchingRegions, 0, 1);
	ViewerLabelUtils.setStyle(styledText, matchingRegions, boldStylerProvider.getBoldStyler());
	}

	@Override
	public Image getImage() {
	return TexUIResources.INSTANCE.getCommandImage(this.command);
	}


	@Override
	public boolean isAutoInsertable() {
	return true;
	}


	@Override
	protected void doApply(final char trigger, final int stateMask, final int caretOffset,
	final int replacementOffset, final int replacementLength) throws BadLocationException {
	final LtxAssistInvocationContext context= getInvocationContext();
	final IDocument document= context.getDocument();
	final ApplyData applyData= getApplyData();

	final StringBuilder replacement= new StringBuilder(this.command.getControlWord());
	if ((stateMask & 0x1) == 0x1) {
	replacement.insert(0, '\\');
	}
	int cursor= replacement.length();
	int mode= 0;
	IntList positions= null;
	if (this.command == EnvDefinitions.VERBATIM_verb_COMMAND) {
	mode= 201;
	}
	else if ((this.command.getType() & TexCommand.MASK_MAIN) != TexCommand.ENV) {
	final List<Argument> args= this.command.getArguments();
	if (args != null && !args.isEmpty()) {
	final boolean isFirstOptional= args.get(0).isOptional();
	int idxFirstRequired= -1;
	for (int i= (isFirstOptional) ? 1 : 0; i < args.size(); i++) {
	final Argument arg= args.get(i);
	if (arg.isRequired()) {
	idxFirstRequired= i;
	break;
	}
	}
	if (idxFirstRequired >= 0) {
	if (replacementOffset+replacementLength < document.getLength()-1
	&& (document.getChar(replacementOffset+replacementLength) == '{'
	\|\| (isFirstOptional && document.getChar(replacementOffset+replacementLength) == '[') )) {
	cursor ++;
	mode= 10;
	}
	else if (!isFollowedByOpeningBracket(
	replacementOffset + replacementLength, isFirstOptional, context )) {
	replacement.append('{');
	cursor ++;
	mode= 11;
	}
	if (mode >= 10) {
	if (mode == 11 && !isClosedBracket(
	replacementOffset, replacementOffset + replacementLength, context )) {
	replacement.append('}');

	positions= new IntArrayList();
	mode= 0;
	if (isFirstOptional) {
	positions.add(mode);
	}
	mode++;
	positions.add(mode++);
	for (int i= idxFirstRequired+1; i < args.size(); i++) {
	if (args.get(i).isRequired()) {
	replacement.append("{}");
	mode++;
	positions.add(mode++);
	}
	else if (positions.getAt(positions.size() - 1) != mode) {
	positions.add(mode);
	}
	}
	if (positions.getAt(positions.size() - 1) != mode) {
	positions.add(mode);
	}
	mode= 110 + 1;
	// add multiple arguments
	}
	}
	}
	}
	}
	document.replace(replacementOffset, replacementLength, replacement.toString());

	applyData.setSelection(replacementOffset + cursor);
	if (mode > 100 && mode < 200) {
	createLinkedMode(replacementOffset + cursor - (mode - 110), positions).enter();
	}
	else if (mode > 200 && mode < 300) {
	createLinkedVerbMode(replacementOffset + cursor);
	}
	if ((this.command.getType() & TexCommand.MASK_MAIN) == TexCommand.GENERICENV) {
	reinvokeAssist();
	}
	}

	private LinkedModeUI createLinkedMode(final int offset, final IntList positions)
	throws BadLocationException {
	final LtxAssistInvocationContext context= getInvocationContext();
	final IDocument document= context.getDocument();

	final LinkedModeModel model= new LinkedModeModel();
	int pos= 0;

	final List<LinkedPosition> linked= new ArrayList<>(positions.size());
	for (int i= 0; i < positions.size() - 1; i++) {
	final LinkedPositionGroup group= new LinkedPositionGroup();
	final LinkedPosition position= (positions.getAt(i) % 2 == 1) ?
	TexBracketLevel.createPosition('{', document,
	offset + positions.getAt(i), 0, pos++ ) :
	new LinkedPosition(document,
	offset + positions.getAt(i), 0, pos++ );
	group.addPosition(position);
	linked.add(position);
	model.addGroup(group);
	}

	model.forceInstall();

	final TexBracketLevel level= new TexBracketLevel(model,
	document, context.getEditor().getDocumentContentInfo(),
	linked, BracketLevel.AUTODELETE );

	/* create UI */
	final LinkedModeUI ui= new LinkedModeUI(model, context.getSourceViewer());
	ui.setCyclingMode(LinkedModeUI.CYCLE_WHEN_NO_PARENT);
	ui.setExitPosition(context.getSourceViewer(), offset + positions.getAt(positions.size() - 1), 0, pos);
	ui.setSimpleMode(true);
	ui.setExitPolicy(level);
	return ui;
	}

	private void createLinkedVerbMode(final int offset) throws BadLocationException {
	final LtxAssistInvocationContext context= getInvocationContext();
	final IDocument document= context.getDocument();

	final LinkedSepMode mode= new LinkedSepMode(context.getSourceViewer(), document, offset);
	Display.getCurrent().asyncExec(new Runnable() {
	@Override
	public void run() {
	mode.install();
	}
	});
	}

	}