org.eclipse.lsp4e/src/org/eclipse/lsp4e/operations/completion/LSIncompleteCompletionProposal.java - lsp4e/lsp4e - Git at Google

 /*******************************************************************************
  * Copyright (c) 2016, 2017 Red Hat Inc. 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
  *
  * Contributors:
  *   Lucas Bullen (Red Hat Inc.) - initial implementation
  *   Michał Niewrzał (Rogue Wave Software Inc.)
  *   Lucas Bullen (Red Hat Inc.) - Refactored for incomplete completion lists
  *******************************************************************************/
 package org.eclipse.lsp4e.operations.completion;

 import java.util.ArrayList;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;

 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.jdt.annotation.NonNull;
 import org.eclipse.jface.text.AbstractReusableInformationControlCreator;
 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.DefaultInformationControl;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.IInformationControl;
 import org.eclipse.jface.text.IInformationControlCreator;
 import org.eclipse.jface.text.IRegion;
 import org.eclipse.jface.text.ITextViewer;
 import org.eclipse.jface.text.Region;
 import org.eclipse.jface.text.contentassist.BoldStylerProvider;
 import org.eclipse.jface.text.contentassist.ICompletionProposal;
 import org.eclipse.jface.text.contentassist.ICompletionProposalExtension3;
 import org.eclipse.jface.text.contentassist.ICompletionProposalExtension4;
 import org.eclipse.jface.text.contentassist.ICompletionProposalExtension5;
 import org.eclipse.jface.text.contentassist.ICompletionProposalExtension6;
 import org.eclipse.jface.text.contentassist.ICompletionProposalExtension7;
 import org.eclipse.jface.text.contentassist.IContextInformation;
 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.viewers.StyledString;
 import org.eclipse.lsp4e.LSPEclipseUtils;
 import org.eclipse.lsp4e.LanguageServerPlugin;
 import org.eclipse.lsp4e.LanguageServiceAccessor.LSPDocumentInfo;
 import org.eclipse.lsp4e.ui.LSPImages;
 import org.eclipse.lsp4j.CompletionItem;
 import org.eclipse.lsp4j.CompletionOptions;
 import org.eclipse.lsp4j.InsertTextFormat;
 import org.eclipse.lsp4j.Position;
 import org.eclipse.lsp4j.Range;
 import org.eclipse.lsp4j.ServerCapabilities;
 import org.eclipse.lsp4j.TextEdit;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.ui.texteditor.link.EditorLinkedModeUI;

 import com.google.common.collect.ImmutableList;

 public class LSIncompleteCompletionProposal
 		implements ICompletionProposal, ICompletionProposalExtension3, ICompletionProposalExtension4,
 		ICompletionProposalExtension5, ICompletionProposalExtension6, ICompletionProposalExtension7,
 		IContextInformation {

 	protected CompletionItem item;
 	private int initialOffset = -1;
 	protected int bestOffset = -1;
 	protected ITextViewer viewer;
 	private IRegion selection;
 	private LinkedPosition firstPosition;
 	private LSPDocumentInfo info;

 	public LSIncompleteCompletionProposal(@NonNull CompletionItem item, int offset, LSPDocumentInfo info) {
 		this.item = item;
 		this.info = info;
 		this.initialOffset = offset;
 		this.bestOffset = getPrefixCompletionStart(info.getDocument(), offset);
 	}

 	public int getBestOffset() {
 		return this.bestOffset;
 	}

 	public void updateOffset(int offset) {
 		this.bestOffset = getPrefixCompletionStart(info.getDocument(), offset);
 	}

 	public CompletionItem getItem() {
 		return this.item;
 	}

 	@Override
 	public StyledString getStyledDisplayString(IDocument document, int offset, BoldStylerProvider boldStylerProvider) {
 		String rawString = getDisplayString();
 		StyledString res = new StyledString(rawString);
 		if (offset > this.bestOffset) {
 			try {
 				String subString = document.get(this.bestOffset, offset - this.bestOffset);
 				if (item.getTextEdit() != null) {
 					int start = LSPEclipseUtils.toOffset(item.getTextEdit().getRange().getStart(), document);
 					int end = offset;
 					subString = document.get(start, end - start);
 				}
 				int lastIndex = 0;
 				subString = subString.toLowerCase();
 				String lowerRawString = rawString.toLowerCase();
 				for (Character c : subString.toCharArray()) {
 					int index = lowerRawString.indexOf(c, lastIndex);
 					if (index < 0) {
 						return res;
 					} else {
 						res.setStyle(index, 1, boldStylerProvider.getBoldStyler());
 						lastIndex = index + 1;
 					}
 				}
 			} catch (BadLocationException e) {
 				LanguageServerPlugin.logError(e);
 			}
 		}
 		return res;
 	}

 	@Override
 	public String getDisplayString() {
 		return this.item.getLabel();
 	}

 	@Override
 	public StyledString getStyledDisplayString() {
 		return new StyledString(getDisplayString());
 	}

 	@Override
 	public boolean isAutoInsertable() {
 		// TODO consider what's best
 		return false;
 	}

 	@Override
 	public IInformationControlCreator getInformationControlCreator() {
 		return new AbstractReusableInformationControlCreator() {
 			@Override
 			public IInformationControl doCreateInformationControl(Shell shell) {
 				return new DefaultInformationControl(shell, true);
 			}
 		};
 	}

 	@Override
 	public Object getAdditionalProposalInfo(IProgressMonitor monitor) {
 		ServerCapabilities capabilities = info.getCapabilites();
 		if (capabilities != null) {
 			CompletionOptions options = capabilities.getCompletionProvider();
 			if (options != null && Boolean.TRUE.equals(options.getResolveProvider())) {
 				CompletableFuture<CompletionItem> resolvedItem = info.getLanguageClient().getTextDocumentService()
 						.resolveCompletionItem(item);
 				try {
 					updateCompletionItem(resolvedItem.get(500, TimeUnit.MILLISECONDS));
 				} catch (InterruptedException | ExecutionException | TimeoutException e) {
 					LanguageServerPlugin.logError(e);
 				}
 			}
 		}

 		StringBuilder res = new StringBuilder();
 		if (this.item.getDetail() != null) {
 			res.append("<p>" + this.item.getDetail() + "</p>"); //$NON-NLS-1$ //$NON-NLS-2$
 		}
 		if (res.length() > 0) {
 			res.append("<br/>"); //$NON-NLS-1$
 		}
 		if (this.item.getDocumentation() != null) {
 			res.append("<p>" + this.item.getDocumentation() + "</p>"); //$NON-NLS-1$ //$NON-NLS-2$
 		}

 		return res.toString();
 	}

 	private void updateCompletionItem(CompletionItem resolvedItem) {
 		if (resolvedItem == null) {
 			return;
 		}
 		if (resolvedItem.getLabel() != null) {
 			item.setLabel(resolvedItem.getLabel());
 		}
 		if (resolvedItem.getKind() != null) {
 			item.setKind(resolvedItem.getKind());
 		}
 		if (resolvedItem.getDetail() != null) {
 			item.setDetail(resolvedItem.getDetail());
 		}
 		if (resolvedItem.getDocumentation() != null) {
 			item.setDocumentation(resolvedItem.getDocumentation());
 		}
 		if (resolvedItem.getInsertText() != null) {
 			item.setInsertText(resolvedItem.getInsertText());
 		}
 		if (resolvedItem.getInsertTextFormat() != null) {
 			item.setInsertTextFormat(resolvedItem.getInsertTextFormat());
 		}
 		if (resolvedItem.getTextEdit() != null) {
 			item.setTextEdit(resolvedItem.getTextEdit());
 		}
 		if (resolvedItem.getAdditionalTextEdits() != null) {
 			item.setAdditionalTextEdits(resolvedItem.getAdditionalTextEdits());
 		}
 	}

 	@Override
 	public CharSequence getPrefixCompletionText(IDocument document, int completionOffset) {
 		return item.getInsertText().substring(completionOffset - this.bestOffset);
 	}

 	@Override
 	public int getPrefixCompletionStart(IDocument document, int completionOffset) {
 		if (this.item.getTextEdit() != null) {
 			try {
 				return LSPEclipseUtils.toOffset(this.item.getTextEdit().getRange().getStart(), document);
 			} catch (BadLocationException e) {
 				LanguageServerPlugin.logError(e);
 			}
 		}
 		String insertText = getInsertText();
 		try {
 			String subDoc = document.get(
 					Math.max(0, completionOffset - insertText.length()),
 					Math.min(insertText.length(), completionOffset));
 			for (int i = 0; i < insertText.length() && i < completionOffset; i++) {
 				String tentativeCommonString = subDoc.substring(i);
 				if (insertText.startsWith(tentativeCommonString)) {
 					return completionOffset - tentativeCommonString.length();
 				}
 			}
 		} catch (BadLocationException e) {
 			LanguageServerPlugin.logError(e);
 		}
 		return completionOffset;
 	}

 	@Override
 	public void apply(IDocument document) {
 		apply(document, Character.MIN_VALUE, 0, this.bestOffset);
 	}

 	protected void apply(IDocument document, char trigger, int stateMask, int offset) {
 		String insertText = null;
 		TextEdit textEdit = item.getTextEdit();
 		try {
 			if (textEdit == null) {
 				insertText = getInsertText();
 				Position start = LSPEclipseUtils.toPosition(this.bestOffset, document);
 				Position end = LSPEclipseUtils.toPosition(offset, document); // need 2 distinct objects
 				textEdit = new TextEdit(new Range(start, end), insertText);
 			} else if (offset > this.initialOffset) {
 				// characters were added after completion was activated
 				int shift = offset - this.initialOffset;
 				textEdit.getRange().getEnd().setCharacter(textEdit.getRange().getEnd().getCharacter() + shift);
 			}
 			{ // workaround https://github.com/Microsoft/vscode/issues/17036
 				Position start = textEdit.getRange().getStart();
 				Position end = textEdit.getRange().getEnd();
 				if (start.getLine() > end.getLine() || (start.getLine() == end.getLine() && start.getCharacter() > end.getCharacter())) {
 					textEdit.getRange().setEnd(start);
 					textEdit.getRange().setStart(end);
 				}
 			}
 			{ // allow completion items to be wrong with a too wide range
 				Position documentEnd = LSPEclipseUtils.toPosition(document.getLength(), document);
 				Position textEditEnd = textEdit.getRange().getEnd();
 				if (documentEnd.getLine() < textEditEnd.getLine()
 					|| (documentEnd.getLine() == textEditEnd.getLine() && documentEnd.getCharacter() < textEditEnd.getCharacter())) {
 					textEdit.getRange().setEnd(documentEnd);
 				}
 			}

 			if (insertText != null) {
 				// try to reuse existing characters after completion location
 				int shift = offset - this.bestOffset;
 				int commonSize = 0;
 				while (commonSize < insertText.length() - shift
 					&& document.getLength() > offset + commonSize
 					&& document.getChar(this.bestOffset + shift + commonSize) == insertText.charAt(commonSize + shift)) {
 					commonSize++;
 				}
 				textEdit.getRange().getEnd().setCharacter(textEdit.getRange().getEnd().getCharacter() + commonSize);
 			}
 			insertText = textEdit.getNewText();
 			LinkedHashMap<String, List<LinkedPosition>> regions = new LinkedHashMap<>();
 			int insertionOffset = LSPEclipseUtils.toOffset(textEdit.getRange().getStart(), document);
 			insertionOffset = computeNewOffset(item.getAdditionalTextEdits(), insertionOffset, document);
 			if (item.getInsertTextFormat() == InsertTextFormat.Snippet) {
 				int currentOffset = 0;
 				while ((currentOffset = insertText.indexOf('$', currentOffset)) != -1) {
 					StringBuilder keyBuilder = new StringBuilder();
 					String defaultValue = ""; //$NON-NLS-1$
 					int length = 1;
 					while (currentOffset + length < insertText.length() && Character.isDigit(insertText.charAt(currentOffset + length))) {
 						keyBuilder.append(insertText.charAt(currentOffset + length));
 						length++;
 					}
 					if (length == 1 && insertText.length() >= 2 && insertText.charAt(currentOffset + 1) == '{') {
 						length++;
 						while (currentOffset + length < insertText.length() && Character.isDigit(insertText.charAt(currentOffset + length))) {
 							keyBuilder.append(insertText.charAt(currentOffset + length));
 							length++;
 						}
 						if (currentOffset + length < insertText.length() && insertText.charAt(currentOffset + length) == ':') {
 							length++;
 						}
 						while (currentOffset + length < insertText.length() && insertText.charAt(currentOffset + length) != '}') {
 							defaultValue += insertText.charAt(currentOffset + length);
 							length++;
 						}
 						if (currentOffset + length < insertText.length() && insertText.charAt(currentOffset + length) == '}') {
 							length++;
 						}
 					}
 					if (keyBuilder.length() > 0) {
 						String key = keyBuilder.toString();
 						if (!regions.containsKey(key)) {
 							regions.put(key, new ArrayList<>());
 						}
 						insertText = insertText.substring(0, currentOffset) + defaultValue + insertText.substring(currentOffset + length);
 						LinkedPosition position = new LinkedPosition(document, insertionOffset + currentOffset, defaultValue.length());
 						if (firstPosition == null) {
 							firstPosition = position;
 						}
 						regions.get(key).add(position);
 						currentOffset += defaultValue.length();
 					} else {
 						currentOffset++;
 					}
 				}
 			}
 			textEdit.setNewText(insertText); // insertText now has placeholder removed
 			List<TextEdit> additionalEdits = item.getAdditionalTextEdits();
 			if (additionalEdits != null && !additionalEdits.isEmpty()) {
 				ImmutableList.Builder<TextEdit> allEdits = ImmutableList.builder();
 				allEdits.add(textEdit);
 				allEdits.addAll(additionalEdits);
 				LSPEclipseUtils.applyEdits(document, allEdits.build());
 			} else {
 				LSPEclipseUtils.applyEdit(textEdit, document);
 			}

 			if (viewer != null && !regions.isEmpty()) {
 				LinkedModeModel model = new LinkedModeModel();
 				for (List<LinkedPosition> positions: regions.values()) {
 					LinkedPositionGroup group = new LinkedPositionGroup();
 					for (LinkedPosition position : positions) {
 						group.addPosition(position);
 					}
 					model.addGroup(group);
 				}
 				model.forceInstall();

 				LinkedModeUI ui = new EditorLinkedModeUI(model, viewer);
 				// ui.setSimpleMode(true);
 				// ui.setExitPolicy(new ExitPolicy(closingCharacter, document));
 				// ui.setExitPosition(getTextViewer(), exit, 0, Integer.MAX_VALUE);
 				ui.setCyclingMode(LinkedModeUI.CYCLE_NEVER);
 				ui.enter();
 			} else {
 				selection = new Region(insertionOffset + textEdit.getNewText().length(), 0);
 			}
 		} catch (BadLocationException ex) {
 			LanguageServerPlugin.logError(ex);
 		}
 	}

 	private int computeNewOffset(List<TextEdit> additionalTextEdits, int insertionOffset, IDocument doc) {
 		if (additionalTextEdits != null && !additionalTextEdits.isEmpty()) {
 			int adjustment = 0;
 			for (TextEdit edit : additionalTextEdits) {
 				try {
 					Range rng = edit.getRange();
 					int start = LSPEclipseUtils.toOffset(rng.getStart(), doc);
 					if (start <= insertionOffset) {
 						int end = LSPEclipseUtils.toOffset(rng.getEnd(), doc);
 						int orgLen = end - start;
 						int newLeng = edit.getNewText().length();
 						int editChange = newLeng - orgLen;
 						adjustment += editChange;
 					}
 				} catch (BadLocationException e) {
 					LanguageServerPlugin.logError(e);
 				}
 			}
 			return insertionOffset + adjustment;
 		}
 		return insertionOffset;
 	}

 	protected String getInsertText() {
 		String insertText = this.item.getInsertText();
 		if (this.item.getTextEdit() != null) {
 			insertText = this.item.getTextEdit().getNewText();
 		}
 		if (insertText == null) {
 			insertText = this.item.getLabel();
 		}
 		return insertText;
 	}

 	@Override
 	public Point getSelection(IDocument document) {
 		if (this.firstPosition != null) {
 			return new Point(this.firstPosition.getOffset(), this.firstPosition.getLength());
 		}
 		if (selection == null) {
 			return null;
 		}
 		return new Point(selection.getOffset(), selection.getLength());
 	}

 	@Override
 	public String getAdditionalProposalInfo() {
 		return this.item.getDetail();
 	}

 	@Override
 	public Image getImage() {
 		return LSPImages.imageFromCompletionItem(this.item);
 	}

 	@Override
 	public IContextInformation getContextInformation() {
 		return this;
 	}

 	@Override
 	public String getContextDisplayString() {
 		return getAdditionalProposalInfo();
 	}

 	@Override
 	public String getInformationDisplayString() {
 		return getAdditionalProposalInfo();
 	}

 	public String getSortText() {
 		if (item.getSortText() != null && !item.getSortText().isEmpty()) {
 			return item.getSortText();
 		}
 		return item.getLabel();
 	}

 	public int getNumberOfModifsBeforeOffset() {
 		if (this.item.getTextEdit() == null) {
 			// only insertion and offset is moved back in case document contains prefix
 			// of insertion, so no change done before offset
 			return 0;
 		}
 		int res = 0;
 		try {
 			int startOffset = LSPEclipseUtils.toOffset(this.item.getTextEdit().getRange().getStart(), this.info.getDocument());
 			String insert = this.item.getTextEdit().getNewText();
 			String subDoc = this.info.getDocument().get(startOffset, Math.min(
 					startOffset + insert.length(),
 					this.info.getDocument().getLength() - startOffset));
 			for (int i = 0; i < subDoc.length() && i < insert.length(); i++) {
 				if (subDoc.charAt(i) != insert.charAt(i)) {
 					res++;
 				}
 			}
 		} catch (BadLocationException e) {
 			LanguageServerPlugin.logError(e);
 		}
 		return res;

 	}

 }
	/*******************************************************************************
	* Copyright (c) 2016, 2017 Red Hat Inc. 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
	*
	* Contributors:
	* Lucas Bullen (Red Hat Inc.) - initial implementation
	* Michał Niewrzał (Rogue Wave Software Inc.)
	* Lucas Bullen (Red Hat Inc.) - Refactored for incomplete completion lists
	*******************************************************************************/
	package org.eclipse.lsp4e.operations.completion;

	import java.util.ArrayList;
	import java.util.LinkedHashMap;
	import java.util.List;
	import java.util.concurrent.CompletableFuture;
	import java.util.concurrent.ExecutionException;
	import java.util.concurrent.TimeUnit;
	import java.util.concurrent.TimeoutException;

	import org.eclipse.core.runtime.IProgressMonitor;
	import org.eclipse.jdt.annotation.NonNull;
	import org.eclipse.jface.text.AbstractReusableInformationControlCreator;
	import org.eclipse.jface.text.BadLocationException;
	import org.eclipse.jface.text.DefaultInformationControl;
	import org.eclipse.jface.text.IDocument;
	import org.eclipse.jface.text.IInformationControl;
	import org.eclipse.jface.text.IInformationControlCreator;
	import org.eclipse.jface.text.IRegion;
	import org.eclipse.jface.text.ITextViewer;
	import org.eclipse.jface.text.Region;
	import org.eclipse.jface.text.contentassist.BoldStylerProvider;
	import org.eclipse.jface.text.contentassist.ICompletionProposal;
	import org.eclipse.jface.text.contentassist.ICompletionProposalExtension3;
	import org.eclipse.jface.text.contentassist.ICompletionProposalExtension4;
	import org.eclipse.jface.text.contentassist.ICompletionProposalExtension5;
	import org.eclipse.jface.text.contentassist.ICompletionProposalExtension6;
	import org.eclipse.jface.text.contentassist.ICompletionProposalExtension7;
	import org.eclipse.jface.text.contentassist.IContextInformation;
	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.viewers.StyledString;
	import org.eclipse.lsp4e.LSPEclipseUtils;
	import org.eclipse.lsp4e.LanguageServerPlugin;
	import org.eclipse.lsp4e.LanguageServiceAccessor.LSPDocumentInfo;
	import org.eclipse.lsp4e.ui.LSPImages;
	import org.eclipse.lsp4j.CompletionItem;
	import org.eclipse.lsp4j.CompletionOptions;
	import org.eclipse.lsp4j.InsertTextFormat;
	import org.eclipse.lsp4j.Position;
	import org.eclipse.lsp4j.Range;
	import org.eclipse.lsp4j.ServerCapabilities;
	import org.eclipse.lsp4j.TextEdit;
	import org.eclipse.swt.graphics.Image;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.widgets.Shell;
	import org.eclipse.ui.texteditor.link.EditorLinkedModeUI;

	import com.google.common.collect.ImmutableList;

	public class LSIncompleteCompletionProposal
	implements ICompletionProposal, ICompletionProposalExtension3, ICompletionProposalExtension4,
	ICompletionProposalExtension5, ICompletionProposalExtension6, ICompletionProposalExtension7,
	IContextInformation {

	protected CompletionItem item;
	private int initialOffset = -1;
	protected int bestOffset = -1;
	protected ITextViewer viewer;
	private IRegion selection;
	private LinkedPosition firstPosition;
	private LSPDocumentInfo info;

	public LSIncompleteCompletionProposal(@NonNull CompletionItem item, int offset, LSPDocumentInfo info) {
	this.item = item;
	this.info = info;
	this.initialOffset = offset;
	this.bestOffset = getPrefixCompletionStart(info.getDocument(), offset);
	}

	public int getBestOffset() {
	return this.bestOffset;
	}

	public void updateOffset(int offset) {
	this.bestOffset = getPrefixCompletionStart(info.getDocument(), offset);
	}

	public CompletionItem getItem() {
	return this.item;
	}

	@Override
	public StyledString getStyledDisplayString(IDocument document, int offset, BoldStylerProvider boldStylerProvider) {
	String rawString = getDisplayString();
	StyledString res = new StyledString(rawString);
	if (offset > this.bestOffset) {
	try {
	String subString = document.get(this.bestOffset, offset - this.bestOffset);
	if (item.getTextEdit() != null) {
	int start = LSPEclipseUtils.toOffset(item.getTextEdit().getRange().getStart(), document);
	int end = offset;
	subString = document.get(start, end - start);
	}
	int lastIndex = 0;
	subString = subString.toLowerCase();
	String lowerRawString = rawString.toLowerCase();
	for (Character c : subString.toCharArray()) {
	int index = lowerRawString.indexOf(c, lastIndex);
	if (index < 0) {
	return res;
	} else {
	res.setStyle(index, 1, boldStylerProvider.getBoldStyler());
	lastIndex = index + 1;
	}
	}
	} catch (BadLocationException e) {
	LanguageServerPlugin.logError(e);
	}
	}
	return res;
	}

	@Override
	public String getDisplayString() {
	return this.item.getLabel();
	}

	@Override
	public StyledString getStyledDisplayString() {
	return new StyledString(getDisplayString());
	}

	@Override
	public boolean isAutoInsertable() {
	// TODO consider what's best
	return false;
	}

	@Override
	public IInformationControlCreator getInformationControlCreator() {
	return new AbstractReusableInformationControlCreator() {
	@Override
	public IInformationControl doCreateInformationControl(Shell shell) {
	return new DefaultInformationControl(shell, true);
	}
	};
	}

	@Override
	public Object getAdditionalProposalInfo(IProgressMonitor monitor) {
	ServerCapabilities capabilities = info.getCapabilites();
	if (capabilities != null) {
	CompletionOptions options = capabilities.getCompletionProvider();
	if (options != null && Boolean.TRUE.equals(options.getResolveProvider())) {
	CompletableFuture<CompletionItem> resolvedItem = info.getLanguageClient().getTextDocumentService()
	.resolveCompletionItem(item);
	try {
	updateCompletionItem(resolvedItem.get(500, TimeUnit.MILLISECONDS));
	} catch (InterruptedException \| ExecutionException \| TimeoutException e) {
	LanguageServerPlugin.logError(e);
	}
	}
	}

	StringBuilder res = new StringBuilder();
	if (this.item.getDetail() != null) {
	res.append("<p>" + this.item.getDetail() + "</p>"); //$NON-NLS-1$ //$NON-NLS-2$
	}
	if (res.length() > 0) {
	res.append("<br/>"); //$NON-NLS-1$
	}
	if (this.item.getDocumentation() != null) {
	res.append("<p>" + this.item.getDocumentation() + "</p>"); //$NON-NLS-1$ //$NON-NLS-2$
	}

	return res.toString();
	}

	private void updateCompletionItem(CompletionItem resolvedItem) {
	if (resolvedItem == null) {
	return;
	}
	if (resolvedItem.getLabel() != null) {
	item.setLabel(resolvedItem.getLabel());
	}
	if (resolvedItem.getKind() != null) {
	item.setKind(resolvedItem.getKind());
	}
	if (resolvedItem.getDetail() != null) {
	item.setDetail(resolvedItem.getDetail());
	}
	if (resolvedItem.getDocumentation() != null) {
	item.setDocumentation(resolvedItem.getDocumentation());
	}
	if (resolvedItem.getInsertText() != null) {
	item.setInsertText(resolvedItem.getInsertText());
	}
	if (resolvedItem.getInsertTextFormat() != null) {
	item.setInsertTextFormat(resolvedItem.getInsertTextFormat());
	}
	if (resolvedItem.getTextEdit() != null) {
	item.setTextEdit(resolvedItem.getTextEdit());
	}
	if (resolvedItem.getAdditionalTextEdits() != null) {
	item.setAdditionalTextEdits(resolvedItem.getAdditionalTextEdits());
	}
	}

	@Override
	public CharSequence getPrefixCompletionText(IDocument document, int completionOffset) {
	return item.getInsertText().substring(completionOffset - this.bestOffset);
	}

	@Override
	public int getPrefixCompletionStart(IDocument document, int completionOffset) {
	if (this.item.getTextEdit() != null) {
	try {
	return LSPEclipseUtils.toOffset(this.item.getTextEdit().getRange().getStart(), document);
	} catch (BadLocationException e) {
	LanguageServerPlugin.logError(e);
	}
	}
	String insertText = getInsertText();
	try {
	String subDoc = document.get(
	Math.max(0, completionOffset - insertText.length()),
	Math.min(insertText.length(), completionOffset));
	for (int i = 0; i < insertText.length() && i < completionOffset; i++) {
	String tentativeCommonString = subDoc.substring(i);
	if (insertText.startsWith(tentativeCommonString)) {
	return completionOffset - tentativeCommonString.length();
	}
	}
	} catch (BadLocationException e) {
	LanguageServerPlugin.logError(e);
	}
	return completionOffset;
	}

	@Override
	public void apply(IDocument document) {
	apply(document, Character.MIN_VALUE, 0, this.bestOffset);
	}

	protected void apply(IDocument document, char trigger, int stateMask, int offset) {
	String insertText = null;
	TextEdit textEdit = item.getTextEdit();
	try {
	if (textEdit == null) {
	insertText = getInsertText();
	Position start = LSPEclipseUtils.toPosition(this.bestOffset, document);
	Position end = LSPEclipseUtils.toPosition(offset, document); // need 2 distinct objects
	textEdit = new TextEdit(new Range(start, end), insertText);
	} else if (offset > this.initialOffset) {
	// characters were added after completion was activated
	int shift = offset - this.initialOffset;
	textEdit.getRange().getEnd().setCharacter(textEdit.getRange().getEnd().getCharacter() + shift);
	}
	{ // workaround https://github.com/Microsoft/vscode/issues/17036
	Position start = textEdit.getRange().getStart();
	Position end = textEdit.getRange().getEnd();
	if (start.getLine() > end.getLine() \|\| (start.getLine() == end.getLine() && start.getCharacter() > end.getCharacter())) {
	textEdit.getRange().setEnd(start);
	textEdit.getRange().setStart(end);
	}
	}
	{ // allow completion items to be wrong with a too wide range
	Position documentEnd = LSPEclipseUtils.toPosition(document.getLength(), document);
	Position textEditEnd = textEdit.getRange().getEnd();
	if (documentEnd.getLine() < textEditEnd.getLine()
	\|\| (documentEnd.getLine() == textEditEnd.getLine() && documentEnd.getCharacter() < textEditEnd.getCharacter())) {
	textEdit.getRange().setEnd(documentEnd);
	}
	}

	if (insertText != null) {
	// try to reuse existing characters after completion location
	int shift = offset - this.bestOffset;
	int commonSize = 0;
	while (commonSize < insertText.length() - shift
	&& document.getLength() > offset + commonSize
	&& document.getChar(this.bestOffset + shift + commonSize) == insertText.charAt(commonSize + shift)) {
	commonSize++;
	}
	textEdit.getRange().getEnd().setCharacter(textEdit.getRange().getEnd().getCharacter() + commonSize);
	}
	insertText = textEdit.getNewText();
	LinkedHashMap<String, List<LinkedPosition>> regions = new LinkedHashMap<>();
	int insertionOffset = LSPEclipseUtils.toOffset(textEdit.getRange().getStart(), document);
	insertionOffset = computeNewOffset(item.getAdditionalTextEdits(), insertionOffset, document);
	if (item.getInsertTextFormat() == InsertTextFormat.Snippet) {
	int currentOffset = 0;
	while ((currentOffset = insertText.indexOf('$', currentOffset)) != -1) {
	StringBuilder keyBuilder = new StringBuilder();
	String defaultValue = ""; //$NON-NLS-1$
	int length = 1;
	while (currentOffset + length < insertText.length() && Character.isDigit(insertText.charAt(currentOffset + length))) {
	keyBuilder.append(insertText.charAt(currentOffset + length));
	length++;
	}
	if (length == 1 && insertText.length() >= 2 && insertText.charAt(currentOffset + 1) == '{') {
	length++;
	while (currentOffset + length < insertText.length() && Character.isDigit(insertText.charAt(currentOffset + length))) {
	keyBuilder.append(insertText.charAt(currentOffset + length));
	length++;
	}
	if (currentOffset + length < insertText.length() && insertText.charAt(currentOffset + length) == ':') {
	length++;
	}
	while (currentOffset + length < insertText.length() && insertText.charAt(currentOffset + length) != '}') {
	defaultValue += insertText.charAt(currentOffset + length);
	length++;
	}
	if (currentOffset + length < insertText.length() && insertText.charAt(currentOffset + length) == '}') {
	length++;
	}
	}
	if (keyBuilder.length() > 0) {
	String key = keyBuilder.toString();
	if (!regions.containsKey(key)) {
	regions.put(key, new ArrayList<>());
	}
	insertText = insertText.substring(0, currentOffset) + defaultValue + insertText.substring(currentOffset + length);
	LinkedPosition position = new LinkedPosition(document, insertionOffset + currentOffset, defaultValue.length());
	if (firstPosition == null) {
	firstPosition = position;
	}
	regions.get(key).add(position);
	currentOffset += defaultValue.length();
	} else {
	currentOffset++;
	}
	}
	}
	textEdit.setNewText(insertText); // insertText now has placeholder removed
	List<TextEdit> additionalEdits = item.getAdditionalTextEdits();
	if (additionalEdits != null && !additionalEdits.isEmpty()) {
	ImmutableList.Builder<TextEdit> allEdits = ImmutableList.builder();
	allEdits.add(textEdit);
	allEdits.addAll(additionalEdits);
	LSPEclipseUtils.applyEdits(document, allEdits.build());
	} else {
	LSPEclipseUtils.applyEdit(textEdit, document);
	}

	if (viewer != null && !regions.isEmpty()) {
	LinkedModeModel model = new LinkedModeModel();
	for (List<LinkedPosition> positions: regions.values()) {
	LinkedPositionGroup group = new LinkedPositionGroup();
	for (LinkedPosition position : positions) {
	group.addPosition(position);
	}
	model.addGroup(group);
	}
	model.forceInstall();

	LinkedModeUI ui = new EditorLinkedModeUI(model, viewer);
	// ui.setSimpleMode(true);
	// ui.setExitPolicy(new ExitPolicy(closingCharacter, document));
	// ui.setExitPosition(getTextViewer(), exit, 0, Integer.MAX_VALUE);
	ui.setCyclingMode(LinkedModeUI.CYCLE_NEVER);
	ui.enter();
	} else {
	selection = new Region(insertionOffset + textEdit.getNewText().length(), 0);
	}
	} catch (BadLocationException ex) {
	LanguageServerPlugin.logError(ex);
	}
	}

	private int computeNewOffset(List<TextEdit> additionalTextEdits, int insertionOffset, IDocument doc) {
	if (additionalTextEdits != null && !additionalTextEdits.isEmpty()) {
	int adjustment = 0;
	for (TextEdit edit : additionalTextEdits) {
	try {
	Range rng = edit.getRange();
	int start = LSPEclipseUtils.toOffset(rng.getStart(), doc);
	if (start <= insertionOffset) {
	int end = LSPEclipseUtils.toOffset(rng.getEnd(), doc);
	int orgLen = end - start;
	int newLeng = edit.getNewText().length();
	int editChange = newLeng - orgLen;
	adjustment += editChange;
	}
	} catch (BadLocationException e) {
	LanguageServerPlugin.logError(e);
	}
	}
	return insertionOffset + adjustment;
	}
	return insertionOffset;
	}

	protected String getInsertText() {
	String insertText = this.item.getInsertText();
	if (this.item.getTextEdit() != null) {
	insertText = this.item.getTextEdit().getNewText();
	}
	if (insertText == null) {
	insertText = this.item.getLabel();
	}
	return insertText;
	}

	@Override
	public Point getSelection(IDocument document) {
	if (this.firstPosition != null) {
	return new Point(this.firstPosition.getOffset(), this.firstPosition.getLength());
	}
	if (selection == null) {
	return null;
	}
	return new Point(selection.getOffset(), selection.getLength());
	}

	@Override
	public String getAdditionalProposalInfo() {
	return this.item.getDetail();
	}

	@Override
	public Image getImage() {
	return LSPImages.imageFromCompletionItem(this.item);
	}

	@Override
	public IContextInformation getContextInformation() {
	return this;
	}

	@Override
	public String getContextDisplayString() {
	return getAdditionalProposalInfo();
	}

	@Override
	public String getInformationDisplayString() {
	return getAdditionalProposalInfo();
	}

	public String getSortText() {
	if (item.getSortText() != null && !item.getSortText().isEmpty()) {
	return item.getSortText();
	}
	return item.getLabel();
	}

	public int getNumberOfModifsBeforeOffset() {
	if (this.item.getTextEdit() == null) {
	// only insertion and offset is moved back in case document contains prefix
	// of insertion, so no change done before offset
	return 0;
	}
	int res = 0;
	try {
	int startOffset = LSPEclipseUtils.toOffset(this.item.getTextEdit().getRange().getStart(), this.info.getDocument());
	String insert = this.item.getTextEdit().getNewText();
	String subDoc = this.info.getDocument().get(startOffset, Math.min(
	startOffset + insert.length(),
	this.info.getDocument().getLength() - startOffset));
	for (int i = 0; i < subDoc.length() && i < insert.length(); i++) {
	if (subDoc.charAt(i) != insert.charAt(i)) {
	res++;
	}
	}
	} catch (BadLocationException e) {
	LanguageServerPlugin.logError(e);
	}
	return res;

	}

	}