private void createStringProposal(ContentAssistContext context, ICompletionProposalAcceptor acceptor,
		String feature, RuleCall ruleCall) {
	String proposalText = feature != null ? feature : Strings.toFirstUpper(ruleCall.getRule().getName().toLowerCase());
	proposalText = getValueConverter().toString(proposalText, ruleCall.getRule().getName());
	String displayText = proposalText;
	if (feature != null)
		displayText = displayText + " - " + ruleCall.getRule().getName();
	ICompletionProposal proposal = createCompletionProposal(proposalText, displayText, null, context);
	if (proposal instanceof ConfigurableCompletionProposal) {
		ConfigurableCompletionProposal configurable = (ConfigurableCompletionProposal) proposal;
		configurable.setSelectionStart(configurable.getReplacementOffset() + 1);
		configurable.setSelectionLength(proposalText.length() - 2);
		configurable.setAutoInsertable(false);
		configurable.setSimpleLinkedMode(context.getViewer(), proposalText.charAt(0), '\t');
		
	}
	acceptor.accept(proposal);
}
 

private ICompletionProposal[] computeStyleProposals(String selectedText,
		Point selectedRange) {
	if (styleManager == null) {
		styleManager = TexStyleCompletionManager.getInstance();
	}
	return styleManager.getStyleCompletions(selectedText, selectedRange);
	/*
	 * ICompletionProposal[] result = new
	 * ICompletionProposal[STYLETAGS.length];
	 * 
	 * // Loop through all styles for (int i = 0; i < STYLETAGS.length; i++)
	 * { String tag = STYLETAGS[i];
	 * 
	 * // Compute replacement text String replacement = "{" + tag + " " +
	 * selectedText + "}";
	 * 
	 * // Derive cursor position int cursor = tag.length() + 2;
	 * 
	 * // Compute a suitable context information IContextInformation
	 * contextInfo = new ContextInformation(null, STYLELABELS[i]+" Style");
	 * 
	 * // Construct proposal result[i] = new CompletionProposal(replacement,
	 * selectedRange.x, selectedRange.y, cursor, null, STYLELABELS[i],
	 * contextInfo, replacement); } return result;
	 */
}
 

@Override
public ICompletionProposal[] computeCompletionProposals(ITextViewer viewer, int offset) {
	ModeAware proposalProvider = getModeAwareProposalProvider();
	if (proposalProvider == null)
		return new ICompletionProposal[0];
	int i = 0;
	CompletionProposalComputer proposalComputer = createCompletionProposalComputer(viewer, offset);
	while(i++ < 1000) { // just to prevent endless loop in case #isLastMode has an error
		proposalProvider.nextMode();
		if (currentAssistant != null)
			currentAssistant.setStatusMessage(getStatusMessage());
		ICompletionProposal[] result = computeCompletionProposals(xtextDocumentUtil.getXtextDocument(viewer), proposalComputer);
		if (result != null && result.length > 0)
			return result;
		if (proposalProvider.isLastMode()) {
			return new ICompletionProposal[0];	
		}
	}
	throw new IllegalStateException("#isLastMode did not return true for 1000 times");
}
 

private List<IContextInformation> addContextInformations(JavaContentAssistInvocationContext context, int offset) {
	List<ICompletionProposal> proposals= internalComputeCompletionProposals(offset, context);
	List<IContextInformation> result= new ArrayList<IContextInformation>(proposals.size());
	List<IContextInformation> anonymousResult= new ArrayList<IContextInformation>(proposals.size());

	for (Iterator<ICompletionProposal> it= proposals.iterator(); it.hasNext();) {
		ICompletionProposal proposal= it.next();
		IContextInformation contextInformation= proposal.getContextInformation();
		if (contextInformation != null) {
			ContextInformationWrapper wrapper= new ContextInformationWrapper(contextInformation);
			wrapper.setContextInformationPosition(offset);
			if (proposal instanceof AnonymousTypeCompletionProposal)
				anonymousResult.add(wrapper);
			else
				result.add(wrapper);
		}
	}

	if (result.size() == 0)
		return anonymousResult;
	return result;

}
 

@Override
public ICompletionProposal[] computeCompletionProposals(ITextViewer viewer,
		int offset) {
	CompletionContext context = computeContext(viewer, offset);
	List<ICompletionProposal> completionProposals = new ArrayList<ICompletionProposal>();
	doComputeCompletionProposals(context, completionProposals);
	
	if (completionProposals.isEmpty() /*&& !isAstUpToDate()*/) {
		IModuleSymbol moduleSymbol = context.getModuleSymbol();
		if (moduleSymbol == null) {
			EmptyCompletionProposal emptyCompletionProposal = new EmptyCompletionProposal(Messages.XdsOutlinePage_Loading, 
					LOADING_IMAGE, viewer.getSelectedRange().x);
			return new ICompletionProposal[]{emptyCompletionProposal, emptyCompletionProposal};
		}
		else {
			return null;
		}
	}
	return completionProposals.toArray(new ICompletionProposal[0]);
}
 

/**
 * Try to execute the correction command.
 * 
 * @return <code>true</code> iff the correction could be started
 * @since 3.6
 */
public boolean doExecute() {
	ISelection selection= fEditor.getSelectionProvider().getSelection();
	ICompilationUnit cu= JavaUI.getWorkingCopyManager().getWorkingCopy(fEditor.getEditorInput());
	IAnnotationModel model= JavaUI.getDocumentProvider().getAnnotationModel(fEditor.getEditorInput());
	if (selection instanceof ITextSelection && cu != null && model != null) {
		if (! ActionUtil.isEditable(fEditor)) {
			return false;
		}
		ICompletionProposal proposal= findCorrection(fId, fIsAssist, (ITextSelection) selection, cu, model);
		if (proposal != null) {
			invokeProposal(proposal, ((ITextSelection) selection).getOffset());
			return true;
		}
	}
	return false;
}
 

private void setItem(TableItem[] items, int i)
{
	TableItem item = items[i];
	ICompletionProposal proposal = fFilteredProposals[i];
	item.setData("isAlt", "false");
		
	item.setImage(0, proposal.getImage());
	item.setText(1, proposal.getDisplayString());
	boolean isItalics = false;
	if (!(isItalics))
	{
		setDefaultStyle(item);
    }
	item.setData(proposal);

}
 

public ICompletionProposal[] computeCompletionProposals(IContentAssistSubjectControl contentAssistSubject, int documentOffset) {
	if (fTempNameProposals.length == 0)
		return null;
	String input= contentAssistSubject.getDocument().get();

	ArrayList<JavaCompletionProposal> proposals= new ArrayList<JavaCompletionProposal>();
	String prefix= input.substring(0, documentOffset);
	Image image= fImageRegistry.get(fProposalImageDescriptor);
	for (int i= 0; i < fTempNameProposals.length; i++) {
		String tempName= fTempNameProposals[i];
		if (tempName.length() == 0 || ! tempName.startsWith(prefix))
			continue;
		JavaCompletionProposal proposal= new JavaCompletionProposal(tempName, 0, input.length(), image, tempName, 0);
		proposals.add(proposal);
	}
	fErrorMessage= proposals.size() > 0 ? null : JavaUIMessages.JavaEditor_codeassist_noCompletions;
	return proposals.toArray(new ICompletionProposal[proposals.size()]);
}
 

@Override
	public final ICompletionProposal[] computeCompletionProposals(ITextViewer viewer, int offset) {
		resetComputeState();
		
		// The code below has been commented, it causes a bug with templates with "${word_selection} " usage,
		// and it's not clear this functionality made sense in the first place.
		
//		if(viewer instanceof LangSourceViewer) {
//			LangSourceViewer sourceViewer = (LangSourceViewer) viewer;
//			if(sourceViewer.getSelectedRange().y > 0) {
//				// Correct the invocation offset for content assist. 
//				// The issue is that if text is selected, the cursor can either be on the left, or the right
//				// but the offset used will always be the left side of the selection, unless we correct it.
//				
//				int caretOffset = sourceViewer.getTextWidget().getCaretOffset();
//				offset = sourceViewer.widgetOffset2ModelOffset(caretOffset);
//			}
//		}
		
		return doComputeCompletionProposals(viewer, offset);
	}
 

private void addModulaSymbolToCompletionProposals(List<ICompletionProposal> completionProposals, Set<ICompletionProposal> proposalsSet,
        IModulaSymbol s, Predicate<IModulaSymbol> symbolFilter) 
{
    if (s == null || s.getName() == null) {
        return; // parser sometimes may produce it 
    }

    if (symbolFilter != null && !symbolFilter.test(s)) {
        return;
    }
    
    String proposalText =  s.getName();
    
    String filterPrefix = context.getBeforeCursorWordPart();
    if (filterPrefix != null && !StringUtils.startsWithIgnoreCase(proposalText, filterPrefix)) {
        return;
    }

    addProposal(completionProposals, proposalsSet, s);
}
 

private void createStringProposal(ContentAssistContext context, ICompletionProposalAcceptor acceptor,
		String feature, RuleCall ruleCall) {
	String proposalText = feature != null ? feature : Strings.toFirstUpper(ruleCall.getRule().getName().toLowerCase());
	proposalText = getValueConverter().toString(proposalText, ruleCall.getRule().getName());
	String displayText = proposalText;
	if (feature != null)
		displayText = displayText + " - " + ruleCall.getRule().getName();
	ICompletionProposal proposal = createCompletionProposal(proposalText, displayText, null, context);
	if (proposal instanceof ConfigurableCompletionProposal) {
		ConfigurableCompletionProposal configurable = (ConfigurableCompletionProposal) proposal;
		configurable.setSelectionStart(configurable.getReplacementOffset() + 1);
		configurable.setSelectionLength(proposalText.length() - 2);
		configurable.setAutoInsertable(false);
		configurable.setSimpleLinkedMode(context.getViewer(), proposalText.charAt(0), '\t');
		
	}
	acceptor.accept(proposal);
}
 

private void dottedExpressionProposals(CompletionContext context,
		List<ICompletionProposal> proposals, Set<ICompletionProposal> proposalsSet) {
	Predicate<IModulaSymbol> symbolFilter = createSymbolFilter(context);
	IModulaSymbol symbol = context.getReferencedSymbol();
	if (symbol == null) {
		return;
	}
	if (symbol instanceof IModuleAliasSymbol) {
		symbol = ((IModuleAliasSymbol)symbol).getReference();
       }
	ITypeSymbol typeSymbol = JavaUtils.as(ITypeSymbol.class, symbol);
	if (typeSymbol != null) {
		addCompletionProposalsFromTypeSymbol(proposals, proposalsSet, typeSymbol, symbolFilter);
	}
	else {
		IModuleSymbol moduleSymbol = JavaUtils.as(IModuleSymbol.class, symbol);
		if (moduleSymbol != null) {
			addCompletionProposalsFromDefinitionModule(proposals, proposalsSet, moduleSymbol, symbolFilter);
		}
	}
}
 

/**
 *  If length of line at 'lineNum' is 'len', then validate all proposals for invocation
 *  index varying from '(len - numCharsCompleted)' to 'len'.
 */
private static void validateExpectedProposals(IJavaProject javaProject,
    String fullyQualifiedClassName, String source, int lineNum, int numCharsCompleted,
    String... expectedProposals) throws CoreException, BadLocationException {
  IProgressMonitor monitor = new NullProgressMonitor();

  ICompilationUnit iCompilationUnit = JavaProjectUtilities.createCompilationUnit(
      javaProject, fullyQualifiedClassName, source);
  CompilationUnitEditor cuEditor = (CompilationUnitEditor) JavaUI.openInEditor(iCompilationUnit);

  ISourceViewer viewer = cuEditor.getViewer();
  IDocument document = viewer.getDocument();

  IRegion lineInformation = document.getLineInformation(lineNum);
  JsniMethodBodyCompletionProposalComputer jcpc = new JsniMethodBodyCompletionProposalComputer();

  for (int numCharsToOverwrite = 0; numCharsToOverwrite <= numCharsCompleted;
      numCharsToOverwrite++){
    int invocationOffset = lineInformation.getOffset()
        + lineInformation.getLength() - numCharsToOverwrite;
    JavaContentAssistInvocationContext context = new JavaContentAssistInvocationContext(
        viewer, invocationOffset, cuEditor);
    List<ICompletionProposal> completions = jcpc.computeCompletionProposals(
        context, monitor);

    int indentationUnits = JsniMethodBodyCompletionProposalComputer.measureIndentationUnits(
        document, lineNum, lineInformation.getOffset(), javaProject);
    List<String> expected = createJsniBlocks(javaProject, indentationUnits,
        expectedProposals);
    for (int i = 0; i < expected.size(); i++){
      String expectedBlock = expected.get(i).substring(numCharsCompleted - numCharsToOverwrite);
      expected.set(i, expectedBlock);
    }
    assertExpectedProposals(expected, completions, numCharsToOverwrite);
  }
}
 

private List<ICompletionProposal> filterTemplateProposals(ICompletionProposal[] templateProposals, String prefix) {
    if (templateProposals != null && templateProposals.length > 0) {
        List<ICompletionProposal> proposals = Arrays.asList(templateProposals);
        if (!prefix.isEmpty()) {
            return proposals.stream() //
                    .filter(e -> e.getDisplayString().toLowerCase().contains(prefix.toLowerCase())) //
                    .collect(Collectors.toList());
        }
        return proposals;
    } else {
        return Collections.emptyList();
    }
}
 

@Override
public ICompletionProposal[] computeCompletionProposals(final ITextViewer textViewer, final int documentOffset) {
    if (expressions == null) {
        return new ICompletionProposal[0];
    }
    ICompletionProposal[] proposals = null;

    proposals = buildProposals(expressions, documentOffset, textViewer);
    return proposals;

}
 

@Override
public ICompletionProposal[] computeCompletionProposals(ITextViewer viewer, int offset) {

	IDocument document = viewer.getDocument();

	try {
		int lineOfOffset = document.getLineOfOffset(offset);
		int lineOffset = document.getLineOffset(lineOfOffset);

		// do not show any content assist in case the offset is not at the
		// beginning of a line
		if (offset != lineOffset) {
			return new ICompletionProposal[0];
		}
	} catch (BadLocationException e) {
		// ignore here and just continue
	}

	List<ICompletionProposal> completionProposals = new ArrayList<ICompletionProposal>();

	for (String c : proposals) {
		// Only add proposal if it is not already present
		if (!(viewer.getDocument().get().contains(c))) {
			completionProposals.add(new CompletionProposal(c, offset, 0, c.length()));
		}
	}

	return completionProposals.toArray(new ICompletionProposal[completionProposals.size()]);
}
 

private ICompletionProposal[] allProposalsAt(RegionWithCursor offset, N4ContentAssistProcessorTestBuilder fixture) {
	AtomicReference<ICompletionProposal[]> w = new AtomicReference<>();

	Display.getDefault().syncExec(() -> {

		try {
			w.set(fixture.computeCompletionProposals(offset
					.getGlobalCursorOffset()));
		} catch (Exception e) {
			logger.warn("Cannot compute Completion Proposals", e);
		}
	});

	return w.get();
}
 

@Override
public void adjustCrossReferencePriority(ICompletionProposal proposal, String prefix) {
	//		if (proposal instanceof SARLCompletionProposal) {
	//			final SARLCompletionProposal configurableProposal = (SARLCompletionProposal) proposal;
	//			final EObject eobject = configurableProposal.getReferencedFeature();
	//			if (eobject instanceof JvmIdentifiableElement) {
	//				//final JvmIdentifiableElement idElement = (JvmIdentifiableElement) eobject;
	//			}
	//		}
	super.adjustCrossReferencePriority(proposal, prefix);
}
 

/**
 * {@inheritDoc} Code copied from parent. Override required to run in UI because of getSourceViewer, which creates a new Shell.
 */
public ICompletionProposal[] computeCompletionProposals(final XtextTestSource testSource, final int cursorPosition) {
  Pair<ICompletionProposal[], BadLocationException> result = UiThreadDispatcher.dispatchAndWait(new Function<Pair<ICompletionProposal[], BadLocationException>>() {
    @Override
    public Pair<ICompletionProposal[], BadLocationException> run() {
      final IXtextDocument xtextDocument = getDocument(testSource.getXtextResource(), testSource.getContent());
      return internalComputeCompletionProposals(cursorPosition, xtextDocument);
    }
  });
  if (result.getSecond() != null) {
    throw new WrappedException("Error computing completion proposals.", result.getSecond());
  }
  return result.getFirst();
}
 

public static ICompletionProposal[] collectAssists(PropertiesAssistContext invocationContext) throws BadLocationException, BadPartitioningException {
	ArrayList<ICompletionProposal> resultingCollections= new ArrayList<ICompletionProposal>();

	getEscapeUnescapeBackslashProposals(invocationContext, resultingCollections);
	getCreateFieldsInAccessorClassProposals(invocationContext, resultingCollections);
	getRemovePropertiesProposals(invocationContext, resultingCollections);
	getRenameKeysProposals(invocationContext, resultingCollections);

	if (resultingCollections.size() == 0)
		return null;
	return resultingCollections.toArray(new ICompletionProposal[resultingCollections.size()]);
}
 

/**
 * addCloseTagProposals
 * 
 * @param lexemeProvider
 * @param offset
 * @param result
 */
private boolean addDefaultCloseTagProposals(LocationType fineLocation, List<ICompletionProposal> proposals,
		ILexemeProvider<HTMLTokenType> lexemeProvider, int offset)
{
	HTMLParseState state = null;
	boolean addedProposal = false;
	// Looks like no unclosed tags that make sense. Suggest every non-self-closing tag.
	List<ElementElement> elements = this._queryHelper.getElements();
	if (elements != null)
	{
		for (ElementElement element : elements)
		{
			if (state == null)
			{
				state = new HTMLParseState(_document.get());
			}
			if (state.isEmptyTagType(element.getName()))
			{
				continue;
			}
			proposals.add(createCloseTagProposal(element, lexemeProvider, offset,
					ICommonCompletionProposal.RELEVANCE_HIGH));
			addedProposal = true;
		}
	}
	return addedProposal;
}
 

private ICompletionProposal createProposal(String text) {
  if (isCursorPositionValid) {
    return new ReplacementCompletionProposal(text, getReplaceOffset(),
        getReplaceLength(), cursorPosition, null, text, image);
  } else {
    return new ReplacementCompletionProposal(text, getReplaceOffset(),
        getReplaceLength(),
        ReplacementCompletionProposal.DEFAULT_CURSOR_POSITION, null, text,
        image);
  }
}
 

public ApplyOperation(int offset,String username,String path,List<ICompletionProposal> propList){
	this.offset = offset;
	this.last_offset = offset;
	this.username = username;
	this.path = path;
	this.propList = propList;
        InputString.add('.');
	
}
 

/**
 * Proposes a getter that is assumed to delegate to a method with the same
 * name as the java method.
 */
private void proposeGetterDelegate(IJavaProject project, IMethod method,
    int invocationOffset, int indentationUnits, boolean isStatic,
    List<ICompletionProposal> proposals, int numCharsFilled, 
    int numCharsToOverwrite) throws JavaModelException {
  String methodName = method.getElementName();
  String[] parameterNames = method.getParameterNames();
  String expression = "return "
      + createJsMethodInvocationExpression(methodName, isStatic,
          parameterNames);
  String code = createJsniBlock(project, expression, indentationUnits);
  proposals.add(createProposal(method.getFlags(), code, invocationOffset,
      numCharsFilled, numCharsToOverwrite, expression));
}
 

public ICompletionProposal[] computeCompletionProposals(ITextViewer viewer, int offset) {

        List<ICompletionProposal> finalProposals = new ArrayList<ICompletionProposal>();
        List<String> proposals = new ArrayList<String>();
        ICompletionProposal[] toReturn = null;
        try {
            toReturn = doComputeProposal(viewer, offset, finalProposals, proposals);
        } catch (Exception ex) {
            toReturn = new ICompletionProposal[proposals.size()];
            return proposals.toArray(toReturn);
        }
        return toReturn;
    }
 

private void createCompletionProposalsControl(Composite parent, ICompletionProposal[] proposals) {
	Composite composite= new Composite(parent, SWT.NONE);
	composite.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
	GridLayout layout2= new GridLayout(1, false);
	layout2.marginHeight= 0;
	layout2.marginWidth= 0;
	layout2.verticalSpacing= 2;
	composite.setLayout(layout2);

	Label separator= new Label(composite, SWT.SEPARATOR | SWT.HORIZONTAL);
	GridData gridData= new GridData(SWT.FILL, SWT.CENTER, true, false);
	separator.setLayoutData(gridData);

	Label quickFixLabel= new Label(composite, SWT.NONE);
	GridData layoutData= new GridData(SWT.BEGINNING, SWT.CENTER, false, false);
	layoutData.horizontalIndent= 4;
	quickFixLabel.setLayoutData(layoutData);
	String text;
	if (proposals.length == 1) {
		text= JavaHoverMessages.AbstractAnnotationHover_message_singleQuickFix;
	} else {
		text= Messages.format(JavaHoverMessages.AbstractAnnotationHover_message_multipleQuickFix, new Object[] { String.valueOf(proposals.length) });
	}
	quickFixLabel.setText(text);

	setColorAndFont(composite, parent.getForeground(), parent.getBackground(), JFaceResources.getDialogFont());
	createCompletionProposalsList(composite, proposals);
}
 

protected String getSortString(ICompletionProposal proposal) {
	String sortString;
	if(proposal instanceof LangCompletionProposal) {
		LangCompletionProposal langProposal = (LangCompletionProposal) proposal;
		sortString = langProposal.getSortString();
	} else {
		sortString = proposal.getDisplayString();
	}
	return sortString == null ? "\uFFFF" : sortString;
}
 

/**
 * Create the "no proposals" proposal
 * 
 * @return
 */
private ICompletionProposal[] createNoProposal()
{
	fEmptyProposal.fOffset = fFilterOffset;
	fEmptyProposal.fDisplayString = JFaceTextMessages.
			getString("CompletionProposalPopup.no_proposals");  //$NON-NLS-1$
	modifySelection(-1, -1); // deselect everything
	return new ICompletionProposal[] { fEmptyProposal };
}
 

@Test
public void should_computeCompletionProposals_returns_no_proposals_for_unsupported_expression() throws Exception {
    when(contentAssistContext.getPerceivedCompletionNode()).thenReturn(null);
    doReturn(Collections.emptyList()).when(proposalComputer).getContractInputs(context);
    final List<ICompletionProposal> proposals = proposalComputer.computeCompletionProposals(context, null);
    assertThat(proposals).isEmpty();
}
 

@Test
public void testSpellingQuickfixInMlComment() throws Exception {
	xtextEditor.getDocument().set(MODEL_WITH_SPELLING_QUICKFIX_IN_ML_COLMMENT);
	ICompletionProposal[] quickAssistProposals = computeQuickAssistProposals(getDocument().getLength());
	List<ICompletionProposal> proposals = Arrays.asList(quickAssistProposals);
	assertSpellingQuickfixProposals(proposals);
}