contrib/org.eclipse.objectteams.jdt.nullity/src/org/eclipse/objectteams/internal/jdt/nullity/quickfix/QuickFixes.java - gerrit/objectteams/org.eclipse.objectteams - Git at Google

 /*******************************************************************************
  * Copyright (c) 2011 GK Software AG 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:
  *     Stephan Herrmann - initial API and implementation
  *******************************************************************************/
 package org.eclipse.objectteams.internal.jdt.nullity.quickfix;

 import static org.eclipse.objectteams.internal.jdt.nullity.Constants.IProblem.RequiredNonNullButProvidedNull;
 import static org.eclipse.objectteams.internal.jdt.nullity.Constants.IProblem.RequiredNonNullButProvidedPotentialNull;
 import static org.eclipse.objectteams.internal.jdt.nullity.Constants.IProblem.RequiredNonNullButProvidedUnknown;
 import static org.eclipse.objectteams.internal.jdt.nullity.Constants.IProblem.IllegalDefinitionToNonNullParameter;
 import static org.eclipse.objectteams.internal.jdt.nullity.Constants.IProblem.IllegalRedefinitionToNonNullParameter;
 import static org.eclipse.objectteams.internal.jdt.nullity.Constants.IProblem.IllegalReturnNullityRedefinition;
 import static org.eclipse.objectteams.internal.jdt.nullity.Constants.IProblem.ParameterLackingNonNullAnnotation;
 import static org.eclipse.objectteams.internal.jdt.nullity.Constants.IProblem.ParameterLackingNullableAnnotation;

 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.Hashtable;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;

 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.jdt.core.ICompilationUnit;
 import org.eclipse.jdt.core.IJavaElement;
 import org.eclipse.jdt.core.compiler.IProblem;
 import org.eclipse.jdt.core.dom.ASTNode;
 import org.eclipse.jdt.core.dom.CompilationUnit;
 import org.eclipse.jdt.core.dom.IBinding;
 import org.eclipse.jdt.core.dom.IVariableBinding;
 import org.eclipse.jdt.core.dom.SimpleName;
 import org.eclipse.jdt.core.dom.VariableDeclaration;
 import org.eclipse.jdt.internal.corext.dom.ASTNodes;
 import org.eclipse.jdt.internal.corext.fix.CompilationUnitRewriteOperationsFix;
 import org.eclipse.jdt.internal.corext.fix.CompilationUnitRewriteOperationsFix.CompilationUnitRewriteOperation;
 import org.eclipse.jdt.internal.corext.util.JavaModelUtil;
 import org.eclipse.jdt.internal.ui.JavaPluginImages;
 import org.eclipse.jdt.internal.ui.text.correction.ProblemLocation;
 import org.eclipse.jdt.internal.ui.text.correction.proposals.FixCorrectionProposal;
 import org.eclipse.jdt.ui.cleanup.ICleanUpFix;
 import org.eclipse.jdt.ui.text.java.IInvocationContext;
 import org.eclipse.jdt.ui.text.java.IJavaCompletionProposal;
 import org.eclipse.jdt.ui.text.java.IProblemLocation;
 import org.eclipse.objectteams.internal.jdt.nullity.NullCompilerOptions;
 import org.eclipse.swt.graphics.Image;

 /**
  * Quickfixes for null-annotation related problems.
  *
  * @author stephan
  */
 @SuppressWarnings("restriction")
 public class QuickFixes implements org.eclipse.jdt.ui.text.java.IQuickFixProcessor {

 	/** Small adaptation just to make available the 'compilationUnit' passed at instantiation time. */
 	static class MyCURewriteOperationsFix extends CompilationUnitRewriteOperationsFix {
 		CompilationUnit cu;
 		public MyCURewriteOperationsFix(String name, CompilationUnit compilationUnit, CompilationUnitRewriteOperation[] operations)
 		{
 			super(name, compilationUnit, operations);
 			this.cu = compilationUnit;
 		}
 	}

 	public boolean hasCorrections(ICompilationUnit cu, int problemId) {
 		switch (problemId) {
 		case RequiredNonNullButProvidedNull:
 		case RequiredNonNullButProvidedPotentialNull:
 		case RequiredNonNullButProvidedUnknown:
 		case IllegalReturnNullityRedefinition:
 		case IllegalRedefinitionToNonNullParameter:
 		case IllegalDefinitionToNonNullParameter:
 		case ParameterLackingNonNullAnnotation:
 		case ParameterLackingNullableAnnotation:
 		case IProblem.NonNullLocalVariableComparisonYieldsFalse:
 		case IProblem.RedundantNullCheckOnNonNullLocalVariable:
 				return true;
 		default:
 			return false;
 		}
 	}

 	/* (non-Javadoc)
 	 * @see IAssistProcessor#getCorrections(org.eclipse.jdt.internal.ui.text.correction.IAssistContext, org.eclipse.jdt.internal.ui.text.correction.IProblemLocation[])
 	 */
 	public IJavaCompletionProposal[] getCorrections(IInvocationContext context, IProblemLocation[] locations) throws CoreException {
 		if (locations == null || locations.length == 0) {
 			return null;
 		}

 		HashSet<Integer> handledProblems= new HashSet<Integer>(locations.length);
 		ArrayList<IJavaCompletionProposal> resultingCollections= new ArrayList<IJavaCompletionProposal>();
 		for (int i= 0; i < locations.length; i++) {
 			IProblemLocation curr= locations[i];
 			Integer id= new Integer(curr.getProblemId());
 			if (handledProblems.add(id)) {
 				process(context, curr, resultingCollections);
 			}
 		}
 		return (IJavaCompletionProposal[]) resultingCollections.toArray(new IJavaCompletionProposal[resultingCollections.size()]);
 	}

 	void process(IInvocationContext context, IProblemLocation problem, Collection<IJavaCompletionProposal> proposals) {
 		int id= problem.getProblemId();
 		if (id == 0) { // no proposals for none-problem locations
 			return;
 		}
 		CompilationUnit astRoot= context.getASTRoot();
 		ASTNode selectedNode= problem.getCoveringNode(astRoot);

 		switch (id) {
 		case IllegalReturnNullityRedefinition:
 		case IllegalDefinitionToNonNullParameter:
 		case IllegalRedefinitionToNonNullParameter:
 			addNullAnnotationInSignatureProposal(context, problem, proposals, false);
 			addNullAnnotationInSignatureProposal(context, problem, proposals, true);
 			break;
 		case RequiredNonNullButProvidedNull:
 		case RequiredNonNullButProvidedPotentialNull:
 		case RequiredNonNullButProvidedUnknown:
 		case ParameterLackingNonNullAnnotation:
 		case ParameterLackingNullableAnnotation:
 		case IProblem.NonNullLocalVariableComparisonYieldsFalse:
 		case IProblem.RedundantNullCheckOnNonNullLocalVariable:
 			if (isComplainingAboutArgument(selectedNode)
 				|| isComplainingAboutReturn(selectedNode))
 				addNullAnnotationInSignatureProposal(context, problem, proposals, false);
 			break;
 		}
 	}

 	@SuppressWarnings("unchecked")
 	void addNullAnnotationInSignatureProposal(IInvocationContext context,
 											  IProblemLocation problem,
 											  @SuppressWarnings("rawtypes") Collection proposals,
 											  boolean modifyOverridden)
 	{
 		MyCURewriteOperationsFix fix= createNullAnnotationInSignatureFix(context.getASTRoot(), problem, modifyOverridden);

 		if (fix != null) {
 			Image image= JavaPluginImages.get(JavaPluginImages.IMG_CORRECTION_CHANGE);
 			Map<String, String> options= new Hashtable<String, String>();
 			if (fix.cu != context.getASTRoot()) {
 				// workaround: adjust the unit to operate on, depending on the findings of RewriteOperations.createAddAnnotationOperation(..)
 				final CompilationUnit cu = fix.cu;
 				final IInvocationContext originalContext = context;
 				context = new IInvocationContext() {
 					public int getSelectionOffset() {
 						return originalContext.getSelectionOffset();
 					}
 					public int getSelectionLength() {
 						return originalContext.getSelectionLength();
 					}
 					public ASTNode getCoveringNode() {
 						return originalContext.getCoveringNode();
 					}
 					public ASTNode getCoveredNode() {
 						return originalContext.getCoveredNode();
 					}
 					public ICompilationUnit getCompilationUnit() {
 						return (ICompilationUnit) cu.getJavaElement();
 					}

 					public CompilationUnit getASTRoot() {
 						return cu;
 					}
 				};
 			}
 			int relevance = modifyOverridden ? 15 : 20; // TODO(SH): insert suitable values, just raise local change above change in overridden method
 			FixCorrectionProposal proposal= new FixCorrectionProposal(fix, new NullAnnotationsCleanUp(options, this, problem.getProblemId()), relevance, image, context);
 			proposals.add(proposal);
 		}
 	}

 	boolean isComplainingAboutArgument(ASTNode selectedNode) {
 		if (!(selectedNode instanceof SimpleName)) {
 			return false;
 		}
 		SimpleName nameNode= (SimpleName) selectedNode;
 		IBinding binding = nameNode.resolveBinding();
 		if (binding.getKind() == IBinding.VARIABLE && ((IVariableBinding) binding).isParameter())
 			return true;
 		VariableDeclaration argDecl = (VariableDeclaration) ASTNodes.getParent(selectedNode, VariableDeclaration.class);
 		if (argDecl != null)
 			binding = argDecl.resolveBinding();
 		if (binding.getKind() == IBinding.VARIABLE && ((IVariableBinding) binding).isParameter())
 			return true;
 		return false;
 	}

 	boolean isComplainingAboutReturn(ASTNode selectedNode) {
 		return selectedNode.getParent().getNodeType() == ASTNode.RETURN_STATEMENT;
 	}

 	MyCURewriteOperationsFix createNullAnnotationInSignatureFix(CompilationUnit compilationUnit, IProblemLocation problem, boolean modifyOverridden)
 	{
 		String nullableAnnotationName = getNullableAnnotationName(compilationUnit.getJavaElement(), false);
 		String nonNullAnnotationName = getNonNullAnnotationName(compilationUnit.getJavaElement(), false);
 		String annotationToAdd = nullableAnnotationName;
 		String annotationToRemove = nonNullAnnotationName;

 		switch (problem.getProblemId()) {
 		case IllegalDefinitionToNonNullParameter:
 		case IllegalRedefinitionToNonNullParameter:
 		// case ParameterLackingNullableAnnotation: // never proposed with modifyOverridden
 			if (modifyOverridden) {
 				annotationToAdd = nonNullAnnotationName;
 				annotationToRemove = nullableAnnotationName;
 			}
 			break;
 		case ParameterLackingNonNullAnnotation:
 		case IllegalReturnNullityRedefinition:
 			if (!modifyOverridden) {
 				annotationToAdd = nonNullAnnotationName;
 				annotationToRemove = nullableAnnotationName;
 			}
 			break;
 		// all others propose to add @Nullable
 		}

 		// when performing one change at a time we can actually modify another CU than the current one:
 		RewriteOperations.SignatureAnnotationRewriteOperation operation =
 			RewriteOperations.createAddAnnotationOperation(
 				compilationUnit, problem, annotationToAdd, annotationToRemove, null,
 				false/*thisUnitOnly*/, true/*allowRemove*/, modifyOverridden);
 		if (operation == null)
 			return null;

 		return new MyCURewriteOperationsFix(operation.getMessage(),
 											operation.getCompilationUnit(), // note that this uses the findings from createAddAnnotationOperation(..)
 											new RewriteOperations.SignatureAnnotationRewriteOperation[] {operation});
 	}

 	// Entry for NullAnnotationsCleanup:
 	public ICleanUpFix createCleanUp(CompilationUnit compilationUnit, IProblemLocation[] locations, int problemID)
 	{

 		ICompilationUnit cu= (ICompilationUnit)compilationUnit.getJavaElement();
 		if (!JavaModelUtil.is50OrHigher(cu.getJavaProject()))
 			return null;

 		List<CompilationUnitRewriteOperation> operations= new ArrayList<CompilationUnitRewriteOperation>();

 		if (locations == null) {
 			org.eclipse.jdt.core.compiler.IProblem[] problems= compilationUnit.getProblems();
 			locations= new IProblemLocation[problems.length];
 			for (int i= 0; i < problems.length; i++) {
 				if (problems[i].getID() == problemID)
 					locations[i]= new ProblemLocation(problems[i]);
 			}
 		}

 		createAddNullAnnotationOperations(compilationUnit, locations, operations);

 		if (operations.size() == 0)
 			return null;

 		CompilationUnitRewriteOperation[] operationsArray= operations.toArray(new CompilationUnitRewriteOperation[operations.size()]);
 		return new MyCURewriteOperationsFix(FixMessages.QuickFixes_add_annotation_change_name, compilationUnit, operationsArray);
 	}

 	@SuppressWarnings({ "rawtypes", "unchecked" })
 	void createAddNullAnnotationOperations(CompilationUnit compilationUnit, IProblemLocation[] locations, List result) {
 		String nullableAnnotationName = getNullableAnnotationName(compilationUnit.getJavaElement(), false);
 		String nonNullAnnotationName = getNonNullAnnotationName(compilationUnit.getJavaElement(), false);
 		Set<String> handledPositions = new HashSet<String>();
 		for (int i= 0; i < locations.length; i++) {
 			IProblemLocation problem= locations[i];
 			if (problem == null) continue; // problem was filtered out by createCleanUp()
 			String annotationToAdd = nullableAnnotationName;
 			String annotationToRemove = nonNullAnnotationName;
 			switch (problem.getProblemId()) {
 			case IllegalDefinitionToNonNullParameter:
 			case IllegalRedefinitionToNonNullParameter:
 			case ParameterLackingNonNullAnnotation:
 			case IllegalReturnNullityRedefinition:
 				annotationToAdd = nonNullAnnotationName;
 				annotationToRemove = nullableAnnotationName;
 				// all others propose to add @Nullable
 			}
 			// when performing multiple changes we can only modify the one CU that the CleanUp infrastructure provides to the operation.
 			CompilationUnitRewriteOperation fix = RewriteOperations.createAddAnnotationOperation(
 						compilationUnit, problem, annotationToAdd, annotationToRemove,
 						handledPositions, true/*thisUnitOnly*/, false/*allowRemove*/, false/*modifyOverridden*/);
 			if (fix != null)
 				result.add(fix);
 		}
 	}

 	public static boolean isMissingNullAnnotationProblem(int id) {
 		return id == RequiredNonNullButProvidedNull || id == RequiredNonNullButProvidedPotentialNull
 				|| id == IllegalReturnNullityRedefinition
 				|| mayIndicateParameterNullcheck(id);
 	}

 	public static boolean mayIndicateParameterNullcheck(int problemId) {
 		return problemId == IProblem.NonNullLocalVariableComparisonYieldsFalse || problemId == IProblem.RedundantNullCheckOnNonNullLocalVariable;
 	}

 	public static boolean hasExplicitNullAnnotation(ICompilationUnit compilationUnit, int offset) {
 // FIXME(SH): check for existing annotations disabled due to lack of precision:
 //		      should distinguish what is actually annotated (return? param? which?)
 //		try {
 //			IJavaElement problemElement = compilationUnit.getElementAt(offset);
 //			if (problemElement.getElementType() == IJavaElement.METHOD) {
 //				IMethod method = (IMethod) problemElement;
 //				String nullable = getNullableAnnotationName(compilationUnit, true);
 //				String nonnull = getNonNullAnnotationName(compilationUnit, true);
 //				for (IAnnotation annotation : method.getAnnotations()) {
 //					if (   annotation.getElementName().equals(nonnull)
 //						|| annotation.getElementName().equals(nullable))
 //						return true;
 //				}
 //			}
 //		} catch (JavaModelException jme) {
 //			/* nop */
 //		}
 		return false;
 	}

 	public static String getNullableAnnotationName(IJavaElement javaElement, boolean makeSimple) {
 		String qualifiedName = javaElement.getJavaProject().getOption(NullCompilerOptions.OPTION_NullableAnnotationName, true);
 		int lastDot;
 		if (makeSimple && qualifiedName != null && (lastDot = qualifiedName.lastIndexOf('.')) != -1)
 			return qualifiedName.substring(lastDot+1);
 		return qualifiedName;
 	}

 	public static String getNonNullAnnotationName(IJavaElement javaElement, boolean makeSimple) {
 		String qualifiedName = javaElement.getJavaProject().getOption(NullCompilerOptions.OPTION_NonNullAnnotationName, true);
 		int lastDot;
 		if (makeSimple && qualifiedName != null && (lastDot = qualifiedName.lastIndexOf('.')) != -1)
 			return qualifiedName.substring(lastDot+1);
 		return qualifiedName;
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2011 GK Software AG 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:
	* Stephan Herrmann - initial API and implementation
	*******************************************************************************/
	package org.eclipse.objectteams.internal.jdt.nullity.quickfix;

	import static org.eclipse.objectteams.internal.jdt.nullity.Constants.IProblem.RequiredNonNullButProvidedNull;
	import static org.eclipse.objectteams.internal.jdt.nullity.Constants.IProblem.RequiredNonNullButProvidedPotentialNull;
	import static org.eclipse.objectteams.internal.jdt.nullity.Constants.IProblem.RequiredNonNullButProvidedUnknown;
	import static org.eclipse.objectteams.internal.jdt.nullity.Constants.IProblem.IllegalDefinitionToNonNullParameter;
	import static org.eclipse.objectteams.internal.jdt.nullity.Constants.IProblem.IllegalRedefinitionToNonNullParameter;
	import static org.eclipse.objectteams.internal.jdt.nullity.Constants.IProblem.IllegalReturnNullityRedefinition;
	import static org.eclipse.objectteams.internal.jdt.nullity.Constants.IProblem.ParameterLackingNonNullAnnotation;
	import static org.eclipse.objectteams.internal.jdt.nullity.Constants.IProblem.ParameterLackingNullableAnnotation;

	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.HashSet;
	import java.util.Hashtable;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;

	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.jdt.core.ICompilationUnit;
	import org.eclipse.jdt.core.IJavaElement;
	import org.eclipse.jdt.core.compiler.IProblem;
	import org.eclipse.jdt.core.dom.ASTNode;
	import org.eclipse.jdt.core.dom.CompilationUnit;
	import org.eclipse.jdt.core.dom.IBinding;
	import org.eclipse.jdt.core.dom.IVariableBinding;
	import org.eclipse.jdt.core.dom.SimpleName;
	import org.eclipse.jdt.core.dom.VariableDeclaration;
	import org.eclipse.jdt.internal.corext.dom.ASTNodes;
	import org.eclipse.jdt.internal.corext.fix.CompilationUnitRewriteOperationsFix;
	import org.eclipse.jdt.internal.corext.fix.CompilationUnitRewriteOperationsFix.CompilationUnitRewriteOperation;
	import org.eclipse.jdt.internal.corext.util.JavaModelUtil;
	import org.eclipse.jdt.internal.ui.JavaPluginImages;
	import org.eclipse.jdt.internal.ui.text.correction.ProblemLocation;
	import org.eclipse.jdt.internal.ui.text.correction.proposals.FixCorrectionProposal;
	import org.eclipse.jdt.ui.cleanup.ICleanUpFix;
	import org.eclipse.jdt.ui.text.java.IInvocationContext;
	import org.eclipse.jdt.ui.text.java.IJavaCompletionProposal;
	import org.eclipse.jdt.ui.text.java.IProblemLocation;
	import org.eclipse.objectteams.internal.jdt.nullity.NullCompilerOptions;
	import org.eclipse.swt.graphics.Image;

	/**
	* Quickfixes for null-annotation related problems.
	*
	* @author stephan
	*/
	@SuppressWarnings("restriction")
	public class QuickFixes implements org.eclipse.jdt.ui.text.java.IQuickFixProcessor {

	/** Small adaptation just to make available the 'compilationUnit' passed at instantiation time. */
	static class MyCURewriteOperationsFix extends CompilationUnitRewriteOperationsFix {
	CompilationUnit cu;
	public MyCURewriteOperationsFix(String name, CompilationUnit compilationUnit, CompilationUnitRewriteOperation[] operations)
	{
	super(name, compilationUnit, operations);
	this.cu = compilationUnit;
	}
	}

	public boolean hasCorrections(ICompilationUnit cu, int problemId) {
	switch (problemId) {
	case RequiredNonNullButProvidedNull:
	case RequiredNonNullButProvidedPotentialNull:
	case RequiredNonNullButProvidedUnknown:
	case IllegalReturnNullityRedefinition:
	case IllegalRedefinitionToNonNullParameter:
	case IllegalDefinitionToNonNullParameter:
	case ParameterLackingNonNullAnnotation:
	case ParameterLackingNullableAnnotation:
	case IProblem.NonNullLocalVariableComparisonYieldsFalse:
	case IProblem.RedundantNullCheckOnNonNullLocalVariable:
	return true;
	default:
	return false;
	}
	}

	/* (non-Javadoc)
	* @see IAssistProcessor#getCorrections(org.eclipse.jdt.internal.ui.text.correction.IAssistContext, org.eclipse.jdt.internal.ui.text.correction.IProblemLocation[])
	*/
	public IJavaCompletionProposal[] getCorrections(IInvocationContext context, IProblemLocation[] locations) throws CoreException {
	if (locations == null \|\| locations.length == 0) {
	return null;
	}

	HashSet<Integer> handledProblems= new HashSet<Integer>(locations.length);
	ArrayList<IJavaCompletionProposal> resultingCollections= new ArrayList<IJavaCompletionProposal>();
	for (int i= 0; i < locations.length; i++) {
	IProblemLocation curr= locations[i];
	Integer id= new Integer(curr.getProblemId());
	if (handledProblems.add(id)) {
	process(context, curr, resultingCollections);
	}
	}
	return (IJavaCompletionProposal[]) resultingCollections.toArray(new IJavaCompletionProposal[resultingCollections.size()]);
	}

	void process(IInvocationContext context, IProblemLocation problem, Collection<IJavaCompletionProposal> proposals) {
	int id= problem.getProblemId();
	if (id == 0) { // no proposals for none-problem locations
	return;
	}
	CompilationUnit astRoot= context.getASTRoot();
	ASTNode selectedNode= problem.getCoveringNode(astRoot);

	switch (id) {
	case IllegalReturnNullityRedefinition:
	case IllegalDefinitionToNonNullParameter:
	case IllegalRedefinitionToNonNullParameter:
	addNullAnnotationInSignatureProposal(context, problem, proposals, false);
	addNullAnnotationInSignatureProposal(context, problem, proposals, true);
	break;
	case RequiredNonNullButProvidedNull:
	case RequiredNonNullButProvidedPotentialNull:
	case RequiredNonNullButProvidedUnknown:
	case ParameterLackingNonNullAnnotation:
	case ParameterLackingNullableAnnotation:
	case IProblem.NonNullLocalVariableComparisonYieldsFalse:
	case IProblem.RedundantNullCheckOnNonNullLocalVariable:
	if (isComplainingAboutArgument(selectedNode)
	\|\| isComplainingAboutReturn(selectedNode))
	addNullAnnotationInSignatureProposal(context, problem, proposals, false);
	break;
	}
	}

	@SuppressWarnings("unchecked")
	void addNullAnnotationInSignatureProposal(IInvocationContext context,
	IProblemLocation problem,
	@SuppressWarnings("rawtypes") Collection proposals,
	boolean modifyOverridden)
	{
	MyCURewriteOperationsFix fix= createNullAnnotationInSignatureFix(context.getASTRoot(), problem, modifyOverridden);

	if (fix != null) {
	Image image= JavaPluginImages.get(JavaPluginImages.IMG_CORRECTION_CHANGE);
	Map<String, String> options= new Hashtable<String, String>();
	if (fix.cu != context.getASTRoot()) {
	// workaround: adjust the unit to operate on, depending on the findings of RewriteOperations.createAddAnnotationOperation(..)
	final CompilationUnit cu = fix.cu;
	final IInvocationContext originalContext = context;
	context = new IInvocationContext() {
	public int getSelectionOffset() {
	return originalContext.getSelectionOffset();
	}
	public int getSelectionLength() {
	return originalContext.getSelectionLength();
	}
	public ASTNode getCoveringNode() {
	return originalContext.getCoveringNode();
	}
	public ASTNode getCoveredNode() {
	return originalContext.getCoveredNode();
	}
	public ICompilationUnit getCompilationUnit() {
	return (ICompilationUnit) cu.getJavaElement();
	}

	public CompilationUnit getASTRoot() {
	return cu;
	}
	};
	}
	int relevance = modifyOverridden ? 15 : 20; // TODO(SH): insert suitable values, just raise local change above change in overridden method
	FixCorrectionProposal proposal= new FixCorrectionProposal(fix, new NullAnnotationsCleanUp(options, this, problem.getProblemId()), relevance, image, context);
	proposals.add(proposal);
	}
	}

	boolean isComplainingAboutArgument(ASTNode selectedNode) {
	if (!(selectedNode instanceof SimpleName)) {
	return false;
	}
	SimpleName nameNode= (SimpleName) selectedNode;
	IBinding binding = nameNode.resolveBinding();
	if (binding.getKind() == IBinding.VARIABLE && ((IVariableBinding) binding).isParameter())
	return true;
	VariableDeclaration argDecl = (VariableDeclaration) ASTNodes.getParent(selectedNode, VariableDeclaration.class);
	if (argDecl != null)
	binding = argDecl.resolveBinding();
	if (binding.getKind() == IBinding.VARIABLE && ((IVariableBinding) binding).isParameter())
	return true;
	return false;
	}

	boolean isComplainingAboutReturn(ASTNode selectedNode) {
	return selectedNode.getParent().getNodeType() == ASTNode.RETURN_STATEMENT;
	}

	MyCURewriteOperationsFix createNullAnnotationInSignatureFix(CompilationUnit compilationUnit, IProblemLocation problem, boolean modifyOverridden)
	{
	String nullableAnnotationName = getNullableAnnotationName(compilationUnit.getJavaElement(), false);
	String nonNullAnnotationName = getNonNullAnnotationName(compilationUnit.getJavaElement(), false);
	String annotationToAdd = nullableAnnotationName;
	String annotationToRemove = nonNullAnnotationName;

	switch (problem.getProblemId()) {
	case IllegalDefinitionToNonNullParameter:
	case IllegalRedefinitionToNonNullParameter:
	// case ParameterLackingNullableAnnotation: // never proposed with modifyOverridden
	if (modifyOverridden) {
	annotationToAdd = nonNullAnnotationName;
	annotationToRemove = nullableAnnotationName;
	}
	break;
	case ParameterLackingNonNullAnnotation:
	case IllegalReturnNullityRedefinition:
	if (!modifyOverridden) {
	annotationToAdd = nonNullAnnotationName;
	annotationToRemove = nullableAnnotationName;
	}
	break;
	// all others propose to add @Nullable
	}

	// when performing one change at a time we can actually modify another CU than the current one:
	RewriteOperations.SignatureAnnotationRewriteOperation operation =
	RewriteOperations.createAddAnnotationOperation(
	compilationUnit, problem, annotationToAdd, annotationToRemove, null,
	false/thisUnitOnly/, true/allowRemove/, modifyOverridden);
	if (operation == null)
	return null;

	return new MyCURewriteOperationsFix(operation.getMessage(),
	operation.getCompilationUnit(), // note that this uses the findings from createAddAnnotationOperation(..)
	new RewriteOperations.SignatureAnnotationRewriteOperation[] {operation});
	}

	// Entry for NullAnnotationsCleanup:
	public ICleanUpFix createCleanUp(CompilationUnit compilationUnit, IProblemLocation[] locations, int problemID)
	{

	ICompilationUnit cu= (ICompilationUnit)compilationUnit.getJavaElement();
	if (!JavaModelUtil.is50OrHigher(cu.getJavaProject()))
	return null;

	List<CompilationUnitRewriteOperation> operations= new ArrayList<CompilationUnitRewriteOperation>();

	if (locations == null) {
	org.eclipse.jdt.core.compiler.IProblem[] problems= compilationUnit.getProblems();
	locations= new IProblemLocation[problems.length];
	for (int i= 0; i < problems.length; i++) {
	if (problems[i].getID() == problemID)
	locations[i]= new ProblemLocation(problems[i]);
	}
	}

	createAddNullAnnotationOperations(compilationUnit, locations, operations);

	if (operations.size() == 0)
	return null;

	CompilationUnitRewriteOperation[] operationsArray= operations.toArray(new CompilationUnitRewriteOperation[operations.size()]);
	return new MyCURewriteOperationsFix(FixMessages.QuickFixes_add_annotation_change_name, compilationUnit, operationsArray);
	}

	@SuppressWarnings({ "rawtypes", "unchecked" })
	void createAddNullAnnotationOperations(CompilationUnit compilationUnit, IProblemLocation[] locations, List result) {
	String nullableAnnotationName = getNullableAnnotationName(compilationUnit.getJavaElement(), false);
	String nonNullAnnotationName = getNonNullAnnotationName(compilationUnit.getJavaElement(), false);
	Set<String> handledPositions = new HashSet<String>();
	for (int i= 0; i < locations.length; i++) {
	IProblemLocation problem= locations[i];
	if (problem == null) continue; // problem was filtered out by createCleanUp()
	String annotationToAdd = nullableAnnotationName;
	String annotationToRemove = nonNullAnnotationName;
	switch (problem.getProblemId()) {
	case IllegalDefinitionToNonNullParameter:
	case IllegalRedefinitionToNonNullParameter:
	case ParameterLackingNonNullAnnotation:
	case IllegalReturnNullityRedefinition:
	annotationToAdd = nonNullAnnotationName;
	annotationToRemove = nullableAnnotationName;
	// all others propose to add @Nullable
	}
	// when performing multiple changes we can only modify the one CU that the CleanUp infrastructure provides to the operation.
	CompilationUnitRewriteOperation fix = RewriteOperations.createAddAnnotationOperation(
	compilationUnit, problem, annotationToAdd, annotationToRemove,
	handledPositions, true/thisUnitOnly/, false/allowRemove/, false/modifyOverridden/);
	if (fix != null)
	result.add(fix);
	}
	}

	public static boolean isMissingNullAnnotationProblem(int id) {
	return id == RequiredNonNullButProvidedNull \|\| id == RequiredNonNullButProvidedPotentialNull
	\|\| id == IllegalReturnNullityRedefinition
	\|\| mayIndicateParameterNullcheck(id);
	}

	public static boolean mayIndicateParameterNullcheck(int problemId) {
	return problemId == IProblem.NonNullLocalVariableComparisonYieldsFalse \|\| problemId == IProblem.RedundantNullCheckOnNonNullLocalVariable;
	}

	public static boolean hasExplicitNullAnnotation(ICompilationUnit compilationUnit, int offset) {
	// FIXME(SH): check for existing annotations disabled due to lack of precision:
	// should distinguish what is actually annotated (return? param? which?)
	// try {
	// IJavaElement problemElement = compilationUnit.getElementAt(offset);
	// if (problemElement.getElementType() == IJavaElement.METHOD) {
	// IMethod method = (IMethod) problemElement;
	// String nullable = getNullableAnnotationName(compilationUnit, true);
	// String nonnull = getNonNullAnnotationName(compilationUnit, true);
	// for (IAnnotation annotation : method.getAnnotations()) {
	// if ( annotation.getElementName().equals(nonnull)
	// \|\| annotation.getElementName().equals(nullable))
	// return true;
	// }
	// }
	// } catch (JavaModelException jme) {
	// /* nop */
	// }
	return false;
	}

	public static String getNullableAnnotationName(IJavaElement javaElement, boolean makeSimple) {
	String qualifiedName = javaElement.getJavaProject().getOption(NullCompilerOptions.OPTION_NullableAnnotationName, true);
	int lastDot;
	if (makeSimple && qualifiedName != null && (lastDot = qualifiedName.lastIndexOf('.')) != -1)
	return qualifiedName.substring(lastDot+1);
	return qualifiedName;
	}

	public static String getNonNullAnnotationName(IJavaElement javaElement, boolean makeSimple) {
	String qualifiedName = javaElement.getJavaProject().getOption(NullCompilerOptions.OPTION_NonNullAnnotationName, true);
	int lastDot;
	if (makeSimple && qualifiedName != null && (lastDot = qualifiedName.lastIndexOf('.')) != -1)
	return qualifiedName.substring(lastDot+1);
	return qualifiedName;
	}
	}