org.eclipse.jdt.ui/core extension/org/eclipse/jdt/internal/corext/template/java/JavaContext.java - jdt/eclipse.jdt.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2006 IBM Corporation 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:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.jdt.internal.corext.template.java;

 import java.lang.reflect.InvocationTargetException;

 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;

 import org.eclipse.swt.widgets.Shell;

 import org.eclipse.jface.dialogs.MessageDialog;
 import org.eclipse.jface.preference.IPreferenceStore;

 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.BadPositionCategoryException;
 import org.eclipse.jface.text.DefaultPositionUpdater;
 import org.eclipse.jface.text.Document;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.IPositionUpdater;
 import org.eclipse.jface.text.IRegion;
 import org.eclipse.jface.text.Position;
 import org.eclipse.jface.text.TextUtilities;
 import org.eclipse.jface.text.templates.Template;
 import org.eclipse.jface.text.templates.TemplateBuffer;
 import org.eclipse.jface.text.templates.TemplateContextType;
 import org.eclipse.jface.text.templates.TemplateException;
 import org.eclipse.jface.text.templates.TemplateTranslator;
 import org.eclipse.jface.text.templates.TemplateVariable;

 import org.eclipse.jdt.core.ICompilationUnit;
 import org.eclipse.jdt.core.IJavaProject;
 import org.eclipse.jdt.core.JavaModelException;
 import org.eclipse.jdt.core.NamingConventions;
 import org.eclipse.jdt.core.Signature;
 import org.eclipse.jdt.core.dom.rewrite.ImportRewrite;

 import org.eclipse.jdt.internal.corext.codemanipulation.StubUtility;
 import org.eclipse.jdt.internal.corext.template.java.CompilationUnitCompletion.LocalVariable;
 import org.eclipse.jdt.internal.corext.util.JavaModelUtil;
 import org.eclipse.jdt.internal.corext.util.Strings;

 import org.eclipse.jdt.ui.JavaUI;
 import org.eclipse.jdt.ui.PreferenceConstants;

 import org.eclipse.jdt.internal.ui.JavaPlugin;
 import org.eclipse.jdt.internal.ui.text.template.contentassist.MultiVariable;
 import org.eclipse.jdt.internal.ui.util.ExceptionHandler;

 /**
  * A context for java source.
  */
 public class JavaContext extends CompilationUnitContext {

 	/** A code completion requester for guessing local variable names. */
 	private CompilationUnitCompletion fCompletion;

 	/**
 	 * Creates a java template context.
 	 *
 	 * @param type   the context type.
 	 * @param document the document.
 	 * @param completionOffset the completion offset within the document.
 	 * @param completionLength the completion length.
 	 * @param compilationUnit the compilation unit (may be <code>null</code>).
 	 */
 	public JavaContext(TemplateContextType type, IDocument document, int completionOffset, int completionLength, ICompilationUnit compilationUnit) {
 		super(type, document, completionOffset, completionLength, compilationUnit);
 	}

 	/**
 	 * Creates a java template context.
 	 *
 	 * @param type   the context type.
 	 * @param document the document.
 	 * @param completionPosition the position defining the completion offset and length
 	 * @param compilationUnit the compilation unit (may be <code>null</code>).
 	 * @since 3.2
 	 */
 	public JavaContext(TemplateContextType type, IDocument document, Position completionPosition, ICompilationUnit compilationUnit) {
 		super(type, document, completionPosition, compilationUnit);
 	}

 	/**
 	 * Returns the indentation level at the position of code completion.
 	 *
 	 * @return the indentation level at the position of the code completion
 	 */
 	private int getIndentation() {
 		int start= getStart();
 		IDocument document= getDocument();
 		try {
 			IRegion region= document.getLineInformationOfOffset(start);
 			String lineContent= document.get(region.getOffset(), region.getLength());
 			ICompilationUnit compilationUnit= getCompilationUnit();
 			IJavaProject project= compilationUnit == null ? null : compilationUnit.getJavaProject();
 			return Strings.computeIndentUnits(lineContent, project);
 		} catch (BadLocationException e) {
 			return 0;
 		}
 	}

 	/*
 	 * @see TemplateContext#evaluate(Template template)
 	 */
 	public TemplateBuffer evaluate(Template template) throws BadLocationException, TemplateException {

 		if (!canEvaluate(template))
 			throw new TemplateException(JavaTemplateMessages.Context_error_cannot_evaluate);

 		TemplateTranslator translator= new TemplateTranslator() {
 			/*
 			 * @see org.eclipse.jface.text.templates.TemplateTranslator#createVariable(java.lang.String, java.lang.String, int[])
 			 */
 			protected TemplateVariable createVariable(String type, String name, int[] offsets) {
 				return new MultiVariable(type, name, offsets);
 			}
 		};
 		TemplateBuffer buffer= translator.translate(template);

 		getContextType().resolve(buffer, this);

 		IPreferenceStore prefs= JavaPlugin.getDefault().getPreferenceStore();
 		boolean useCodeFormatter= prefs.getBoolean(PreferenceConstants.TEMPLATES_USE_CODEFORMATTER);

 		IJavaProject project= getCompilationUnit() != null ? getCompilationUnit().getJavaProject() : null;
 		JavaFormatter formatter= new JavaFormatter(TextUtilities.getDefaultLineDelimiter(getDocument()), getIndentation(), useCodeFormatter, project);
 		formatter.format(buffer, this);

 		return buffer;
 	}

 	/*
 	 * @see TemplateContext#canEvaluate(Template templates)
 	 */
 	public boolean canEvaluate(Template template) {
 		if (fForceEvaluation)
 			return true;

 		String key= getKey();
 		return
 			template.matches(key, getContextType().getId()) &&
 			key.length() != 0 && template.getName().toLowerCase().startsWith(key.toLowerCase());
 	}

 	/*
 	 * @see DocumentTemplateContext#getCompletionPosition();
 	 */
 	public int getStart() {

 		if (fIsManaged && getCompletionLength() > 0)
 			return super.getStart();

 		try {
 			IDocument document= getDocument();

 			int start= getCompletionOffset();
 			int end= getCompletionOffset() + getCompletionLength();

 			while (start != 0 && Character.isUnicodeIdentifierPart(document.getChar(start - 1)))
 				start--;

 			while (start != end && Character.isWhitespace(document.getChar(start)))
 				start++;

 			if (start == end)
 				start= getCompletionOffset();

 				return start;

 		} catch (BadLocationException e) {
 			return super.getStart();
 		}
 	}

 	/*
 	 * @see org.eclipse.jdt.internal.corext.template.DocumentTemplateContext#getEnd()
 	 */
 	public int getEnd() {

 		if (fIsManaged || getCompletionLength() == 0)
 			return super.getEnd();

 		try {
 			IDocument document= getDocument();

 			int start= getCompletionOffset();
 			int end= getCompletionOffset() + getCompletionLength();

 			while (start != end && Character.isWhitespace(document.getChar(end - 1)))
 				end--;

 			return end;

 		} catch (BadLocationException e) {
 			return super.getEnd();
 		}
 	}

 	/*
 	 * @see org.eclipse.jdt.internal.corext.template.DocumentTemplateContext#getKey()
 	 */
 	public String getKey() {

 		if (getCompletionLength() == 0)
 			return super.getKey();

 		try {
 			IDocument document= getDocument();

 			int start= getStart();
 			int end= getCompletionOffset();
 			return start <= end
 				? document.get(start, end - start)
 				: ""; //$NON-NLS-1$

 		} catch (BadLocationException e) {
 			return super.getKey();
 		}
 	}

 	/**
 	 * Returns the character before the start position of the completion.
 	 *
 	 * @return the character before the start position of the completion
 	 */
 	public char getCharacterBeforeStart() {
 		int start= getStart();

 		try {
 			return start == 0
 				? ' '
 				: getDocument().getChar(start - 1);

 		} catch (BadLocationException e) {
 			return ' ';
 		}
 	}

 	private static void handleException(Shell shell, Exception e) {
 		String title= JavaTemplateMessages.JavaContext_error_title;
 		if (e instanceof CoreException)
 			ExceptionHandler.handle((CoreException)e, shell, title, null);
 		else if (e instanceof InvocationTargetException)
 			ExceptionHandler.handle((InvocationTargetException)e, shell, title, null);
 		else {
 			JavaPlugin.log(e);
 			MessageDialog.openError(shell, title, e.getMessage());
 		}
 	}

 	private CompilationUnitCompletion getCompletion() {
 		ICompilationUnit compilationUnit= getCompilationUnit();
 		if (fCompletion == null) {
 			fCompletion= new CompilationUnitCompletion(compilationUnit);

 			if (compilationUnit != null) {
 				try {
 					compilationUnit.codeComplete(getStart(), fCompletion);
 				} catch (JavaModelException e) {
 					// ignore
 				}
 			}
 		}

 		return fCompletion;
 	}

 	/**
 	 * Returns the names of local arrays.
 	 *
 	 * @return the names of local arrays
 	 */
 	public String[] getArrays() {
 		CompilationUnitCompletion completion= getCompletion();
 		LocalVariable[] localArrays= completion.findLocalArrays();

 		String[] ret= new String[localArrays.length];
 		for (int i= 0; i < ret.length; i++) {
 			ret[i]= localArrays[i].getName();
 		}
 		return ret;
 	}

 	/**
 	 * Returns the names of the types of the local arrays grouped based on local
 	 * variables.
 	 *
 	 * @return the names of the types of the local arrays
 	 */
 	public String[][] getArrayTypes() {
 		// TODO propose super types?
 		CompilationUnitCompletion completion= getCompletion();
 		LocalVariable[] localArrays= completion.findLocalArrays();

 		String[][] ret= new String[localArrays.length][];

 		for (int i= 0; i < localArrays.length; i++) {
 			ret[i]= localArrays[i].getMemberTypeNames();
 		}

 		return ret;
 	}

 	/**
 	 * Returns proposals for a variable name of a local array element grouped
 	 * based on local array-typed variables.
 	 *
 	 * @return proposals for a variable name
 	 */
 	public String[][] getArrayElements() {
 		ICompilationUnit cu= getCompilationUnit();
 		if (cu == null) {
 			return new String[0][];
 		}

 		CompilationUnitCompletion completion= getCompletion();
 		LocalVariable[] localArrays= completion.findLocalArrays();

 		return suggestElementNames(localArrays, true);
 	}

 	/**
 	 * Returns an array index name. 'i', 'j', 'k' are tried until no name
 	 * collision with an existing local variable occurs. If all names collide,
 	 * <code>null</code> is returned.
 	 *
 	 * @return a name for an index variable or <code>null</code>
 	 */
 	public String getIndex() {
 		CompilationUnitCompletion completion= getCompletion();
 		String[] proposals= {"i", "j", "k"};  //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$

 		for (int i= 0; i != proposals.length; i++) {
 			String proposal = proposals[i];

 			if (!completion.existsLocalName(proposal))
 				return proposal;
 		}

 		return null;
 	}

 	/**
 	 * Returns the names of local collections.
 	 *
 	 * @return the names of local collection
 	 */
 	public String[] getCollections() {
 		CompilationUnitCompletion completion= getCompletion();

 		LocalVariable[] localCollections= completion.findLocalCollections();
 		String[] ret= new String[localCollections.length];
 		for (int i= 0; i < ret.length; i++) {
 			ret[i]= localCollections[i].getName();
 		}

 		return ret;
 	}

 	/**
 	 * Returns the names of local iterables.
 	 *
 	 * @return the names of local iterables
 	 */
 	public String[] getIterables() {
 		CompilationUnitCompletion completion= getCompletion();
 		LocalVariable[] localCollections= completion.findLocalIterables();
 		String[] ret= new String[localCollections.length];
 		for (int i= 0; i < ret.length; i++) {
 			ret[i]= localCollections[i].getName();
 		}

 		return ret;
 	}

 	/**
 	 * Returns the names of the types of the local iterables grouped based on
 	 * local variables.
 	 *
 	 * @return the names of the types of the local iterables
 	 */
 	public String[][] getIterableTypes() {
 		CompilationUnitCompletion completion= getCompletion();
 		LocalVariable[] iterables= completion.findLocalIterables();

 		String[][] ret= new String[iterables.length][];

 		for (int i= 0; i < iterables.length; i++) {
 			ret[i]= iterables[i].getMemberTypeNames();
 		}

 		return ret;
 	}

 	/**
 	 * Returns proposals for a variable name of a local iterable element
 	 * grouped based on local array and collection variables.
 	 *
 	 * @return proposals for a variable name
 	 */
 	public String[][] getIterableElements() {
 		ICompilationUnit cu= getCompilationUnit();
 		if (cu == null) {
 			return new String[0][];
 		}

 		CompilationUnitCompletion completion= getCompletion();
 		LocalVariable[] iterables= completion.findLocalIterables();

 		return suggestElementNames(iterables, false);
 	}

 	private String[][] suggestElementNames(LocalVariable[] iterables, boolean excludeIndex) throws IllegalArgumentException {
 		String[] excludes= computeExcludes(excludeIndex);
 		String[][] ret= new String[iterables.length][];
 		for (int i= 0; i < iterables.length; i++) {
 			ret[i]= suggestVariableName(iterables[i], excludes);
 		}
 		return ret;
 	}

 	private String[] computeExcludes(boolean excludeIndex) {
 		String[] excludes= getCompletion().getLocalVariableNames();
 		if (excludeIndex) {
 			String index= getIndex();
 			if (index != null) {
 				String[] allExcludes= new String[excludes.length + 1];
 				System.arraycopy(excludes, 0, allExcludes, 0, excludes.length);
 				allExcludes[excludes.length]= index;
 				excludes= allExcludes;
 			}
 		}
 		return excludes;
 	}

 	private String[] suggestVariableName(LocalVariable iterable, String[] excludes) throws IllegalArgumentException {
 		IJavaProject project= getCompilationUnit().getJavaProject();
 		String memberTypeSig= iterable.getMemberTypeSignature();
 		int memberDimensions= Signature.getArrayCount(memberTypeSig);
 		String elementTypeSig= Signature.getElementType(memberTypeSig);

 		String erasure= Signature.getTypeErasure(elementTypeSig);
 		String fullName= Signature.toString(erasure);
 		String memberPackage= Signature.getQualifier(fullName);
 		String memberTypeName= Signature.getSimpleName(fullName);

 		String[] proposals= NamingConventions.suggestLocalVariableNames(project, memberPackage, memberTypeName, memberDimensions, excludes);
 		return proposals;
 	}

 	/**
 	 * Returns an iterator name ('iter'). If 'iter' already exists as local
 	 * variable, <code>null</code> is returned.
 	 *
 	 * @return an iterator name or <code>null</code>
 	 */
 	public String getIterator() {
 		CompilationUnitCompletion completion= getCompletion();
 		String[] proposals= {"iter"}; //$NON-NLS-1$

 		for (int i= 0; i != proposals.length; i++) {
 			String proposal = proposals[i];

 			if (!completion.existsLocalName(proposal))
 				return proposal;
 		}

 		return null;
 	}

 	public void addIteratorImport() {
 		ICompilationUnit cu= getCompilationUnit();
 		if (cu == null) {
 			return;
 		}

 		try {
 			Position position= new Position(getCompletionOffset(), getCompletionLength());
 			IDocument document= getDocument();
 			final String category= "__template_position_importer" + System.currentTimeMillis(); //$NON-NLS-1$
 			IPositionUpdater updater= new DefaultPositionUpdater(category);
 			document.addPositionCategory(category);
 			document.addPositionUpdater(updater);
 			document.addPosition(position);

 			try {

 				ImportRewrite rewrite= StubUtility.createImportRewrite(cu, true);
 				rewrite.addImport("java.util.Iterator"); //$NON-NLS-1$
 				JavaModelUtil.applyEdit(cu, rewrite.rewriteImports(null), false, null);

 				setCompletionOffset(position.getOffset());
 				setCompletionLength(position.getLength());

 			} catch (CoreException e) {
 				handleException(null, e);
 			} finally {
 				document.removePosition(position);
 				document.removePositionUpdater(updater);
 				document.removePositionCategory(category);
 			}

 		} catch (BadLocationException e) {
 			handleException(null, e);
 		} catch (BadPositionCategoryException e) {
 			handleException(null, e);
 		}
 	}

 	/**
 	 * Evaluates a 'java' template in the context of a compilation unit
 	 *
 	 * @param template the template to be evaluated
 	 * @param compilationUnit the compilation unit in which to evaluate the template
 	 * @param position the position inside the compilation unit for which to evaluate the template
 	 * @return the evaluated template
 	 * @throws CoreException in case the template is of an unknown context type
 	 * @throws BadLocationException in case the position is invalid in the compilation unit
 	 * @throws TemplateException in case the evaluation fails
 	 */
 	public static String evaluateTemplate(Template template, ICompilationUnit compilationUnit, int position) throws CoreException, BadLocationException, TemplateException {

 		TemplateContextType contextType= JavaPlugin.getDefault().getTemplateContextRegistry().getContextType(JavaContextType.NAME);
 		if (contextType == null)
 			throw new CoreException(new Status(IStatus.ERROR, JavaUI.ID_PLUGIN, IStatus.ERROR, JavaTemplateMessages.JavaContext_error_message, null));

 		IDocument document= new Document();
 		if (compilationUnit != null && compilationUnit.exists())
 			document.set(compilationUnit.getSource());

 		JavaContext context= new JavaContext(contextType, document, position, 0, compilationUnit);
 		context.setForceEvaluation(true);

 		TemplateBuffer buffer= context.evaluate(template);
 		if (buffer == null)
 			return null;
 		return buffer.getString();
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2000, 2006 IBM Corporation 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:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.jdt.internal.corext.template.java;

	import java.lang.reflect.InvocationTargetException;

	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Status;

	import org.eclipse.swt.widgets.Shell;

	import org.eclipse.jface.dialogs.MessageDialog;
	import org.eclipse.jface.preference.IPreferenceStore;

	import org.eclipse.jface.text.BadLocationException;
	import org.eclipse.jface.text.BadPositionCategoryException;
	import org.eclipse.jface.text.DefaultPositionUpdater;
	import org.eclipse.jface.text.Document;
	import org.eclipse.jface.text.IDocument;
	import org.eclipse.jface.text.IPositionUpdater;
	import org.eclipse.jface.text.IRegion;
	import org.eclipse.jface.text.Position;
	import org.eclipse.jface.text.TextUtilities;
	import org.eclipse.jface.text.templates.Template;
	import org.eclipse.jface.text.templates.TemplateBuffer;
	import org.eclipse.jface.text.templates.TemplateContextType;
	import org.eclipse.jface.text.templates.TemplateException;
	import org.eclipse.jface.text.templates.TemplateTranslator;
	import org.eclipse.jface.text.templates.TemplateVariable;

	import org.eclipse.jdt.core.ICompilationUnit;
	import org.eclipse.jdt.core.IJavaProject;
	import org.eclipse.jdt.core.JavaModelException;
	import org.eclipse.jdt.core.NamingConventions;
	import org.eclipse.jdt.core.Signature;
	import org.eclipse.jdt.core.dom.rewrite.ImportRewrite;

	import org.eclipse.jdt.internal.corext.codemanipulation.StubUtility;
	import org.eclipse.jdt.internal.corext.template.java.CompilationUnitCompletion.LocalVariable;
	import org.eclipse.jdt.internal.corext.util.JavaModelUtil;
	import org.eclipse.jdt.internal.corext.util.Strings;

	import org.eclipse.jdt.ui.JavaUI;
	import org.eclipse.jdt.ui.PreferenceConstants;

	import org.eclipse.jdt.internal.ui.JavaPlugin;
	import org.eclipse.jdt.internal.ui.text.template.contentassist.MultiVariable;
	import org.eclipse.jdt.internal.ui.util.ExceptionHandler;

	/**
	* A context for java source.
	*/
	public class JavaContext extends CompilationUnitContext {

	/** A code completion requester for guessing local variable names. */
	private CompilationUnitCompletion fCompletion;

	/**
	* Creates a java template context.
	*
	* @param type the context type.
	* @param document the document.
	* @param completionOffset the completion offset within the document.
	* @param completionLength the completion length.
	* @param compilationUnit the compilation unit (may be <code>null</code>).
	*/
	public JavaContext(TemplateContextType type, IDocument document, int completionOffset, int completionLength, ICompilationUnit compilationUnit) {
	super(type, document, completionOffset, completionLength, compilationUnit);
	}

	/**
	* Creates a java template context.
	*
	* @param type the context type.
	* @param document the document.
	* @param completionPosition the position defining the completion offset and length
	* @param compilationUnit the compilation unit (may be <code>null</code>).
	* @since 3.2
	*/
	public JavaContext(TemplateContextType type, IDocument document, Position completionPosition, ICompilationUnit compilationUnit) {
	super(type, document, completionPosition, compilationUnit);
	}

	/**
	* Returns the indentation level at the position of code completion.
	*
	* @return the indentation level at the position of the code completion
	*/
	private int getIndentation() {
	int start= getStart();
	IDocument document= getDocument();
	try {
	IRegion region= document.getLineInformationOfOffset(start);
	String lineContent= document.get(region.getOffset(), region.getLength());
	ICompilationUnit compilationUnit= getCompilationUnit();
	IJavaProject project= compilationUnit == null ? null : compilationUnit.getJavaProject();
	return Strings.computeIndentUnits(lineContent, project);
	} catch (BadLocationException e) {
	return 0;
	}
	}

	/*
	* @see TemplateContext#evaluate(Template template)
	*/
	public TemplateBuffer evaluate(Template template) throws BadLocationException, TemplateException {

	if (!canEvaluate(template))
	throw new TemplateException(JavaTemplateMessages.Context_error_cannot_evaluate);

	TemplateTranslator translator= new TemplateTranslator() {
	/*
	* @see org.eclipse.jface.text.templates.TemplateTranslator#createVariable(java.lang.String, java.lang.String, int[])
	*/
	protected TemplateVariable createVariable(String type, String name, int[] offsets) {
	return new MultiVariable(type, name, offsets);
	}
	};
	TemplateBuffer buffer= translator.translate(template);

	getContextType().resolve(buffer, this);

	IPreferenceStore prefs= JavaPlugin.getDefault().getPreferenceStore();
	boolean useCodeFormatter= prefs.getBoolean(PreferenceConstants.TEMPLATES_USE_CODEFORMATTER);

	IJavaProject project= getCompilationUnit() != null ? getCompilationUnit().getJavaProject() : null;
	JavaFormatter formatter= new JavaFormatter(TextUtilities.getDefaultLineDelimiter(getDocument()), getIndentation(), useCodeFormatter, project);
	formatter.format(buffer, this);

	return buffer;
	}

	/*
	* @see TemplateContext#canEvaluate(Template templates)
	*/
	public boolean canEvaluate(Template template) {
	if (fForceEvaluation)
	return true;

	String key= getKey();
	return
	template.matches(key, getContextType().getId()) &&
	key.length() != 0 && template.getName().toLowerCase().startsWith(key.toLowerCase());
	}

	/*
	* @see DocumentTemplateContext#getCompletionPosition();
	*/
	public int getStart() {

	if (fIsManaged && getCompletionLength() > 0)
	return super.getStart();

	try {
	IDocument document= getDocument();

	int start= getCompletionOffset();
	int end= getCompletionOffset() + getCompletionLength();

	while (start != 0 && Character.isUnicodeIdentifierPart(document.getChar(start - 1)))
	start--;

	while (start != end && Character.isWhitespace(document.getChar(start)))
	start++;

	if (start == end)
	start= getCompletionOffset();

	return start;

	} catch (BadLocationException e) {
	return super.getStart();
	}
	}

	/*
	* @see org.eclipse.jdt.internal.corext.template.DocumentTemplateContext#getEnd()
	*/
	public int getEnd() {

	if (fIsManaged \|\| getCompletionLength() == 0)
	return super.getEnd();

	try {
	IDocument document= getDocument();

	int start= getCompletionOffset();
	int end= getCompletionOffset() + getCompletionLength();

	while (start != end && Character.isWhitespace(document.getChar(end - 1)))
	end--;

	return end;

	} catch (BadLocationException e) {
	return super.getEnd();
	}
	}

	/*
	* @see org.eclipse.jdt.internal.corext.template.DocumentTemplateContext#getKey()
	*/
	public String getKey() {

	if (getCompletionLength() == 0)
	return super.getKey();

	try {
	IDocument document= getDocument();

	int start= getStart();
	int end= getCompletionOffset();
	return start <= end
	? document.get(start, end - start)
	: ""; //$NON-NLS-1$

	} catch (BadLocationException e) {
	return super.getKey();
	}
	}

	/**
	* Returns the character before the start position of the completion.
	*
	* @return the character before the start position of the completion
	*/
	public char getCharacterBeforeStart() {
	int start= getStart();

	try {
	return start == 0
	? ' '
	: getDocument().getChar(start - 1);

	} catch (BadLocationException e) {
	return ' ';
	}
	}

	private static void handleException(Shell shell, Exception e) {
	String title= JavaTemplateMessages.JavaContext_error_title;
	if (e instanceof CoreException)
	ExceptionHandler.handle((CoreException)e, shell, title, null);
	else if (e instanceof InvocationTargetException)
	ExceptionHandler.handle((InvocationTargetException)e, shell, title, null);
	else {
	JavaPlugin.log(e);
	MessageDialog.openError(shell, title, e.getMessage());
	}
	}

	private CompilationUnitCompletion getCompletion() {
	ICompilationUnit compilationUnit= getCompilationUnit();
	if (fCompletion == null) {
	fCompletion= new CompilationUnitCompletion(compilationUnit);

	if (compilationUnit != null) {
	try {
	compilationUnit.codeComplete(getStart(), fCompletion);
	} catch (JavaModelException e) {
	// ignore
	}
	}
	}

	return fCompletion;
	}

	/**
	* Returns the names of local arrays.
	*
	* @return the names of local arrays
	*/
	public String[] getArrays() {
	CompilationUnitCompletion completion= getCompletion();
	LocalVariable[] localArrays= completion.findLocalArrays();

	String[] ret= new String[localArrays.length];
	for (int i= 0; i < ret.length; i++) {
	ret[i]= localArrays[i].getName();
	}
	return ret;
	}

	/**
	* Returns the names of the types of the local arrays grouped based on local
	* variables.
	*
	* @return the names of the types of the local arrays
	*/
	public String[][] getArrayTypes() {
	// TODO propose super types?
	CompilationUnitCompletion completion= getCompletion();
	LocalVariable[] localArrays= completion.findLocalArrays();

	String[][] ret= new String[localArrays.length][];

	for (int i= 0; i < localArrays.length; i++) {
	ret[i]= localArrays[i].getMemberTypeNames();
	}

	return ret;
	}

	/**
	* Returns proposals for a variable name of a local array element grouped
	* based on local array-typed variables.
	*
	* @return proposals for a variable name
	*/
	public String[][] getArrayElements() {
	ICompilationUnit cu= getCompilationUnit();
	if (cu == null) {
	return new String[0][];
	}

	CompilationUnitCompletion completion= getCompletion();
	LocalVariable[] localArrays= completion.findLocalArrays();

	return suggestElementNames(localArrays, true);
	}

	/**
	* Returns an array index name. 'i', 'j', 'k' are tried until no name
	* collision with an existing local variable occurs. If all names collide,
	* <code>null</code> is returned.
	*
	* @return a name for an index variable or <code>null</code>
	*/
	public String getIndex() {
	CompilationUnitCompletion completion= getCompletion();
	String[] proposals= {"i", "j", "k"}; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$

	for (int i= 0; i != proposals.length; i++) {
	String proposal = proposals[i];

	if (!completion.existsLocalName(proposal))
	return proposal;
	}

	return null;
	}

	/**
	* Returns the names of local collections.
	*
	* @return the names of local collection
	*/
	public String[] getCollections() {
	CompilationUnitCompletion completion= getCompletion();

	LocalVariable[] localCollections= completion.findLocalCollections();
	String[] ret= new String[localCollections.length];
	for (int i= 0; i < ret.length; i++) {
	ret[i]= localCollections[i].getName();
	}

	return ret;
	}

	/**
	* Returns the names of local iterables.
	*
	* @return the names of local iterables
	*/
	public String[] getIterables() {
	CompilationUnitCompletion completion= getCompletion();
	LocalVariable[] localCollections= completion.findLocalIterables();
	String[] ret= new String[localCollections.length];
	for (int i= 0; i < ret.length; i++) {
	ret[i]= localCollections[i].getName();
	}

	return ret;
	}

	/**
	* Returns the names of the types of the local iterables grouped based on
	* local variables.
	*
	* @return the names of the types of the local iterables
	*/
	public String[][] getIterableTypes() {
	CompilationUnitCompletion completion= getCompletion();
	LocalVariable[] iterables= completion.findLocalIterables();

	String[][] ret= new String[iterables.length][];

	for (int i= 0; i < iterables.length; i++) {
	ret[i]= iterables[i].getMemberTypeNames();
	}

	return ret;
	}

	/**
	* Returns proposals for a variable name of a local iterable element
	* grouped based on local array and collection variables.
	*
	* @return proposals for a variable name
	*/
	public String[][] getIterableElements() {
	ICompilationUnit cu= getCompilationUnit();
	if (cu == null) {
	return new String[0][];
	}

	CompilationUnitCompletion completion= getCompletion();
	LocalVariable[] iterables= completion.findLocalIterables();

	return suggestElementNames(iterables, false);
	}

	private String[][] suggestElementNames(LocalVariable[] iterables, boolean excludeIndex) throws IllegalArgumentException {
	String[] excludes= computeExcludes(excludeIndex);
	String[][] ret= new String[iterables.length][];
	for (int i= 0; i < iterables.length; i++) {
	ret[i]= suggestVariableName(iterables[i], excludes);
	}
	return ret;
	}

	private String[] computeExcludes(boolean excludeIndex) {
	String[] excludes= getCompletion().getLocalVariableNames();
	if (excludeIndex) {
	String index= getIndex();
	if (index != null) {
	String[] allExcludes= new String[excludes.length + 1];
	System.arraycopy(excludes, 0, allExcludes, 0, excludes.length);
	allExcludes[excludes.length]= index;
	excludes= allExcludes;
	}
	}
	return excludes;
	}

	private String[] suggestVariableName(LocalVariable iterable, String[] excludes) throws IllegalArgumentException {
	IJavaProject project= getCompilationUnit().getJavaProject();
	String memberTypeSig= iterable.getMemberTypeSignature();
	int memberDimensions= Signature.getArrayCount(memberTypeSig);
	String elementTypeSig= Signature.getElementType(memberTypeSig);

	String erasure= Signature.getTypeErasure(elementTypeSig);
	String fullName= Signature.toString(erasure);
	String memberPackage= Signature.getQualifier(fullName);
	String memberTypeName= Signature.getSimpleName(fullName);

	String[] proposals= NamingConventions.suggestLocalVariableNames(project, memberPackage, memberTypeName, memberDimensions, excludes);
	return proposals;
	}

	/**
	* Returns an iterator name ('iter'). If 'iter' already exists as local
	* variable, <code>null</code> is returned.
	*
	* @return an iterator name or <code>null</code>
	*/
	public String getIterator() {
	CompilationUnitCompletion completion= getCompletion();
	String[] proposals= {"iter"}; //$NON-NLS-1$

	for (int i= 0; i != proposals.length; i++) {
	String proposal = proposals[i];

	if (!completion.existsLocalName(proposal))
	return proposal;
	}

	return null;
	}

	public void addIteratorImport() {
	ICompilationUnit cu= getCompilationUnit();
	if (cu == null) {
	return;
	}

	try {
	Position position= new Position(getCompletionOffset(), getCompletionLength());
	IDocument document= getDocument();
	final String category= "__template_position_importer" + System.currentTimeMillis(); //$NON-NLS-1$
	IPositionUpdater updater= new DefaultPositionUpdater(category);
	document.addPositionCategory(category);
	document.addPositionUpdater(updater);
	document.addPosition(position);

	try {

	ImportRewrite rewrite= StubUtility.createImportRewrite(cu, true);
	rewrite.addImport("java.util.Iterator"); //$NON-NLS-1$
	JavaModelUtil.applyEdit(cu, rewrite.rewriteImports(null), false, null);

	setCompletionOffset(position.getOffset());
	setCompletionLength(position.getLength());

	} catch (CoreException e) {
	handleException(null, e);
	} finally {
	document.removePosition(position);
	document.removePositionUpdater(updater);
	document.removePositionCategory(category);
	}

	} catch (BadLocationException e) {
	handleException(null, e);
	} catch (BadPositionCategoryException e) {
	handleException(null, e);
	}
	}

	/**
	* Evaluates a 'java' template in the context of a compilation unit
	*
	* @param template the template to be evaluated
	* @param compilationUnit the compilation unit in which to evaluate the template
	* @param position the position inside the compilation unit for which to evaluate the template
	* @return the evaluated template
	* @throws CoreException in case the template is of an unknown context type
	* @throws BadLocationException in case the position is invalid in the compilation unit
	* @throws TemplateException in case the evaluation fails
	*/
	public static String evaluateTemplate(Template template, ICompilationUnit compilationUnit, int position) throws CoreException, BadLocationException, TemplateException {

	TemplateContextType contextType= JavaPlugin.getDefault().getTemplateContextRegistry().getContextType(JavaContextType.NAME);
	if (contextType == null)
	throw new CoreException(new Status(IStatus.ERROR, JavaUI.ID_PLUGIN, IStatus.ERROR, JavaTemplateMessages.JavaContext_error_message, null));

	IDocument document= new Document();
	if (compilationUnit != null && compilationUnit.exists())
	document.set(compilationUnit.getSource());

	JavaContext context= new JavaContext(contextType, document, position, 0, compilationUnit);
	context.setForceEvaluation(true);

	TemplateBuffer buffer= context.evaluate(template);
	if (buffer == null)
	return null;
	return buffer.getString();
	}

	}