org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/java/JavaCompletionProposalComputer.java - jdt/eclipse.jdt.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2013 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.ui.text.java;

 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;

 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.widgets.Shell;

 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.OperationCanceledException;

 import org.eclipse.jface.dialogs.ErrorDialog;
 import org.eclipse.jface.dialogs.MessageDialog;

 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.ITextViewer;
 import org.eclipse.jface.text.contentassist.ICompletionProposal;
 import org.eclipse.jface.text.contentassist.IContextInformation;
 import org.eclipse.jface.text.contentassist.IContextInformationExtension;

 import org.eclipse.ui.IWorkbenchCommandConstants;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.keys.IBindingService;

 import org.eclipse.jdt.core.CompletionProposal;
 import org.eclipse.jdt.core.CompletionRequestor;
 import org.eclipse.jdt.core.ICompilationUnit;
 import org.eclipse.jdt.core.JavaModelException;

 import org.eclipse.jdt.internal.corext.util.Messages;

 import org.eclipse.jdt.ui.PreferenceConstants;
 import org.eclipse.jdt.ui.text.java.CompletionProposalCollector;
 import org.eclipse.jdt.ui.text.java.ContentAssistInvocationContext;
 import org.eclipse.jdt.ui.text.java.IJavaCompletionProposalComputer;
 import org.eclipse.jdt.ui.text.java.JavaContentAssistInvocationContext;

 import org.eclipse.jdt.internal.ui.text.JavaHeuristicScanner;
 import org.eclipse.jdt.internal.ui.text.Symbols;

 /**
  * Computes Java completion proposals and context infos.
  *
  * @since 3.2
  */
 public class JavaCompletionProposalComputer implements IJavaCompletionProposalComputer {

 	private static final class ContextInformationWrapper implements IContextInformation, IContextInformationExtension {

 		private final IContextInformation fContextInformation;
 		private int fPosition;

 		public ContextInformationWrapper(IContextInformation contextInformation) {
 			fContextInformation= contextInformation;
 		}

 		/*
 		 * @see IContextInformation#getContextDisplayString()
 		 */
 		@Override
 		public String getContextDisplayString() {
 			return fContextInformation.getContextDisplayString();
 		}

 			/*
 		 * @see IContextInformation#getImage()
 		 */
 		@Override
 		public Image getImage() {
 			return fContextInformation.getImage();
 		}

 		/*
 		 * @see IContextInformation#getInformationDisplayString()
 		 */
 		@Override
 		public String getInformationDisplayString() {
 			return fContextInformation.getInformationDisplayString();
 		}

 		/*
 		 * @see IContextInformationExtension#getContextInformationPosition()
 		 */
 		@Override
 		public int getContextInformationPosition() {
 			return fPosition;
 		}

 		public void setContextInformationPosition(int position) {
 			fPosition= position;
 		}

 		/*
 		 * @see org.eclipse.jface.text.contentassist.IContextInformation#equals(java.lang.Object)
 		 */
 		@Override
 		public boolean equals(Object object) {
 			if (object instanceof ContextInformationWrapper)
 				return fContextInformation.equals(((ContextInformationWrapper) object).fContextInformation);
 			else
 				return fContextInformation.equals(object);
 		}

 		/*
 		 * @see java.lang.Object#hashCode()
 		 * @since 3.5
 		 */
 		@Override
 		public int hashCode() {
 			return fContextInformation.hashCode();
 		}
 	}

 	private static final long JAVA_CODE_ASSIST_TIMEOUT= Long.getLong("org.eclipse.jdt.ui.codeAssistTimeout", 5000).longValue(); // ms //$NON-NLS-1$

 	private String fErrorMessage;

 	private final IProgressMonitor fTimeoutProgressMonitor;

 	public JavaCompletionProposalComputer() {
 		fTimeoutProgressMonitor= createTimeoutProgressMonitor(JAVA_CODE_ASSIST_TIMEOUT);
 	}

 	protected int guessContextInformationPosition(ContentAssistInvocationContext context) {
 		return context.getInvocationOffset();
 	}

 	protected final int guessMethodContextInformationPosition(ContentAssistInvocationContext context) {
 		final int contextPosition= context.getInvocationOffset();

 		IDocument document= context.getDocument();
 		JavaHeuristicScanner scanner= new JavaHeuristicScanner(document);
 		int bound= Math.max(-1, contextPosition - 2000);

 		// try the innermost scope of parentheses that looks like a method call
 		int pos= contextPosition - 1;
 		do {
 			int paren= scanner.findOpeningPeer(pos, bound, '(', ')');
 			if (paren == JavaHeuristicScanner.NOT_FOUND)
 				break;
 			int token= scanner.previousToken(paren - 1, bound);
 			// next token must be a method name (identifier) or the closing angle of a
 			// constructor call of a parameterized type.
 			if (token == Symbols.TokenIDENT || token == Symbols.TokenGREATERTHAN)
 				return paren + 1;
 			pos= paren - 1;
 		} while (true);

 		return contextPosition;
 	}

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

 	}

 	/*
 	 * @see org.eclipse.jface.text.contentassist.ICompletionProposalComputer#computeContextInformation(org.eclipse.jface.text.contentassist.TextContentAssistInvocationContext, org.eclipse.core.runtime.IProgressMonitor)
 	 */
 	@Override
 	public List<IContextInformation> computeContextInformation(ContentAssistInvocationContext context, IProgressMonitor monitor) {
 		if (context instanceof JavaContentAssistInvocationContext) {
 			JavaContentAssistInvocationContext javaContext= (JavaContentAssistInvocationContext) context;

 			int contextInformationPosition= guessContextInformationPosition(javaContext);
 			List<IContextInformation> result= addContextInformations(javaContext, contextInformationPosition);
 			return result;
 		}
 		return Collections.emptyList();
 	}

 	/*
 	 * @see org.eclipse.jface.text.contentassist.ICompletionProposalComputer#computeCompletionProposals(org.eclipse.jface.text.contentassist.TextContentAssistInvocationContext, org.eclipse.core.runtime.IProgressMonitor)
 	 */
 	@Override
 	public List<ICompletionProposal> computeCompletionProposals(ContentAssistInvocationContext context, IProgressMonitor monitor) {
 		if (context instanceof JavaContentAssistInvocationContext) {
 			JavaContentAssistInvocationContext javaContext= (JavaContentAssistInvocationContext) context;
 			return internalComputeCompletionProposals(context.getInvocationOffset(), javaContext);
 		}
 		return Collections.emptyList();
 	}

 	private List<ICompletionProposal> internalComputeCompletionProposals(int offset, JavaContentAssistInvocationContext context) {
 		ICompilationUnit unit= context.getCompilationUnit();
 		if (unit == null)
 			return Collections.emptyList();

 		ITextViewer viewer= context.getViewer();

 		CompletionProposalCollector collector= createCollector(context);
 		collector.setInvocationContext(context);

 		// Allow completions for unresolved types - since 3.3
 		collector.setAllowsRequiredProposals(CompletionProposal.FIELD_REF, CompletionProposal.TYPE_REF, true);
 		collector.setAllowsRequiredProposals(CompletionProposal.FIELD_REF, CompletionProposal.TYPE_IMPORT, true);
 		collector.setAllowsRequiredProposals(CompletionProposal.FIELD_REF, CompletionProposal.FIELD_IMPORT, true);

 		collector.setAllowsRequiredProposals(CompletionProposal.METHOD_REF, CompletionProposal.TYPE_REF, true);
 		collector.setAllowsRequiredProposals(CompletionProposal.METHOD_REF, CompletionProposal.TYPE_IMPORT, true);
 		collector.setAllowsRequiredProposals(CompletionProposal.METHOD_REF, CompletionProposal.METHOD_IMPORT, true);

 		collector.setAllowsRequiredProposals(CompletionProposal.CONSTRUCTOR_INVOCATION, CompletionProposal.TYPE_REF, true);

 		collector.setAllowsRequiredProposals(CompletionProposal.ANONYMOUS_CLASS_CONSTRUCTOR_INVOCATION, CompletionProposal.TYPE_REF, true);
 		collector.setAllowsRequiredProposals(CompletionProposal.ANONYMOUS_CLASS_DECLARATION, CompletionProposal.TYPE_REF, true);

 		collector.setAllowsRequiredProposals(CompletionProposal.TYPE_REF, CompletionProposal.TYPE_REF, true);

 		// Set the favorite list to propose static members - since 3.3
 		collector.setFavoriteReferences(getFavoriteStaticMembers());

 		try {
 			Point selection= viewer.getSelectedRange();
 			if (selection.y > 0)
 				collector.setReplacementLength(selection.y);
 			unit.codeComplete(offset, collector, fTimeoutProgressMonitor);
 		} catch (OperationCanceledException x) {
 			IBindingService bindingSvc= PlatformUI.getWorkbench().getAdapter(IBindingService.class);
 			String keyBinding= bindingSvc.getBestActiveBindingFormattedFor(IWorkbenchCommandConstants.EDIT_CONTENT_ASSIST);
 			fErrorMessage= Messages.format(JavaTextMessages.CompletionProcessor_error_javaCompletion_took_too_long_message, keyBinding);
 		} catch (JavaModelException x) {
 			Shell shell= viewer.getTextWidget().getShell();
 			if (x.isDoesNotExist() && !unit.getJavaProject().isOnClasspath(unit))
 				MessageDialog.openInformation(shell, JavaTextMessages.CompletionProcessor_error_notOnBuildPath_title, JavaTextMessages.CompletionProcessor_error_notOnBuildPath_message);
 			else
 				ErrorDialog.openError(shell, JavaTextMessages.CompletionProcessor_error_accessing_title, JavaTextMessages.CompletionProcessor_error_accessing_message, x.getStatus());
 		}

 		ICompletionProposal[] javaProposals= collector.getJavaCompletionProposals();
 		int contextInformationOffset= guessMethodContextInformationPosition(context);
 		if (contextInformationOffset != offset) {
 			for (int i= 0; i < javaProposals.length; i++) {
 				if (javaProposals[i] instanceof JavaMethodCompletionProposal) {
 					JavaMethodCompletionProposal jmcp= (JavaMethodCompletionProposal) javaProposals[i];
 					jmcp.setContextInformationPosition(contextInformationOffset);
 				}
 			}
 		}

 		List<ICompletionProposal> proposals= new ArrayList<>(Arrays.asList(javaProposals));
 		if (proposals.size() == 0) {
 			String error= collector.getErrorMessage();
 			if (error.length() > 0)
 				fErrorMessage= error;
 		}
 		return proposals;
 	}

 	/**
 	 * Returns a new progress monitor that get cancelled after the given timeout.
 	 *
 	 * @param timeout the timeout in ms
 	 * @return the progress monitor
 	 * @since 3.5
 	 */
 	private IProgressMonitor createTimeoutProgressMonitor(final long timeout) {
 		return new IProgressMonitor() {

 			private long fEndTime;

 			@Override
 			public void beginTask(String name, int totalWork) {
 				fEndTime= System.currentTimeMillis() + timeout;
 			}
 			@Override
 			public boolean isCanceled() {
 				return fEndTime <= System.currentTimeMillis();
 			}
 			@Override
 			public void done() {
 			}
 			@Override
 			public void internalWorked(double work) {
 			}
 			@Override
 			public void setCanceled(boolean value) {
 			}
 			@Override
 			public void setTaskName(String name) {
 			}
 			@Override
 			public void subTask(String name) {
 			}
 			@Override
 			public void worked(int work) {
 			}
 		};
 	}

 	/**
 	 * Returns the array with favorite static members.
 	 *
 	 * @return the <code>String</code> array with with favorite static members
 	 * @see CompletionRequestor#setFavoriteReferences(String[])
 	 * @since 3.3
 	 */
 	private String[] getFavoriteStaticMembers() {
 		String serializedFavorites= PreferenceConstants.getPreferenceStore().getString(PreferenceConstants.CODEASSIST_FAVORITE_STATIC_MEMBERS);
 		if (serializedFavorites != null && serializedFavorites.length() > 0)
 			return serializedFavorites.split(";"); //$NON-NLS-1$
 		return new String[0];
 	}

 	/**
 	 * Creates the collector used to get proposals from core.
 	 *
 	 * @param context the context
 	 * @return the collector
 	 */
 	protected CompletionProposalCollector createCollector(JavaContentAssistInvocationContext context) {
 		if (PreferenceConstants.getPreferenceStore().getBoolean(PreferenceConstants.CODEASSIST_FILL_ARGUMENT_NAMES))
 			return new FillArgumentNamesCompletionProposalCollector(context);
 		else
 			return new CompletionProposalCollector(context.getCompilationUnit(), true);
 	}

 	/*
 	 * @see org.eclipse.jface.text.contentassist.ICompletionProposalComputer#getErrorMessage()
 	 */
 	@Override
 	public String getErrorMessage() {
 		return fErrorMessage;
 	}

 	/*
 	 * @see org.eclipse.jdt.ui.text.java.IJavaCompletionProposalComputer#sessionStarted()
 	 */
 	@Override
 	public void sessionStarted() {
 	}

 	/*
 	 * @see org.eclipse.jdt.ui.text.java.IJavaCompletionProposalComputer#sessionEnded()
 	 */
 	@Override
 	public void sessionEnded() {
 		fErrorMessage= null;
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2013 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.ui.text.java;

	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.Collections;
	import java.util.Iterator;
	import java.util.List;

	import org.eclipse.swt.graphics.Image;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.widgets.Shell;

	import org.eclipse.core.runtime.IProgressMonitor;
	import org.eclipse.core.runtime.OperationCanceledException;

	import org.eclipse.jface.dialogs.ErrorDialog;
	import org.eclipse.jface.dialogs.MessageDialog;

	import org.eclipse.jface.text.IDocument;
	import org.eclipse.jface.text.ITextViewer;
	import org.eclipse.jface.text.contentassist.ICompletionProposal;
	import org.eclipse.jface.text.contentassist.IContextInformation;
	import org.eclipse.jface.text.contentassist.IContextInformationExtension;

	import org.eclipse.ui.IWorkbenchCommandConstants;
	import org.eclipse.ui.PlatformUI;
	import org.eclipse.ui.keys.IBindingService;

	import org.eclipse.jdt.core.CompletionProposal;
	import org.eclipse.jdt.core.CompletionRequestor;
	import org.eclipse.jdt.core.ICompilationUnit;
	import org.eclipse.jdt.core.JavaModelException;

	import org.eclipse.jdt.internal.corext.util.Messages;

	import org.eclipse.jdt.ui.PreferenceConstants;
	import org.eclipse.jdt.ui.text.java.CompletionProposalCollector;
	import org.eclipse.jdt.ui.text.java.ContentAssistInvocationContext;
	import org.eclipse.jdt.ui.text.java.IJavaCompletionProposalComputer;
	import org.eclipse.jdt.ui.text.java.JavaContentAssistInvocationContext;

	import org.eclipse.jdt.internal.ui.text.JavaHeuristicScanner;
	import org.eclipse.jdt.internal.ui.text.Symbols;

	/**
	* Computes Java completion proposals and context infos.
	*
	* @since 3.2
	*/
	public class JavaCompletionProposalComputer implements IJavaCompletionProposalComputer {

	private static final class ContextInformationWrapper implements IContextInformation, IContextInformationExtension {

	private final IContextInformation fContextInformation;
	private int fPosition;

	public ContextInformationWrapper(IContextInformation contextInformation) {
	fContextInformation= contextInformation;
	}

	/*
	* @see IContextInformation#getContextDisplayString()
	*/
	@Override
	public String getContextDisplayString() {
	return fContextInformation.getContextDisplayString();
	}

	/*
	* @see IContextInformation#getImage()
	*/
	@Override
	public Image getImage() {
	return fContextInformation.getImage();
	}

	/*
	* @see IContextInformation#getInformationDisplayString()
	*/
	@Override
	public String getInformationDisplayString() {
	return fContextInformation.getInformationDisplayString();
	}

	/*
	* @see IContextInformationExtension#getContextInformationPosition()
	*/
	@Override
	public int getContextInformationPosition() {
	return fPosition;
	}

	public void setContextInformationPosition(int position) {
	fPosition= position;
	}

	/*
	* @see org.eclipse.jface.text.contentassist.IContextInformation#equals(java.lang.Object)
	*/
	@Override
	public boolean equals(Object object) {
	if (object instanceof ContextInformationWrapper)
	return fContextInformation.equals(((ContextInformationWrapper) object).fContextInformation);
	else
	return fContextInformation.equals(object);
	}

	/*
	* @see java.lang.Object#hashCode()
	* @since 3.5
	*/
	@Override
	public int hashCode() {
	return fContextInformation.hashCode();
	}
	}

	private static final long JAVA_CODE_ASSIST_TIMEOUT= Long.getLong("org.eclipse.jdt.ui.codeAssistTimeout", 5000).longValue(); // ms //$NON-NLS-1$

	private String fErrorMessage;

	private final IProgressMonitor fTimeoutProgressMonitor;

	public JavaCompletionProposalComputer() {
	fTimeoutProgressMonitor= createTimeoutProgressMonitor(JAVA_CODE_ASSIST_TIMEOUT);
	}

	protected int guessContextInformationPosition(ContentAssistInvocationContext context) {
	return context.getInvocationOffset();
	}

	protected final int guessMethodContextInformationPosition(ContentAssistInvocationContext context) {
	final int contextPosition= context.getInvocationOffset();

	IDocument document= context.getDocument();
	JavaHeuristicScanner scanner= new JavaHeuristicScanner(document);
	int bound= Math.max(-1, contextPosition - 2000);

	// try the innermost scope of parentheses that looks like a method call
	int pos= contextPosition - 1;
	do {
	int paren= scanner.findOpeningPeer(pos, bound, '(', ')');
	if (paren == JavaHeuristicScanner.NOT_FOUND)
	break;
	int token= scanner.previousToken(paren - 1, bound);
	// next token must be a method name (identifier) or the closing angle of a
	// constructor call of a parameterized type.
	if (token == Symbols.TokenIDENT \|\| token == Symbols.TokenGREATERTHAN)
	return paren + 1;
	pos= paren - 1;
	} while (true);

	return contextPosition;
	}

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

	}

	/*
	* @see org.eclipse.jface.text.contentassist.ICompletionProposalComputer#computeContextInformation(org.eclipse.jface.text.contentassist.TextContentAssistInvocationContext, org.eclipse.core.runtime.IProgressMonitor)
	*/
	@Override
	public List<IContextInformation> computeContextInformation(ContentAssistInvocationContext context, IProgressMonitor monitor) {
	if (context instanceof JavaContentAssistInvocationContext) {
	JavaContentAssistInvocationContext javaContext= (JavaContentAssistInvocationContext) context;

	int contextInformationPosition= guessContextInformationPosition(javaContext);
	List<IContextInformation> result= addContextInformations(javaContext, contextInformationPosition);
	return result;
	}
	return Collections.emptyList();
	}

	/*
	* @see org.eclipse.jface.text.contentassist.ICompletionProposalComputer#computeCompletionProposals(org.eclipse.jface.text.contentassist.TextContentAssistInvocationContext, org.eclipse.core.runtime.IProgressMonitor)
	*/
	@Override
	public List<ICompletionProposal> computeCompletionProposals(ContentAssistInvocationContext context, IProgressMonitor monitor) {
	if (context instanceof JavaContentAssistInvocationContext) {
	JavaContentAssistInvocationContext javaContext= (JavaContentAssistInvocationContext) context;
	return internalComputeCompletionProposals(context.getInvocationOffset(), javaContext);
	}
	return Collections.emptyList();
	}

	private List<ICompletionProposal> internalComputeCompletionProposals(int offset, JavaContentAssistInvocationContext context) {
	ICompilationUnit unit= context.getCompilationUnit();
	if (unit == null)
	return Collections.emptyList();

	ITextViewer viewer= context.getViewer();

	CompletionProposalCollector collector= createCollector(context);
	collector.setInvocationContext(context);

	// Allow completions for unresolved types - since 3.3
	collector.setAllowsRequiredProposals(CompletionProposal.FIELD_REF, CompletionProposal.TYPE_REF, true);
	collector.setAllowsRequiredProposals(CompletionProposal.FIELD_REF, CompletionProposal.TYPE_IMPORT, true);
	collector.setAllowsRequiredProposals(CompletionProposal.FIELD_REF, CompletionProposal.FIELD_IMPORT, true);

	collector.setAllowsRequiredProposals(CompletionProposal.METHOD_REF, CompletionProposal.TYPE_REF, true);
	collector.setAllowsRequiredProposals(CompletionProposal.METHOD_REF, CompletionProposal.TYPE_IMPORT, true);
	collector.setAllowsRequiredProposals(CompletionProposal.METHOD_REF, CompletionProposal.METHOD_IMPORT, true);

	collector.setAllowsRequiredProposals(CompletionProposal.CONSTRUCTOR_INVOCATION, CompletionProposal.TYPE_REF, true);

	collector.setAllowsRequiredProposals(CompletionProposal.ANONYMOUS_CLASS_CONSTRUCTOR_INVOCATION, CompletionProposal.TYPE_REF, true);
	collector.setAllowsRequiredProposals(CompletionProposal.ANONYMOUS_CLASS_DECLARATION, CompletionProposal.TYPE_REF, true);

	collector.setAllowsRequiredProposals(CompletionProposal.TYPE_REF, CompletionProposal.TYPE_REF, true);

	// Set the favorite list to propose static members - since 3.3
	collector.setFavoriteReferences(getFavoriteStaticMembers());

	try {
	Point selection= viewer.getSelectedRange();
	if (selection.y > 0)
	collector.setReplacementLength(selection.y);
	unit.codeComplete(offset, collector, fTimeoutProgressMonitor);
	} catch (OperationCanceledException x) {
	IBindingService bindingSvc= PlatformUI.getWorkbench().getAdapter(IBindingService.class);
	String keyBinding= bindingSvc.getBestActiveBindingFormattedFor(IWorkbenchCommandConstants.EDIT_CONTENT_ASSIST);
	fErrorMessage= Messages.format(JavaTextMessages.CompletionProcessor_error_javaCompletion_took_too_long_message, keyBinding);
	} catch (JavaModelException x) {
	Shell shell= viewer.getTextWidget().getShell();
	if (x.isDoesNotExist() && !unit.getJavaProject().isOnClasspath(unit))
	MessageDialog.openInformation(shell, JavaTextMessages.CompletionProcessor_error_notOnBuildPath_title, JavaTextMessages.CompletionProcessor_error_notOnBuildPath_message);
	else
	ErrorDialog.openError(shell, JavaTextMessages.CompletionProcessor_error_accessing_title, JavaTextMessages.CompletionProcessor_error_accessing_message, x.getStatus());
	}

	ICompletionProposal[] javaProposals= collector.getJavaCompletionProposals();
	int contextInformationOffset= guessMethodContextInformationPosition(context);
	if (contextInformationOffset != offset) {
	for (int i= 0; i < javaProposals.length; i++) {
	if (javaProposals[i] instanceof JavaMethodCompletionProposal) {
	JavaMethodCompletionProposal jmcp= (JavaMethodCompletionProposal) javaProposals[i];
	jmcp.setContextInformationPosition(contextInformationOffset);
	}
	}
	}

	List<ICompletionProposal> proposals= new ArrayList<>(Arrays.asList(javaProposals));
	if (proposals.size() == 0) {
	String error= collector.getErrorMessage();
	if (error.length() > 0)
	fErrorMessage= error;
	}
	return proposals;
	}

	/**
	* Returns a new progress monitor that get cancelled after the given timeout.
	*
	* @param timeout the timeout in ms
	* @return the progress monitor
	* @since 3.5
	*/
	private IProgressMonitor createTimeoutProgressMonitor(final long timeout) {
	return new IProgressMonitor() {

	private long fEndTime;

	@Override
	public void beginTask(String name, int totalWork) {
	fEndTime= System.currentTimeMillis() + timeout;
	}
	@Override
	public boolean isCanceled() {
	return fEndTime <= System.currentTimeMillis();
	}
	@Override
	public void done() {
	}
	@Override
	public void internalWorked(double work) {
	}
	@Override
	public void setCanceled(boolean value) {
	}
	@Override
	public void setTaskName(String name) {
	}
	@Override
	public void subTask(String name) {
	}
	@Override
	public void worked(int work) {
	}
	};
	}

	/**
	* Returns the array with favorite static members.
	*
	* @return the <code>String</code> array with with favorite static members
	* @see CompletionRequestor#setFavoriteReferences(String[])
	* @since 3.3
	*/
	private String[] getFavoriteStaticMembers() {
	String serializedFavorites= PreferenceConstants.getPreferenceStore().getString(PreferenceConstants.CODEASSIST_FAVORITE_STATIC_MEMBERS);
	if (serializedFavorites != null && serializedFavorites.length() > 0)
	return serializedFavorites.split(";"); //$NON-NLS-1$
	return new String[0];
	}

	/**
	* Creates the collector used to get proposals from core.
	*
	* @param context the context
	* @return the collector
	*/
	protected CompletionProposalCollector createCollector(JavaContentAssistInvocationContext context) {
	if (PreferenceConstants.getPreferenceStore().getBoolean(PreferenceConstants.CODEASSIST_FILL_ARGUMENT_NAMES))
	return new FillArgumentNamesCompletionProposalCollector(context);
	else
	return new CompletionProposalCollector(context.getCompilationUnit(), true);
	}

	/*
	* @see org.eclipse.jface.text.contentassist.ICompletionProposalComputer#getErrorMessage()
	*/
	@Override
	public String getErrorMessage() {
	return fErrorMessage;
	}

	/*
	* @see org.eclipse.jdt.ui.text.java.IJavaCompletionProposalComputer#sessionStarted()
	*/
	@Override
	public void sessionStarted() {
	}

	/*
	* @see org.eclipse.jdt.ui.text.java.IJavaCompletionProposalComputer#sessionEnded()
	*/
	@Override
	public void sessionEnded() {
	fErrorMessage= null;
	}
	}