org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/SemanticHighlightingReconciler.java - jdt/eclipse.jdt.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2019 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/

 package org.eclipse.jdt.internal.ui.javaeditor;

 import java.util.ArrayList;
 import java.util.List;

 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Shell;

 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.core.runtime.jobs.Job;

 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.ITextInputListener;
 import org.eclipse.jface.text.Position;
 import org.eclipse.jface.text.TextPresentation;
 import org.eclipse.jface.text.source.ISourceViewer;

 import org.eclipse.ui.IWorkbenchPartSite;

 import org.eclipse.jdt.core.ITypeRoot;
 import org.eclipse.jdt.core.dom.AST;
 import org.eclipse.jdt.core.dom.ASTNode;
 import org.eclipse.jdt.core.dom.CompilationUnit;
 import org.eclipse.jdt.core.dom.ConstructorInvocation;
 import org.eclipse.jdt.core.dom.Expression;
 import org.eclipse.jdt.core.dom.IMethodBinding;
 import org.eclipse.jdt.core.dom.SimpleName;
 import org.eclipse.jdt.core.dom.SimpleType;
 import org.eclipse.jdt.core.dom.SuperConstructorInvocation;
 import org.eclipse.jdt.core.dom.YieldStatement;
 import org.eclipse.jdt.core.manipulation.SharedASTProviderCore;

 import org.eclipse.jdt.internal.ui.JavaPlugin;
 import org.eclipse.jdt.internal.ui.javaeditor.SemanticHighlightingManager.HighlightedPosition;
 import org.eclipse.jdt.internal.ui.javaeditor.SemanticHighlightingManager.Highlighting;
 import org.eclipse.jdt.internal.ui.javaeditor.SemanticHighlightings.DeprecatedMemberHighlighting;
 import org.eclipse.jdt.internal.ui.javaeditor.SemanticHighlightings.VarKeywordHighlighting;
 import org.eclipse.jdt.internal.ui.javaeditor.SemanticHighlightings.YieldKeywordHighlighting;
 import org.eclipse.jdt.internal.ui.text.java.IJavaReconcilingListener;


 /**
  * Semantic highlighting reconciler - Background thread implementation.
  *
  * @since 3.0
  */
 public class SemanticHighlightingReconciler implements IJavaReconcilingListener, ITextInputListener {

 	/**
 	 * Collects positions from the AST.
 	 */
 	private class PositionCollector extends PositionCollectorCore {

 		/** The semantic token */
 		private SemanticToken fToken= new SemanticToken();


 		@Override
 		protected boolean visitLiteral(Expression node) {
 			fToken.update(node);
 			for (int i= 0, n= fJobSemanticHighlightings.length; i < n; i++) {
 				SemanticHighlighting semanticHighlighting= fJobSemanticHighlightings[i];
 				if (fJobHighlightings[i].isEnabled() && semanticHighlighting.consumesLiteral(fToken)) {
 					int offset= node.getStartPosition();
 					int length= node.getLength();
 					if (offset > -1 && length > 0)
 						addPosition(offset, length, fJobHighlightings[i]);
 					break;
 				}
 			}
 			fToken.clear();
 			return false;
 		}

 		/*
 		 * @see org.eclipse.jdt.internal.corext.dom.GenericVisitor#visit(org.eclipse.jdt.core.dom.ConstructorInvocation)
 		 * @since 3.5
 		 */
 		@Override
 		public boolean visit(ConstructorInvocation node) {
 			// XXX Hack for performance reasons (should loop over fJobSemanticHighlightings can call consumes(*))
 			if (fJobDeprecatedMemberHighlighting != null) {
 				IMethodBinding constructorBinding= node.resolveConstructorBinding();
 				if (constructorBinding != null && constructorBinding.isDeprecated()) {
 					int offset= node.getStartPosition();
 					int length= 4;
 					if (offset > -1 && length > 0)
 						addPosition(offset, length, fJobDeprecatedMemberHighlighting);
 				}
 			}
 			return true;
 		}

 		/*
 		 * @see org.eclipse.jdt.internal.corext.dom.GenericVisitor#visit(org.eclipse.jdt.core.dom.ConstructorInvocation)
 		 * @since 3.5
 		 */
 		@Override
 		public boolean visit(SuperConstructorInvocation node) {
 			// XXX Hack for performance reasons (should loop over fJobSemanticHighlightings can call consumes(*))
 			if (fJobDeprecatedMemberHighlighting != null) {
 				IMethodBinding constructorBinding= node.resolveConstructorBinding();
 				if (constructorBinding != null && constructorBinding.isDeprecated()) {
 					int offset= node.getStartPosition();
 					int length= 5;
 					if (offset > -1 && length > 0)
 						addPosition(offset, length, fJobDeprecatedMemberHighlighting);
 				}
 			}
 			return true;
 		}

 		@Override
 		public boolean visit(SimpleType node) {
 			if (node.getAST().apiLevel() >= AST.JLS10 && node.isVar()) {
 				int offset= node.getStartPosition();
 				int length= node.getLength();
 				if (offset > -1 && length > 0) {
 					for (int i= 0; i < fJobSemanticHighlightings.length; i++) {
 						SemanticHighlighting semanticHighlighting= fJobSemanticHighlightings[i];
 						if (semanticHighlighting instanceof VarKeywordHighlighting) {
 							addPosition(offset, length, fJobHighlightings[i]);
 							return false;
 						}
 					}
 				}
 			}
 			return true;
 		}

 		@Override
 		public boolean visit(YieldStatement node) {
 			AST ast= node.getAST();
 			if (ast.isPreviewEnabled() && !node.isImplicit()) {
 				int offset= node.getStartPosition();
 				int length= 5; // length of 'yield'
 				if (offset > -1 && length > 0) {
 					for (int i= 0; i < fJobSemanticHighlightings.length; i++) {
 						SemanticHighlighting semanticHighlighting= fJobSemanticHighlightings[i];
 						if (semanticHighlighting instanceof YieldKeywordHighlighting) {
 							addPosition(offset, length, fJobHighlightings[i]);
 							return false;
 						}
 					}
 				}
 			}
 			return true;
 		}

 		/*
 		 * @see org.eclipse.jdt.core.dom.ASTVisitor#visit(org.eclipse.jdt.core.dom.SimpleName)
 		 */
 		@Override
 		public boolean visit(SimpleName node) {
 			fToken.update(node);
 			for (int i= 0, n= fJobSemanticHighlightings.length; i < n; i++) {
 				SemanticHighlighting semanticHighlighting= fJobSemanticHighlightings[i];
 				if (fJobHighlightings[i].isEnabled() && semanticHighlighting.consumes(fToken)) {
 					int offset= node.getStartPosition();
 					int length= node.getLength();
 					if (offset > -1 && length > 0)
 						addPosition(offset, length, fJobHighlightings[i]);
 					break;
 				}
 			}
 			fToken.clear();
 			return false;
 		}

 		/**
 		 * Add a position with the given range and highlighting iff it does not exist already.
 		 * @param offset The range offset
 		 * @param length The range length
 		 * @param highlighting The highlighting
 		 */
 		private void addPosition(int offset, int length, Highlighting highlighting) {
 			boolean isExisting= false;
 			// TODO: use binary search
 			for (int i= 0, n= fRemovedPositions.size(); i < n; i++) {
 				HighlightedPosition position= (HighlightedPosition) fRemovedPositions.get(i);
 				if (position == null)
 					continue;
 				if (position.isEqual(offset, length, highlighting)) {
 					isExisting= true;
 					fRemovedPositions.set(i, null);
 					fNOfRemovedPositions--;
 					break;
 				}
 			}

 			if (!isExisting) {
 				Position position= fJobPresenter.createHighlightedPosition(offset, length, highlighting);
 				fAddedPositions.add(position);
 			}
 		}

 		/**
 		 * Retain the positions completely contained in the given range.
 		 * @param offset The range offset
 		 * @param length The range length
 		 */
 		@Override
 		protected void retainPositions(int offset, int length) {
 			// TODO: use binary search
 			for (int i= 0, n= fRemovedPositions.size(); i < n; i++) {
 				HighlightedPosition position= (HighlightedPosition) fRemovedPositions.get(i);
 				if (position != null && position.isContained(offset, length)) {
 					fRemovedPositions.set(i, null);
 					fNOfRemovedPositions--;
 				}
 			}
 		}
 	}

 	/** Position collector */
 	private PositionCollector fCollector= new PositionCollector();

 	/** The Java editor this semantic highlighting reconciler is installed on */
 	private JavaEditor fEditor;
 	/** The source viewer this semantic highlighting reconciler is installed on */
 	private ISourceViewer fSourceViewer;
 	/** The semantic highlighting presenter */
 	private SemanticHighlightingPresenter fPresenter;
 	/** Semantic highlightings */
 	private SemanticHighlighting[] fSemanticHighlightings;
 	/** Highlightings */
 	private Highlighting[] fHighlightings;

 	/** Background job's added highlighted positions */
 	private List<Position> fAddedPositions= new ArrayList<>();
 	/** Background job's removed highlighted positions */
 	private List<Position> fRemovedPositions= new ArrayList<>();
 	/** Number of removed positions */
 	private int fNOfRemovedPositions;

 	/** Background job */
 	private Job fJob;
 	/** Background job lock */
 	private final Object fJobLock= new Object();
 	/**
 	 * Reconcile operation lock.
 	 * @since 3.2
 	 */
 	private final Object fReconcileLock= new Object();
 	/**
 	 * <code>true</code> if any thread is executing
 	 * <code>reconcile</code>, <code>false</code> otherwise.
 	 * @since 3.2
 	 */
 	private boolean fIsReconciling= false;

 	/** The semantic highlighting presenter - cache for background thread, only valid during {@link #reconciled(CompilationUnit, boolean, IProgressMonitor)} */
 	private SemanticHighlightingPresenter fJobPresenter;
 	/** Semantic highlightings - cache for background thread, only valid during {@link #reconciled(CompilationUnit, boolean, IProgressMonitor)} */
 	private SemanticHighlighting[] fJobSemanticHighlightings;
 	/** Highlightings - cache for background thread, only valid during {@link #reconciled(CompilationUnit, boolean, IProgressMonitor)} */
 	private Highlighting[] fJobHighlightings;

 	/**
 	 * XXX Hack for performance reasons (should loop over fJobSemanticHighlightings can call consumes(*))
 	 * @since 3.5
 	 */
 	private Highlighting fJobDeprecatedMemberHighlighting;

 	/*
 	 * @see org.eclipse.jdt.internal.ui.text.java.IJavaReconcilingListener#aboutToBeReconciled()
 	 */
 	@Override
 	public void aboutToBeReconciled() {
 		// Do nothing
 	}

 	/*
 	 * @see org.eclipse.jdt.internal.ui.text.java.IJavaReconcilingListener#reconciled(CompilationUnit, boolean, IProgressMonitor)
 	 */
 	@Override
 	public void reconciled(CompilationUnit ast, boolean forced, IProgressMonitor progressMonitor) {
 		// ensure at most one thread can be reconciling at any time
 		synchronized (fReconcileLock) {
 			if (fIsReconciling)
 				return;
 			else
 				fIsReconciling= true;
 		}
 		fJobPresenter= fPresenter;
 		fJobSemanticHighlightings= fSemanticHighlightings;
 		fJobHighlightings= fHighlightings;

 		try {
 			if (fJobPresenter == null || fJobSemanticHighlightings == null || fJobHighlightings == null)
 				return;

 			fJobPresenter.setCanceled(progressMonitor.isCanceled());

 			if (ast == null || fJobPresenter.isCanceled())
 				return;

 			ASTNode[] subtrees= getAffectedSubtrees(ast);
 			if (subtrees.length == 0)
 				return;

 			startReconcilingPositions();

 			if (!fJobPresenter.isCanceled()) {
 				fJobDeprecatedMemberHighlighting= null;
 				for (int i= 0, n= fJobSemanticHighlightings.length; i < n; i++) {
 					SemanticHighlighting semanticHighlighting= fJobSemanticHighlightings[i];
 					if (fJobHighlightings[i].isEnabled() && semanticHighlighting instanceof DeprecatedMemberHighlighting) {
 						fJobDeprecatedMemberHighlighting= fJobHighlightings[i];
 						break;
 					}
 				}
 				reconcilePositions(subtrees);
 			}

 			TextPresentation textPresentation= null;
 			if (!fJobPresenter.isCanceled())
 				textPresentation= fJobPresenter.createPresentation(fAddedPositions, fRemovedPositions);

 			if (!fJobPresenter.isCanceled())
 				updatePresentation(textPresentation, fAddedPositions, fRemovedPositions);

 			stopReconcilingPositions();
 		} finally {
 			fJobPresenter= null;
 			fJobSemanticHighlightings= null;
 			fJobHighlightings= null;
 			fJobDeprecatedMemberHighlighting= null;
 			synchronized (fReconcileLock) {
 				fIsReconciling= false;
 			}
 		}
 	}

 	/**
 	 * @param node Root node
 	 * @return Array of subtrees that may be affected by past document changes
 	 */
 	private ASTNode[] getAffectedSubtrees(ASTNode node) {
 		// TODO: only return nodes which are affected by document changes - would require an 'anchor' concept for taking distant effects into account
 		return new ASTNode[] { node };
 	}

 	/**
 	 * Start reconciling positions.
 	 */
 	private void startReconcilingPositions() {
 		fJobPresenter.addAllPositions(fRemovedPositions);
 		fNOfRemovedPositions= fRemovedPositions.size();
 	}

 	/**
 	 * Reconcile positions based on the AST subtrees
 	 *
 	 * @param subtrees the AST subtrees
 	 */
 	private void reconcilePositions(ASTNode[] subtrees) {
 		// FIXME: remove positions not covered by subtrees


 		for (int i= 0, n= subtrees.length; i < n; i++)
 			subtrees[i].accept(fCollector);
 		List<Position> oldPositions= fRemovedPositions;
 		List<Position> newPositions= new ArrayList<>(fNOfRemovedPositions);
 		for (int i= 0, n= oldPositions.size(); i < n; i ++) {
 			Position current= oldPositions.get(i);
 			if (current != null)
 				newPositions.add(current);
 		}
 		fRemovedPositions= newPositions;
 	}

 	/**
 	 * Update the presentation.
 	 *
 	 * @param textPresentation the text presentation
 	 * @param addedPositions the added positions
 	 * @param removedPositions the removed positions
 	 */
 	private void updatePresentation(TextPresentation textPresentation, List<Position> addedPositions, List<Position> removedPositions) {
 		Runnable runnable= fJobPresenter.createUpdateRunnable(textPresentation, addedPositions, removedPositions);
 		if (runnable == null)
 			return;

 		JavaEditor editor= fEditor;
 		if (editor == null)
 			return;

 		IWorkbenchPartSite site= editor.getSite();
 		if (site == null)
 			return;

 		Shell shell= site.getShell();
 		if (shell == null || shell.isDisposed())
 			return;

 		Display display= shell.getDisplay();
 		if (display == null || display.isDisposed())
 			return;

 		display.asyncExec(runnable);
 	}

 	/**
 	 * Stop reconciling positions.
 	 */
 	private void stopReconcilingPositions() {
 		fRemovedPositions.clear();
 		fNOfRemovedPositions= 0;
 		fAddedPositions.clear();
 	}

 	/**
 	 * Install this reconciler on the given editor, presenter and highlightings.
 	 * @param editor the editor
 	 * @param sourceViewer the source viewer
 	 * @param presenter the semantic highlighting presenter
 	 * @param semanticHighlightings the semantic highlightings
 	 * @param highlightings the highlightings
 	 */
 	public void install(JavaEditor editor, ISourceViewer sourceViewer, SemanticHighlightingPresenter presenter, SemanticHighlighting[] semanticHighlightings, Highlighting[] highlightings) {
 		fPresenter= presenter;
 		fSemanticHighlightings= semanticHighlightings;
 		fHighlightings= highlightings;

 		fEditor= editor;
 		fSourceViewer= sourceViewer;

 		if (fEditor instanceof CompilationUnitEditor) {
 			((CompilationUnitEditor)fEditor).addReconcileListener(this);
 		} else if (fEditor == null) {
 			fSourceViewer.addTextInputListener(this);
 			scheduleJob();
 		}
 	}

 	/**
 	 * Uninstall this reconciler from the editor
 	 */
 	public void uninstall() {
 		if (fPresenter != null)
 			fPresenter.setCanceled(true);

 		if (fEditor != null) {
 			if (fEditor instanceof CompilationUnitEditor)
 				((CompilationUnitEditor)fEditor).removeReconcileListener(this);
 			else
 				fSourceViewer.removeTextInputListener(this);
 			fEditor= null;
 		}

 		fSourceViewer= null;
 		fSemanticHighlightings= null;
 		fHighlightings= null;
 		fPresenter= null;
 	}

 	/**
 	 * Schedule a background job for retrieving the AST and reconciling the Semantic Highlighting model.
 	 */
 	private void scheduleJob() {
 		final ITypeRoot element= fEditor.getInputJavaElement();

 		synchronized (fJobLock) {
 			final Job oldJob= fJob;
 			if (fJob != null) {
 				fJob.cancel();
 				fJob= null;
 			}

 			if (element != null) {
 				fJob= new Job(JavaEditorMessages.SemanticHighlighting_job) {
 					@Override
 					protected IStatus run(IProgressMonitor monitor) {
 						if (oldJob != null) {
 							try {
 								oldJob.join();
 							} catch (InterruptedException e) {
 								JavaPlugin.log(e);
 								return Status.CANCEL_STATUS;
 							}
 						}
 						if (monitor.isCanceled())
 							return Status.CANCEL_STATUS;
 						CompilationUnit ast= SharedASTProviderCore.getAST(element, SharedASTProviderCore.WAIT_YES, monitor);
 						reconciled(ast, false, monitor);
 						synchronized (fJobLock) {
 							// allow the job to be gc'ed
 							if (fJob == this)
 								fJob= null;
 						}
 						return Status.OK_STATUS;
 					}
 				};
 				fJob.setSystem(true);
 				fJob.setPriority(Job.DECORATE);
 				fJob.schedule();
 			}
 		}
 	}

 	/*
 	 * @see org.eclipse.jface.text.ITextInputListener#inputDocumentAboutToBeChanged(org.eclipse.jface.text.IDocument, org.eclipse.jface.text.IDocument)
 	 */
 	@Override
 	public void inputDocumentAboutToBeChanged(IDocument oldInput, IDocument newInput) {
 		synchronized (fJobLock) {
 			if (fJob != null) {
 				fJob.cancel();
 				fJob= null;
 			}
 		}
 	}

 	/*
 	 * @see org.eclipse.jface.text.ITextInputListener#inputDocumentChanged(org.eclipse.jface.text.IDocument, org.eclipse.jface.text.IDocument)
 	 */
 	@Override
 	public void inputDocumentChanged(IDocument oldInput, IDocument newInput) {
 		if (newInput != null)
 			scheduleJob();
 	}

 	/**
 	 * Refreshes the highlighting.
 	 *
 	 * @since 3.2
 	 */
 	public void refresh() {
 		scheduleJob();
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2019 IBM Corporation and others.
	*
	* This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License 2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/

	package org.eclipse.jdt.internal.ui.javaeditor;

	import java.util.ArrayList;
	import java.util.List;

	import org.eclipse.swt.widgets.Display;
	import org.eclipse.swt.widgets.Shell;

	import org.eclipse.core.runtime.IProgressMonitor;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Status;
	import org.eclipse.core.runtime.jobs.Job;

	import org.eclipse.jface.text.IDocument;
	import org.eclipse.jface.text.ITextInputListener;
	import org.eclipse.jface.text.Position;
	import org.eclipse.jface.text.TextPresentation;
	import org.eclipse.jface.text.source.ISourceViewer;

	import org.eclipse.ui.IWorkbenchPartSite;

	import org.eclipse.jdt.core.ITypeRoot;
	import org.eclipse.jdt.core.dom.AST;
	import org.eclipse.jdt.core.dom.ASTNode;
	import org.eclipse.jdt.core.dom.CompilationUnit;
	import org.eclipse.jdt.core.dom.ConstructorInvocation;
	import org.eclipse.jdt.core.dom.Expression;
	import org.eclipse.jdt.core.dom.IMethodBinding;
	import org.eclipse.jdt.core.dom.SimpleName;
	import org.eclipse.jdt.core.dom.SimpleType;
	import org.eclipse.jdt.core.dom.SuperConstructorInvocation;
	import org.eclipse.jdt.core.dom.YieldStatement;
	import org.eclipse.jdt.core.manipulation.SharedASTProviderCore;

	import org.eclipse.jdt.internal.ui.JavaPlugin;
	import org.eclipse.jdt.internal.ui.javaeditor.SemanticHighlightingManager.HighlightedPosition;
	import org.eclipse.jdt.internal.ui.javaeditor.SemanticHighlightingManager.Highlighting;
	import org.eclipse.jdt.internal.ui.javaeditor.SemanticHighlightings.DeprecatedMemberHighlighting;
	import org.eclipse.jdt.internal.ui.javaeditor.SemanticHighlightings.VarKeywordHighlighting;
	import org.eclipse.jdt.internal.ui.javaeditor.SemanticHighlightings.YieldKeywordHighlighting;
	import org.eclipse.jdt.internal.ui.text.java.IJavaReconcilingListener;


	/**
	* Semantic highlighting reconciler - Background thread implementation.
	*
	* @since 3.0
	*/
	public class SemanticHighlightingReconciler implements IJavaReconcilingListener, ITextInputListener {

	/**
	* Collects positions from the AST.
	*/
	private class PositionCollector extends PositionCollectorCore {

	/** The semantic token */
	private SemanticToken fToken= new SemanticToken();


	@Override
	protected boolean visitLiteral(Expression node) {
	fToken.update(node);
	for (int i= 0, n= fJobSemanticHighlightings.length; i < n; i++) {
	SemanticHighlighting semanticHighlighting= fJobSemanticHighlightings[i];
	if (fJobHighlightings[i].isEnabled() && semanticHighlighting.consumesLiteral(fToken)) {
	int offset= node.getStartPosition();
	int length= node.getLength();
	if (offset > -1 && length > 0)
	addPosition(offset, length, fJobHighlightings[i]);
	break;
	}
	}
	fToken.clear();
	return false;
	}

	/*
	* @see org.eclipse.jdt.internal.corext.dom.GenericVisitor#visit(org.eclipse.jdt.core.dom.ConstructorInvocation)
	* @since 3.5
	*/
	@Override
	public boolean visit(ConstructorInvocation node) {
	// XXX Hack for performance reasons (should loop over fJobSemanticHighlightings can call consumes(*))
	if (fJobDeprecatedMemberHighlighting != null) {
	IMethodBinding constructorBinding= node.resolveConstructorBinding();
	if (constructorBinding != null && constructorBinding.isDeprecated()) {
	int offset= node.getStartPosition();
	int length= 4;
	if (offset > -1 && length > 0)
	addPosition(offset, length, fJobDeprecatedMemberHighlighting);
	}
	}
	return true;
	}

	/*
	* @see org.eclipse.jdt.internal.corext.dom.GenericVisitor#visit(org.eclipse.jdt.core.dom.ConstructorInvocation)
	* @since 3.5
	*/
	@Override
	public boolean visit(SuperConstructorInvocation node) {
	// XXX Hack for performance reasons (should loop over fJobSemanticHighlightings can call consumes(*))
	if (fJobDeprecatedMemberHighlighting != null) {
	IMethodBinding constructorBinding= node.resolveConstructorBinding();
	if (constructorBinding != null && constructorBinding.isDeprecated()) {
	int offset= node.getStartPosition();
	int length= 5;
	if (offset > -1 && length > 0)
	addPosition(offset, length, fJobDeprecatedMemberHighlighting);
	}
	}
	return true;
	}

	@Override
	public boolean visit(SimpleType node) {
	if (node.getAST().apiLevel() >= AST.JLS10 && node.isVar()) {
	int offset= node.getStartPosition();
	int length= node.getLength();
	if (offset > -1 && length > 0) {
	for (int i= 0; i < fJobSemanticHighlightings.length; i++) {
	SemanticHighlighting semanticHighlighting= fJobSemanticHighlightings[i];
	if (semanticHighlighting instanceof VarKeywordHighlighting) {
	addPosition(offset, length, fJobHighlightings[i]);
	return false;
	}
	}
	}
	}
	return true;
	}

	@Override
	public boolean visit(YieldStatement node) {
	AST ast= node.getAST();
	if (ast.isPreviewEnabled() && !node.isImplicit()) {
	int offset= node.getStartPosition();
	int length= 5; // length of 'yield'
	if (offset > -1 && length > 0) {
	for (int i= 0; i < fJobSemanticHighlightings.length; i++) {
	SemanticHighlighting semanticHighlighting= fJobSemanticHighlightings[i];
	if (semanticHighlighting instanceof YieldKeywordHighlighting) {
	addPosition(offset, length, fJobHighlightings[i]);
	return false;
	}
	}
	}
	}
	return true;
	}

	/*
	* @see org.eclipse.jdt.core.dom.ASTVisitor#visit(org.eclipse.jdt.core.dom.SimpleName)
	*/
	@Override
	public boolean visit(SimpleName node) {
	fToken.update(node);
	for (int i= 0, n= fJobSemanticHighlightings.length; i < n; i++) {
	SemanticHighlighting semanticHighlighting= fJobSemanticHighlightings[i];
	if (fJobHighlightings[i].isEnabled() && semanticHighlighting.consumes(fToken)) {
	int offset= node.getStartPosition();
	int length= node.getLength();
	if (offset > -1 && length > 0)
	addPosition(offset, length, fJobHighlightings[i]);
	break;
	}
	}
	fToken.clear();
	return false;
	}

	/**
	* Add a position with the given range and highlighting iff it does not exist already.
	* @param offset The range offset
	* @param length The range length
	* @param highlighting The highlighting
	*/
	private void addPosition(int offset, int length, Highlighting highlighting) {
	boolean isExisting= false;
	// TODO: use binary search
	for (int i= 0, n= fRemovedPositions.size(); i < n; i++) {
	HighlightedPosition position= (HighlightedPosition) fRemovedPositions.get(i);
	if (position == null)
	continue;
	if (position.isEqual(offset, length, highlighting)) {
	isExisting= true;
	fRemovedPositions.set(i, null);
	fNOfRemovedPositions--;
	break;
	}
	}

	if (!isExisting) {
	Position position= fJobPresenter.createHighlightedPosition(offset, length, highlighting);
	fAddedPositions.add(position);
	}
	}

	/**
	* Retain the positions completely contained in the given range.
	* @param offset The range offset
	* @param length The range length
	*/
	@Override
	protected void retainPositions(int offset, int length) {
	// TODO: use binary search
	for (int i= 0, n= fRemovedPositions.size(); i < n; i++) {
	HighlightedPosition position= (HighlightedPosition) fRemovedPositions.get(i);
	if (position != null && position.isContained(offset, length)) {
	fRemovedPositions.set(i, null);
	fNOfRemovedPositions--;
	}
	}
	}
	}

	/** Position collector */
	private PositionCollector fCollector= new PositionCollector();

	/** The Java editor this semantic highlighting reconciler is installed on */
	private JavaEditor fEditor;
	/** The source viewer this semantic highlighting reconciler is installed on */
	private ISourceViewer fSourceViewer;
	/** The semantic highlighting presenter */
	private SemanticHighlightingPresenter fPresenter;
	/** Semantic highlightings */
	private SemanticHighlighting[] fSemanticHighlightings;
	/** Highlightings */
	private Highlighting[] fHighlightings;

	/** Background job's added highlighted positions */
	private List<Position> fAddedPositions= new ArrayList<>();
	/** Background job's removed highlighted positions */
	private List<Position> fRemovedPositions= new ArrayList<>();
	/** Number of removed positions */
	private int fNOfRemovedPositions;

	/** Background job */
	private Job fJob;
	/** Background job lock */
	private final Object fJobLock= new Object();
	/**
	* Reconcile operation lock.
	* @since 3.2
	*/
	private final Object fReconcileLock= new Object();
	/**
	* <code>true</code> if any thread is executing
	* <code>reconcile</code>, <code>false</code> otherwise.
	* @since 3.2
	*/
	private boolean fIsReconciling= false;

	/** The semantic highlighting presenter - cache for background thread, only valid during {@link #reconciled(CompilationUnit, boolean, IProgressMonitor)} */
	private SemanticHighlightingPresenter fJobPresenter;
	/** Semantic highlightings - cache for background thread, only valid during {@link #reconciled(CompilationUnit, boolean, IProgressMonitor)} */
	private SemanticHighlighting[] fJobSemanticHighlightings;
	/** Highlightings - cache for background thread, only valid during {@link #reconciled(CompilationUnit, boolean, IProgressMonitor)} */
	private Highlighting[] fJobHighlightings;

	/**
	* XXX Hack for performance reasons (should loop over fJobSemanticHighlightings can call consumes(*))
	* @since 3.5
	*/
	private Highlighting fJobDeprecatedMemberHighlighting;

	/*
	* @see org.eclipse.jdt.internal.ui.text.java.IJavaReconcilingListener#aboutToBeReconciled()
	*/
	@Override
	public void aboutToBeReconciled() {
	// Do nothing
	}

	/*
	* @see org.eclipse.jdt.internal.ui.text.java.IJavaReconcilingListener#reconciled(CompilationUnit, boolean, IProgressMonitor)
	*/
	@Override
	public void reconciled(CompilationUnit ast, boolean forced, IProgressMonitor progressMonitor) {
	// ensure at most one thread can be reconciling at any time
	synchronized (fReconcileLock) {
	if (fIsReconciling)
	return;
	else
	fIsReconciling= true;
	}
	fJobPresenter= fPresenter;
	fJobSemanticHighlightings= fSemanticHighlightings;
	fJobHighlightings= fHighlightings;

	try {
	if (fJobPresenter == null \|\| fJobSemanticHighlightings == null \|\| fJobHighlightings == null)
	return;

	fJobPresenter.setCanceled(progressMonitor.isCanceled());

	if (ast == null \|\| fJobPresenter.isCanceled())
	return;

	ASTNode[] subtrees= getAffectedSubtrees(ast);
	if (subtrees.length == 0)
	return;

	startReconcilingPositions();

	if (!fJobPresenter.isCanceled()) {
	fJobDeprecatedMemberHighlighting= null;
	for (int i= 0, n= fJobSemanticHighlightings.length; i < n; i++) {
	SemanticHighlighting semanticHighlighting= fJobSemanticHighlightings[i];
	if (fJobHighlightings[i].isEnabled() && semanticHighlighting instanceof DeprecatedMemberHighlighting) {
	fJobDeprecatedMemberHighlighting= fJobHighlightings[i];
	break;
	}
	}
	reconcilePositions(subtrees);
	}

	TextPresentation textPresentation= null;
	if (!fJobPresenter.isCanceled())
	textPresentation= fJobPresenter.createPresentation(fAddedPositions, fRemovedPositions);

	if (!fJobPresenter.isCanceled())
	updatePresentation(textPresentation, fAddedPositions, fRemovedPositions);

	stopReconcilingPositions();
	} finally {
	fJobPresenter= null;
	fJobSemanticHighlightings= null;
	fJobHighlightings= null;
	fJobDeprecatedMemberHighlighting= null;
	synchronized (fReconcileLock) {
	fIsReconciling= false;
	}
	}
	}

	/**
	* @param node Root node
	* @return Array of subtrees that may be affected by past document changes
	*/
	private ASTNode[] getAffectedSubtrees(ASTNode node) {
	// TODO: only return nodes which are affected by document changes - would require an 'anchor' concept for taking distant effects into account
	return new ASTNode[] { node };
	}

	/**
	* Start reconciling positions.
	*/
	private void startReconcilingPositions() {
	fJobPresenter.addAllPositions(fRemovedPositions);
	fNOfRemovedPositions= fRemovedPositions.size();
	}

	/**
	* Reconcile positions based on the AST subtrees
	*
	* @param subtrees the AST subtrees
	*/
	private void reconcilePositions(ASTNode[] subtrees) {
	// FIXME: remove positions not covered by subtrees



	for (int i= 0, n= subtrees.length; i < n; i++)
	subtrees[i].accept(fCollector);
	List<Position> oldPositions= fRemovedPositions;
	List<Position> newPositions= new ArrayList<>(fNOfRemovedPositions);
	for (int i= 0, n= oldPositions.size(); i < n; i ++) {
	Position current= oldPositions.get(i);
	if (current != null)
	newPositions.add(current);
	}
	fRemovedPositions= newPositions;
	}

	/**
	* Update the presentation.
	*
	* @param textPresentation the text presentation
	* @param addedPositions the added positions
	* @param removedPositions the removed positions
	*/
	private void updatePresentation(TextPresentation textPresentation, List<Position> addedPositions, List<Position> removedPositions) {
	Runnable runnable= fJobPresenter.createUpdateRunnable(textPresentation, addedPositions, removedPositions);
	if (runnable == null)
	return;

	JavaEditor editor= fEditor;
	if (editor == null)
	return;

	IWorkbenchPartSite site= editor.getSite();
	if (site == null)
	return;

	Shell shell= site.getShell();
	if (shell == null \|\| shell.isDisposed())
	return;

	Display display= shell.getDisplay();
	if (display == null \|\| display.isDisposed())
	return;

	display.asyncExec(runnable);
	}

	/**
	* Stop reconciling positions.
	*/
	private void stopReconcilingPositions() {
	fRemovedPositions.clear();
	fNOfRemovedPositions= 0;
	fAddedPositions.clear();
	}

	/**
	* Install this reconciler on the given editor, presenter and highlightings.
	* @param editor the editor
	* @param sourceViewer the source viewer
	* @param presenter the semantic highlighting presenter
	* @param semanticHighlightings the semantic highlightings
	* @param highlightings the highlightings
	*/
	public void install(JavaEditor editor, ISourceViewer sourceViewer, SemanticHighlightingPresenter presenter, SemanticHighlighting[] semanticHighlightings, Highlighting[] highlightings) {
	fPresenter= presenter;
	fSemanticHighlightings= semanticHighlightings;
	fHighlightings= highlightings;

	fEditor= editor;
	fSourceViewer= sourceViewer;

	if (fEditor instanceof CompilationUnitEditor) {
	((CompilationUnitEditor)fEditor).addReconcileListener(this);
	} else if (fEditor == null) {
	fSourceViewer.addTextInputListener(this);
	scheduleJob();
	}
	}

	/**
	* Uninstall this reconciler from the editor
	*/
	public void uninstall() {
	if (fPresenter != null)
	fPresenter.setCanceled(true);

	if (fEditor != null) {
	if (fEditor instanceof CompilationUnitEditor)
	((CompilationUnitEditor)fEditor).removeReconcileListener(this);
	else
	fSourceViewer.removeTextInputListener(this);
	fEditor= null;
	}

	fSourceViewer= null;
	fSemanticHighlightings= null;
	fHighlightings= null;
	fPresenter= null;
	}

	/**
	* Schedule a background job for retrieving the AST and reconciling the Semantic Highlighting model.
	*/
	private void scheduleJob() {
	final ITypeRoot element= fEditor.getInputJavaElement();

	synchronized (fJobLock) {
	final Job oldJob= fJob;
	if (fJob != null) {
	fJob.cancel();
	fJob= null;
	}

	if (element != null) {
	fJob= new Job(JavaEditorMessages.SemanticHighlighting_job) {
	@Override
	protected IStatus run(IProgressMonitor monitor) {
	if (oldJob != null) {
	try {
	oldJob.join();
	} catch (InterruptedException e) {
	JavaPlugin.log(e);
	return Status.CANCEL_STATUS;
	}
	}
	if (monitor.isCanceled())
	return Status.CANCEL_STATUS;
	CompilationUnit ast= SharedASTProviderCore.getAST(element, SharedASTProviderCore.WAIT_YES, monitor);
	reconciled(ast, false, monitor);
	synchronized (fJobLock) {
	// allow the job to be gc'ed
	if (fJob == this)
	fJob= null;
	}
	return Status.OK_STATUS;
	}
	};
	fJob.setSystem(true);
	fJob.setPriority(Job.DECORATE);
	fJob.schedule();
	}
	}
	}

	/*
	* @see org.eclipse.jface.text.ITextInputListener#inputDocumentAboutToBeChanged(org.eclipse.jface.text.IDocument, org.eclipse.jface.text.IDocument)
	*/
	@Override
	public void inputDocumentAboutToBeChanged(IDocument oldInput, IDocument newInput) {
	synchronized (fJobLock) {
	if (fJob != null) {
	fJob.cancel();
	fJob= null;
	}
	}
	}

	/*
	* @see org.eclipse.jface.text.ITextInputListener#inputDocumentChanged(org.eclipse.jface.text.IDocument, org.eclipse.jface.text.IDocument)
	*/
	@Override
	public void inputDocumentChanged(IDocument oldInput, IDocument newInput) {
	if (newInput != null)
	scheduleJob();
	}

	/**
	* Refreshes the highlighting.
	*
	* @since 3.2
	*/
	public void refresh() {
	scheduleJob();
	}
	}