/*******************************************************************************
* Copyright (c) 2000, 2011 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.javaeditor;
import java.util.List;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.ISafeRunnable;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.OperationCanceledException;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.SafeRunner;
import org.eclipse.core.runtime.Status;
import org.eclipse.ui.IPartListener2;
import org.eclipse.ui.IWindowListener;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.IWorkbenchPartReference;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.PlatformUI;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.ITypeRoot;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.core.dom.AST;
import org.eclipse.jdt.core.dom.ASTNode;
import org.eclipse.jdt.core.dom.ASTParser;
import org.eclipse.jdt.core.dom.AbstractTypeDeclaration;
import org.eclipse.jdt.core.dom.CompilationUnit;
import org.eclipse.jdt.internal.corext.dom.ASTNodes;
import org.eclipse.jdt.ui.JavaUI;
import org.eclipse.jdt.ui.SharedASTProvider;
import org.eclipse.jdt.ui.SharedASTProvider.WAIT_FLAG;
import org.eclipse.jdt.internal.ui.JavaPlugin;
/**
* Provides a shared AST for clients. The shared AST is
* the AST of the active Java editor's input element.
*
* @since 3.0
*/
public final class ASTProvider {
/**
* @deprecated Use {@link SharedASTProvider#WAIT_YES} instead.
*/
public static final WAIT_FLAG WAIT_YES= SharedASTProvider.WAIT_YES;
/**
* @deprecated Use {@link SharedASTProvider#WAIT_ACTIVE_ONLY} instead.
*/
public static final WAIT_FLAG WAIT_ACTIVE_ONLY= SharedASTProvider.WAIT_ACTIVE_ONLY;
/**
* @deprecated Use {@link SharedASTProvider#WAIT_NO} instead.
*/
public static final WAIT_FLAG WAIT_NO= SharedASTProvider.WAIT_NO;
/**
* Tells whether this class is in debug mode.
* @since 3.0
*/
private static final boolean DEBUG= "true".equalsIgnoreCase(Platform.getDebugOption("org.eclipse.jdt.ui/debug/ASTProvider")); //$NON-NLS-1$//$NON-NLS-2$
/**
* Internal activation listener.
*
* @since 3.0
*/
private class ActivationListener implements IPartListener2, IWindowListener {
/*
* @see org.eclipse.ui.IPartListener2#partActivated(org.eclipse.ui.IWorkbenchPartReference)
*/
public void partActivated(IWorkbenchPartReference ref) {
if (isJavaEditor(ref) && !isActiveEditor(ref))
activeJavaEditorChanged(ref.getPart(true));
}
/*
* @see org.eclipse.ui.IPartListener2#partBroughtToTop(org.eclipse.ui.IWorkbenchPartReference)
*/
public void partBroughtToTop(IWorkbenchPartReference ref) {
if (isJavaEditor(ref) && !isActiveEditor(ref))
activeJavaEditorChanged(ref.getPart(true));
}
/*
* @see org.eclipse.ui.IPartListener2#partClosed(org.eclipse.ui.IWorkbenchPartReference)
*/
public void partClosed(IWorkbenchPartReference ref) {
if (isActiveEditor(ref)) {
if (DEBUG)
System.out.println(getThreadName() + " - " + DEBUG_PREFIX + "closed active editor: " + ref.getTitle()); //$NON-NLS-1$ //$NON-NLS-2$
activeJavaEditorChanged(null);
}
}
/*
* @see org.eclipse.ui.IPartListener2#partDeactivated(org.eclipse.ui.IWorkbenchPartReference)
*/
public void partDeactivated(IWorkbenchPartReference ref) {
}
/*
* @see org.eclipse.ui.IPartListener2#partOpened(org.eclipse.ui.IWorkbenchPartReference)
*/
public void partOpened(IWorkbenchPartReference ref) {
if (isJavaEditor(ref) && !isActiveEditor(ref))
activeJavaEditorChanged(ref.getPart(true));
}
/*
* @see org.eclipse.ui.IPartListener2#partHidden(org.eclipse.ui.IWorkbenchPartReference)
*/
public void partHidden(IWorkbenchPartReference ref) {
}
/*
* @see org.eclipse.ui.IPartListener2#partVisible(org.eclipse.ui.IWorkbenchPartReference)
*/
public void partVisible(IWorkbenchPartReference ref) {
if (isJavaEditor(ref) && !isActiveEditor(ref))
activeJavaEditorChanged(ref.getPart(true));
}
/*
* @see org.eclipse.ui.IPartListener2#partInputChanged(org.eclipse.ui.IWorkbenchPartReference)
*/
public void partInputChanged(IWorkbenchPartReference ref) {
if (isJavaEditor(ref) && isActiveEditor(ref))
activeJavaEditorChanged(ref.getPart(true));
}
/*
* @see org.eclipse.ui.IWindowListener#windowActivated(org.eclipse.ui.IWorkbenchWindow)
*/
public void windowActivated(IWorkbenchWindow window) {
IWorkbenchPartReference ref= window.getPartService().getActivePartReference();
if (isJavaEditor(ref) && !isActiveEditor(ref))
activeJavaEditorChanged(ref.getPart(true));
}
/*
* @see org.eclipse.ui.IWindowListener#windowDeactivated(org.eclipse.ui.IWorkbenchWindow)
*/
public void windowDeactivated(IWorkbenchWindow window) {
}
/*
* @see org.eclipse.ui.IWindowListener#windowClosed(org.eclipse.ui.IWorkbenchWindow)
*/
public void windowClosed(IWorkbenchWindow window) {
if (fActiveEditor != null && fActiveEditor.getSite() != null && window == fActiveEditor.getSite().getWorkbenchWindow()) {
if (DEBUG)
System.out.println(getThreadName() + " - " + DEBUG_PREFIX + "closed active editor: " + fActiveEditor.getTitle()); //$NON-NLS-1$ //$NON-NLS-2$
activeJavaEditorChanged(null);
}
window.getPartService().removePartListener(this);
}
/*
* @see org.eclipse.ui.IWindowListener#windowOpened(org.eclipse.ui.IWorkbenchWindow)
*/
public void windowOpened(IWorkbenchWindow window) {
window.getPartService().addPartListener(this);
}
private boolean isActiveEditor(IWorkbenchPartReference ref) {
return ref != null && isActiveEditor(ref.getPart(false));
}
private boolean isActiveEditor(IWorkbenchPart part) {
return part != null && (part == fActiveEditor);
}
private boolean isJavaEditor(IWorkbenchPartReference ref) {
if (ref == null)
return false;
String id= ref.getId();
// The instanceof check is not need but helps clients, see https://bugs.eclipse.org/bugs/show_bug.cgi?id=84862
return JavaUI.ID_CF_EDITOR.equals(id) || JavaUI.ID_CU_EDITOR.equals(id) || ref.getPart(false) instanceof JavaEditor;
}
}
public static final int SHARED_AST_LEVEL= AST.JLS4;
public static final boolean SHARED_AST_STATEMENT_RECOVERY= true;
public static final boolean SHARED_BINDING_RECOVERY= true;
private static final String DEBUG_PREFIX= "ASTProvider > "; //$NON-NLS-1$
private ITypeRoot fReconcilingJavaElement;
private ITypeRoot fActiveJavaElement;
private CompilationUnit fAST;
private ActivationListener fActivationListener;
private Object fReconcileLock= new Object();
private Object fWaitLock= new Object();
private volatile boolean fIsReconciling;
private IWorkbenchPart fActiveEditor;
/**
* Returns the Java plug-in's AST provider.
*
* @return the AST provider
* @since 3.2
*/
public static ASTProvider getASTProvider() {
return JavaPlugin.getDefault().getASTProvider();
}
/**
* Creates a new AST provider.
*/
public ASTProvider() {
install();
}
/**
* Installs this AST provider.
*/
void install() {
// Create and register activation listener
fActivationListener= new ActivationListener();
PlatformUI.getWorkbench().addWindowListener(fActivationListener);
// Ensure existing windows get connected
IWorkbenchWindow[] windows= PlatformUI.getWorkbench().getWorkbenchWindows();
for (int i= 0, length= windows.length; i < length; i++)
windows[i].getPartService().addPartListener(fActivationListener);
}
void activeJavaEditorChanged(IWorkbenchPart editor) {
ITypeRoot javaElement= null;
if (editor instanceof JavaEditor)
javaElement= ((JavaEditor)editor).getInputJavaElement();
synchronized (this) {
fActiveEditor= editor;
fActiveJavaElement= javaElement;
cache(null, javaElement);
}
if (DEBUG)
System.out.println(getThreadName() + " - " + DEBUG_PREFIX + "active editor is: " + toString(javaElement)); //$NON-NLS-1$ //$NON-NLS-2$
synchronized (fReconcileLock) {
if (fIsReconciling && (fReconcilingJavaElement == null || !fReconcilingJavaElement.equals(javaElement))) {
fIsReconciling= false;
fReconcilingJavaElement= null;
} else if (javaElement == null) {
fIsReconciling= false;
fReconcilingJavaElement= null;
}
}
}
/**
* Returns whether the given compilation unit AST is
* cached by this AST provided.
*
* @param ast the compilation unit AST
* @return <code>true</code> if the given AST is the cached one
*/
public boolean isCached(CompilationUnit ast) {
return ast != null && fAST == ast;
}
/**
* Returns whether this AST provider is active on the given
* compilation unit.
*
* @param cu the compilation unit
* @return <code>true</code> if the given compilation unit is the active one
* @since 3.1
*/
public synchronized boolean isActive(ICompilationUnit cu) {
return cu != null && cu.equals(fActiveJavaElement);
}
/**
* Informs that reconciling for the given element is about to be started.
*
* @param javaElement the Java element
* @see org.eclipse.jdt.internal.ui.text.java.IJavaReconcilingListener#aboutToBeReconciled()
*/
void aboutToBeReconciled(ITypeRoot javaElement) {
if (javaElement == null)
return;
if (DEBUG)
System.out.println(getThreadName() + " - " + DEBUG_PREFIX + "about to reconcile: " + toString(javaElement)); //$NON-NLS-1$ //$NON-NLS-2$
synchronized (fReconcileLock) {
fReconcilingJavaElement= javaElement;
fIsReconciling= true;
}
cache(null, javaElement);
}
/**
* Disposes the cached AST.
*/
private synchronized void disposeAST() {
if (fAST == null)
return;
if (DEBUG)
System.out.println(getThreadName() + " - " + DEBUG_PREFIX + "disposing AST: " + toString(fAST) + " for: " + toString(fActiveJavaElement)); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
fAST= null;
cache(null, null);
}
/**
* Returns a string for the given Java element used for debugging.
*
* @param javaElement the compilation unit AST
* @return a string used for debugging
*/
private String toString(ITypeRoot javaElement) {
if (javaElement == null)
return "null"; //$NON-NLS-1$
else
return javaElement.getElementName();
}
/**
* Returns a string for the given AST used for debugging.
*
* @param ast the compilation unit AST
* @return a string used for debugging
*/
private String toString(CompilationUnit ast) {
if (ast == null)
return "null"; //$NON-NLS-1$
List<AbstractTypeDeclaration> types= ast.types();
if (types != null && types.size() > 0)
return types.get(0).getName().getIdentifier() + "(" + ast.hashCode() + ")"; //$NON-NLS-1$//$NON-NLS-2$
else
return "AST without any type"; //$NON-NLS-1$
}
/**
* Caches the given compilation unit AST for the given Java element.
*
* @param ast the ast
* @param javaElement the java element
*/
private synchronized void cache(CompilationUnit ast, ITypeRoot javaElement) {
if (fActiveJavaElement != null && !fActiveJavaElement.equals(javaElement)) {
if (DEBUG && javaElement != null) // don't report call from disposeAST()
System.out.println(getThreadName() + " - " + DEBUG_PREFIX + "don't cache AST for inactive: " + toString(javaElement)); //$NON-NLS-1$ //$NON-NLS-2$
return;
}
if (DEBUG && (javaElement != null || ast != null)) // don't report call from disposeAST()
System.out.println(getThreadName() + " - " + DEBUG_PREFIX + "caching AST: " + toString(ast) + " for: " + toString(javaElement)); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
if (fAST != null)
disposeAST();
fAST= ast;
// Signal AST change
synchronized (fWaitLock) {
fWaitLock.notifyAll();
}
}
/**
* Returns a shared compilation unit AST for the given Java element.
* <p>
* Clients are not allowed to modify the AST and must synchronize all access to its nodes.
* </p>
*
* @param input the Java element, must not be <code>null</code>
* @param waitFlag {@link SharedASTProvider#WAIT_YES}, {@link SharedASTProvider#WAIT_NO} or
* {@link SharedASTProvider#WAIT_ACTIVE_ONLY}
* @param progressMonitor the progress monitor or <code>null</code>
* @return the AST or <code>null</code> if the AST is not available
*/
public CompilationUnit getAST(final ITypeRoot input, WAIT_FLAG waitFlag, IProgressMonitor progressMonitor) {
if (input == null || waitFlag == null)
throw new IllegalArgumentException("input or wait flag are null"); //$NON-NLS-1$
if (progressMonitor != null && progressMonitor.isCanceled())
return null;
boolean isActiveElement;
synchronized (this) {
isActiveElement= input.equals(fActiveJavaElement);
if (isActiveElement) {
if (fAST != null) {
if (DEBUG)
System.out.println(getThreadName() + " - " + DEBUG_PREFIX + "returning cached AST:" + toString(fAST) + " for: " + input.getElementName()); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
return fAST;
}
if (waitFlag == SharedASTProvider.WAIT_NO) {
if (DEBUG)
System.out.println(getThreadName() + " - " + DEBUG_PREFIX + "returning null (WAIT_NO) for: " + input.getElementName()); //$NON-NLS-1$ //$NON-NLS-2$
return null;
}
}
}
final boolean canReturnNull= waitFlag == SharedASTProvider.WAIT_NO || (waitFlag == SharedASTProvider.WAIT_ACTIVE_ONLY && !(isActiveElement && fAST == null));
boolean isReconciling= false;
final ITypeRoot activeElement;
if (isActiveElement) {
synchronized (fReconcileLock) {
activeElement= fReconcilingJavaElement;
isReconciling= isReconciling(input);
if (!isReconciling && !canReturnNull)
aboutToBeReconciled(input);
}
} else
activeElement= null;
if (isReconciling) {
try {
// Wait for AST
synchronized (fWaitLock) {
if (isReconciling(input)) {
if (DEBUG)
System.out.println(getThreadName() + " - " + DEBUG_PREFIX + "waiting for AST for: " + input.getElementName()); //$NON-NLS-1$ //$NON-NLS-2$
fWaitLock.wait();
}
}
// Check whether active element is still valid
synchronized (this) {
if (activeElement == fActiveJavaElement && fAST != null) {
if (DEBUG)
System.out.println(getThreadName() + " - " + DEBUG_PREFIX + "...got AST: " + toString(fAST) + " for: " + input.getElementName()); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
return fAST;
}
}
return getAST(input, waitFlag, progressMonitor);
} catch (InterruptedException e) {
return null; // thread has been interrupted don't compute AST
}
} else if (canReturnNull)
return null;
CompilationUnit ast= null;
try {
ast= createAST(input, progressMonitor);
if (progressMonitor != null && progressMonitor.isCanceled()) {
ast= null;
if (DEBUG)
System.out.println(getThreadName() + " - " + DEBUG_PREFIX + "Ignore created AST for: " + input.getElementName() + " - operation has been cancelled"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
}
} finally {
if (isActiveElement) {
if (fAST != null) {
// in the meantime, reconcile created a new AST. Return that one
if (DEBUG)
System.out.println(getThreadName() + " - " + DEBUG_PREFIX + "Ignore created AST for " + input.getElementName() + " - AST from reconciler is newer"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
reconciled(fAST, input, null);
return fAST;
} else
reconciled(ast, input, null);
}
}
return ast;
}
/**
* Tells whether the given Java element is the one
* reported as currently being reconciled.
*
* @param javaElement the Java element
* @return <code>true</code> if reported as currently being reconciled
*/
private boolean isReconciling(ITypeRoot javaElement) {
return javaElement != null && javaElement.equals(fReconcilingJavaElement) && fIsReconciling;
}
/**
* Creates a new compilation unit AST.
*
* @param input the Java element for which to create the AST
* @param progressMonitor the progress monitor
* @return AST
*/
private static CompilationUnit createAST(final ITypeRoot input, final IProgressMonitor progressMonitor) {
if (!hasSource(input))
return null;
if (progressMonitor != null && progressMonitor.isCanceled())
return null;
final ASTParser parser = ASTParser.newParser(SHARED_AST_LEVEL);
parser.setResolveBindings(true);
parser.setStatementsRecovery(SHARED_AST_STATEMENT_RECOVERY);
parser.setBindingsRecovery(SHARED_BINDING_RECOVERY);
parser.setSource(input);
if (progressMonitor != null && progressMonitor.isCanceled())
return null;
final CompilationUnit root[]= new CompilationUnit[1];
SafeRunner.run(new ISafeRunnable() {
public void run() {
try {
if (progressMonitor != null && progressMonitor.isCanceled())
return;
if (DEBUG)
System.err.println(getThreadName() + " - " + DEBUG_PREFIX + "creating AST for: " + input.getElementName()); //$NON-NLS-1$ //$NON-NLS-2$
root[0]= (CompilationUnit)parser.createAST(progressMonitor);
//mark as unmodifiable
ASTNodes.setFlagsToAST(root[0], ASTNode.PROTECT);
} catch (OperationCanceledException ex) {
return;
}
}
public void handleException(Throwable ex) {
IStatus status= new Status(IStatus.ERROR, JavaUI.ID_PLUGIN, IStatus.OK, "Error in JDT Core during AST creation", ex); //$NON-NLS-1$
JavaPlugin.getDefault().getLog().log(status);
}
});
return root[0];
}
/**
* Checks whether the given Java element has accessible source.
*
* @param je the Java element to test
* @return <code>true</code> if the element has source
* @since 3.2
*/
private static boolean hasSource(ITypeRoot je) {
if (je == null || !je.exists())
return false;
try {
return je.getBuffer() != null;
} catch (JavaModelException ex) {
IStatus status= new Status(IStatus.ERROR, JavaUI.ID_PLUGIN, IStatus.OK, "Error in JDT Core during AST creation", ex); //$NON-NLS-1$
JavaPlugin.getDefault().getLog().log(status);
}
return false;
}
/**
* Disposes this AST provider.
*/
public void dispose() {
// Dispose activation listener
PlatformUI.getWorkbench().removeWindowListener(fActivationListener);
fActivationListener= null;
disposeAST();
synchronized (fWaitLock) {
fWaitLock.notifyAll();
}
}
/**
* Update internal structures after reconcile.
*
* @param ast the compilation unit AST or <code>null</code> if the working copy was consistent
* or reconciliation has been cancelled
* @param javaElement the Java element for which the AST was built
* @param progressMonitor the progress monitor
* @see org.eclipse.jdt.internal.ui.text.java.IJavaReconcilingListener#reconciled(CompilationUnit,
* boolean, IProgressMonitor)
*/
void reconciled(CompilationUnit ast, ITypeRoot javaElement, IProgressMonitor progressMonitor) {
if (DEBUG)
System.out.println(getThreadName() + " - " + DEBUG_PREFIX + "reconciled: " + toString(javaElement) + ", AST: " + toString(ast)); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
synchronized (fReconcileLock) {
fIsReconciling= false;
if (javaElement == null || !javaElement.equals(fReconcilingJavaElement)) {
if (DEBUG)
System.out.println(getThreadName() + " - " + DEBUG_PREFIX + " ignoring AST of out-dated editor"); //$NON-NLS-1$ //$NON-NLS-2$
// Signal - threads might wait for wrong element
synchronized (fWaitLock) {
fWaitLock.notifyAll();
}
return;
}
cache(ast, javaElement);
}
}
private static String getThreadName() {
String name= Thread.currentThread().getName();
if (name != null)
return name;
else
return Thread.currentThread().toString();
}
}