/*******************************************************************************
* Copyright (c) 2010 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.wst.sse.ui.internal.contentassist;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IContributor;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.InvalidRegistryObjectException;
import org.eclipse.core.runtime.PerformanceStats;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.Status;
import org.eclipse.wst.sse.ui.contentassist.CompletionProposalInvocationContext;
import org.eclipse.wst.sse.ui.contentassist.ICompletionProposalComputer;
import org.eclipse.wst.sse.ui.internal.Logger;
import org.eclipse.wst.sse.ui.internal.SSEUIPlugin;
import org.osgi.framework.Bundle;
/**
* Wraps an {@link ICompletionProposalComputer} provided by an extension to the
* <code>org.eclipse.wst.sse.ui.completionProposal</code> extension point.
* Instances are immutable. Instances can be obtained from a
* {@link CompletionProposalComputerRegistry}.
*
* @see CompletionProposalComputerRegistry
*/
final class CompletionProposalComputerDescriptor {
/** The default category id. */
private static final String DEFAULT_CATEGORY_ID= "org.eclipse.wst.sse.ui.defaultProposalCategory"; //$NON-NLS-1$
/** The extension schema name of the category id attribute. */
private static final String ATTR_CATEGORY_ID= "categoryId"; //$NON-NLS-1$
/** The extension schema name for element ID attributes */
private static final String ATTR_ID= "id"; //$NON-NLS-1$
/** The extension schema name for element name attributes */
private static final String ATTR_NAME= "name"; //$NON-NLS-1$
/** The extension schema name of the class attribute. */
private static final String ATTR_CLASS= "class"; //$NON-NLS-1$
/** The extension schema name of the activate attribute. */
private static final String ATTRACTIVATE= "activate"; //$NON-NLS-1$
/** The extension schema name of the content type child elements. */
private static final String ELEM_CONTENT_TYPE = "contentType"; //$NON-NLS-1$
/** The extension schema name of the partition type child elements. */
private static final String ELEM_PARTITION_TYPE= "partitionType"; //$NON-NLS-1$
/** The name of the performance event used to trace extensions. */
private static final String PERFORMANCE_EVENT= SSEUIPlugin.ID + "/perf/content_assist/extensions"; //$NON-NLS-1$
/**
* If <code>true</code>, execution time of extensions is measured and the data forwarded to
* core's {@link PerformanceStats} service.
*/
private static final boolean MEASURE_PERFORMANCE= PerformanceStats.isEnabled(PERFORMANCE_EVENT);
/**
* Independently of the {@link PerformanceStats} service, any operation that takes longer than
* {@value} milliseconds will be flagged as an violation. This timeout does not apply to the
* first invocation, as it may take longer due to plug-in initialization etc. See also
* {@link #fIsReportingDelay}.
*/
private static final long MAX_DELAY= 500000;
/* log constants */
private static final String COMPUTE_COMPLETION_PROPOSALS= "computeCompletionProposals()"; //$NON-NLS-1$
private static final String COMPUTE_CONTEXT_INFORMATION= "computeContextInformation()"; //$NON-NLS-1$
private static final String SESSION_STARTED= "sessionStarted()"; //$NON-NLS-1$
private static final String SESSION_ENDED= "sessionEnded()"; //$NON-NLS-1$
/** The identifier of the extension. */
private final String fId;
/** The name of the extension. */
private final String fName;
/** The class name of the provided <code>ISSECompletionProposalComputer</code>. */
private final String fClass;
/** The activate attribute value. */
private final boolean fActivate;
/** The configuration element of this extension. */
private final IConfigurationElement fElement;
/** The computer, if instantiated, <code>null</code> otherwise. */
private ICompletionProposalComputer fComputer;
/** The UI category. */
private final CompletionProposalCategory fCategory;
/** The first error message in the most recent operation, or <code>null</code>. */
private String fLastError;
/**
* Tells whether to inform the user when <code>MAX_DELAY</code> has been exceeded.
* We start timing execution after the first session because the first may take
* longer due to plug-in activation and initialization.
*/
private boolean fIsReportingDelay = false;
/** The start of the last operation. */
private long fStart;
/**
* Tells whether we tried to load the computer.
* @since 3.4
*/
boolean fTriedLoadingComputer = false;
/**
* <p>Creates a new descriptor.</p>
* <p><b>NOTE: </b> This will not add this new descriptor to the given
* {@link CompletionProposalComputerRegistry}. That can not be done
* until this descriptor is done being constructed. Therefore be sure
* to call {@link #addToRegistry()} after creating a new descriptor.</p>
*
* @param element the configuration element to read
* @param categories the categories
*
* @throws InvalidRegistryObjectException if this extension is no longer valid
* @throws CoreException if the extension contains invalid values
*/
CompletionProposalComputerDescriptor(IConfigurationElement element, List categories) throws InvalidRegistryObjectException, CoreException {
Assert.isLegal(element != null);
fElement = element;
//get & verify ID
fId = fElement.getAttribute(ATTR_ID);
ContentAssistUtils.checkExtensionAttributeNotNull(fId, ATTR_ID, fElement);
//get & verify optional name
String name= fElement.getAttribute(ATTR_NAME);
if (name == null) {
fName= fId;
} else {
fName= name;
}
//get & verify activate plugin attribute
String activateAttribute= fElement.getAttribute(ATTRACTIVATE);
fActivate = Boolean.valueOf(activateAttribute).booleanValue();
//get & verify class
fClass= fElement.getAttribute(ATTR_CLASS);
ContentAssistUtils.checkExtensionAttributeNotNull(fClass, ATTR_CLASS, fElement);
//get & verify optional category id
String categoryId= fElement.getAttribute(ATTR_CATEGORY_ID);
if (categoryId == null) {
categoryId= DEFAULT_CATEGORY_ID;
}
//find the category with the determined category id
CompletionProposalCategory category= null;
for (Iterator it= categories.iterator(); it.hasNext();) {
CompletionProposalCategory cat= (CompletionProposalCategory) it.next();
if (cat.getId().equals(categoryId)) {
category= cat;
break;
}
}
/* create a category if it does not exist
* else just set the category
*/
if (category == null) {
fCategory = new CompletionProposalCategory(categoryId, fName);
/* will add the new category to the registers list of categories,
* by the magic of object references
*/
categories.add(fCategory);
} else {
fCategory = category;
}
}
/**
* <p>Adds this descriptor to the {@link CompletionProposalComputerRegistry}.</p>
* <p><b>NOTE: </b>Must be done after descriptor creation or the descriptor will
* not be added to the registry. Can not be done in constructor because
* descriptor must be constructed before it can be added to the registry</p>
*
*
* @throws InvalidRegistryObjectException
* @throws CoreException
*/
void addToRegistry() throws InvalidRegistryObjectException, CoreException {
parseActivationAndAddToRegistry(this.fElement, this);
}
/**
* @return the category that the wrapped {@link ICompletionProposalComputer} is
* associated with.
*/
CompletionProposalCategory getCategory() {
return fCategory;
}
/**
* @return the contributor of the described {@link ICompletionProposalComputer}
*/
IContributor getContributor() {
try {
return fElement.getContributor();
} catch (InvalidRegistryObjectException e) {
return null;
}
}
/**
* @return Returns the id of the described {@link ICompletionProposalComputer}
*/
public String getId() {
return fId;
}
/**
* @return the name of the described {@link ICompletionProposalComputer}
*/
public String getName() {
return fName;
}
/**
* Returns a new instance of the computer as described in the
* extension's xml. Note that the safest way to access the computer
* is by using the
* {@linkplain #computeCompletionProposals(ContentAssistInvocationContext, IProgressMonitor) computeCompletionProposals}
* and
* {@linkplain #computeContextInformation(ContentAssistInvocationContext, IProgressMonitor) computeContextInformation}
* methods. These delegate the functionality to the contributed
* computer, but handle instance creation and any exceptions thrown.
*
* @return a new instance of the completion proposal computer as
* described by this descriptor
*
* @throws CoreException if the creation fails
* @throws InvalidRegistryObjectException if the extension is not
* valid any longer (e.g. due to plug-in unloading)
*/
public ICompletionProposalComputer createComputer() throws CoreException, InvalidRegistryObjectException {
return (ICompletionProposalComputer) fElement.createExecutableExtension(ATTR_CLASS);
}
/**
* <p>Safely computes completion proposals through the described extension.</p>
*
* @param context the invocation context passed on to the extension
* @param monitor the progress monitor passed on to the extension
* @return the list of computed completion proposals (element type:
* {@link org.eclipse.jface.text.contentassist.ICompletionProposal})
*/
public List computeCompletionProposals(CompletionProposalInvocationContext context, IProgressMonitor monitor) {
List completionProposals = Collections.EMPTY_LIST;
if (isEnabled()) {
IStatus status = null;
try {
// plugin must be active to get computer
ICompletionProposalComputer computer = getComputer(true);
if (computer != null) {
try {
PerformanceStats stats= startMeter(context, computer);
//ask the computer for the proposals
List proposals = computer.computeCompletionProposals(context, monitor);
stopMeter(stats, COMPUTE_COMPLETION_PROPOSALS);
if (proposals != null) {
fLastError = computer.getErrorMessage();
completionProposals = proposals;
} else {
status = createAPIViolationStatus(COMPUTE_COMPLETION_PROPOSALS);
}
} finally {
fIsReportingDelay = true;
}
}
} catch (InvalidRegistryObjectException x) {
status= createExceptionStatus(x);
} catch (CoreException x) {
status= createExceptionStatus(x);
} catch (RuntimeException x) {
status= createExceptionStatus(x);
} finally {
monitor.done();
}
if(status != null) {
Logger.log(status);
}
}
return completionProposals;
}
/**
* <p>Safely computes context information objects through the described extension.</p>
*
* @param context the invocation context passed on to the extension
* @param monitor the progress monitor passed on to the extension
* @return the list of computed context information objects (element type:
* {@link org.eclipse.jface.text.contentassist.IContextInformation})
*/
public List computeContextInformation(CompletionProposalInvocationContext context, IProgressMonitor monitor) {
List contextInformation = Collections.EMPTY_LIST;
if (isEnabled()) {
IStatus status = null;
try {
// plugin must be active to get computer
ICompletionProposalComputer computer = getComputer(true);
if (computer != null) {
PerformanceStats stats= startMeter(context, computer);
List proposals= computer.computeContextInformation(context, monitor);
stopMeter(stats, COMPUTE_CONTEXT_INFORMATION);
if (proposals != null) {
fLastError= computer.getErrorMessage();
contextInformation = proposals;
} else {
status = createAPIViolationStatus(COMPUTE_CONTEXT_INFORMATION);
}
}
} catch (InvalidRegistryObjectException x) {
status= createExceptionStatus(x);
} catch (CoreException x) {
status= createExceptionStatus(x);
} catch (RuntimeException x) {
status= createExceptionStatus(x);
} finally {
monitor.done();
}
if(status != null) {
Logger.log(status);
}
}
return contextInformation;
}
/**
* <p>Notifies the described extension of a proposal computation session start.</p>
*
* <p><b>Note: </b>This method is called every time code assist is invoked and
* is <strong>not</strong> filtered by content type or partition type.</p>
*/
public void sessionStarted() {
if (isEnabled()) {
IStatus status = null;
try {
// plugin must be active to get computer
ICompletionProposalComputer computer = getComputer(true);
if (computer != null) {
PerformanceStats stats = startMeter(SESSION_STARTED, computer);
computer.sessionStarted();
stopMeter(stats, SESSION_ENDED);
}
} catch (InvalidRegistryObjectException x) {
status= createExceptionStatus(x);
} catch (CoreException x) {
status= createExceptionStatus(x);
} catch (RuntimeException x) {
status= createExceptionStatus(x);
}
if(status != null) {
Logger.log(status);
}
}
}
/**
* <p>Notifies the described extension of a proposal computation session end.</p>
*
* <p><b>Note: </b>This method is called every time code assist is invoked and
* is <strong>not</strong> filtered by content type or partition type.</p>
*/
public void sessionEnded() {
if (isEnabled()) {
IStatus status = null;
try {
// plugin must be active to get computer
ICompletionProposalComputer computer = getComputer(true);
if (computer != null) {
PerformanceStats stats= startMeter(SESSION_ENDED, computer);
computer.sessionEnded();
stopMeter(stats, SESSION_ENDED);
}
} catch (InvalidRegistryObjectException x) {
status= createExceptionStatus(x);
} catch (CoreException x) {
status= createExceptionStatus(x);
} catch (RuntimeException x) {
status= createExceptionStatus(x);
}
if(status != null) {
Logger.log(status);
}
}
}
/**
* @return the error message from the described {@link ICompletionProposalComputer}
*/
public String getErrorMessage() {
return fLastError;
}
/**
* @see java.lang.Object#toString()
*/
public String toString() {
return fId + ": " + fName; //$NON-NLS-1$
}
/**
* <p>Parses the given configuration element for its activation context,
* that is to say the content types and partiton types and updates the registry
* to associated the given computer descriptor with the parsed activation contexts.</P>
*
* <p>This is useful for parsing both <tt>proposalComputer</tt> elements and
* <tt>proposalComputerExtendedActivation</tt> elements.</p>
*
* @param element {@link IConfigurationElement} containing the activation context
* @param desc {@link CompletionProposalComputerDescriptor} to associate with the parsed activation context
*
* @throws InvalidRegistryObjectException
* @throws CoreException
*/
protected static void parseActivationAndAddToRegistry(IConfigurationElement element,
CompletionProposalComputerDescriptor desc) throws InvalidRegistryObjectException, CoreException {
/* if this descriptor is specific to a content type/s add it to the registry as such
* else add to registry for all content types
*/
IConfigurationElement[] contentTypes = element.getChildren(ELEM_CONTENT_TYPE);
if(contentTypes.length > 0) {
for(int contentTypeIndex = 0; contentTypeIndex < contentTypes.length; ++contentTypeIndex) {
String contentTypeID = contentTypes[contentTypeIndex].getAttribute(ATTR_ID);
ContentAssistUtils.checkExtensionAttributeNotNull(contentTypeID, ATTR_ID, contentTypes[contentTypeIndex]);
/* if this descriptor is for specific partition types in the content type
* add it to the registry as such
* else add to the registry for all partition types in the content type
*/
IConfigurationElement[] partitionTypes = contentTypes[contentTypeIndex].getChildren(ELEM_PARTITION_TYPE);
if(partitionTypes.length > 0) {
for (int partitionTypeIndex = 0; partitionTypeIndex < partitionTypes.length; ++partitionTypeIndex) {
String partitionTypeID = partitionTypes[partitionTypeIndex].getAttribute(ATTR_ID);
ContentAssistUtils.checkExtensionAttributeNotNull(partitionTypeID, ATTR_ID, partitionTypes[partitionTypeIndex]);
CompletionProposalComputerRegistry.getDefault().putDescription(contentTypeID, partitionTypeID, desc);
CompletionProposalComputerRegistry.getDefault().putAutoActivator(contentTypeID, partitionTypeID, partitionTypes[partitionTypeIndex]);
}
} else {
CompletionProposalComputerRegistry.getDefault().putDescription(contentTypeID, null, desc);
}
}
} else {
Logger.log(Logger.WARNING, "The configuration element: " + element + " does not contain any content types."); //$NON-NLS-1$ //$NON-NLS-2$
}
}
/**
* @return <code>true</code> if the plugin that contains the {@link IConfigurationElement}
* associated with this descriptor is loaded, <code>false</code> otherwise.
*/
private boolean isPluginLoaded() {
Bundle bundle= getBundle();
return bundle != null && bundle.getState() == Bundle.ACTIVE;
}
/**
* @return the {@link Bundle} that contains the {@link IConfigurationElement} associated
* with this descriptor
*/
private Bundle getBundle() {
String namespace= fElement.getDeclaringExtension().getContributor().getName();
Bundle bundle= Platform.getBundle(namespace);
return bundle;
}
/**
* <p>Returns a cached instance of the computer as described in the
* extension's xml. If the computer is not yet created and
* <code>canCreate</code> is <code>true</code> then {@link #createComputer()}
* is called and the result cached.</p>
*
* @param canCreate <code>true</code> if the proposal computer can be created
* @return a new instance of the completion proposal computer as
* described by this descriptor
*
* @throws CoreException if the creation fails
* @throws InvalidRegistryObjectException if the extension is not
* valid any longer (e.g. due to plug-in unloading)
*/
private synchronized ICompletionProposalComputer getComputer(boolean canCreate) throws CoreException, InvalidRegistryObjectException {
if (fComputer == null && canCreate && !fTriedLoadingComputer && (fActivate || isPluginLoaded())) {
fTriedLoadingComputer= true;
fComputer= createComputer();
}
return fComputer;
}
/**
* @return the enablement state of the category this describer is associated with
*/
private boolean isEnabled() {
return fCategory.isEnabled();
}
/**
* <p>Starts the meter for measuring the computers performance</p>
*
* @param context
* @param computer
* @return
*/
private PerformanceStats startMeter(Object context, ICompletionProposalComputer computer) {
final PerformanceStats stats;
if (MEASURE_PERFORMANCE) {
stats= PerformanceStats.getStats(PERFORMANCE_EVENT, computer);
stats.startRun(context.toString());
} else {
stats= null;
}
if (fIsReportingDelay) {
fStart= System.currentTimeMillis();
}
return stats;
}
/**
* <p>Stops the meter for measuring the computers performance</p>
*
* @param context
* @param computer
* @return
*/
private void stopMeter(final PerformanceStats stats, String operation) {
if (MEASURE_PERFORMANCE) {
stats.endRun();
if (stats.isFailure()) {
IStatus status= createPerformanceStatus(operation);
Logger.log(status);
return;
}
}
if (fIsReportingDelay) {
long current= System.currentTimeMillis();
if (current - fStart > MAX_DELAY) {
IStatus status= createPerformanceStatus(operation);
Logger.log(status);
}
}
}
/**
* @return A message explaining that the described {@link ICompletionProposalComputer} failed in some way
*/
private String createBlameMessage() {
return "The ''" + getName() + "'' proposal computer from the ''" + //$NON-NLS-1$ //$NON-NLS-2$
fElement.getDeclaringExtension().getContributor().getName() + "'' plug-in did not complete normally."; //$NON-NLS-1$
}
/**
* <p>Create a status message describing that the extension has become invalid</p>
*
* @param x the associated {@link InvalidRegistryObjectException}
* @return the created {@link IStatus}
*/
private IStatus createExceptionStatus(InvalidRegistryObjectException x) {
String blame= createBlameMessage();
String reason= "The extension has become invalid."; //$NON-NLS-1$
return new Status(IStatus.INFO, SSEUIPlugin.ID, IStatus.OK, blame + " " + reason, x); //$NON-NLS-1$
}
/**
* <p>create a status message explaining that the extension could not be instantiated</p>
*
* @param x the associated {@link CoreException}
* @return the created {@link IStatus}
*/
private IStatus createExceptionStatus(CoreException x) {
String blame = createBlameMessage();
String reason = "Unable to instantiate the extension."; //$NON-NLS-1$
return new Status(IStatus.ERROR, SSEUIPlugin.ID, IStatus.OK, blame + " " + reason, x); //$NON-NLS-1$
}
/**
* <p>Create a status message explaining the extension has thrown a runtime exception</p>
*
* @param x the associated {@link RuntimeException}
* @return the created {@link IStatus}
*/
private IStatus createExceptionStatus(RuntimeException x) {
String blame= createBlameMessage();
String reason= "The extension has thrown a runtime exception."; //$NON-NLS-1$
return new Status(IStatus.WARNING, SSEUIPlugin.ID, IStatus.OK, blame + " " + reason, x); //$NON-NLS-1$
}
/**
* <p>Create a status message explaining the extension has violated the API of the extension point</p>
*
* @param operation the operation that created the API violation
* @return the created {@link IStatus}
*/
private IStatus createAPIViolationStatus(String operation) {
String blame = createBlameMessage();
String reason = "The extension violated the API contract of the ''" + operation + "'' operation."; //$NON-NLS-1$ //$NON-NLS-2$
return new Status(IStatus.WARNING, SSEUIPlugin.ID, IStatus.OK, blame + " " + reason, null); //$NON-NLS-1$
}
/**
* <p>Create a status message explaining that the extension took to long during an operation</p>
*
* @param operation the operation that took to long
* @return the created {@link IStatus}
*/
private IStatus createPerformanceStatus(String operation) {
String blame= createBlameMessage();
String reason = "The extension took too long to return from the ''" + operation + "'' operation."; //$NON-NLS-1$ //$NON-NLS-2$
return new Status(IStatus.WARNING, SSEUIPlugin.ID, IStatus.OK, blame + " " + reason, null); //$NON-NLS-1$
}
}