bundles/org.eclipse.wst.sse.ui/src/org/eclipse/wst/sse/ui/internal/contentassist/CompletionProposalCategory.java - sourceediting/webtools.sourceediting - Git at Google

 /*******************************************************************************
  * 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.net.URL;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;

 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.FileLocator;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.Path;
 import org.eclipse.core.runtime.SubProgressMonitor;
 import org.eclipse.jface.action.LegacyActionTools;
 import org.eclipse.jface.resource.ImageDescriptor;
 import org.eclipse.wst.sse.core.internal.util.Assert;
 import org.eclipse.wst.sse.ui.contentassist.CompletionProposalInvocationContext;
 import org.eclipse.wst.sse.ui.preferences.ICompletionProposalCategoriesConfigurationReader;
 import org.osgi.framework.Bundle;

 /**
  * Describes a category extension to the
  * <code>org.eclipse.wst.sse.ui.completionProposal</code> extension point.
  */
 public final class CompletionProposalCategory {
 	/** The extension schema name of the icon attribute. */
 	private static final String ICON= "icon"; //$NON-NLS-1$

 	/** The extension schema name of the ID attribute. */
 	private static final String ID= "id"; //$NON-NLS-1$

 	/** The extension schema name of the name attribute. */
 	private static final String NAME= "name"; //$NON-NLS-1$

 	/** ID of this completion category */
 	private final String fId;

 	/** Name of this completion category */
 	private final String fName;

 	/** The image descriptor for this category, or <code>null</code> if none specified. */
 	private final ImageDescriptor fImage;

 	/** The last error reported by this category */
 	private String fLastError = null;

 	/**
 	 * <p>Construct the category by parsing the given element.</p>
 	 *
 	 * @param element {@link IConfigurationElement} containing the configuration of this category
 	 * @throws CoreException if the given {@link IConfigurationElement} does not contain the correct
 	 * elements and attributes.
 	 */
 	CompletionProposalCategory(IConfigurationElement element) throws CoreException {
 		Assert.isLegal(element != null);

 		//get & verify ID
 		fId = element.getAttribute(ID);
 		ContentAssistUtils.checkExtensionAttributeNotNull(fId, ID, element);

 		//get & verify optional name
 		String name= element.getAttribute(NAME);
 		if (name == null) {
 			fName = fId;
 		} else {
 			fName= name;
 		}

 		//get & verify optional icon
 		String icon= element.getAttribute(ICON);
 		ImageDescriptor img= null;
 		if (icon != null) {
 			Bundle bundle= ContentAssistUtils.getBundle(element);
 			if (bundle != null) {
 				Path path= new Path(icon);
 				URL url= FileLocator.find(bundle, path, null);
 				img= ImageDescriptor.createFromURL(url);
 			}
 		}
 		fImage= img;
 	}

 	/**
 	 * <p>Creates a category with the given name and ID</p>
 	 *
 	 * @param id the unique ID of the new category
 	 * @param name the name of the new category
 	 */
 	CompletionProposalCategory(String id, String name) {
 		fId= id;
 		fName= name;
 		fImage= null;
 	}

 	/**
 	 * <p>Returns the unique identifier of the category</p>
 	 *
 	 * @return Returns the id
 	 */
 	public String getId() {
 		return fId;
 	}

 	/**
 	 * <p>Returns the human readable name of the category.
 	 * It may contain mnemonics.</p>
 	 *
 	 * @return Returns the name
 	 */
 	public String getName() {
 		return fName;
 	}

 	/**
 	 * <p>Returns the human readable name of the category
 	 * without mnemonic hint in order to be displayed
 	 * in a message.</p>
 	 *
 	 * @return Returns the name
 	 */
 	public String getDisplayName() {
 		return LegacyActionTools.removeMnemonics(fName);
 	}

 	/**
 	 * <p>Returns the image descriptor of the category.</p>
 	 *
 	 * @return the image descriptor of the category
 	 */
 	public ImageDescriptor getImageDescriptor() {
 		return fImage;
 	}

 	/**
 	 * @return <code>true</code> if this category should be displayed on
 	 * its own content assist page, <code>false</code> otherwise
 	 */
 	public boolean isDisplayedOnOwnPage(String contentTypeID) {
 		boolean displayOnOwnPage = ICompletionProposalCategoriesConfigurationReader.DEFAULT_DISPLAY_ON_OWN_PAGE;

 		ICompletionProposalCategoriesConfigurationReader properties =
 			CompletionProposoalCatigoriesConfigurationRegistry.getDefault().getReadableConfiguration(contentTypeID);
 		if(properties != null) {
 			displayOnOwnPage = properties.shouldDisplayOnOwnPage(this.fId);
 		}

 		return displayOnOwnPage;
 	}

 	/**
 	 * @return <code>true</code> if this category should be displayed in
 	 * the default content assist page, <code>false</code> otherwise
 	 */
 	public boolean isIncludedOnDefaultPage(String contentTypeID) {
 		boolean includeOnDefaultPage = ICompletionProposalCategoriesConfigurationReader.DEFAULT_INCLUDE_ON_DEFAULTS_PAGE;

 		ICompletionProposalCategoriesConfigurationReader properties =
 			CompletionProposoalCatigoriesConfigurationRegistry.getDefault().getReadableConfiguration(contentTypeID);
 		if(properties != null) {
 			includeOnDefaultPage = properties.shouldDisplayOnDefaultPage(this.fId);
 		}

 		return includeOnDefaultPage;
 	}

 	/**
 	 * <p>Given a content type ID determines the rank of this
 	 * category for sorting the content assist pages</p>
 	 *
 	 * @return the sort rank of this category
 	 */
 	public int getPageSortRank(String contentTypeID) {
 		int sortOrder = ICompletionProposalCategoriesConfigurationReader.DEFAULT_SORT_ORDER;

 		ICompletionProposalCategoriesConfigurationReader properties =
 			CompletionProposoalCatigoriesConfigurationRegistry.getDefault().getReadableConfiguration(contentTypeID);
 		if(properties != null) {
 			sortOrder = properties.getPageSortOrder(this.fId);
 		}

 		return sortOrder;
 	}

 	/**
 	 * <p>Given a content type ID determines the rank of this
 	 * category for sorting on the default content assist page
 	 * with other categories</p>
 	 *
 	 * @return the sort rank of this category
 	 */
 	public int getDefaultPageSortRank(String contentTypeID) {
 		int sortOrder = ICompletionProposalCategoriesConfigurationReader.DEFAULT_SORT_ORDER;

 		ICompletionProposalCategoriesConfigurationReader properties =
 			CompletionProposoalCatigoriesConfigurationRegistry.getDefault().getReadableConfiguration(contentTypeID);
 		if(properties != null) {
 			sortOrder = properties.getDefaultPageSortOrder(this.fId);
 		}

 		return sortOrder;
 	}

 	/**
 	 * <p><b>NOTE: </b> enablement is not the same as weather a category
 	 * should be displayed on its own page or the default page, it describes
 	 * if the category should be used at all.  Currently categories are always
 	 * enabled.  There maybe cases in the future where a category should be
 	 * disabled entirely though.</p>
 	 *
 	 * @return <code>true</code> if this category is enabled,
 	 * <code>false</code> otherwise
 	 */
 	public boolean isEnabled() {
 		return true;
 	}

 	/**
 	 * @return <code>true</code> if the category contains any computers, <code>false</code>
 	 *         otherwise
 	 */
 	public boolean hasComputers() {
 		List descriptors=  CompletionProposalComputerRegistry.getDefault().getProposalComputerDescriptors();
 		for (Iterator it= descriptors.iterator(); it.hasNext();) {
 			CompletionProposalComputerDescriptor desc= (CompletionProposalComputerDescriptor) it.next();
 			if (desc.getCategory() == this) {
 				return true;
 			}
 		}
 		return false;
 	}

 	/**
 	 * @param contentTypeID the content type ID
 	 * @param partitionTypeID the partition
 	 * @return <code>true</code> if the category contains any computers, in the given partition type
 	 * in the given content type, <code>false</code> otherwise
 	 */
 	public boolean hasComputers(String contentTypeID, String partitionTypeID) {
 		List descriptors = CompletionProposalComputerRegistry.getDefault().getProposalComputerDescriptors(contentTypeID, partitionTypeID);
 		for (Iterator it = descriptors.iterator(); it.hasNext();) {
 			CompletionProposalComputerDescriptor desc= (CompletionProposalComputerDescriptor) it.next();
 			if (desc.getCategory() == this) {
 				return true;
 			}
 		}
 		return false;
 	}

 	/**
 	 * @param contentTypeID the content type ID
 	 * @return <code>true</code> if the category contains any computers, in the given partition type
 	 * in the given content type, <code>false</code> otherwise
 	 */
 	public boolean hasComputers(String contentTypeID) {
 		List descriptors = CompletionProposalComputerRegistry.getDefault().getProposalComputerDescriptors(contentTypeID);
 		for (Iterator it = descriptors.iterator(); it.hasNext();) {
 			CompletionProposalComputerDescriptor desc= (CompletionProposalComputerDescriptor) it.next();
 			if (desc.getCategory() == this) {
 				return true;
 			}
 		}
 		return false;
 	}

 	/**
 	 * <p>Safely computes completion proposals of all computers of this category through their
 	 * extension.</p>
 	 *
 	 * @param context the invocation context passed on to the extension
 	 * @param contentTypeID the content type ID where the invocation occurred
 	 * @param partitionTypeID the partition type where the invocation occurred
 	 * @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,
 			String contentTypeID, String partitionTypeID, SubProgressMonitor monitor) {

 		fLastError = null;
 		List result = new ArrayList();
 		List descriptors = new ArrayList(CompletionProposalComputerRegistry.getDefault().getProposalComputerDescriptors(contentTypeID, partitionTypeID));
 		for (Iterator it = descriptors.iterator(); it.hasNext();) {
 			CompletionProposalComputerDescriptor desc = (CompletionProposalComputerDescriptor) it.next();
 			if (desc.getCategory() == this) {
 				result.addAll(desc.computeCompletionProposals(context, monitor));
 			}

 			if (fLastError == null && desc.getErrorMessage() != null) {
 				fLastError = desc.getErrorMessage();
 			}
 		}
 		return result;
 	}

 	/**
 	 * <p>Safely computes context information objects of all computers of this category through their
 	 * extension.</p>
 	 *
 	 * @param context the invocation context passed on to the extension
 	 * @param contentTypeID the content type ID where the invocation occurred
 	 * @param partitionTypeID the partition type where the invocation occurred
 	 * @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,
 			String contentTypeID, String partitionTypeID, SubProgressMonitor monitor) {

 		fLastError= null;
 		List result= new ArrayList();
 		List descriptors= new ArrayList(CompletionProposalComputerRegistry.getDefault().getProposalComputerDescriptors(contentTypeID, partitionTypeID));
 		for (Iterator it= descriptors.iterator(); it.hasNext();) {
 			CompletionProposalComputerDescriptor desc= (CompletionProposalComputerDescriptor) it.next();
 			if (desc.getCategory() == this && (isIncludedOnDefaultPage(contentTypeID) || isDisplayedOnOwnPage(contentTypeID))) {
 				result.addAll(desc.computeContextInformation(context, monitor));
 			}
 			if (fLastError == null) {
 				fLastError= desc.getErrorMessage();
 			}
 		}
 		return result;
 	}

 	/**
 	 * @return the last error message reported by a computer in this category
 	 */
 	public String getErrorMessage() {
 		return fLastError;
 	}

 	/**
 	 * <p>Notifies the computers in this category of a proposal computation session start.</p>
 	 */
 	public void sessionStarted() {
 		List descriptors= new ArrayList(CompletionProposalComputerRegistry.getDefault().getProposalComputerDescriptors());
 		for (Iterator it= descriptors.iterator(); it.hasNext();) {
 			CompletionProposalComputerDescriptor desc= (CompletionProposalComputerDescriptor) it.next();
 			if (desc.getCategory() == this)
 				desc.sessionStarted();
 			if (fLastError == null)
 				fLastError= desc.getErrorMessage();
 		}
 	}

 	/**
 	 * <p>Notifies the computers in this category of a proposal computation session end.</p>
 	 */
 	public void sessionEnded() {
 		List descriptors= new ArrayList(CompletionProposalComputerRegistry.getDefault().getProposalComputerDescriptors());
 		for (Iterator it= descriptors.iterator(); it.hasNext();) {
 			CompletionProposalComputerDescriptor desc= (CompletionProposalComputerDescriptor) it.next();
 			if (desc.getCategory() == this)
 				desc.sessionEnded();
 			if (fLastError == null)
 				fLastError= desc.getErrorMessage();
 		}
 	}

 	/**
 	 * @see java.lang.Object#toString()
 	 */
 	public String toString() {
 		return fId + ": " + fName; //$NON-NLS-1$
 	}
 }
	/*******************************************************************************
	* 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.net.URL;
	import java.util.ArrayList;
	import java.util.Iterator;
	import java.util.List;

	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.FileLocator;
	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.Path;
	import org.eclipse.core.runtime.SubProgressMonitor;
	import org.eclipse.jface.action.LegacyActionTools;
	import org.eclipse.jface.resource.ImageDescriptor;
	import org.eclipse.wst.sse.core.internal.util.Assert;
	import org.eclipse.wst.sse.ui.contentassist.CompletionProposalInvocationContext;
	import org.eclipse.wst.sse.ui.preferences.ICompletionProposalCategoriesConfigurationReader;
	import org.osgi.framework.Bundle;

	/**
	* Describes a category extension to the
	* <code>org.eclipse.wst.sse.ui.completionProposal</code> extension point.
	*/
	public final class CompletionProposalCategory {
	/** The extension schema name of the icon attribute. */
	private static final String ICON= "icon"; //$NON-NLS-1$

	/** The extension schema name of the ID attribute. */
	private static final String ID= "id"; //$NON-NLS-1$

	/** The extension schema name of the name attribute. */
	private static final String NAME= "name"; //$NON-NLS-1$

	/** ID of this completion category */
	private final String fId;

	/** Name of this completion category */
	private final String fName;

	/** The image descriptor for this category, or <code>null</code> if none specified. */
	private final ImageDescriptor fImage;

	/** The last error reported by this category */
	private String fLastError = null;

	/**
	* <p>Construct the category by parsing the given element.</p>
	*
	* @param element {@link IConfigurationElement} containing the configuration of this category
	* @throws CoreException if the given {@link IConfigurationElement} does not contain the correct
	* elements and attributes.
	*/
	CompletionProposalCategory(IConfigurationElement element) throws CoreException {
	Assert.isLegal(element != null);

	//get & verify ID
	fId = element.getAttribute(ID);
	ContentAssistUtils.checkExtensionAttributeNotNull(fId, ID, element);

	//get & verify optional name
	String name= element.getAttribute(NAME);
	if (name == null) {
	fName = fId;
	} else {
	fName= name;
	}

	//get & verify optional icon
	String icon= element.getAttribute(ICON);
	ImageDescriptor img= null;
	if (icon != null) {
	Bundle bundle= ContentAssistUtils.getBundle(element);
	if (bundle != null) {
	Path path= new Path(icon);
	URL url= FileLocator.find(bundle, path, null);
	img= ImageDescriptor.createFromURL(url);
	}
	}
	fImage= img;
	}

	/**
	* <p>Creates a category with the given name and ID</p>
	*
	* @param id the unique ID of the new category
	* @param name the name of the new category
	*/
	CompletionProposalCategory(String id, String name) {
	fId= id;
	fName= name;
	fImage= null;
	}

	/**
	* <p>Returns the unique identifier of the category</p>
	*
	* @return Returns the id
	*/
	public String getId() {
	return fId;
	}

	/**
	* <p>Returns the human readable name of the category.
	* It may contain mnemonics.</p>
	*
	* @return Returns the name
	*/
	public String getName() {
	return fName;
	}

	/**
	* <p>Returns the human readable name of the category
	* without mnemonic hint in order to be displayed
	* in a message.</p>
	*
	* @return Returns the name
	*/
	public String getDisplayName() {
	return LegacyActionTools.removeMnemonics(fName);
	}

	/**
	* <p>Returns the image descriptor of the category.</p>
	*
	* @return the image descriptor of the category
	*/
	public ImageDescriptor getImageDescriptor() {
	return fImage;
	}

	/**
	* @return <code>true</code> if this category should be displayed on
	* its own content assist page, <code>false</code> otherwise
	*/
	public boolean isDisplayedOnOwnPage(String contentTypeID) {
	boolean displayOnOwnPage = ICompletionProposalCategoriesConfigurationReader.DEFAULT_DISPLAY_ON_OWN_PAGE;

	ICompletionProposalCategoriesConfigurationReader properties =
	CompletionProposoalCatigoriesConfigurationRegistry.getDefault().getReadableConfiguration(contentTypeID);
	if(properties != null) {
	displayOnOwnPage = properties.shouldDisplayOnOwnPage(this.fId);
	}

	return displayOnOwnPage;
	}

	/**
	* @return <code>true</code> if this category should be displayed in
	* the default content assist page, <code>false</code> otherwise
	*/
	public boolean isIncludedOnDefaultPage(String contentTypeID) {
	boolean includeOnDefaultPage = ICompletionProposalCategoriesConfigurationReader.DEFAULT_INCLUDE_ON_DEFAULTS_PAGE;

	ICompletionProposalCategoriesConfigurationReader properties =
	CompletionProposoalCatigoriesConfigurationRegistry.getDefault().getReadableConfiguration(contentTypeID);
	if(properties != null) {
	includeOnDefaultPage = properties.shouldDisplayOnDefaultPage(this.fId);
	}

	return includeOnDefaultPage;
	}

	/**
	* <p>Given a content type ID determines the rank of this
	* category for sorting the content assist pages</p>
	*
	* @return the sort rank of this category
	*/
	public int getPageSortRank(String contentTypeID) {
	int sortOrder = ICompletionProposalCategoriesConfigurationReader.DEFAULT_SORT_ORDER;

	ICompletionProposalCategoriesConfigurationReader properties =
	CompletionProposoalCatigoriesConfigurationRegistry.getDefault().getReadableConfiguration(contentTypeID);
	if(properties != null) {
	sortOrder = properties.getPageSortOrder(this.fId);
	}

	return sortOrder;
	}

	/**
	* <p>Given a content type ID determines the rank of this
	* category for sorting on the default content assist page
	* with other categories</p>
	*
	* @return the sort rank of this category
	*/
	public int getDefaultPageSortRank(String contentTypeID) {
	int sortOrder = ICompletionProposalCategoriesConfigurationReader.DEFAULT_SORT_ORDER;

	ICompletionProposalCategoriesConfigurationReader properties =
	CompletionProposoalCatigoriesConfigurationRegistry.getDefault().getReadableConfiguration(contentTypeID);
	if(properties != null) {
	sortOrder = properties.getDefaultPageSortOrder(this.fId);
	}

	return sortOrder;
	}

	/**
	* <p><b>NOTE: </b> enablement is not the same as weather a category
	* should be displayed on its own page or the default page, it describes
	* if the category should be used at all. Currently categories are always
	* enabled. There maybe cases in the future where a category should be
	* disabled entirely though.</p>
	*
	* @return <code>true</code> if this category is enabled,
	* <code>false</code> otherwise
	*/
	public boolean isEnabled() {
	return true;
	}

	/**
	* @return <code>true</code> if the category contains any computers, <code>false</code>
	* otherwise
	*/
	public boolean hasComputers() {
	List descriptors= CompletionProposalComputerRegistry.getDefault().getProposalComputerDescriptors();
	for (Iterator it= descriptors.iterator(); it.hasNext();) {
	CompletionProposalComputerDescriptor desc= (CompletionProposalComputerDescriptor) it.next();
	if (desc.getCategory() == this) {
	return true;
	}
	}
	return false;
	}

	/**
	* @param contentTypeID the content type ID
	* @param partitionTypeID the partition
	* @return <code>true</code> if the category contains any computers, in the given partition type
	* in the given content type, <code>false</code> otherwise
	*/
	public boolean hasComputers(String contentTypeID, String partitionTypeID) {
	List descriptors = CompletionProposalComputerRegistry.getDefault().getProposalComputerDescriptors(contentTypeID, partitionTypeID);
	for (Iterator it = descriptors.iterator(); it.hasNext();) {
	CompletionProposalComputerDescriptor desc= (CompletionProposalComputerDescriptor) it.next();
	if (desc.getCategory() == this) {
	return true;
	}
	}
	return false;
	}

	/**
	* @param contentTypeID the content type ID
	* @return <code>true</code> if the category contains any computers, in the given partition type
	* in the given content type, <code>false</code> otherwise
	*/
	public boolean hasComputers(String contentTypeID) {
	List descriptors = CompletionProposalComputerRegistry.getDefault().getProposalComputerDescriptors(contentTypeID);
	for (Iterator it = descriptors.iterator(); it.hasNext();) {
	CompletionProposalComputerDescriptor desc= (CompletionProposalComputerDescriptor) it.next();
	if (desc.getCategory() == this) {
	return true;
	}
	}
	return false;
	}

	/**
	* <p>Safely computes completion proposals of all computers of this category through their
	* extension.</p>
	*
	* @param context the invocation context passed on to the extension
	* @param contentTypeID the content type ID where the invocation occurred
	* @param partitionTypeID the partition type where the invocation occurred
	* @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,
	String contentTypeID, String partitionTypeID, SubProgressMonitor monitor) {

	fLastError = null;
	List result = new ArrayList();
	List descriptors = new ArrayList(CompletionProposalComputerRegistry.getDefault().getProposalComputerDescriptors(contentTypeID, partitionTypeID));
	for (Iterator it = descriptors.iterator(); it.hasNext();) {
	CompletionProposalComputerDescriptor desc = (CompletionProposalComputerDescriptor) it.next();
	if (desc.getCategory() == this) {
	result.addAll(desc.computeCompletionProposals(context, monitor));
	}

	if (fLastError == null && desc.getErrorMessage() != null) {
	fLastError = desc.getErrorMessage();
	}
	}
	return result;
	}

	/**
	* <p>Safely computes context information objects of all computers of this category through their
	* extension.</p>
	*
	* @param context the invocation context passed on to the extension
	* @param contentTypeID the content type ID where the invocation occurred
	* @param partitionTypeID the partition type where the invocation occurred
	* @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,
	String contentTypeID, String partitionTypeID, SubProgressMonitor monitor) {

	fLastError= null;
	List result= new ArrayList();
	List descriptors= new ArrayList(CompletionProposalComputerRegistry.getDefault().getProposalComputerDescriptors(contentTypeID, partitionTypeID));
	for (Iterator it= descriptors.iterator(); it.hasNext();) {
	CompletionProposalComputerDescriptor desc= (CompletionProposalComputerDescriptor) it.next();
	if (desc.getCategory() == this && (isIncludedOnDefaultPage(contentTypeID) \|\| isDisplayedOnOwnPage(contentTypeID))) {
	result.addAll(desc.computeContextInformation(context, monitor));
	}
	if (fLastError == null) {
	fLastError= desc.getErrorMessage();
	}
	}
	return result;
	}

	/**
	* @return the last error message reported by a computer in this category
	*/
	public String getErrorMessage() {
	return fLastError;
	}

	/**
	* <p>Notifies the computers in this category of a proposal computation session start.</p>
	*/
	public void sessionStarted() {
	List descriptors= new ArrayList(CompletionProposalComputerRegistry.getDefault().getProposalComputerDescriptors());
	for (Iterator it= descriptors.iterator(); it.hasNext();) {
	CompletionProposalComputerDescriptor desc= (CompletionProposalComputerDescriptor) it.next();
	if (desc.getCategory() == this)
	desc.sessionStarted();
	if (fLastError == null)
	fLastError= desc.getErrorMessage();
	}
	}

	/**
	* <p>Notifies the computers in this category of a proposal computation session end.</p>
	*/
	public void sessionEnded() {
	List descriptors= new ArrayList(CompletionProposalComputerRegistry.getDefault().getProposalComputerDescriptors());
	for (Iterator it= descriptors.iterator(); it.hasNext();) {
	CompletionProposalComputerDescriptor desc= (CompletionProposalComputerDescriptor) it.next();
	if (desc.getCategory() == this)
	desc.sessionEnded();
	if (fLastError == null)
	fLastError= desc.getErrorMessage();
	}
	}

	/**
	* @see java.lang.Object#toString()
	*/
	public String toString() {
	return fId + ": " + fName; //$NON-NLS-1$
	}
	}