org.eclipse.wst.common.snippets/src/org/eclipse/wst/common/snippets/internal/model/SnippetManager.java - webtools-common/webtools.common.snippets - Git at Google

 /*******************************************************************************
  * Copyright (c) 2004 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.common.snippets.internal.model;

 import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Iterator;
 import java.util.List;

 import javax.xml.parsers.DocumentBuilder;

 import org.eclipse.core.resources.IWorkspaceRunnable;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.gef.palette.PaletteContainer;
 import org.eclipse.wst.common.snippets.core.ISnippetsEntry;
 import org.eclipse.wst.common.snippets.internal.Debug;
 import org.eclipse.wst.common.snippets.internal.IEntryChangeListener;
 import org.eclipse.wst.common.snippets.internal.ISnippetCategory;
 import org.eclipse.wst.common.snippets.internal.ISnippetManager;
 import org.eclipse.wst.common.snippets.internal.Logger;
 import org.eclipse.wst.common.snippets.internal.SnippetDefinitions;
 import org.eclipse.wst.common.snippets.internal.SnippetsPlugin;
 import org.eclipse.wst.common.snippets.internal.palette.ModelFactoryForPlugins;
 import org.eclipse.wst.common.snippets.internal.palette.ModelFactoryForUser;
 import org.eclipse.wst.common.snippets.internal.palette.SnippetPaletteRoot;
 import org.eclipse.wst.common.snippets.internal.palette.UserModelDumper;
 import org.eclipse.wst.common.snippets.internal.palette.WorkspaceModelDumper;
 import org.eclipse.wst.common.snippets.internal.team.CategoryFileInfo;
 import org.eclipse.wst.common.snippets.internal.util.CommonXML;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;
 import org.xml.sax.SAXException;


 /**
  *
  * SnippetManager
  *
  * Manages the Library model across multiple views
  */
 public class SnippetManager implements ISnippetManager, PropertyChangeListener {

 	protected static String hiddenStateFilename = "hidden.xml"; //$NON-NLS-1$

 	private static SnippetManager instance = null;

 	public synchronized static SnippetManager getInstance() {
 		if (instance == null) {
 			instance = new SnippetManager();
 			try {
 				hiddenStateFilename = SnippetsPlugin.getDefault().getStateLocation().toString() + "/hidden.xml"; //$NON-NLS-1$
 			}
 			catch (Exception e) {
 				hiddenStateFilename = "/hidden.xml"; //$NON-NLS-1$
 			}
 			// hook resource listener and load categories from workspace
 			// nsd_TODO: disable in-workspace support until fully stabilized
 			// SnippetsPlugin.getDefault().initializeResourceChangeListener();
 		}
 		return instance;
 	}

 	private SnippetDefinitions definitions = null;

 	protected IEntryChangeListener[] fListeners;

 	private SnippetPaletteRoot fRoot;

 	public SnippetManager() {
 		super();
 	}

 	public void addEntryChangeListener(IEntryChangeListener listener) {
 		if (fListeners == null) {
 			fListeners = new IEntryChangeListener[]{listener};
 		}
 		else {
 			IEntryChangeListener[] newListeners = new IEntryChangeListener[fListeners.length + 1];
 			newListeners[0] = listener;
 			System.arraycopy(fListeners, 0, newListeners, 1, fListeners.length);
 			fListeners = newListeners;
 		}
 	}

 	protected ISnippetsEntry findEntry(SnippetDefinitions defs, String id) {
 		List categories = defs.getCategories();
 		ISnippetsEntry match = null;
 		for (int i = 0; match == null && i < categories.size(); i++) {
 			ISnippetCategory category = (ISnippetCategory) categories.get(i);
 			if (category.getId().equals(id)) {
 				match = category;
 			}
 			else {
 				for (int j = 0; match == null && j < category.getChildren().size(); j++) {
 					ISnippetsEntry item = (ISnippetsEntry) category.getChildren().get(j);
 					if (item.getId().equals(id)) {
 						match = item;
 					}
 				}
 			}
 		}
 		return match;
 	}

 	/**
 	 * Find a ISnippetsEntry by it's ID field. Not at all efficient.
 	 *
 	 * @param id
 	 * @return
 	 */
 	public ISnippetsEntry findEntry(String id) {
 		return findEntry(getDefinitions(), id);
 	}

 	/**
 	 * @param oldDefinitions
 	 * @param newDefinitions
 	 */
 	private void fireModelChanged(SnippetDefinitions oldDefinitions, SnippetDefinitions newDefinitions) {
 		if (fListeners == null)
 			return;
 		for (int i = 0; i < fListeners.length; i++)
 			fListeners[i].modelChanged(oldDefinitions, newDefinitions);
 	}

 	/**
 	 * @return
 	 */
 	public SnippetDefinitions getDefinitions() {
 		if (definitions == null) {
 			synchronized (getInstance()) {
 				// load definitions
 				definitions = loadDefinitions();
 				if (fRoot == null) {
 					fRoot = new SnippetPaletteRoot(definitions);
 				}
 				// hide categories so marked
 				String[] hiddenIDs = loadHiddenState();
 				for (int i = 0; i < hiddenIDs.length; i++) {
 					ISnippetsEntry entry = findEntry(definitions, hiddenIDs[i]);
 					if (entry != null) {
 						entry.setVisible(false);
 					}
 				}
 			}
 		}
 		return definitions;
 	}

 	/**
 	 * @return
 	 */
 	public IEntryChangeListener[] getListeners() {
 		return fListeners;
 	}

 	public SnippetPaletteRoot getPaletteRoot() {
 		if (fRoot == null) {
 			fRoot = new SnippetPaletteRoot(getDefinitions());
 		}
 		return fRoot;
 	}

 	/**
 	 * @return
 	 */
 	protected SnippetDefinitions loadDefinitions() {
 		// nsd_TODO: Ensure selection is constant across views
 		// (LibrarySelectionManager?)
 		SnippetDefinitions defs = new SnippetDefinitions();

 		// Load all of the definitions from their sources (probably could
 		// break
 		// this into extensions with providers)
 		SnippetDefinitions pluginDefs = ModelFactoryForPlugins.getInstance().loadCurrent();
 		if (Debug.debugDefinitionPersistence)
 			System.out.println("SnippetManager loaded " + pluginDefs.getCategories().size() + " categories from plug-ins"); //$NON-NLS-1$ //$NON-NLS-2$
 		SnippetDefinitions userDefs = ModelFactoryForUser.getInstance().loadCurrent();
 		if (Debug.debugDefinitionPersistence)
 			System.out.println("SnippetManager loaded " + userDefs.getCategories().size() + " records for categories from user.xml"); //$NON-NLS-1$ //$NON-NLS-2$
 		// SnippetDefinitions sharedDefs =
 		// ModelFactoryForWorkspace.getInstance().loadCurrent();
 		// if (Debug.debugDefinitionPersistence)
 		// System.out.println("SnippetManager loaded " +
 		// userDefs.getCategories().size() + " records for categories from
 		// workspace"); //$NON-NLS-1$ //$NON-NLS-2$

 		// the user categories also store placeholders for the non-user
 		// categories
 		defs.getCategories().addAll(userDefs.getCategories());

 		// Merge plugin drawers by replacing the placeholder drawers with the
 		// ones generated from the plugins
 		for (int i = 0; i < pluginDefs.getCategories().size(); i++) {
 			ISnippetCategory category = (ISnippetCategory) pluginDefs.getCategories().get(i);
 			String id = category.getId();
 			ISnippetsEntry existingEntry = findEntry(defs, id);
 			int existingIndex = defs.getCategories().indexOf(existingEntry);
 			if (existingEntry != null && existingIndex > -1) {
 				// copy filters from existingEntry to pluginDefs category
 				category.setFilters(existingEntry.getFilters());
 				defs.getCategories().set(existingIndex, category);
 			}
 			else {
 				defs.getCategories().add(category);
 			}
 		}

 		// TODO: Merge workspace drawers

 		// Remove stale plugin/workspace contributed drawers
 		// Place-holders are stored without children so any that are not
 		// refilled
 		// should be removed. Empty contributed drawers will be removed as
 		// well.
 		Iterator it = defs.getCategories().iterator();
 		while (it.hasNext()) {
 			ISnippetCategory category = (ISnippetCategory) it.next();
 			if (category.getSourceType() != ISnippetsEntry.SNIPPET_SOURCE_USER && category.getChildren().isEmpty())
 				it.remove();
 		}

 		return defs;
 	}

 	/**
 	 * Load the list of categories that aren't to be visible
 	 */
 	protected String[] loadHiddenState() {
 		Document document = null;
 		String[] results = new String[0];
 		try {
 			DocumentBuilder builder = CommonXML.getDocumentBuilder();
 			if (builder != null) {
 				document = builder.parse(hiddenStateFilename);
 			}
 			else {
 				Logger.log(Logger.ERROR, "SnippetManager couldn't obtain a DocumentBuilder"); //$NON-NLS-1$
 			}
 		}
 		catch (FileNotFoundException e) {
 			// typical of new workspace, don't log it
 			document = null;
 		}
 		catch (IOException e) {
 			Logger.logException("SnippetManager could not load hidden state", e); //$NON-NLS-1$
 		}
 		catch (SAXException e) {
 			Logger.logException("SnippetManager could not load hidden state", e); //$NON-NLS-1$
 		}
 		if (document != null) {
 			List names = new ArrayList(0);
 			Element hidden = document.getDocumentElement();
 			if (hidden != null) {
 				NodeList list = hidden.getChildNodes();
 				for (int i = 0; i < list.getLength(); i++) {
 					Node childNode = list.item(i);
 					if (childNode.getNodeType() == Node.ELEMENT_NODE && childNode.getNodeName().equals(SnippetsPlugin.NAMES.HIDE)) {
 						Element entry = (Element) childNode;
 						String id = null;
 						if (entry.hasAttribute(SnippetsPlugin.NAMES.CATEGORY)) {
 							id = entry.getAttribute(SnippetsPlugin.NAMES.CATEGORY);
 						}
 						else if (entry.hasAttribute(SnippetsPlugin.NAMES.ITEM)) {
 							id = entry.getAttribute(SnippetsPlugin.NAMES.ITEM);
 						}
 						if (id != null && id.length() > 0) {
 							names.add(id);
 						}
 					}
 				}
 				results = (String[]) names.toArray(results);
 			}
 		}
 		if (Debug.debugDefinitionPersistence)
 			System.out.println("SnippetManager remembered " + results.length + " hidden categories"); //$NON-NLS-1$ //$NON-NLS-2$
 		return results;
 	}

 	/**
 	 * @see java.beans.PropertyChangeListener#propertyChange(java.beans.PropertyChangeEvent)
 	 */
 	public void propertyChange(PropertyChangeEvent evt) {
 		if (evt.getPropertyName().equals(PaletteContainer.PROPERTY_CHILDREN)) {
 			SnippetDefinitions oldDefinitions = getDefinitions();
 			definitions = new SnippetDefinitions();
 			definitions.setCategories((List) evt.getNewValue());
 			fireModelChanged(oldDefinitions, definitions);
 		}
 	}

 	public void removeEntryChangeListener(IEntryChangeListener listener) {
 		if (fListeners.length == 1) {
 			fListeners = null;
 		}
 		else {
 			List newListenersList = new ArrayList(Arrays.asList(fListeners));
 			newListenersList.remove(listener);
 			IEntryChangeListener[] newListeners = new IEntryChangeListener[newListenersList.size() - 1];
 			newListeners = (IEntryChangeListener[]) newListenersList.toArray(newListeners);
 			fListeners = newListeners;
 		}
 	}

 	public void resetDefinitions() {
 		SnippetDefinitions oldDefinitions = definitions;
 		definitions = null;
 		if (fRoot != null)
 			fRoot.setDefinitions(getDefinitions());
 		fireModelChanged(oldDefinitions, getDefinitions());
 	}

 	public synchronized void saveDefinitions() {
 		if (definitions == null)
 			return;

 		// save the list of categories to not see
 		saveHiddenState();
 		if (Debug.debugDefinitionPersistence)
 			System.out.println("SnippetManager saved hidden state"); //$NON-NLS-1$

 		// save the model
 		UserModelDumper.getInstance().write(getDefinitions());
 		if (Debug.debugDefinitionPersistence)
 			System.out.println("SnippetManager wrote user records"); //$NON-NLS-1$
 		List categories = getDefinitions().getCategories();
 		final List workspaceCategories = new ArrayList();
 		for (int i = 0; i < categories.size(); i++) {
 			ISnippetCategory category = (ISnippetCategory) categories.get(i);
 			if (category.getSourceType() == ISnippetsEntry.SNIPPET_SOURCE_WORKSPACE) {
 				CategoryFileInfo info = (CategoryFileInfo) category.getSourceDescriptor();
 				if (info != null && info.getFile() != null) {
 					workspaceCategories.add(info);
 				}
 			}
 		}
 		IWorkspaceRunnable operation = new IWorkspaceRunnable() {

 			public void run(IProgressMonitor monitor) throws CoreException {
 				for (int i = 0; i < workspaceCategories.size(); i++) {
 					CategoryFileInfo info = (CategoryFileInfo) workspaceCategories.get(i);
 					if (Debug.debugDefinitionPersistence)
 						System.out.println("save workspace category: " + info.getCategory().getLabel()); //$NON-NLS-1$
 					WorkspaceModelDumper.getInstance().write(info.getCategory(), info.getFile());
 				}
 			}
 		};
 		try {
 			ResourcesPlugin.getWorkspace().run(operation, new NullProgressMonitor());
 		}
 		catch (Exception e) {
 			Logger.logException(e);
 		}
 	}

 	/**
 	 * Save the list of categories that aren't visible
 	 */
 	protected void saveHiddenState() {
 		Document document = CommonXML.getDocumentBuilder().getDOMImplementation().createDocument(null, "hidden", null); //$NON-NLS-1$
 		try {
 			FileOutputStream ostream = new FileOutputStream(hiddenStateFilename);
 			List categoryIDs = new ArrayList(0);
 			List itemIDs = new ArrayList(0);
 			// collect all of the hidden entry IDs
 			for (int i = 0; i < getDefinitions().getCategories().size(); i++) {
 				ISnippetCategory category = (ISnippetCategory) getDefinitions().getCategories().get(i);
 				if (!category.isVisible() && !categoryIDs.contains(category.getId())) {
 					categoryIDs.add(category.getId());
 				}
 				for (int j = 0; j < category.getChildren().size(); j++) {
 					ISnippetsEntry entry = (ISnippetsEntry) category.getChildren().get(j);
 					if (!entry.isVisible() && !itemIDs.contains(entry.getId())) {
 						itemIDs.add(entry.getId());
 					}
 				}
 			}
 			// save those IDs in <hide category="id"/> tags
 			for (int j = 0; j < categoryIDs.size(); j++) {
 				Element hidden = document.createElement(SnippetsPlugin.NAMES.HIDE);
 				hidden.setAttribute(SnippetsPlugin.NAMES.CATEGORY, categoryIDs.get(j).toString());
 				document.getDocumentElement().appendChild(hidden);
 			}
 			for (int j = 0; j < itemIDs.size(); j++) {
 				Element hidden = document.createElement(SnippetsPlugin.NAMES.HIDE);
 				hidden.setAttribute(SnippetsPlugin.NAMES.ITEM, itemIDs.get(j).toString());
 				document.getDocumentElement().appendChild(hidden);
 			}
 			CommonXML.serialize(document, ostream);
 			ostream.close();
 		}
 		catch (IOException e) {
 			Logger.logException(e);
 		}
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2004 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.common.snippets.internal.model;

	import java.beans.PropertyChangeEvent;
	import java.beans.PropertyChangeListener;
	import java.io.FileNotFoundException;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.Iterator;
	import java.util.List;

	import javax.xml.parsers.DocumentBuilder;

	import org.eclipse.core.resources.IWorkspaceRunnable;
	import org.eclipse.core.resources.ResourcesPlugin;
	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IProgressMonitor;
	import org.eclipse.core.runtime.NullProgressMonitor;
	import org.eclipse.gef.palette.PaletteContainer;
	import org.eclipse.wst.common.snippets.core.ISnippetsEntry;
	import org.eclipse.wst.common.snippets.internal.Debug;
	import org.eclipse.wst.common.snippets.internal.IEntryChangeListener;
	import org.eclipse.wst.common.snippets.internal.ISnippetCategory;
	import org.eclipse.wst.common.snippets.internal.ISnippetManager;
	import org.eclipse.wst.common.snippets.internal.Logger;
	import org.eclipse.wst.common.snippets.internal.SnippetDefinitions;
	import org.eclipse.wst.common.snippets.internal.SnippetsPlugin;
	import org.eclipse.wst.common.snippets.internal.palette.ModelFactoryForPlugins;
	import org.eclipse.wst.common.snippets.internal.palette.ModelFactoryForUser;
	import org.eclipse.wst.common.snippets.internal.palette.SnippetPaletteRoot;
	import org.eclipse.wst.common.snippets.internal.palette.UserModelDumper;
	import org.eclipse.wst.common.snippets.internal.palette.WorkspaceModelDumper;
	import org.eclipse.wst.common.snippets.internal.team.CategoryFileInfo;
	import org.eclipse.wst.common.snippets.internal.util.CommonXML;
	import org.w3c.dom.Document;
	import org.w3c.dom.Element;
	import org.w3c.dom.Node;
	import org.w3c.dom.NodeList;
	import org.xml.sax.SAXException;


	/**
	*
	* SnippetManager
	*
	* Manages the Library model across multiple views
	*/
	public class SnippetManager implements ISnippetManager, PropertyChangeListener {

	protected static String hiddenStateFilename = "hidden.xml"; //$NON-NLS-1$

	private static SnippetManager instance = null;

	public synchronized static SnippetManager getInstance() {
	if (instance == null) {
	instance = new SnippetManager();
	try {
	hiddenStateFilename = SnippetsPlugin.getDefault().getStateLocation().toString() + "/hidden.xml"; //$NON-NLS-1$
	}
	catch (Exception e) {
	hiddenStateFilename = "/hidden.xml"; //$NON-NLS-1$
	}
	// hook resource listener and load categories from workspace
	// nsd_TODO: disable in-workspace support until fully stabilized
	// SnippetsPlugin.getDefault().initializeResourceChangeListener();
	}
	return instance;
	}

	private SnippetDefinitions definitions = null;

	protected IEntryChangeListener[] fListeners;

	private SnippetPaletteRoot fRoot;

	public SnippetManager() {
	super();
	}

	public void addEntryChangeListener(IEntryChangeListener listener) {
	if (fListeners == null) {
	fListeners = new IEntryChangeListener[]{listener};
	}
	else {
	IEntryChangeListener[] newListeners = new IEntryChangeListener[fListeners.length + 1];
	newListeners[0] = listener;
	System.arraycopy(fListeners, 0, newListeners, 1, fListeners.length);
	fListeners = newListeners;
	}
	}

	protected ISnippetsEntry findEntry(SnippetDefinitions defs, String id) {
	List categories = defs.getCategories();
	ISnippetsEntry match = null;
	for (int i = 0; match == null && i < categories.size(); i++) {
	ISnippetCategory category = (ISnippetCategory) categories.get(i);
	if (category.getId().equals(id)) {
	match = category;
	}
	else {
	for (int j = 0; match == null && j < category.getChildren().size(); j++) {
	ISnippetsEntry item = (ISnippetsEntry) category.getChildren().get(j);
	if (item.getId().equals(id)) {
	match = item;
	}
	}
	}
	}
	return match;
	}

	/**
	* Find a ISnippetsEntry by it's ID field. Not at all efficient.
	*
	* @param id
	* @return
	*/
	public ISnippetsEntry findEntry(String id) {
	return findEntry(getDefinitions(), id);
	}

	/**
	* @param oldDefinitions
	* @param newDefinitions
	*/
	private void fireModelChanged(SnippetDefinitions oldDefinitions, SnippetDefinitions newDefinitions) {
	if (fListeners == null)
	return;
	for (int i = 0; i < fListeners.length; i++)
	fListeners[i].modelChanged(oldDefinitions, newDefinitions);
	}

	/**
	* @return
	*/
	public SnippetDefinitions getDefinitions() {
	if (definitions == null) {
	synchronized (getInstance()) {
	// load definitions
	definitions = loadDefinitions();
	if (fRoot == null) {
	fRoot = new SnippetPaletteRoot(definitions);
	}
	// hide categories so marked
	String[] hiddenIDs = loadHiddenState();
	for (int i = 0; i < hiddenIDs.length; i++) {
	ISnippetsEntry entry = findEntry(definitions, hiddenIDs[i]);
	if (entry != null) {
	entry.setVisible(false);
	}
	}
	}
	}
	return definitions;
	}

	/**
	* @return
	*/
	public IEntryChangeListener[] getListeners() {
	return fListeners;
	}

	public SnippetPaletteRoot getPaletteRoot() {
	if (fRoot == null) {
	fRoot = new SnippetPaletteRoot(getDefinitions());
	}
	return fRoot;
	}

	/**
	* @return
	*/
	protected SnippetDefinitions loadDefinitions() {
	// nsd_TODO: Ensure selection is constant across views
	// (LibrarySelectionManager?)
	SnippetDefinitions defs = new SnippetDefinitions();

	// Load all of the definitions from their sources (probably could
	// break
	// this into extensions with providers)
	SnippetDefinitions pluginDefs = ModelFactoryForPlugins.getInstance().loadCurrent();
	if (Debug.debugDefinitionPersistence)
	System.out.println("SnippetManager loaded " + pluginDefs.getCategories().size() + " categories from plug-ins"); //$NON-NLS-1$ //$NON-NLS-2$
	SnippetDefinitions userDefs = ModelFactoryForUser.getInstance().loadCurrent();
	if (Debug.debugDefinitionPersistence)
	System.out.println("SnippetManager loaded " + userDefs.getCategories().size() + " records for categories from user.xml"); //$NON-NLS-1$ //$NON-NLS-2$
	// SnippetDefinitions sharedDefs =
	// ModelFactoryForWorkspace.getInstance().loadCurrent();
	// if (Debug.debugDefinitionPersistence)
	// System.out.println("SnippetManager loaded " +
	// userDefs.getCategories().size() + " records for categories from
	// workspace"); //$NON-NLS-1$ //$NON-NLS-2$

	// the user categories also store placeholders for the non-user
	// categories
	defs.getCategories().addAll(userDefs.getCategories());

	// Merge plugin drawers by replacing the placeholder drawers with the
	// ones generated from the plugins
	for (int i = 0; i < pluginDefs.getCategories().size(); i++) {
	ISnippetCategory category = (ISnippetCategory) pluginDefs.getCategories().get(i);
	String id = category.getId();
	ISnippetsEntry existingEntry = findEntry(defs, id);
	int existingIndex = defs.getCategories().indexOf(existingEntry);
	if (existingEntry != null && existingIndex > -1) {
	// copy filters from existingEntry to pluginDefs category
	category.setFilters(existingEntry.getFilters());
	defs.getCategories().set(existingIndex, category);
	}
	else {
	defs.getCategories().add(category);
	}
	}

	// TODO: Merge workspace drawers

	// Remove stale plugin/workspace contributed drawers
	// Place-holders are stored without children so any that are not
	// refilled
	// should be removed. Empty contributed drawers will be removed as
	// well.
	Iterator it = defs.getCategories().iterator();
	while (it.hasNext()) {
	ISnippetCategory category = (ISnippetCategory) it.next();
	if (category.getSourceType() != ISnippetsEntry.SNIPPET_SOURCE_USER && category.getChildren().isEmpty())
	it.remove();
	}

	return defs;
	}

	/**
	* Load the list of categories that aren't to be visible
	*/
	protected String[] loadHiddenState() {
	Document document = null;
	String[] results = new String[0];
	try {
	DocumentBuilder builder = CommonXML.getDocumentBuilder();
	if (builder != null) {
	document = builder.parse(hiddenStateFilename);
	}
	else {
	Logger.log(Logger.ERROR, "SnippetManager couldn't obtain a DocumentBuilder"); //$NON-NLS-1$
	}
	}
	catch (FileNotFoundException e) {
	// typical of new workspace, don't log it
	document = null;
	}
	catch (IOException e) {
	Logger.logException("SnippetManager could not load hidden state", e); //$NON-NLS-1$
	}
	catch (SAXException e) {
	Logger.logException("SnippetManager could not load hidden state", e); //$NON-NLS-1$
	}
	if (document != null) {
	List names = new ArrayList(0);
	Element hidden = document.getDocumentElement();
	if (hidden != null) {
	NodeList list = hidden.getChildNodes();
	for (int i = 0; i < list.getLength(); i++) {
	Node childNode = list.item(i);
	if (childNode.getNodeType() == Node.ELEMENT_NODE && childNode.getNodeName().equals(SnippetsPlugin.NAMES.HIDE)) {
	Element entry = (Element) childNode;
	String id = null;
	if (entry.hasAttribute(SnippetsPlugin.NAMES.CATEGORY)) {
	id = entry.getAttribute(SnippetsPlugin.NAMES.CATEGORY);
	}
	else if (entry.hasAttribute(SnippetsPlugin.NAMES.ITEM)) {
	id = entry.getAttribute(SnippetsPlugin.NAMES.ITEM);
	}
	if (id != null && id.length() > 0) {
	names.add(id);
	}
	}
	}
	results = (String[]) names.toArray(results);
	}
	}
	if (Debug.debugDefinitionPersistence)
	System.out.println("SnippetManager remembered " + results.length + " hidden categories"); //$NON-NLS-1$ //$NON-NLS-2$
	return results;
	}

	/**
	* @see java.beans.PropertyChangeListener#propertyChange(java.beans.PropertyChangeEvent)
	*/
	public void propertyChange(PropertyChangeEvent evt) {
	if (evt.getPropertyName().equals(PaletteContainer.PROPERTY_CHILDREN)) {
	SnippetDefinitions oldDefinitions = getDefinitions();
	definitions = new SnippetDefinitions();
	definitions.setCategories((List) evt.getNewValue());
	fireModelChanged(oldDefinitions, definitions);
	}
	}

	public void removeEntryChangeListener(IEntryChangeListener listener) {
	if (fListeners.length == 1) {
	fListeners = null;
	}
	else {
	List newListenersList = new ArrayList(Arrays.asList(fListeners));
	newListenersList.remove(listener);
	IEntryChangeListener[] newListeners = new IEntryChangeListener[newListenersList.size() - 1];
	newListeners = (IEntryChangeListener[]) newListenersList.toArray(newListeners);
	fListeners = newListeners;
	}
	}

	public void resetDefinitions() {
	SnippetDefinitions oldDefinitions = definitions;
	definitions = null;
	if (fRoot != null)
	fRoot.setDefinitions(getDefinitions());
	fireModelChanged(oldDefinitions, getDefinitions());
	}

	public synchronized void saveDefinitions() {
	if (definitions == null)
	return;

	// save the list of categories to not see
	saveHiddenState();
	if (Debug.debugDefinitionPersistence)
	System.out.println("SnippetManager saved hidden state"); //$NON-NLS-1$

	// save the model
	UserModelDumper.getInstance().write(getDefinitions());
	if (Debug.debugDefinitionPersistence)
	System.out.println("SnippetManager wrote user records"); //$NON-NLS-1$
	List categories = getDefinitions().getCategories();
	final List workspaceCategories = new ArrayList();
	for (int i = 0; i < categories.size(); i++) {
	ISnippetCategory category = (ISnippetCategory) categories.get(i);
	if (category.getSourceType() == ISnippetsEntry.SNIPPET_SOURCE_WORKSPACE) {
	CategoryFileInfo info = (CategoryFileInfo) category.getSourceDescriptor();
	if (info != null && info.getFile() != null) {
	workspaceCategories.add(info);
	}
	}
	}
	IWorkspaceRunnable operation = new IWorkspaceRunnable() {

	public void run(IProgressMonitor monitor) throws CoreException {
	for (int i = 0; i < workspaceCategories.size(); i++) {
	CategoryFileInfo info = (CategoryFileInfo) workspaceCategories.get(i);
	if (Debug.debugDefinitionPersistence)
	System.out.println("save workspace category: " + info.getCategory().getLabel()); //$NON-NLS-1$
	WorkspaceModelDumper.getInstance().write(info.getCategory(), info.getFile());
	}
	}
	};
	try {
	ResourcesPlugin.getWorkspace().run(operation, new NullProgressMonitor());
	}
	catch (Exception e) {
	Logger.logException(e);
	}
	}

	/**
	* Save the list of categories that aren't visible
	*/
	protected void saveHiddenState() {
	Document document = CommonXML.getDocumentBuilder().getDOMImplementation().createDocument(null, "hidden", null); //$NON-NLS-1$
	try {
	FileOutputStream ostream = new FileOutputStream(hiddenStateFilename);
	List categoryIDs = new ArrayList(0);
	List itemIDs = new ArrayList(0);
	// collect all of the hidden entry IDs
	for (int i = 0; i < getDefinitions().getCategories().size(); i++) {
	ISnippetCategory category = (ISnippetCategory) getDefinitions().getCategories().get(i);
	if (!category.isVisible() && !categoryIDs.contains(category.getId())) {
	categoryIDs.add(category.getId());
	}
	for (int j = 0; j < category.getChildren().size(); j++) {
	ISnippetsEntry entry = (ISnippetsEntry) category.getChildren().get(j);
	if (!entry.isVisible() && !itemIDs.contains(entry.getId())) {
	itemIDs.add(entry.getId());
	}
	}
	}
	// save those IDs in <hide category="id"/> tags
	for (int j = 0; j < categoryIDs.size(); j++) {
	Element hidden = document.createElement(SnippetsPlugin.NAMES.HIDE);
	hidden.setAttribute(SnippetsPlugin.NAMES.CATEGORY, categoryIDs.get(j).toString());
	document.getDocumentElement().appendChild(hidden);
	}
	for (int j = 0; j < itemIDs.size(); j++) {
	Element hidden = document.createElement(SnippetsPlugin.NAMES.HIDE);
	hidden.setAttribute(SnippetsPlugin.NAMES.ITEM, itemIDs.get(j).toString());
	document.getDocumentElement().appendChild(hidden);
	}
	CommonXML.serialize(document, ostream);
	ostream.close();
	}
	catch (IOException e) {
	Logger.logException(e);
	}
	}

	}