examples/org.eclipse.swt.examples.launcher/src/org/eclipse/swt/examples/launcher/LauncherPlugin.java - platform/eclipse.platform.swt - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2007 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.swt.examples.launcher;


 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
 import java.text.MessageFormat;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.MissingResourceException;
 import java.util.ResourceBundle;
 import java.util.Set;

 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtensionRegistry;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.swt.graphics.Image;
 import org.eclipse.swt.graphics.ImageData;
 import org.eclipse.ui.plugin.AbstractUIPlugin;
 import org.osgi.framework.Bundle;
 import org.osgi.framework.BundleContext;

 /**
  * The main plugin class to be used in the desktop.
  */
 public class LauncherPlugin extends AbstractUIPlugin {
 	//The shared instance.
 	private static LauncherPlugin plugin;
 	private static ResourceBundle resourceBundle;

 	public static final String
 		LAUNCH_ITEMS_POINT_ID = "org.eclipse.swt.examples.launcher.launchItems",
 		LAUNCH_ITEMS_XML_CATEGORY = "category",
 		LAUNCH_ITEMS_XML_ITEM = "item",
 		LAUNCH_ITEMS_XML_ITEM_ICON = "icon",
 		LAUNCH_ITEMS_XML_ITEM_DESCRIPTION = "description",
 		LAUNCH_ITEMS_XML_PROGRAM = "program",
 		LAUNCH_ITEMS_XML_PROGRAM_PLUGIN = "pluginId",
 		LAUNCH_ITEMS_XML_PROGRAM_CLASS = "mainClass",
 		LAUNCH_ITEMS_XML_VIEW = "view",
 		LAUNCH_ITEMS_XML_VIEW_VIEWID = "viewId",
 		LAUNCH_ITEMS_XML_ATTRIB_ID = "id",
 		LAUNCH_ITEMS_XML_ATTRIB_NAME = "name",
 		LAUNCH_ITEMS_XML_ATTRIB_ENABLED = "enabled",
 		LAUNCH_ITEMS_XML_ATTRIB_CATEGORY = "category",
 		LAUNCH_ITEMS_XML_VALUE_TRUE = "true",
 		LAUNCH_ITEMS_XML_VALUE_FALSE = "false";

 	static final int
 		liClosedFolder = 0,
 		liOpenFolder = 1,
 		liGenericExample = 2;
 	static final String[] imageLocations = {
 		"icons/closedFolder.gif",
 		"icons/openFolder.gif",
 		"icons/generic_example.gif" };
 	static Image images[];

 	/**
 	 * Constructs the LauncherPlugin.
 	 */
 	public LauncherPlugin() {
 		super();
 		plugin = this;
 	}

     @Override
 	public void start(BundleContext context) throws Exception {
         super.start(context);
         resourceBundle = Platform.getResourceBundle(getBundle());
     }

 	/**
 	 * Clean up
 	 */
 	@Override
 	public void stop(BundleContext context) throws Exception {
 		freeResources();
 		super.stop(context);
 	}

 	/**
 	 * Returns the shared instance.
 	 */
 	public static LauncherPlugin getDefault() {
 		return plugin;
 	}

 	/**
 	 * Loads the resources
 	 */
 	public static void initResources() {
 		if (images == null) {
 			images = new Image[imageLocations.length];

 			for (int i = 0; i < imageLocations.length; ++i) {
 				images[i] = getImageFromPlugin(plugin.getBundle(), imageLocations[i]);
 				if (images[i] == null) {
 					freeResources();
 					logError(getResourceString("error.CouldNotLoadResources"), null);
 					throw new IllegalStateException();
 				}
 			}
 		}
 	}

 	/**
 	 * Frees the resources
 	 */
 	public static void freeResources() {
 		if (images != null) {
 			for (Image image : images) {
 				if (image != null) image.dispose();
 			}
 			images = null;
 		}
 	}

 	/**
 	 * Log an error to the ILog for this plugin
 	 *
 	 * @param message the localized error message text
 	 * @param exception the associated exception, or null
 	 */
 	public static void logError(String message, Throwable exception) {
 		plugin.getLog().log(new Status(
 			IStatus.ERROR, plugin.getBundle().getSymbolicName(), 0, message, exception));
 	}

 	/**
 	 * Returns a string from the resource bundle.
 	 * We don't want to crash because of a missing String.
 	 * Returns the key if not found.
 	 */
 	public static String getResourceString(String key) {
 		try {
 			return resourceBundle.getString(key);
 		} catch (MissingResourceException e) {
 			return key;
 		} catch (NullPointerException e) {
 			return "!" + key + "!";
 		}
 	}

 	/**
 	 * Returns a string from the resource bundle and binds it
 	 * with the given arguments. If the key is not found,
 	 * return the key.
 	 */
 	public static String getResourceString(String key, Object[] args) {
 		try {
 			return MessageFormat.format(getResourceString(key), args);
 		} catch (MissingResourceException e) {
 			return key;
 		} catch (NullPointerException e) {
 			return "!" + key + "!";
 		}
 	}

 	/**
      * Constructs a list of available programs from registered extensions.
      *
      * @return an ItemTreeNode representing the root of a tree of items (the root is not to be displayed)
 	 */
 	public static ItemTreeNode getLaunchItemTree() {
 		ItemTreeNode categoryTree =
 			new ItemTreeNode(new ItemDescriptor("<<Root>>", "<<Root>>", null, null, null, null, null, null));

 		// get the platform's public plugin registry
 		IExtensionRegistry extensionRegistry = Platform.getExtensionRegistry();
 		// retrieve all configuration elements registered at our launchItems extension-point
 		IConfigurationElement[] configurationElements =
 			extensionRegistry.getConfigurationElementsFor(LAUNCH_ITEMS_POINT_ID);

 		if (configurationElements == null || configurationElements.length == 0) {
 			logError(getResourceString("error.CouldNotFindRegisteredExtensions"), null);
 			return categoryTree;
 		}

 		/* Collect all launch categories -- coalesce those with same ID */
 		HashMap<String, ItemTreeNode> idMap = new HashMap<>();
 		for (IConfigurationElement ce: configurationElements) {
 			final String ceName = ce.getName();
 			final String attribId = getItemAttribute(ce, LAUNCH_ITEMS_XML_ATTRIB_ID, null);

 			if (idMap.containsKey(attribId)) continue;
 			if (ceName.equalsIgnoreCase(LAUNCH_ITEMS_XML_CATEGORY)) {
 				final String attribName = getItemName(ce);
 				ItemDescriptor theDescriptor = new ItemDescriptor(attribId, attribName,
 					getItemDescription(ce), null, null, null, null, ce);
 				idMap.put(attribId, new ItemTreeNode(theDescriptor));
 			}
 		}

 		/* Generate launch category hierarchy */
 		Set<String> tempIdSet = new HashSet<>(); // used to prevent duplicates from being entered into the tree
 		for (IConfigurationElement ce : configurationElements) {
 			final String ceName = ce.getName();
 			final String attribId = getItemAttribute(ce, LAUNCH_ITEMS_XML_ATTRIB_ID, null);

 			if (tempIdSet.contains(attribId)) continue;
 			if (ceName.equalsIgnoreCase(LAUNCH_ITEMS_XML_CATEGORY)) {
 				final ItemTreeNode theNode = idMap.get(attribId);
 				addItemByCategory(ce, categoryTree, theNode, idMap);
 				tempIdSet.add(attribId);
 			}
 		}

 		/* Generate program tree */
 		for (IConfigurationElement ce : configurationElements) {
 			final String ceName = ce.getName();
 			final String attribId = getItemAttribute(ce, LAUNCH_ITEMS_XML_ATTRIB_ID, null);

 			if (idMap.containsKey(attribId)) continue;
 			if (ceName.equalsIgnoreCase(LAUNCH_ITEMS_XML_CATEGORY)) {
 				// ignore
 			} else if (ceName.equalsIgnoreCase(LAUNCH_ITEMS_XML_ITEM)) {
 				final String enabled = getItemAttribute(ce, LAUNCH_ITEMS_XML_ATTRIB_ENABLED,
 					LAUNCH_ITEMS_XML_VALUE_TRUE);
 				if (enabled.equalsIgnoreCase(LAUNCH_ITEMS_XML_VALUE_FALSE)) continue;
 				ItemDescriptor theDescriptor = createItemDescriptor(ce, attribId);

 				if (theDescriptor != null) {
 					final ItemTreeNode theNode = new ItemTreeNode(theDescriptor);
 					addItemByCategory(ce, categoryTree, theNode, idMap);
 					idMap.put(attribId, theNode);
 				}
 			}
 		}
 		return categoryTree;
 	}


 	/**
 	 * Adds an item to the category tree.
 	 */
 	private static void addItemByCategory(IConfigurationElement ce, ItemTreeNode root,
 		ItemTreeNode theNode, HashMap<String, ItemTreeNode> idMap) {
 		final String attribCategory = getItemAttribute(ce, LAUNCH_ITEMS_XML_ATTRIB_CATEGORY, null);

 		// locate the parent node
 		ItemTreeNode parentNode = null;
 		if (attribCategory != null) {
 			parentNode = idMap.get(attribCategory);
 		}
 		if (parentNode == null) parentNode = root;

 		// add the item
 		parentNode.addSortedNode(theNode);
 	}

 	/**
 	 * Creates an ItemDescriptor from an XML definition.
 	 *
 	 * @param ce the IConfigurationElement describing the item
 	 * @param attribId the attribute id
 	 * @return a new ItemDescriptor, or null if an error occurs
 	 */
 	private static ItemDescriptor createItemDescriptor(IConfigurationElement ce, String attribId) {
 		final String attribName = getItemName(ce);
 		final Image  attribIcon = getItemIcon(ce);
 		final String attribDescription = getItemDescription(ce);

 		IConfigurationElement viewCE = getItemElement(ce, LAUNCH_ITEMS_XML_VIEW);
 		if (viewCE != null) {
 			//Item is a view
 			final String attribView = getItemAttribute(viewCE, LAUNCH_ITEMS_XML_VIEW_VIEWID, null);
 			if (attribView == null) {
 				logError(getResourceString("error.IncompleteViewLaunchItem",
 					new Object[] { attribId } ), null);
 				return null;
 			}
 			return new ItemDescriptor(attribId, attribName, attribDescription,
 					attribIcon, attribView, null, null, viewCE);
 		} else {
 			//Item is a standalone
 			IConfigurationElement programCE = getItemElement(ce, LAUNCH_ITEMS_XML_PROGRAM);
 			if (programCE != null) {
 				final String attribPluginId = getItemAttribute(programCE, LAUNCH_ITEMS_XML_PROGRAM_PLUGIN, null);
 				final String attribClass    = getItemAttribute(programCE, LAUNCH_ITEMS_XML_PROGRAM_CLASS, null);
 				if (attribClass == null || attribPluginId == null) {
 					logError(getResourceString("error.IncompleteProgramLaunchItem",
 					new Object[] { attribId } ), null);
 					return null;
 				}
 				return new ItemDescriptor(attribId, attribName, attribDescription,
 					attribIcon, null, attribClass, attribPluginId, programCE);
 			} else {
 				logError(getResourceString("error.IncompleteLaunchItem",
 					new Object[] { attribId } ), null);
 				return null;
 			}
 		}
 	}

 	/**
 	 * Returns the first instance of a particular child XML element.
 	 *
 	 * @param ce the IConfigurationElement parent
 	 * @param element the name of the element to fetch
 	 * @return the element's IConfigurationElement, or null if not found
 	 */
 	private static IConfigurationElement getItemElement(IConfigurationElement ce, String element) {
 		IConfigurationElement[] elementCEs = ce.getChildren(element);
 		return (elementCEs != null && elementCEs.length != 0) ? elementCEs[0] : null;
 	}

 	/**
 	 * Returns the value of an XML attribute for an item.
 	 *
 	 * @param ce the IConfigurationElement describing the item
 	 * @param attribute the attribute to fetch
 	 * @param defaultValue the value to return if the attribute is not found
 	 * @return the attribute value
 	 */
 	private static String getItemAttribute(IConfigurationElement ce, String attribute, String defaultValue) {
 		String value = ce.getAttribute(attribute);
 		return (value != null) ? value : defaultValue;
 	}

 	/**
 	 * Returns the description string given the IConfigurationElement for an item.
 	 *
 	 * @param ce the IConfigurationElement describing the item
 	 * @return a newline-delimited string that describes this item, or null if none
 	 */
 	private static String getItemDescription(IConfigurationElement ce) {
 		String description = getItemAttribute(ce, LAUNCH_ITEMS_XML_ITEM_DESCRIPTION, "");
 		return (description.length() == 0) ? null : description;
 	}

 	/**
 	 * Returns the name of an item.
 	 *
 	 * @param ce the IConfigurationElement describing the item
 	 * @return the attribute value
 	 */
 	private static String getItemName(IConfigurationElement ce) {
 		return getItemAttribute(ce, LAUNCH_ITEMS_XML_ATTRIB_NAME,
 			getResourceString("launchitem.Missing.name"));
 	}


 	/**
 	 * Returns the icon for an item.
 	 *
 	 * @param ce the IConfigurationElement describing the item
 	 * @return an icon
 	 */
 	private static Image getItemIcon(IConfigurationElement ce) {
 		String iconPath = getItemAttribute(ce, LAUNCH_ITEMS_XML_ITEM_ICON, "");
 		if (iconPath.length() != 0) {
 			String symbolicName = ce.getDeclaringExtension().getContributor().getName();
 			Bundle bundle = Platform.getBundle(symbolicName);
 			Image icon = getImageFromPlugin(bundle, iconPath);
 			if (icon != null) {
 				Image[] newImages = new Image[images.length + 1];
 				System.arraycopy(images, 0, newImages, 0, images.length);
 				newImages[images.length] = icon;
 				images = newImages;
 				return icon;
 			}
 		}
 		return images[liGenericExample];
 	}

 	/**
 	 * Gets an image from a path relative to the plugin install directory.
 	 *
 	 * @param bundle the plugin descriptor for the plugin with the image
 	 * @param iconPath the path relative to the install directory
 	 * @return the image, or null if not found
 	 */
 	private static Image getImageFromPlugin(Bundle bundle, String iconPath) {
 		InputStream is = null;
 		try {
 			URL installUrl = bundle.getEntry("/");
 			URL url = new URL(installUrl, iconPath);
 			is = url.openConnection().getInputStream();
 			ImageData source = new ImageData(is);
 			ImageData mask = source.getTransparencyMask();
 			Image image = new Image(null, source, mask);
 			return image;
 		} catch (Throwable ex) {
 			return null;
 		} finally {
 			try {
 				if (is != null) is.close();
 			} catch (IOException e) {
 			}
 		}
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2007 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.swt.examples.launcher;


	import java.io.IOException;
	import java.io.InputStream;
	import java.net.URL;
	import java.text.MessageFormat;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.MissingResourceException;
	import java.util.ResourceBundle;
	import java.util.Set;

	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.IExtensionRegistry;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Platform;
	import org.eclipse.core.runtime.Status;
	import org.eclipse.swt.graphics.Image;
	import org.eclipse.swt.graphics.ImageData;
	import org.eclipse.ui.plugin.AbstractUIPlugin;
	import org.osgi.framework.Bundle;
	import org.osgi.framework.BundleContext;

	/**
	* The main plugin class to be used in the desktop.
	*/
	public class LauncherPlugin extends AbstractUIPlugin {
	//The shared instance.
	private static LauncherPlugin plugin;
	private static ResourceBundle resourceBundle;

	public static final String
	LAUNCH_ITEMS_POINT_ID = "org.eclipse.swt.examples.launcher.launchItems",
	LAUNCH_ITEMS_XML_CATEGORY = "category",
	LAUNCH_ITEMS_XML_ITEM = "item",
	LAUNCH_ITEMS_XML_ITEM_ICON = "icon",
	LAUNCH_ITEMS_XML_ITEM_DESCRIPTION = "description",
	LAUNCH_ITEMS_XML_PROGRAM = "program",
	LAUNCH_ITEMS_XML_PROGRAM_PLUGIN = "pluginId",
	LAUNCH_ITEMS_XML_PROGRAM_CLASS = "mainClass",
	LAUNCH_ITEMS_XML_VIEW = "view",
	LAUNCH_ITEMS_XML_VIEW_VIEWID = "viewId",
	LAUNCH_ITEMS_XML_ATTRIB_ID = "id",
	LAUNCH_ITEMS_XML_ATTRIB_NAME = "name",
	LAUNCH_ITEMS_XML_ATTRIB_ENABLED = "enabled",
	LAUNCH_ITEMS_XML_ATTRIB_CATEGORY = "category",
	LAUNCH_ITEMS_XML_VALUE_TRUE = "true",
	LAUNCH_ITEMS_XML_VALUE_FALSE = "false";

	static final int
	liClosedFolder = 0,
	liOpenFolder = 1,
	liGenericExample = 2;
	static final String[] imageLocations = {
	"icons/closedFolder.gif",
	"icons/openFolder.gif",
	"icons/generic_example.gif" };
	static Image images[];

	/**
	* Constructs the LauncherPlugin.
	*/
	public LauncherPlugin() {
	super();
	plugin = this;
	}

	@Override
	public void start(BundleContext context) throws Exception {
	super.start(context);
	resourceBundle = Platform.getResourceBundle(getBundle());
	}

	/**
	* Clean up
	*/
	@Override
	public void stop(BundleContext context) throws Exception {
	freeResources();
	super.stop(context);
	}

	/**
	* Returns the shared instance.
	*/
	public static LauncherPlugin getDefault() {
	return plugin;
	}

	/**
	* Loads the resources
	*/
	public static void initResources() {
	if (images == null) {
	images = new Image[imageLocations.length];

	for (int i = 0; i < imageLocations.length; ++i) {
	images[i] = getImageFromPlugin(plugin.getBundle(), imageLocations[i]);
	if (images[i] == null) {
	freeResources();
	logError(getResourceString("error.CouldNotLoadResources"), null);
	throw new IllegalStateException();
	}
	}
	}
	}

	/**
	* Frees the resources
	*/
	public static void freeResources() {
	if (images != null) {
	for (Image image : images) {
	if (image != null) image.dispose();
	}
	images = null;
	}
	}

	/**
	* Log an error to the ILog for this plugin
	*
	* @param message the localized error message text
	* @param exception the associated exception, or null
	*/
	public static void logError(String message, Throwable exception) {
	plugin.getLog().log(new Status(
	IStatus.ERROR, plugin.getBundle().getSymbolicName(), 0, message, exception));
	}

	/**
	* Returns a string from the resource bundle.
	* We don't want to crash because of a missing String.
	* Returns the key if not found.
	*/
	public static String getResourceString(String key) {
	try {
	return resourceBundle.getString(key);
	} catch (MissingResourceException e) {
	return key;
	} catch (NullPointerException e) {
	return "!" + key + "!";
	}
	}

	/**
	* Returns a string from the resource bundle and binds it
	* with the given arguments. If the key is not found,
	* return the key.
	*/
	public static String getResourceString(String key, Object[] args) {
	try {
	return MessageFormat.format(getResourceString(key), args);
	} catch (MissingResourceException e) {
	return key;
	} catch (NullPointerException e) {
	return "!" + key + "!";
	}
	}

	/**
	* Constructs a list of available programs from registered extensions.
	*
	* @return an ItemTreeNode representing the root of a tree of items (the root is not to be displayed)
	*/
	public static ItemTreeNode getLaunchItemTree() {
	ItemTreeNode categoryTree =
	new ItemTreeNode(new ItemDescriptor("<<Root>>", "<<Root>>", null, null, null, null, null, null));

	// get the platform's public plugin registry
	IExtensionRegistry extensionRegistry = Platform.getExtensionRegistry();
	// retrieve all configuration elements registered at our launchItems extension-point
	IConfigurationElement[] configurationElements =
	extensionRegistry.getConfigurationElementsFor(LAUNCH_ITEMS_POINT_ID);

	if (configurationElements == null \|\| configurationElements.length == 0) {
	logError(getResourceString("error.CouldNotFindRegisteredExtensions"), null);
	return categoryTree;
	}

	/* Collect all launch categories -- coalesce those with same ID */
	HashMap<String, ItemTreeNode> idMap = new HashMap<>();
	for (IConfigurationElement ce: configurationElements) {
	final String ceName = ce.getName();
	final String attribId = getItemAttribute(ce, LAUNCH_ITEMS_XML_ATTRIB_ID, null);

	if (idMap.containsKey(attribId)) continue;
	if (ceName.equalsIgnoreCase(LAUNCH_ITEMS_XML_CATEGORY)) {
	final String attribName = getItemName(ce);
	ItemDescriptor theDescriptor = new ItemDescriptor(attribId, attribName,
	getItemDescription(ce), null, null, null, null, ce);
	idMap.put(attribId, new ItemTreeNode(theDescriptor));
	}
	}

	/* Generate launch category hierarchy */
	Set<String> tempIdSet = new HashSet<>(); // used to prevent duplicates from being entered into the tree
	for (IConfigurationElement ce : configurationElements) {
	final String ceName = ce.getName();
	final String attribId = getItemAttribute(ce, LAUNCH_ITEMS_XML_ATTRIB_ID, null);

	if (tempIdSet.contains(attribId)) continue;
	if (ceName.equalsIgnoreCase(LAUNCH_ITEMS_XML_CATEGORY)) {
	final ItemTreeNode theNode = idMap.get(attribId);
	addItemByCategory(ce, categoryTree, theNode, idMap);
	tempIdSet.add(attribId);
	}
	}

	/* Generate program tree */
	for (IConfigurationElement ce : configurationElements) {
	final String ceName = ce.getName();
	final String attribId = getItemAttribute(ce, LAUNCH_ITEMS_XML_ATTRIB_ID, null);

	if (idMap.containsKey(attribId)) continue;
	if (ceName.equalsIgnoreCase(LAUNCH_ITEMS_XML_CATEGORY)) {
	// ignore
	} else if (ceName.equalsIgnoreCase(LAUNCH_ITEMS_XML_ITEM)) {
	final String enabled = getItemAttribute(ce, LAUNCH_ITEMS_XML_ATTRIB_ENABLED,
	LAUNCH_ITEMS_XML_VALUE_TRUE);
	if (enabled.equalsIgnoreCase(LAUNCH_ITEMS_XML_VALUE_FALSE)) continue;
	ItemDescriptor theDescriptor = createItemDescriptor(ce, attribId);

	if (theDescriptor != null) {
	final ItemTreeNode theNode = new ItemTreeNode(theDescriptor);
	addItemByCategory(ce, categoryTree, theNode, idMap);
	idMap.put(attribId, theNode);
	}
	}
	}
	return categoryTree;
	}


	/**
	* Adds an item to the category tree.
	*/
	private static void addItemByCategory(IConfigurationElement ce, ItemTreeNode root,
	ItemTreeNode theNode, HashMap<String, ItemTreeNode> idMap) {
	final String attribCategory = getItemAttribute(ce, LAUNCH_ITEMS_XML_ATTRIB_CATEGORY, null);

	// locate the parent node
	ItemTreeNode parentNode = null;
	if (attribCategory != null) {
	parentNode = idMap.get(attribCategory);
	}
	if (parentNode == null) parentNode = root;

	// add the item
	parentNode.addSortedNode(theNode);
	}

	/**
	* Creates an ItemDescriptor from an XML definition.
	*
	* @param ce the IConfigurationElement describing the item
	* @param attribId the attribute id
	* @return a new ItemDescriptor, or null if an error occurs
	*/
	private static ItemDescriptor createItemDescriptor(IConfigurationElement ce, String attribId) {
	final String attribName = getItemName(ce);
	final Image attribIcon = getItemIcon(ce);
	final String attribDescription = getItemDescription(ce);

	IConfigurationElement viewCE = getItemElement(ce, LAUNCH_ITEMS_XML_VIEW);
	if (viewCE != null) {
	//Item is a view
	final String attribView = getItemAttribute(viewCE, LAUNCH_ITEMS_XML_VIEW_VIEWID, null);
	if (attribView == null) {
	logError(getResourceString("error.IncompleteViewLaunchItem",
	new Object[] { attribId } ), null);
	return null;
	}
	return new ItemDescriptor(attribId, attribName, attribDescription,
	attribIcon, attribView, null, null, viewCE);
	} else {
	//Item is a standalone
	IConfigurationElement programCE = getItemElement(ce, LAUNCH_ITEMS_XML_PROGRAM);
	if (programCE != null) {
	final String attribPluginId = getItemAttribute(programCE, LAUNCH_ITEMS_XML_PROGRAM_PLUGIN, null);
	final String attribClass = getItemAttribute(programCE, LAUNCH_ITEMS_XML_PROGRAM_CLASS, null);
	if (attribClass == null \|\| attribPluginId == null) {
	logError(getResourceString("error.IncompleteProgramLaunchItem",
	new Object[] { attribId } ), null);
	return null;
	}
	return new ItemDescriptor(attribId, attribName, attribDescription,
	attribIcon, null, attribClass, attribPluginId, programCE);
	} else {
	logError(getResourceString("error.IncompleteLaunchItem",
	new Object[] { attribId } ), null);
	return null;
	}
	}
	}

	/**
	* Returns the first instance of a particular child XML element.
	*
	* @param ce the IConfigurationElement parent
	* @param element the name of the element to fetch
	* @return the element's IConfigurationElement, or null if not found
	*/
	private static IConfigurationElement getItemElement(IConfigurationElement ce, String element) {
	IConfigurationElement[] elementCEs = ce.getChildren(element);
	return (elementCEs != null && elementCEs.length != 0) ? elementCEs[0] : null;
	}

	/**
	* Returns the value of an XML attribute for an item.
	*
	* @param ce the IConfigurationElement describing the item
	* @param attribute the attribute to fetch
	* @param defaultValue the value to return if the attribute is not found
	* @return the attribute value
	*/
	private static String getItemAttribute(IConfigurationElement ce, String attribute, String defaultValue) {
	String value = ce.getAttribute(attribute);
	return (value != null) ? value : defaultValue;
	}

	/**
	* Returns the description string given the IConfigurationElement for an item.
	*
	* @param ce the IConfigurationElement describing the item
	* @return a newline-delimited string that describes this item, or null if none
	*/
	private static String getItemDescription(IConfigurationElement ce) {
	String description = getItemAttribute(ce, LAUNCH_ITEMS_XML_ITEM_DESCRIPTION, "");
	return (description.length() == 0) ? null : description;
	}

	/**
	* Returns the name of an item.
	*
	* @param ce the IConfigurationElement describing the item
	* @return the attribute value
	*/
	private static String getItemName(IConfigurationElement ce) {
	return getItemAttribute(ce, LAUNCH_ITEMS_XML_ATTRIB_NAME,
	getResourceString("launchitem.Missing.name"));
	}


	/**
	* Returns the icon for an item.
	*
	* @param ce the IConfigurationElement describing the item
	* @return an icon
	*/
	private static Image getItemIcon(IConfigurationElement ce) {
	String iconPath = getItemAttribute(ce, LAUNCH_ITEMS_XML_ITEM_ICON, "");
	if (iconPath.length() != 0) {
	String symbolicName = ce.getDeclaringExtension().getContributor().getName();
	Bundle bundle = Platform.getBundle(symbolicName);
	Image icon = getImageFromPlugin(bundle, iconPath);
	if (icon != null) {
	Image[] newImages = new Image[images.length + 1];
	System.arraycopy(images, 0, newImages, 0, images.length);
	newImages[images.length] = icon;
	images = newImages;
	return icon;
	}
	}
	return images[liGenericExample];
	}

	/**
	* Gets an image from a path relative to the plugin install directory.
	*
	* @param bundle the plugin descriptor for the plugin with the image
	* @param iconPath the path relative to the install directory
	* @return the image, or null if not found
	*/
	private static Image getImageFromPlugin(Bundle bundle, String iconPath) {
	InputStream is = null;
	try {
	URL installUrl = bundle.getEntry("/");
	URL url = new URL(installUrl, iconPath);
	is = url.openConnection().getInputStream();
	ImageData source = new ImageData(is);
	ImageData mask = source.getTransparencyMask();
	Image image = new Image(null, source, mask);
	return image;
	} catch (Throwable ex) {
	return null;
	} finally {
	try {
	if (is != null) is.close();
	} catch (IOException e) {
	}
	}
	}
	}