| /*************************************************************************************************** |
| * Copyright (c) 2003, 2006 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.internal.emf.utilities; |
| |
| import java.util.ArrayList; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Set; |
| |
| import org.eclipse.core.runtime.CoreException; |
| import org.eclipse.core.runtime.IConfigurationElement; |
| import org.eclipse.wst.common.core.util.RegistryReader; |
| import org.eclipse.wst.common.internal.emf.plugin.EcoreUtilitiesPlugin; |
| import org.eclipse.wst.common.internal.emf.resource.Translator; |
| |
| /** |
| * This is the TranslatorManager class used by the TranslatorService in order to discover |
| * and cache all of the extended Translators to be used by EMF2DOMAdapterImpl. |
| */ |
| public class TranslatorManager { |
| |
| /** |
| * The singleton TranslatorManager instance |
| */ |
| private static final TranslatorManager INSTANCE = new TranslatorManager(); |
| |
| /** |
| * Cache of all the TranslatorDescriptors |
| */ |
| private final Set translators = new HashSet(); |
| |
| /** |
| * Default static empty array used when no descriptors found |
| */ |
| private static final TranslatorDescriptor[] NO_EXTENDED_TRANSLATORS = new TranslatorDescriptor[0]; |
| |
| /** |
| * Returns the singleton instance of the TranslatorManager |
| * @return TranslatorManager INSTANCE |
| */ |
| public static TranslatorManager getInstance() { |
| return INSTANCE; |
| } |
| |
| /** |
| * Private constructor |
| */ |
| private TranslatorManager() { |
| new TranslatorRegistry().readRegistry(); |
| } |
| |
| /** |
| * Simple Registry Reader used by Translator Manager to recognize the Translator extensions |
| */ |
| private class TranslatorRegistry extends RegistryReader { |
| |
| /** |
| * The Translator element of the extension point. |
| */ |
| public static final String TRANSLATOR = "translator"; //$NON-NLS-1$ |
| |
| /** |
| * Default constructor |
| */ |
| public TranslatorRegistry() { |
| super(EcoreUtilitiesPlugin.ID, EcoreUtilitiesPlugin.TRANSLATOR_EXTENSTION_POINT); |
| } |
| |
| /** |
| * Add the configuration element if it matchs the expected translator element name |
| */ |
| @Override |
| public boolean readElement(IConfigurationElement element) { |
| boolean result = false; |
| if (TRANSLATOR.equals(element.getName())) { |
| addTranslatorDescriptor(new TranslatorDescriptor(element)); |
| result = true; |
| } |
| return result; |
| } |
| } |
| |
| /** |
| * Describes a Translator extension point element |
| */ |
| public class TranslatorDescriptor { |
| |
| /** |
| * Qualified class name attribute |
| */ |
| public static final String CLASSNAME = "className"; //$NON-NLS-1$ |
| |
| /** |
| * The config element for this Descriptor |
| */ |
| private final IConfigurationElement configElement; |
| |
| /** |
| * the cached qualified className value of this descriptor |
| */ |
| private String className; |
| |
| /** |
| * Constructor |
| * @param aConfigElement |
| */ |
| public TranslatorDescriptor(IConfigurationElement aConfigElement) { |
| super(); |
| configElement = aConfigElement; |
| className = configElement.getAttribute(CLASSNAME); |
| } |
| |
| /** |
| * Retrieve the cached value of the qualified class name of the extended Translator |
| * @return String classname |
| */ |
| public String getClassName() { |
| return className; |
| } |
| |
| /** |
| * Create the actual Translator instance from the configuration element. |
| * @return Translator |
| */ |
| public Translator createTranslator() { |
| Translator instance = null; |
| try { |
| instance = (Translator) configElement.createExecutableExtension(CLASSNAME); |
| } catch (CoreException e) { |
| EcoreUtilitiesPlugin.logError(e); |
| } |
| return instance; |
| } |
| } |
| |
| /** |
| * Add the TranslatorDescriptor to the cache of descriptor extensions. |
| * @param descriptor |
| */ |
| private void addTranslatorDescriptor(TranslatorDescriptor descriptor) { |
| Assert.isNotNull(descriptor); |
| translators.add(descriptor); |
| } |
| |
| /** |
| * Find all the associated TranslatorDescriptors for the Traslator extensions defined. |
| * @return TranslatorDescriptor[] |
| */ |
| public TranslatorDescriptor[] findTranslators() { |
| List result = new ArrayList(); |
| TranslatorDescriptor descriptor = null; |
| for (Iterator translatorsItr = translators.iterator(); translatorsItr.hasNext();) { |
| descriptor = (TranslatorDescriptor) translatorsItr.next(); |
| result.add(descriptor); |
| } |
| if (result.size() == 0) { |
| return NO_EXTENDED_TRANSLATORS; |
| } |
| return (TranslatorDescriptor[]) result.toArray(new TranslatorDescriptor[result.size()]); |
| } |
| } |