Proper loading of the profiles and packages from the SRS

[EMFCompare2.git] / plugins / org.eclipse.emf.compare.ide / src / org / eclipse / emf / compare / ide / internal / utils / NoNotificationParserPool.java

/*******************************************************************************
 * Copyright (c) 2012, 2015 Obeo.
 * 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:
 *     Obeo - initial API and implementation
 *******************************************************************************/
package org.eclipse.emf.compare.ide.internal.utils;

import java.util.Iterator;
import java.util.Map;

import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.xmi.UnresolvedReferenceException;
import org.eclipse.emf.ecore.xmi.XMLDefaultHandler;
import org.eclipse.emf.ecore.xmi.XMLHelper;
import org.eclipse.emf.ecore.xmi.XMLLoad;
import org.eclipse.emf.ecore.xmi.XMLResource;
import org.eclipse.emf.ecore.xmi.impl.XMLHandler;

/**
 * This implementation of an {@link org.eclipse.emf.ecore.xmi.XMLParserPool} aims at disabling all
 * notifications when the {@link XMLResource#OPTION_DISABLE_NOTIFY option} is set, including the notifications
 * at the very end of parsing.
 * <p>
 * This is one of the steps that allows EMF Compare to bypass UML's CacheAdapter when loading UML models from
 * the logical model.
 * </p>
 * 
 * @author <a href="mailto:laurent.goubet@obeo.fr">Laurent Goubet</a>
 */
public class NoNotificationParserPool extends NotifyingParserPool {
        /**
         * Default constructor.
         * 
         * @param containmentOnly
         *            only set containment reference values. The model will be mostly empty except for its
         *            containment tree.
         */
        public NoNotificationParserPool(boolean containmentOnly) {
                super(containmentOnly);
        }

        @Override
        protected XMLDefaultHandler createDefaultHandler(XMLResource resource, XMLLoad xmlLoad, XMLHelper helper,
                        Map<?, ?> options) {
                final XMLDefaultHandler handler = super.createDefaultHandler(resource, xmlLoad, helper, options);
                if (handler instanceof XMLHandler) {
                        return new NoNotificationXMLHandler((XMLHandler)handler, resource, helper, options);
                }
                return handler;
        }

        /**
         * The only purpose of this xml handler is to disable the notifications that are sent from the default
         * implementation of {@link #endDocument()} .
         * 
         * @author <a href="mailto:laurent.goubet@obeo.fr">Laurent Goubet</a>
         */
        private class NoNotificationXMLHandler extends ForwardingXMLHandler {
                /**
                 * Creates this forwarding handler given its delegate. All other parameters are only used to call the
                 * mandatory super-constructor... but none should be of any use here.
                 * 
                 * @param delegate
                 *            Our delegate XMLHandler.
                 * @param xmlResource
                 *            The resource we'll be loading. Mandatory for the super-constructor, but we'll forward
                 *            all calls to {@code delegate} anyway.
                 * @param helper
                 *            The xml helper to use. Mandatory for the super-constructor, but we'll forward all calls
                 *            to {@code delegate} anyway.
                 * @param options
                 *            The load options that were specified. Mandatory for the super-constructor, but we'll
                 *            forward all calls to {@code delegate} anyway.
                 */
                public NoNotificationXMLHandler(XMLHandler delegate, XMLResource xmlResource, XMLHelper helper,
                                Map<?, ?> options) {
                        super(delegate, xmlResource, helper, options);
                }

                /**
                 * {@inheritDoc}
                 * 
                 * @see org.eclipse.emf.ecore.xmi.impl.XMLHandler#endDocument()
                 */
                @Override
                public void endDocument() {
                        // prevent the sending of notifications at the end of loading
                        // "disableNotify" at true would still send some from here
                        setField("disableNotify", delegate(), Boolean.FALSE); //$NON-NLS-1$
                        super.endDocument();
                        setField("disableNotify", delegate(), Boolean.TRUE); //$NON-NLS-1$

                        if (containmentOnly) {
                                // Same document references are all left as proxies since we haven't set them.
                                // The xml handler would diagnose that has an error.
                                final Iterator<Resource.Diagnostic> errors = xmlResource.getErrors().iterator();
                                while (errors.hasNext()) {
                                        final Resource.Diagnostic diagnostic = errors.next();
                                        if (diagnostic instanceof UnresolvedReferenceException) {
                                                errors.remove();
                                        }
                                }
                        }
                }
        }
}